Hybrid zero-voltage switching (ZVS) control for power inverters

DOEpatents

Amirahmadi, Ahmadreza; Hu, Haibing; Batarseh, Issa

2016-11-01

A power inverter combination includes a half-bridge power inverter including first and second semiconductor power switches receiving input power having an intermediate node therebetween providing an inductor current through an inductor. A controller includes input comparison circuitry receiving the inductor current having outputs coupled to first inputs of pulse width modulation (PWM) generation circuitry, and a predictive control block having an output coupled to second inputs of the PWM generation circuitry. The predictive control block is coupled to receive a measure of Vin and an output voltage at a grid connection point. A memory stores a current control algorithm configured for resetting a PWM period for a switching signal applied to control nodes of the first and second power switch whenever the inductor current reaches a predetermined upper limit or a predetermined lower limit.

Modeling of switching regulator power stages with and without zero-inductor-current dwell time

NASA Technical Reports Server (NTRS)

Lee, F. C. Y.; Yu, Y.

1979-01-01

State-space techniques are employed to derive accurate models for the three basic switching converter power stages: buck, boost, and buck/boost operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without dwell time as a special case of the discontinuous-current mode when the dwell time vanishes. Abrupt changes of system behavior, including a reduction of the system order when the dwell time appears, are shown both analytically and experimentally. Merits resulting from the present modeling technique in comparison with existing modeling techniques are illustrated.

Light-weight DC to very high voltage DC converter

DOEpatents

Druce, Robert L.; Kirbie, Hugh C.; Newton, Mark A.

1998-01-01

A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

Design and development of repetitive capacitor charging power supply based on series-parallel resonant converter topology.

PubMed

Patel, Ankur; Nagesh, K V; Kolge, Tanmay; Chakravarthy, D P

2011-04-01

LCL resonant converter based repetitive capacitor charging power supply (CCPS) is designed and developed in the division. The LCL converter acts as a constant current source when switching frequency is equal to the resonant frequency. When both resonant inductors' values of LCL converter are same, it results in inherent zero current switching (ZCS) in switches. In this paper, ac analysis with fundamental frequency approximation of LCL resonant tank circuit, frequency dependent of current gain converter followed by design, development, simulation, and practical result is described. Effect of change in switching frequency and resonant frequency and change in resonant inductors ratio on CCPS will be discussed. An efficient CCPS of average output power of 1.2 kJ/s, output voltage 3 kV, and 300 Hz repetition rate is developed in the division. The performance of this CCPS has been evaluated in the laboratory by charging several values of load capacitance at various repetition rates. These results indicate that this design is very feasible for use in capacitor-charging applications. © 2011 American Institute of Physics

Induction heating apparatus and methods of operation thereof

DOEpatents

Richardson, John G.

2006-08-01

Methods of operation of an induction melter include providing material within a cooled crucible proximate an inductor. A desired electromagnetic flux skin depth for heating the material within the crucible may be selected, and a frequency of an alternating current for energizing the inductor and for producing the desired skin depth may be selected. The alternating current frequency may be adjusted after energizing the inductor to maintain the desired electromagnetic flux skin depth. The desired skin depth may be substantially maintained as the temperature of the material varies. An induction heating apparatus includes a sensor configured to detect changes in at least one physical characteristic of a material to be heated in a crucible, and a controller configured for selectively varying a frequency of an alternating current for energizing an inductor at least partially in response to changes in the physical characteristic to be detected by the sensor.

Light-weight DC to very high voltage DC converter

DOEpatents

Druce, R.L.; Kirbie, H.C.; Newton, M.A.

1998-06-30

A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

Power converter using near-load output capacitance, direct inductor contact, and/or remote current sense

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coteus, Paul W.; Ferencz, Andrew; Hall, Shawn A.

An apparatus includes a first circuit board including first components including a load, and a second circuit board including second components including switching power devices and an output inductor. Ground and output voltage contacts between the circuit boards are made through soldered or connectorized interfaces. Certain components on the first circuit board and certain components, including the output inductor, on the second circuit board act as a DC-DC voltage converter for the load. An output capacitance for the conversion is on the first circuit board with no board-to-board interface between the output capacitance and the load. The inductance of themore » board-to-board interface functions as part of the output inductor's inductance and not as a parasitic inductance. Sense components for sensing current through the output inductor are located on the first circuit board. Parasitic inductance of the board-to-board interface has less effect on a sense signal provided to a controller.« less

Cross-differential amplifier

NASA Technical Reports Server (NTRS)

Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

2010-01-01

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Cross-differential amplifier

NASA Technical Reports Server (NTRS)

Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

2011-01-01

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Cross-differential amplifier

NASA Technical Reports Server (NTRS)

Aoki, Ichiro (Inventor); Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor)

2013-01-01

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Cross-differential amplifier

NASA Technical Reports Server (NTRS)

Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

2008-01-01

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Alternate current magnetic property characterization of nonstoichiometric zinc ferrite nanocrystals for inductor fabrication via a solution based process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yun, Hongseok; Kim, Jungkwun; Allen, Mark G.

2016-03-21

We investigate the ac magnetic behavior of solution processable, non-stoichiometric zinc ferrite nanocrystals with a series of sizes and zinc concentrations. Nearly monodisperse Zn{sub x}Fe{sub 3−x}O{sub 4} nanocrystals (x = 0–0.25) with an average size ranging from 7.4 nm to 13.8 nm are synthesized by using a solvothermal method. All the nanocrystals are in a superparamagnetic state at 300 K, which is confirmed by Superconductive Quantum Interference Device magnetometry. Due to the doping of non-magnetic Zn{sup 2+} into A site of ferrite, the saturation magnetization of nanocrystals increases as the size and Zn concentration increases. The ac magnetic permeability measurements at radio frequencies reveal thatmore » the real part of the magnetic permeability of similarly sized ferrite nanocrystals can be enhanced by almost twofold as the Zn{sup 2+} doping level increases from 0 to 0.25. The integration of 12.3 nm Zn{sub 0.25}Fe{sub 2.75}O{sub 4} nanocrystals into a toroidal inductor and a solenoid inductor prepared via a simple solution cast process yields a higher quality factors than air core inductors with the same geometries up to 5 MHz and 9 MHz, respectively, which is in the regime of the switching frequencies for the advanced integrated power converters.« less

3D electroplated inductors with thickness variation for improved broadband performance

NASA Astrophysics Data System (ADS)

Farm-Guoo Tseng, Victor; Bedair, Sarah S.; Lazarus, Nathan

2017-01-01

The performance of an RF spiral inductor is based on the balance between ohmic losses in the outer turns and eddy current losses dominant in the inner turns where the magnetic field is the strongest. In this work, air-core spiral inductors with winding trace thicknesses decreasing towards the center are demonstrated, achieving quality factor improvement over a wide frequency range compared to uniform thickness inductors. A custom 3D copper electroplating process was used to produce spiral inductors with varying winding thicknesses in a single plating step, with patterned gaps in a seed layer used to create delays in the vertical plating. The fabricated center-lowered coil inductors were 80 nH within a one square millimeter area with thickness varying from 60 µm to 10 µm from outer to inner winding. Within the 16 MHz-160 MHz range, the center-lowered inductors were shown to have a maximum to minimum quality factor improvement of 90%-10% when compared to uniform thickness inductors with thicknesses ranging from 60 µm to 10 µm. Compared to the 20 µm uniform thickness inductor which has the optimal performance among all uniform thickness inductors in this frequency range, the center-lowered inductors were shown to achieve a maximum quality factor improvement of 20% at the edge frequencies of 16 MHz and 160 MHz, and a minimum quality factor improvement of 10% near the geometric mean center frequency of 46 MHz.

A PIPO Boost Converter with Low Ripple and Medium Current Application

NASA Astrophysics Data System (ADS)

Bandri, S.; Sofian, A.; Ismail, F.

2018-04-01

This paper presents a Parallel Input Parallel Output (PIPO) boost converter is proposed to gain power ability of converter, and reduce current inductors. The proposed technique will distribute current for n-parallel inductor and switching component. Four parallel boost converters implement on input voltage 20.5Vdc to generate output voltage 28.8Vdc. The PIPO boost converter applied phase shift pulse width modulation which will compare with conventional PIPO boost converters by using a similar pulse for every switching component. The current ripple reduction shows an advantage PIPO boost converter then conventional boost converter. Varies loads and duty cycle will be simulated and analyzed to verify the performance of PIPO boost converter. Finally, the unbalance of current inductor is able to be verified on four area of duty cycle in less than 0.6.

Modeling Intracochlear Magnetic Stimulation: A Finite-Element Analysis.

PubMed

Mukesh, S; Blake, D T; McKinnon, B J; Bhatti, P T

2017-08-01

This study models induced electric fields, and their gradient, produced by pulsatile current stimulation of submillimeter inductors for cochlear implantation. Using finite-element analysis, the lower chamber of the cochlea, scala tympani, is modeled as a cylindrical structure filled with perilymph bounded by tissue, bone, and cochlear neural elements. Single inductors as well as an array of inductors are modeled. The coil strength (~100 nH) and excitation parameters (peak current of 1-5 A, voltages of 16-20 V) are based on a formative feasibility study conducted by our group. In that study, intracochlear micromagnetic stimulation achieved auditory activation as measured through the auditory brainstem response in a feline model. With respect to the finite element simulations, axial symmetry of the inductor geometry is exploited to improve computation time. It is verified that the inductor coil orientation greatly affects the strength of the induced electric field and thereby the ability to affect the transmembrane potential of nearby neural elements. Furthermore, upon comparing an array of micro-inductors with a typical multi-site electrode array, magnetically excited arrays retain greater focus in terms of the gradient of induced electric fields. Once combined with further in vivo analysis, this modeling study may enable further exploration of the mechanism of magnetically induced, and focused neural stimulation.

Novel Electrically Tunable Microwave Solenoid Inductor and Compact Phase Shifter Utilizing Permaloy and PZT Thin Films

DOE PAGES

Wang, Tengxing; Jiang, Wei; Divan, Ralu; ...

2017-08-03

A Permalloy (Py) thin film enabled tunable 3-D solenoid inductor is designed and fabricated. The special configuration of magnetic core is discussed and by selectively patterning Py thin film, the proposed tunable inductor can work at frequency up to several GHz range. The inductance of the solenoid inductor can be electrically tuned by dc current and the tunability is above 10%. Utilizing the implemented Py enabled tunable solenoid inductor and Lead Zirconate Titanate (PZT) thin film enabled metal-insulator-metal (MIM) capacitor, a compact fully electrically tunable lumped elements phase shifter is achieved. The tunable phase shifter has both inductive and capacitivemore » tunability and the dual tunability significantly improves the tuning range and design flexibility. Moreover, the dual tunability is able to retain the equivalent characteristic impedance of the device in the process of the phase being tuned. Here, the phase of the device can be tuned by fully electrical methods and when dc current and dc voltage are provided, the length normalized phase tunability is up to 210°/cm« less

Integrated on-chip inductors with electroplated magnetic yokes (invited)

NASA Astrophysics Data System (ADS)

Wang, Naigang; O'Sullivan, Eugene J.; Herget, Philipp; Rajendran, Bipin; Krupp, Leslie E.; Romankiw, Lubomyr T.; Webb, Bucknell C.; Fontana, Robert; Duch, Elizabeth A.; Joseph, Eric A.; Brown, Stephen L.; Hu, Xiaolin; Decad, Gary M.; Sturcken, Noah; Shepard, Kenneth L.; Gallagher, William J.

2012-04-01

Thin-film ferromagnetic inductors show great potential as the energy storage element for integrated circuits containing on-chip power management. In order to achieve the high energy storage required for power management, on-chip inductors require relatively thick magnetic yoke materials (several microns or more), which can be readily deposited by electroplating through a photoresist mask as demonstrated in this paper, the yoke material of choice being Ni45Fe55, whose properties of relatively high moment and electrical resistivity make it an attractive model yoke material for inductors. Inductors were designed with a variety of yoke geometries, and included both single-turn and multi-turn coil designs, which were fabricated on 200 mm silicon wafers in a CMOS back-end-of-line (BEOL) facility. Each inductor consisted of electroplated copper coils enclosed by the electroplated Ni45Fe55 yokes; aspects of the fabrication of the inductors are discussed. Magnetic properties of the electroplated yoke materials are described, including high frequency permeability measurements. The inductance of 2-turn coil inductors, for example, was enhanced up to about 6 times over the air core equivalent, with an inductance density of 130 nH/mm2 being achieved. The resistance of these non-laminated inductors was relatively large at high frequency due to magnetic and eddy current losses but is expected to improve as the yoke material/structure is further optimized, making electroplated yoke-containing inductors attractive for dc-dc power converters.

Modelling, design and stability analysis of an improved SEPIC converter for renewable energy systems

NASA Astrophysics Data System (ADS)

G, Dileep; Singh, S. N.; Singh, G. K.

2017-09-01

In this paper, a detailed modelling and analysis of a switched inductor (SI)-based improved single-ended primary inductor converter (SEPIC) has been presented. To increase the gain of conventional SEPIC converter, input and output side inductors are replaced with SI structures. Design and stability analysis for continuous conduction mode operation of the proposed SI-SEPIC converter has also been presented in this paper. State space averaging technique is used to model the converter and carry out the stability analysis. Performance and stability analysis of closed loop configuration is predicted by observing the open loop behaviour using Nyquist diagram and Nichols chart. System was found to stable and critically damped.

Using a coupled inductor controlled by fuzzy logic to improve the efficiency of a Buck converter in a PV system

NASA Astrophysics Data System (ADS)

Abouchabana, Nabil; Haddadi, Mourad; Rabhi, Abdelhamid; El Hajjaji, Ahmed

2017-11-01

Photovoltaic generators (PVG) produce a variable power according to the solar radiation (G) and temperature (T). This variation affects the sizing of the components of DC / DC converters, powered by such PVG, and make it difficult. The effects may differ from one component to another. The main and critical one is presented by the inductor, the element that stores the energy during sampled periods. We propose in this work an auto-adaptation of these inductor values to maintain optimal performance of the power yield of these converters. Our idea is to replace the inductor by a coupled inductor where this adjustment is made by the addition of an adjustable electric field in the magnetic core. Low current intensities come from the PVG supply the second inductor of the coupled inductor through a circuit controlled by a fuzzy controller (FC). The whole system is modeled and simulated under MATLAB/SIMULINK for the control part of the system and under PSPICE for the power part of the system. The obtained results show good performances of the proposed converter over the standard one.

Inductive storage for quasi-steady MPD thrusters

NASA Technical Reports Server (NTRS)

Clark, K. E.

1978-01-01

Experiments in which a quasi-steady MPD thruster is driven by a large inductor demonstrate the feasibility of using inductive energy storage to couple an intermittent high power plasma thruster to a lower power steady state supply, such as a thermionic converter. Switching between inductor charging and MPD thrusting phases of the current cycle occurs smoothly, with the voltage spike generated during switching sufficient to initiate the arc discharge in the thruster without an auxiliary starting circuit. Further, the current waveforms delivered by the inductor are of a shape suitable for the quasi-steady thrusting process, and they agree with analytical estimates, indicating that the interaction between the thruster impedance and the inductive source is dynamically stable.

Rolled-up inductor structure for a radiofrequency integrated circuit (RFIC)

DOEpatents

Li, Xiuling; Huang, Wen; Ferreira, Placid M.; Yu, Xin

2015-12-29

A rolled-up inductor structure for a radiofrequency integrated circuit (RFIC) comprises a multilayer sheet in a rolled configuration comprising multiple turns about a longitudinal axis. The multilayer sheet comprises a conductive pattern layer on a strain-relieved layer, and the conductive pattern layer comprises at least one conductive strip having a length extending in a rolling direction. The at least one conductive strip thereby wraps around the longitudinal axis in the rolled configuration. The conductive pattern layer may also comprise two conductive feed lines connected to the conductive strip for passage of electrical current therethrough. The conductive strip serves as an inductor cell of the rolled-up inductor structure.

Characteristics of temperature rise in variable inductor employing magnetorheological fluid driven by a high-frequency pulsed voltage source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ho-Young; Kang, In Man, E-mail: imkang@ee.knu.ac.kr; Shon, Chae-Hwa

2015-05-07

A variable inductor with magnetorheological (MR) fluid has been successfully applied to power electronics applications; however, its thermal characteristics have not been investigated. To evaluate the performance of the variable inductor with respect to temperature, we measured the characteristics of temperature rise and developed a numerical analysis technique. The characteristics of temperature rise were determined experimentally and verified numerically by adopting a multiphysics analysis technique. In order to accurately estimate the temperature distribution in a variable inductor with an MR fluid-gap, the thermal solver should import the heat source from the electromagnetic solver to solve the eddy current problem. Tomore » improve accuracy, the B–H curves of the MR fluid under operating temperature were obtained using the magnetic property measurement system. In addition, the Steinmetz equation was applied to evaluate the core loss in a ferrite core. The predicted temperature rise for a variable inductor showed good agreement with the experimental data and the developed numerical technique can be employed to design a variable inductor with a high-frequency pulsed voltage source.« less

Performance Comparison of Finemet and Metglas Tape Cores Under Non-Sinusoidal Waveforms with DC Bias (POSTPRINT)

DTIC Science & Technology

2017-06-01

dc converter-based test system was built to intentionally introduce inductor current harmonics by varying the filter capacitance and parasitic...the inclusion of distorted waveforms obtained by varying filter capacitance. At higher frequencies, the Metglas cores were found to exhibit greater...was built to intentionally introduce inductor current harmonics by varying the filter capacitance and parasitic inductance of the test system. Both

Superconducting matrix fault current limiter with current-driven trigger mechanism

DOEpatents

Yuan; Xing

2008-04-15

A modular and scalable Matrix-type Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. An inductor is connected in series with the trigger superconductor in the trigger matrix and physically surrounds the superconductor. The current surge during a fault will generate a trigger magnetic field in the series inductor to cause fast and uniform quenching of the trigger superconductor to significantly reduce burnout risk due to superconductor material non-uniformity.

Cost Optimal Design of a Power Inductor by Sequential Gradient Search

NASA Astrophysics Data System (ADS)

Basak, Raju; Das, Arabinda; Sanyal, Amarnath

2018-05-01

Power inductors are used for compensating VAR generated by long EHV transmission lines and in electronic circuits. For the EHV-lines, the rating of the inductor is decided upon by techno-economic considerations on the basis of the line-susceptance. It is a high voltage high current device, absorbing little active power and large reactive power. The cost is quite high- hence the design should be made cost-optimally. The 3-phase power inductor is similar in construction to a 3-phase core-type transformer with the exception that it has only one winding per phase and each limb is provided with an air-gap, the length of which is decided upon by the inductance required. In this paper, a design methodology based on sequential gradient search technique and the corresponding algorithm leading to cost-optimal design of a 3-phase EHV power inductor has been presented. The case-study has been made on a 220 kV long line of NHPC running from Chukha HPS to Birpara of Coochbihar.

Design, Simulation and Fabrication of A MEMS-based Double-layer Spiral Planar Inductor with Patterned Permalloy as Magnetic Layers

NASA Astrophysics Data System (ADS)

Zhu, Xiaomin; Cheng, Ping; Chen, Mingming; Ding, Guifu

2018-03-01

There have been significant efforts to boost the inductance value by adopting the sandwich structures using permalloy magnetic shielding layers. However, this structure will introduce high ac conductor losses and high eddy currents. In order to solve these problems, patterned permalloy can solve this problem effectively. According to the simulation results based on the application of finite element method in the frequency domain, the optimum permalloy pattern is which the blank of the permalloy are perpendicular to the coil inside. The double-layer planar inductor has a size of l5×1.5×0.1mm consisted of 13-turn spiral Cu coil for each layer and a 20μm-thick patterned permalloy magnetic shielding layer. The inductor shows a higher inductance than the traditional planar inductor. The patterned permalloy made the inductor more stable in high frequency than the none-patterned. And the inductor has an inductance of 1.3μH and quality factor of 2.8 at 1.5MHz, with an inductance per unit of 578nH/mm2, which is much higher than that in the reported literatures.

Design Considerations for High Temperature Power Inductors

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

2005-01-01

A uniform B-field approximation model is used to develop design formulas for single-layer wound, toroidal core, ac power inductors that must handle a specified current. Such a geometry is well suited for high temperature, high frequency inductors, where removal of heat from the core becomes critical. Explicit expressions are derived for core radii, core and winding volumes, winding turns and core permeability as functions of a dimensional scaling ratio (S). A limit on the maximum allowed core B-field leads to the result that the minimum core volume is proportional to the permeability, which has a lower bound. Plots versus S are provided for a specific case, to show that good designs can be picked in the overlap regions around the minima in mass and overall size, where the mass and size are relatively flat. Data to 250 C are presented for an MPP core based inductor to show that a quasi-linear, high temperature inductor can be constructed with available materials. A similar development is applied to a toroidal air-core geometry, showing that for the same ratings, such an inductor is considerably bigger and more massive, at least in the single-layer version.

Tests of a low-pressure switch protected by a saturating inductor

NASA Astrophysics Data System (ADS)

Lauer, E. J.; Birx, D. L.

1981-10-01

A triggered low-pressure switch was tested switching a charged capacitor across a damping resistor simulating a transformer. A series saturating inductor protected the switch from electron beam anode damage. The capacitor was 15 micro F and charge voltages up to 50 kV were used. The time to current maximum was 5 to 8 micro S. The current terminated at about 50 micro S and voltage could be reapplied at about 100 micro S.

Power-processing unit

NASA Technical Reports Server (NTRS)

Wessel, Frank J. (Inventor); Hancock, Donald J. (Inventor)

1987-01-01

Power-processing unit uses AC buses (30, 32) to supply all current dependent needs such as connections (54, 56) to an ion thruster through an inductor (88) and the primary of a transformer (90), to assure limited currents to such loads. Where temperature control is also required, such as to the main discharge vaporizer heater connection (36, 38), switches (100, 102) are serially connected with inductor (96) and the primary of transformer (98). Temperature sensor (104) controls the switches (100, 102) for temperature regulation.

Ionization tube simmer current circuit

DOEpatents

Steinkraus, R.F. Jr.

1994-12-13

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

Ionization tube simmer current circuit

DOEpatents

Steinkraus, Jr., Robert F.

1994-01-01

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

Push-pull converter with energy saving circuit for protecting switching transistors from peak power stress

NASA Technical Reports Server (NTRS)

Mclyman, W. T. (Inventor)

1981-01-01

In a push-pull converter, switching transistors are protected from peak power stresses by a separate snubber circuit in parallel with each comprising a capacitor and an inductor in series, and a diode in parallel with the inductor. The diode is connected to conduct current of the same polarity as the base-emitter juction of the transistor so that energy stored in the capacitor while the transistor is switched off, to protect it against peak power stress, discharges through the inductor when the transistor is turned on, and after the capacitor is discharges through the diode. To return this energy to the power supply, or to utilize this energy in some external circuit, the inductor may be replaced by a transformer having its secondary winding connected to the power supply or to the external circuit.

Wire-inhomogeneity detector

DOEpatents

Gibson, G.H.; Smits, R.G.; Eberhard, P.H.

1982-08-31

A device for uncovering imperfections in electrical conducting wire, particularly superconducting wire, by detecting variations in eddy currents. Eddy currents effect the magnetic field in a gap of an inductor, contained in a modified commercial ferrite core, through which the wire being tested is passed. A small increase or decrease in the amount of conductive material, such as copper, in a fixed cross section of wire will unbalance a bridge used to measure the impedance of the inductor, tripping a detector and sounding an alarm.

Apparatus for characterizing conductivity of materials by measuring the effect of induced shielding currents therein

DOEpatents

Doss, James D.

1991-01-01

Apparatus and method for noncontact, radio-frequency shielding current characterization of materials. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples.

Dynamics of inductors for heating of the metal under deformation

NASA Astrophysics Data System (ADS)

Zimin, L. S.; Yeghiazaryan, A. S.; Protsenko, A. N.

2018-01-01

Current issues of creating powerful systems for hot sheet rolling with induction heating application in mechanical engineering and metallurgy were discussed. Electrodynamical and vibroacoustic problems occurring due to the induction heating of objects with complex shapes, particularly the slabs heating prior to rolling, were analysed. The numerical mathematical model using the method of related contours and the principle of virtual displacements is recommended for electrodynamical calculations. For the numerical solution of the vibrational problem, it is reasonable to use the finite element method (FEM). In general, for calculating the distribution forces, the law of Biot-Savart-Laplace method providing the determination of the current density of the skin layer in slab was used. The form of the optimal design of the inductor based on maximum hardness was synthesized while researching the vibrodynamic model of the system "inductor-metal" which provided allowable sound level meeting all established sanitary standards.

Tests of a low-pressure switch protected by a saturating inductor

NASA Astrophysics Data System (ADS)

Lauer, E. J.; Birx, D. L.

Low pressure switches and magnetic switches were tested as possible replacements for the high pressure switches currently used on Experimental Test Accelerator and Advanced Test Accelerator. When the low pressure switch is used with a low impedance transmission line, runaway electrons form a pinched electron beam which damages the anode. The use of the low pressure switch as the first switch in the pulsed power chain was tested; i.e., the switch would be used to connect a charged capacitor across the primary winding of a step up transformer. An inductor with a saturating core is connected in series so that, initially, there is a large inductive voltage drop. As a result, there is small voltage across the switch. By the time the inductor core saturates, the switch has developed sufficient ionization so that the switch voltage remains small, even with peak current, and an electron beam is not produced.

Wire inhomogeneity detector having a core with opposing pole pieces and guide pieces adjacent the opposing pole pieces

DOEpatents

Gibson, George H.; Smits, Robert G.; Eberhard, Philippe H.

1989-01-01

A device for uncovering imperfections in electrical conducting wire, particularly superconducting wire, by detecting variations in eddy currents. Eddy currents effect the magnetic field in a gap of an inductor, contained in a modified commercial ferrite core, through which the wire being tested is passed. A small increase or decrease in the amount of conductive material, such as copper, in a fixed cross section of wire will unbalance a bridge used to measure the impedance of the inductor, tripping a detector and sounding an alarm.

Apparatus for characterizing conductivity of superconducting materials

DOEpatents

Doss, J.D.

1993-12-07

Apparatus and method for noncontact, radio-frequency shielding current characterization of materials. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples. 10 figures.

Apparatus and method for characterizing conductivity of materials

DOEpatents

Doss, J.D.

1988-04-13

Apparatus and method for noncontact, radio-frequency shielding current characterization of materials. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples. 8 figs.

Apparatus for characterizing conductivity of materials by measuring the effect of induced shielding currents therein

DOEpatents

Doss, J.D.

1991-05-14

Apparatus and method for noncontact, radio-frequency shielding current characterization of materials is disclosed. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples. 10 figures.

Compact Superconducting Power Systems for Airborne Applications (Postprint)

DTIC Science & Technology

2009-01-01

rotating machin- ery such as motors and alternators, is to maximize the magnet- ic flux density. This can be achieved by using a higher current...future systems could be driven to much higher power ratios, since the initial machine configuration was a homopolar inductor alternator‡ (HIA). A... Homopolar inductor alternator is an electrically symmetrical synchro- nous generator with a field winding that has a fixed magnetic position in relation to

Coupling Inductor Based Hybrid Millimeter-Wave Switch

NASA Technical Reports Server (NTRS)

Gu, Qun (Inventor); Drouin, Brian J. (Inventor); Tang, Adrian J. (Inventor); Shu, Ran (Inventor)

2017-01-01

A switch comprising a plurality of inductors and a plurality of shunt transistors is described. Each inductor can be electrically coupled between adjacent shunt transistors to form a distributed switch structure. At least two inductors in the plurality of inductors can be inductively coupled with each other. The plurality of inductors can correspond to portions of a coupling inductor, wherein the coupling inductor can have an irregular octagonal shape.

A No-Arc DC Circuit Breaker Based on Zero-Current Interruption

NASA Astrophysics Data System (ADS)

Xiang, Xuewei; Chai, Jianyun; Sun, Xudong

2017-05-01

A dc system has no natural current zero-crossing point, so a dc arc is more difficult to extinguish than an ac arc. In order to effectively solve the problem of the dc arc, this paper proposes a dc circuit breaker (DCCB) capable of implementing a no-arc interruption. The proposed DCCB includes a main branch consisting of a mechanical switch, a diode and a current-limiting inductor, a semi-period resonance circuit consisting of a diode, an inductor and a capacitor, and a buffer branch consisting of a capacitor, a thyristor and a resistor. The mechanical switch is opened in a zero-current state, and the overvoltage caused by the counter electromotive force of the inductor does not exist. Meanwhile, the capacitor has a buffering effect on the voltage. The rising of the voltage of the mechanical switch is slower than the rising of the insulating strength of a contact gap of the mechanical switch, resulting in the contact gap not able to be broken down. Thus, the arc cannot be generated. The simulation results show that the proposed DCCB does not generate the arc in the interruption process, the rise rate of the short circuit current can be effectively limited, and the short circuit fault point can be rapidly isolated from the dc power supply.

Experimental Investigation of DC-Bias Related Core Losses in a Boost Inductor (Postprint)

DTIC Science & Technology

2014-08-01

dc bias-flux conditions. These dc bias conditions result in distorted hysteresis loops , increased core losses, and have been shown to be independent...These dc bias conditions result in dis- torted hysteresis loops , increased core losses, and have been shown to be independent of core material. The...controllable converter load currents, this topology is ideal to study dc-related losses. Inductor core hysteresis loop characterization was accomplished

A Study of 4-level DC-DC Boost Inverter with Passive Component Reduction Consideration

NASA Astrophysics Data System (ADS)

Kasiran, A. N.; Ponniran, A.; Harimon, M. A.; Hamzah, H. H.

2018-04-01

This study is to analyze design principles of boost inductor and capacitor used in the 4-level DC-DC boost converter to realize size reduction of passive component referring to their attributes. The important feature of this circuit is that most of the boost-up energy is transferred from the capacitor-clamped to the output side which the small inductance can be used at the input side. The inductance of the boost inductor is designed by referring the inductor current ripple. On the other hand, the capacitance of the capacitor-clamped is designed by considering voltage stress on semiconductor devices and also the used switching frequency. Besides that, according to the design specifications, the required inductance in 4-level DC-DC boost converter is decreased compared to a conventional conventional DC-DC boost converter. Meanwhile, voltage stress on semiconductor device is depending on the maximum voltage ripple of the capacitor-clamped. A 50 W 4-level DC-DC boost converter prototype has been constructed. The results show that the inductor current ripple was 1.15 A when the inductors, 1 mH and 0.11 mH were used in the conventional and 4-level DC-DC boost converters, respectively. Thus, based on the experimental results, it shows that the reduction of passive components by referring to their attributes in 4-level DC-DC boost converter is achieved. Moreover, the decreasing of voltage stress on the semiconductor devices is an advantage for the selection of low ON-resistance of the devices which will contribute to the reduction of the semiconductor conduction loss. The integration result of boost converter and H-bridge inverter is also shown.

Transient Performance Improvement Circuit (TPIC)s for DC-DC converter applications

NASA Astrophysics Data System (ADS)

Lim, Sungkeun

Gordon Moore famously predicted the exponential increase in transistor integration and computing power that has been witnessed in recent decades [1]. In the near future, it is expected that more than one billion transistors will be integrated per chip, and advanced microprocessors will require clock speeds in excess of several GHz. The increasing number of transistors and high clock speeds will necessitate the consumption of more power. By 2014, it is expected that the maximum power consumption of the microprocessor will reach approximately 150W, and the maximum load current will be around 150A. Today's trend in power and thermal management is to reduce supply voltage as low as possible to reduce delivered power. It is anticipated that the Intel cores will operate on 0.8V of supply voltage by 2014 [2]. A significant challenge in Voltage Regulator Module (VRM) development for next generation microprocessors is to regulate the supply voltage within a certain tolerance band during high slew rate load transitions, since the required supply voltage tolerance band will be much narrower than the current requirement. If VR output impedance is maintained at a constant value from DC to high frequency, large output voltage spikes can be avoided during load cur- rent transients. Based on this, the Adaptive Voltage Position (AVP) concept was developed to achieve constant VR output impedance to improve transient response performance [3]. However, the VR output impedance can not be made constant over the entire frequency range with AVP design, because the AVP design makes the VR output impedance constant only at low frequencies. To make the output impedance constant at high frequencies, many bulk capacitors and ceramic capacitors are required. The tight supply voltage tolerance for the next generation of microprocessors during high slew rate load transitions requires fast transient response power supplies. A VRM can not follow the high slew rate load current transients, because of the slow inductor current slew rate which is determined by the input voltage, output voltage, and the inductance. The remaining inductor current in the power delivery path will charge the output capacitors and develop a voltage across the ESR. As a result, large output voltage spikes occur during load current transients. Due to their limited control bandwidth, traditional VRs can not sufficiently respond rapidly to certain load transients. As a result, a large output voltage spike can occur during load transients, hence requiring a large amount of bulk capacitance to decouple the VR from the load [2]. If the remaining inductor current is removed from the power stage or the inductor current slew rate is changed, the output voltage spikes can be clamped, allowing the output capacitance to be reduced. A new design methodology for a Transient Performance Improvement Circuit(TPIC) based on controlling the output impedance of a regulator is presented. The TPIC works in parallel with a voltage regulator (VR)'s ceramic capacitors to achieve faster voltage regulation without the need for a large bulk capacitance, and can serve as a replacement for bulk capacitors. The specific function of the TPIC is to mimic the behavior of the bulk capacitance in a traditional VRM by sinking and sourcing large currents during transients, allowing the VR to respond quickly to current transients without the need for a large bulk capacitance. This will allow fast transient response without the need for a large bulk capacitor. The main challenge in applying the TPIC is creating a design which will not interfere with VR operation. A TPIC for a 4 Switch Buck-Boost (4SBB) converter is presented which functions by con- trolling the inductor current slew rate during load current transients. By increasing the inductor current slew rate, the remaining inductor current can be removed from the 4SBB power delivery path and the output voltage spike can be clamped. A second TPIC is presented which is designed to improve the performance of an LDO regulator during output current transients. A TPIC for a LDO regulator is proposed to reduce the over voltage spike settling time. During a load current step down transient, the only current discharging path is a light load current. However, it takes a long time to discharge the current charged in the output capacitors with the light load current. The proposed TPIC will make an additional current discharging path to reduce the long settling time. By reducing the settling time, the load current transient frequency of the LDO regulator can be increased. A Ripple Cancellation Circuit (RCC) is proposed to reduce the output voltage ripple. The RCC has a very similar concept with the TPIC which is sinking or injecting additional current to the power stage to compensate the inductor ripple current. The proposed TPICs and RCC have been implemented with a 0.6m CMOS process. A single-phase VR, a 4SBB converter, and a LDO regulator have been utilized with the proposed TPIC to evaluate its performance. The theoretical analysis will be confirmed by Cadence simulation results and experimental results.

High energy overcurrent protective device

DOEpatents

Praeg, Walter F.

1982-01-01

Electrical loads connected to capacitance elements in high voltage direct current systems are protected from damage by capacitance discharge overcurrents by connecting between the capacitance element and the load, a longitudinal inductor comprising a bifilar winding wound about a magnetic core, which forms an incomplete magnetic circuit. A diode is connected across a portion of the bifilar winding which conducts a unidirectional current only. Energy discharged from the capacitance element is stored in the inductor and then dissipated in an L-R circuit including the diode and the coil winding. Multiple high voltage circuits having capacitance elements may be connected to loads through bifilar windings all wound about the aforementioned magnetic core.

Control system and method for a universal power conditioning system

DOEpatents

Lai, Jih-Sheng; Park, Sung Yeul; Chen, Chien-Liang

2014-09-02

A new current loop control system method is proposed for a single-phase grid-tie power conditioning system that can be used under a standalone or a grid-tie mode. This type of inverter utilizes an inductor-capacitor-inductor (LCL) filter as the interface in between inverter and the utility grid. The first set of inductor-capacitor (LC) can be used in the standalone mode, and the complete LCL can be used for the grid-tie mode. A new admittance compensation technique is proposed for the controller design to avoid low stability margin while maintaining sufficient gain at the fundamental frequency. The proposed current loop controller system and admittance compensation technique have been simulated and tested. Simulation results indicate that without the admittance path compensation, the current loop controller output duty cycle is largely offset by an undesired admittance path. At the initial simulation cycle, the power flow may be erratically fed back to the inverter causing catastrophic failure. With admittance path compensation, the output power shows a steady-state offset that matches the design value. Experimental results show that the inverter is capable of both a standalone and a grid-tie connection mode using the LCL filter configuration.

Fabrication and characterization of 3C-silicon carbide micro sensor for wireless blood pressure measurements

NASA Astrophysics Data System (ADS)

Basak, Nupur

A potentially implantable single crystal 3C-SiC pressure sensor for blood pressure measurement was designed, simulated, fabricated, characterized and optimized. This research uses a single crystal 3C-SiC, for the first time, to demonstrate its application as a blood pressure measurement sensor. The sensor, which uses the epitaxial grown 3C-SiC membrane to measure changes in pressure, is designed to be wireless, biocompatible and linear. The SiC material was chosen for its superior physical, chemical and mechanical properties; the capacitive sensor uses a 3C-SiC membrane as one of the electrodes; and, the sensor system is wireless for comfort and to allow for convenient reading of real-time pressure data (wireless communication is enabled by connecting the sensor parallel to a planar inductor). Together, the variable capacitive sensor and planar inductor create a pressure sensitive resonant circuit. The sensor system described above allows for implantation into a human patient's body, after which the planar inductor can be coupled with an external inductor to receive data for real-time blood pressure measurement. Electroplating, thick photo-resist characterization, RIE etching, oxidation, CVD, chemical mechanical polishing and wafer bonding were optimized during the process of fabricating the sensor system and, in addition to detailing the sensor system simulation and characterization; the optimized processes are detailed in the dissertation. This absolute pressure sensor is designed to function optimally within the human blood pressure range of 50-350mmHg. The layout and modeling of the sensor uses finite element analysis (FEA) software. The simulations for membrane deflection, stress analysis and electro-mechanical analysis are performed for 100 μm2 and 400μm2sensors. The membrane deflection-pressure, capacitance-pressure and resonant frequency-pressure graphs were obtained, and detailed in the dissertation, along with the planar inductor simulation for differently sized inductors. Ultimately, an optimized sensor with a size of 400μm2 was chosen because of its high sensitivity. The sensor, and the planar inductor, which is 3mm 2, is comparable to the presently researched implantable chip size. The measured inductance of the gold electroplated inductor is 0.371μH. The capacitance changes from 0.934 pF to 0.997pF with frequency shift of 248MHz to 256 MHz. The sensitivity of the sensor is found to be 0.21 fF/mmHg or 27.462 kHz/mmHg with an average non-linearity of 0.23216%.

Probing of multiple magnetic responses in magnetic inductors using atomic force microscopy.

PubMed

Park, Seongjae; Seo, Hosung; Seol, Daehee; Yoon, Young-Hwan; Kim, Mi Yang; Kim, Yunseok

2016-02-08

Even though nanoscale analysis of magnetic properties is of significant interest, probing methods are relatively less developed compared to the significance of the technique, which has multiple potential applications. Here, we demonstrate an approach for probing various magnetic properties associated with eddy current, coil current and magnetic domains in magnetic inductors using multidimensional magnetic force microscopy (MMFM). The MMFM images provide combined magnetic responses from the three different origins, however, each contribution to the MMFM response can be differentiated through analysis based on the bias dependence of the response. In particular, the bias dependent MMFM images show locally different eddy current behavior with values dependent on the type of materials that comprise the MI. This approach for probing magnetic responses can be further extended to the analysis of local physical features.

Electric machine and current source inverter drive system

DOEpatents

Hsu, John S

2014-06-24

A drive system includes an electric machine and a current source inverter (CSI). This integration of an electric machine and an inverter uses the machine's field excitation coil for not only flux generation in the machine but also for the CSI inductor. This integration of the two technologies, namely the U machine motor and the CSI, opens a new chapter for the component function integration instead of the traditional integration by simply placing separate machine and inverter components in the same housing. Elimination of the CSI inductor adds to the CSI volumetric reduction of the capacitors and the elimination of PMs for the motor further improve the drive system cost, weight, and volume.

Bubble inductors: Pneumatic tuning of a stretchable inductor

NASA Astrophysics Data System (ADS)

Lazarus, Nathan; Bedair, Sarah S.

2018-05-01

From adaptive matching networks in power systems to channel selectable RF filters and circuitry, tunable inductors are fundamental components for circuits requiring reconfigurability. Here we demonstrate a new continuously tunable inductor based on physically stretching the inductor traces themselves. Liquid-metal-based stretchable conductors are wrapped around a pneumatic bubble actuator, allowing the inductor to be collapsed or expanded by application of pressure. In vacuum the bubble collapses, bringing the loop area to nearly zero, while positive pressure brings a dramatic increase in area and loop inductance. Using this approach, the inductor demonstrated in this work was able to achieve a tuning ratio of 2.6 with 1-2 second response time. With conductors available that can stretch by hundreds of percent, this technique is promising for very large tuning ratios in continuously tunable inductors.

Design of 2.4Ghz CMOS Floating Active Inductor LNA using 130nm Technology

NASA Astrophysics Data System (ADS)

Muhamad, M.; Soin, N.; Ramiah, H.

2018-03-01

This paper presents about design and optimization of CMOS active inductor integrated circuit. This active inductor implements using Silterra 0.13μm technology and simulated using Cadence Virtuoso and Spectre RF. The center frequency for this active inductor is at 2.4 GHz which follow IEEE 802.11 b/g/n standard. To reduce the chip size of silicon, active inductor is used instead of passive inductor at low noise amplifier LNA circuit. This inductor test and analyse by low noise amplifier circuit. Comparison between active with passive inductor based on LNA circuit has been performed. Result shown that the active inductor has significantly reduce the chip size with 73 % area without sacrificing the noise figure and gain of LNA which is the most important criteria in LNA. The best low noise amplifier provides a power gain (S21) of 20.7 dB with noise figure (NF) of 2.1dB.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordienko, V.A.; Dubinov, A.E.; Zhuravlev, S.S.

A new type of magnetic confinement system--a Galathea with a myxine in the shape of a convex polyhedron--is proposed. The system was modeled experimentally by passing an RF current through the myxine. On the one hand, the myxine acts as an inductor whose electric field ionizes the gas and, on the other, it acts as an RF magnetic confinement system. A steady-state plasma produced and confined in this system is almost spherical in shape. The electron density and specific (per unit volume) glow intensity of the plasma produced are found to be higher than those in conventional helical inductors.

Development of an electrical model for integrated magnetic inductors

NASA Astrophysics Data System (ADS)

Bechir, M. B.; Yaya, D. D.; Youssouf, M. K.; Soultan, M.; Capraro, S.; Siblini, A.; Chatelon, J. P.; Rousseau, J. J.

2014-07-01

Nowadays, the current trend consists in the development of new technologies with the aim of reducing volume, weight as well as production cost. With the aim of decreasing occupied component area, it will be interesting to use magnetic materials to confine the fields. Therefore, our works concern the modelling and the characterization of magnetic planar inductors. The proposed model is detailed for inductors fabricated with one magnetic layer. The model can take into account, the capacitance between turns and the capacitance between the last turn and the ground plane, the magnetic permeability, the skin and proximity effects of the conductors according to the frequency. The structure of optimization developed to extract the parameters of the model will be presented. Results of extracted parameters are compared with the simulation parameters. A good correlation is observed on Y11 and Y12 parameters on all the broad band frequency.

Development of a dual-field heteropoplar power converter

NASA Technical Reports Server (NTRS)

Eisenhaure, D. B.; Johnson, B.; Bliamptis, T.; St. George, E.

1981-01-01

The design and testing of a 400 watt, dual phase, dual rotor, field modulated inductor alternator is described. The system is designed for use as a flywheel to ac utility line or flywheel to dc bus (electric vehicle) power converter. The machine is unique in that it uses dual rotors and separately controlled fields to produce output current and voltage which are in phase with each other. Having the voltage and current in phase allows the power electronics to be made of simple low cost components. Based on analytical predictions and experimental results, development of a complete 22 kilowatt (30 Hp) power conversion system is recommended. This system would include power electronics and controls and would replace the inductor alternator with an improved electromagnetic conversion system.

A zero-voltage-switched three-phase interleaved buck converter

NASA Astrophysics Data System (ADS)

Hsieh, Yao-Ching; Huang, Bing-Siang; Lin, Jing-Yuan; Pham, Phu Hieu; Chen, Po-Hao; Chiu, Huang-Jen

2018-04-01

This paper proposes a three-phase interleaved buck converter which is composed of three identical paralleled buck converters. The proposed solution has three shunt inductors connected between each other of three basic buck conversion units. With the help of the shunt inductors, the MOSFET parasitic capacitances will resonate to achieve zero-voltage-switching. Furthermore, the decreasing rate of the current through the free-wheeling diodes is limited, and therefore, their reverse-recovery losses can be minimised. The active power switches are controlled by interleaved pulse-width modulation signals to reduce the input and output current ripples. Therefore, the filtering capacitances on the input and output sides can be reduced. The power efficiency is measured to be as high as 98% in experiment with a prototype circuit.

Systematic analysis of CMOS-micromachined inductors with application to mixer matching circuits

NASA Astrophysics Data System (ADS)

Wu, Jerry Chun-Li

The growing demand for consumer voice and data communication systems and military communication applications has created a need for low-power, low-cost, high-performance radio-frequency (RF) front-end. To achieve this goal, bringing passive components, especially inductors, to silicon is imperative. On-chip passive components such as inductors and capacitors generally enhance the reliability and efficiency of silicon-integrated RF cells. They can provide circuit solutions with superior performance and contribute to a higher level of integration. With passive components on chip, there is a great opportunity to have transformers, filters, and matching networks on chip. However, inductors on silicon have a low quality factor (Q) due to both substrate and metal loss. This dissertation demonstrates the systematic analysis of inductors fabricated using standard complementary metal-oxide-semiconductor (CMOS) and micro-electro-mechanical (MEMS) system technologies. We report system-on-chip inductor modeling, simulation, and measurements of effective inductance and quality factors. In this analysis methodology, a number of systematic simulations are performed on regular and micromachined inductors with different parameters such as spiral topology, number of turns, outer diameter, thickness, and percentage of substrate removed by using micromachining technologies. Three different novel support structures of the micromachined spiral inductor are proposed, analyzed, and implemented for larger size suspended inductors. The sensitivity of the structure support and different degree of substrate etching by post-processing is illustrated. The results provide guidelines for the selection of inductor parameters, post-processing methodologies, and its spiral supports to meet the RF design specifications and the stability requirements for mobile communication. The proposed CMOS-micromachined inductor is used in a low cost-effective double-balanced Gilbert mixer with on-chip matching network. The integrated mixer inductor was implemented and tested to prove the concept.

MicroElectroMechanical devices and fabrication technologies for radio-frequency analog signal processing

NASA Astrophysics Data System (ADS)

Young, Darrin Jun

The proliferation of wireless services creates a pressing need for compact and low cost RF transceivers. Modern sub-micron technologies provide the active components needed for miniaturization but fail to deliver high quality passives needed in oscillators and filters. This dissertation demonstrates procedures for adding high quality inductors and tunable capacitors to a standard silicon integrated circuits. Several voltage-controlled oscillators operating in the low Giga-Hertz range demonstrate the suitability of these components for high performance RF building blocks. Two low-temperature processes are described to add inductors and capacitors to silicon ICs. A 3-D coil geometry is used for the inductors rather than the conventional planar spiral to substantially reduce substrate loss and hence improve the quality factor and self-resonant frequency. Measured Q-factors at 1 GHz are 30 for a 4.8 nH device, 16 for 8.2 nH and 13.8 nH inductors. Several enhancements are proposed that are expected to result in a further improvement of the achievable Q-factor. This research investigates the design and fabrication of silicon-based IC-compatible high-Q tunable capacitors and inductors. The goal of this investigation is to develop a monolithic low phase noise radio-frequency voltage-controlled oscillator using these high-performance passive components for wireless communication applications. Monolithic VCOs will help the miniaturization of current radio transceivers, which offers a potential solution to achieve a single hand-held wireless phone with multistandard capabilities. IC-compatible micromachining fabrication technologies have been developed to realize on-chip high-Q RF tunable capacitors and 3-D coil inductors. The capacitors achieve a nominal capacitance value of 2 pF and can be tuned over 15% with 3 V. A quality factor over 60 has been measured at 1 GHz. 3-D coil inductors obtain values of 4.8 nH, 8.2 nH and 13.8 nH. At 1 GHz a Q factor of 30 has been achieved for a 4.8 nH device and a Q of 16 for 8.2 nH and 13.8 nH inductors. A prototype RF voltage-controlled oscillator has been implemented employing the micromachined tunable capacitors and a 8.2 nH 3-D coil inductor. The active electronics, tunable capacitors and inductor are fabricated on separated silicon substrates and wire bonded to form the VCO. This hybrid approach is used to avoid the complexity of building the prototype oscillator. Both passive components are fabricated on silicon substrates and thus amenable to monolithic integration with standard IC process. The VCO achieves a -136 dBc/Hz phase noise at a 3 MHz offset frequency from the carrier, suitable for most wireless communication applications and is tunable from 855 MHz to 863 MHz with 3 V.

Single phase bi-directional AC-DC converter with reduced passive components size and common mode electro-magnetic interference

DOEpatents

Mi, Chris; Li, Siqi

2017-01-31

A bidirectional AC-DC converter is presented with reduced passive component size and common mode electro-magnetic interference. The converter includes an improved input stage formed by two coupled differential inductors, two coupled common and differential inductors, one differential capacitor and two common mode capacitors. With this input structure, the volume, weight and cost of the input stage can be reduced greatly. Additionally, the input current ripple and common mode electro-magnetic interference can be greatly attenuated, so lower switching frequency can be adopted to achieve higher efficiency.

Input current shaped ac-to-dc converters

NASA Technical Reports Server (NTRS)

1985-01-01

Input current shaping techniques for ac-to-dc converters were investigated. Input frequencies much higher than normal, up to 20 kHz were emphasized. Several methods of shaping the input current waveform in ac-to-dc converters were reviewed. The simplest method is the LC filter following the rectifier. The next simplest method is the resistor emulation approach in which the inductor size is determined by the converter switching frequency and not by the line input frequency. Other methods require complicated switch drive algorithms to construct the input current waveshape. For a high-frequency line input, on the order of 20 kHz, the simple LC cannot be discarded so peremptorily, since the inductor size can be compared with that for the resistor emulation method. In fact, since a dc regulator will normally be required after the filter anyway, the total component count is almost the same as for the resistor emulation method, in which the filter is effectively incorporated into the regulator.

Nano-solenoid: helicoid carbon-boron nitride hetero-nanotube

NASA Astrophysics Data System (ADS)

Zhang, Zi-Yue; Miao, Chunyang; Guo, Wanlin

2013-11-01

As a fundamental element of a nanoscale passive circuit, a nano-inductor is proposed based on a hetero-nanotube consisting of a spiral carbon strip and a spiral boron nitride strip. It is shown by density functional theory associated with nonequilibrium Green function calculations that the nanotube exhibits attractive transport properties tunable by tube chirality, diameter, component proportion and connection manner between the two strips, with excellent `OFF' state performance and high current on the order of 10-100 μA. All the hetero-nanotubes show negative differential resistance. The transmission peaks of current are absolutely derived from the helicoid carbon strips or C-BN boundaries, giving rise to a spiral current analogous with an energized nano-solenoid. According to Ampere's Law, the energized nano-solenoid can generate a uniform and tremendous magnetic field of more than 1 tesla, closing to that generated by the main magnet of medical nuclear magnetic resonance. Moreover, the magnitude of magnetic field can be easily modulated by bias voltage, providing great promise for a nano-inductor to realize electromagnetic conversion at the nanoscale.As a fundamental element of a nanoscale passive circuit, a nano-inductor is proposed based on a hetero-nanotube consisting of a spiral carbon strip and a spiral boron nitride strip. It is shown by density functional theory associated with nonequilibrium Green function calculations that the nanotube exhibits attractive transport properties tunable by tube chirality, diameter, component proportion and connection manner between the two strips, with excellent `OFF' state performance and high current on the order of 10-100 μA. All the hetero-nanotubes show negative differential resistance. The transmission peaks of current are absolutely derived from the helicoid carbon strips or C-BN boundaries, giving rise to a spiral current analogous with an energized nano-solenoid. According to Ampere's Law, the energized nano-solenoid can generate a uniform and tremendous magnetic field of more than 1 tesla, closing to that generated by the main magnet of medical nuclear magnetic resonance. Moreover, the magnitude of magnetic field can be easily modulated by bias voltage, providing great promise for a nano-inductor to realize electromagnetic conversion at the nanoscale. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr02914j

The development of differential inductors using double air-bridge structure based on integrated passive device technology

NASA Astrophysics Data System (ADS)

Li, Yang; Yao, Zhao; Fu, Xiao-Qian; Li, Zhi-Ming; Shan, Fu-Kai; Wang, Cong

2017-05-01

Recently, integrated passive devices have become increasingly popular; inductor realization, in particular, offers interesting high performance for RF modules and systems. In this paper, a development of differential inductor fabricated by integrated passive devices technology using a double air-bridge structure is presented. A study of the model development of the differential inductor is first demonstrated. In this model section, a segment box analysis method is applied to provide a clear presentation of the differential inductor. Compared with other work that only shows a brief description of the process, the integrated passive devices process used to fabricate the inductor in this study is elaborated on. Finally, a characterization of differential inductors with different physical layout parameters is illustrated based on inductance and quality factors, which provides a valuable reference for realizing high performance. The proposed work provides a good solution for the design, fabrication and practical application of RF modules and systems.

Superconductor Electronics Fabrication Process with MoNx Kinetic Inductors and Self-Shunted Josephson Junctions

NASA Astrophysics Data System (ADS)

Tolpygo, Sergey K.; Bolkhovsky, Vladimir; Oates, Daniel E.; Rastogi, Ravi; Zarr, Scott; Day, Alexandra L.; Weir, Tarence J.; Wynn, Alex; Johnson, Leonard M.

2018-06-01

Recent progress in superconductor electronics fabrication has enabled single-flux-quantum (SFQ) digital circuits with close to one million Josephson junctions (JJs) on 1-cm$^2$ chips. Increasing the integration scale further is challenging because of the large area of SFQ logic cells, mainly determined by the area of resistively shunted Nb/AlO$_x$-Al/Nb JJs and geometrical inductors utilizing multiple layers of Nb. To overcome these challenges, we are developing a fabrication process with self-shunted high-J$_c$ JJs and compact thin-film MoN$_x$ kinetic inductors instead of geometrical inductors. We present fabrication details and properties of MoN$_x$ films with a wide range of T$_c$, including residual stress, electrical resistivity, critical current, and magnetic field penetration depth {\\lambda}$_0$. As kinetic inductors, we implemented Mo$_2$N films with T$_c$ about 8 K, {\\lambda}$_0$ about 0.51 {\\mu}m, and inductance adjustable in the range from 2 to 8 pH/sq. We also present data on fabrication and electrical characterization of Nb-based self-shunted JJs with AlO$_x$ tunnel barriers and J$_c$ = 0.6 mA/{\\mu}m$^2$, and with 10-nm thick Si$_{1-x}$Nb$_x$ barriers, with x from 0.03 to 0.15, fabricated on 200-mm wafers by co-sputtering. We demonstrate that the electron transport mechanism in Si$_{1-x}$Nb$_x$ barriers at x < 0.08 is inelastic resonant tunneling via chains of multiple localized states. At larger x, their Josephson characteristics are strongly dependent on x and residual stress in Nb electrodes, and in general are inferior to AlO$_x$ tunnel barriers.

Design of air-gapped magnetic-core inductors for superimposed direct and alternating currents

NASA Technical Reports Server (NTRS)

Ohri, A. K.; Wilson, T. G.; Owen, H. A., Jr.

1976-01-01

Using data on standard magnetic-material properties and standard core sizes for air-gap-type cores, an algorithm designed for a computer solution is developed which optimally determines the air-gap length and locates the quiescent point on the normal magnetization curve so as to yield an inductor design with the minimum number of turns for a given ac voltage and frequency and with a given dc bias current superimposed in the same winding. Magnetic-material data used in the design are the normal magnetization curve and a family of incremental permeability curves. A second procedure, which requires a simpler set of calculations, starts from an assigned quiescent point on the normal magnetization curve and first screens candidate core sizes for suitability, then determines the required turns and air-gap length.

Analysis of series resonant converter with series-parallel connection

NASA Astrophysics Data System (ADS)

Lin, Bor-Ren; Huang, Chien-Lan

2011-02-01

In this study, a parallel inductor-inductor-capacitor (LLC) resonant converter series-connected on the primary side and parallel-connected on the secondary side is presented for server power supply systems. Based on series resonant behaviour, the power metal-oxide-semiconductor field-effect transistors are turned on at zero voltage switching and the rectifier diodes are turned off at zero current switching. Thus, the switching losses on the power semiconductors are reduced. In the proposed converter, the primary windings of the two LLC converters are connected in series. Thus, the two converters have the same primary currents to ensure that they can supply the balance load current. On the output side, two LLC converters are connected in parallel to share the load current and to reduce the current stress on the secondary windings and the rectifier diodes. In this article, the principle of operation, steady-state analysis and design considerations of the proposed converter are provided and discussed. Experiments with a laboratory prototype with a 24 V/21 A output for server power supply were performed to verify the effectiveness of the proposed converter.

Microelectromechanical tunable inductor

DOEpatents

Stalford, Harold L [Norman, OK; Hietala, Vincent M [Albuquerque, NM; Fleming, James G [Albuquerque, NM; Fleming, legal representative, Carol

2010-05-04

A microelectromechanical tunable inductor is formed from a pair of substantially-identically-sized coils arranged side by side and coiled up about a central axis which is parallel to a supporting substrate. An in-plane stress gradient is responsible for coiling up the coils which. The inductance provided by the tunable inductor can be electrostatically changed either continuously or in discrete steps using electrodes on the substrate and on each coil. The tunable inductor can be formed with processes which are compatible with conventional IC fabrication so that, in some cases, the tunable inductor can be formed on a semiconductor substrate alongside or on top of an IC.

Saturable inductor and transformer structures for magnetic pulse compression

DOEpatents

Birx, Daniel L.; Reginato, Louis L.

1990-01-01

Saturable inductor and transformer for magnetic compression of an electronic pulse, using a continuous electrical conductor looped several times around a tightly packed core of saturable inductor material.

Methods of Using a Magnetic Field Response Sensor Within Closed, Electrically Conductive Containers

NASA Technical Reports Server (NTRS)

Woodward, Stanley E.; Taylor, Bryant D.

2010-01-01

Magnetic field response sensors are a class of sensors that are powered via oscillating magnetic fields, and when electrically active, respond with their own magnetic fields with attributes dependent upon the magnitude of the physical quantity being measured. A magnetic field response recorder powers and interrogates the magnetic sensors [see Magnetic-Field-Response Measurement- Acquisition System, NASA Tech Briefs Vol. 30, No, 6 (June 2006, page 28)]. Electrically conductive containers have low transmissivity for radio frequency (RF) energy and thus present problems for magnetic field response sensors. It is necessary in some applications to have a magnetic field response sensor s capacitor placed in these containers. Proximity to conductive surfaces alters the inductance and capacitance of the sensors. As the sensor gets closer to a conductive surface, the electric field and magnetic field energy of the sensor is reduced due to eddy currents being induced in the conductive surface. Therefore, the capacitors and inductors cannot be affixed to a conductive surface or embedded in a conductive material. It is necessary to have a fixed separation away from the conductive material. The minimum distance for separation is determined by the desired sensor response signal to noise ratio. Although the inductance is less than what it would be if it were not in proximity to the conductive surface, the inductance is fixed. As long as the inductance is fixed, all variations of the magnetic field response are due to capacitance changes. Numerous variations of inductor mounting can be utilized, such as providing a housing that provides separation from the conductive material as well as protection from impact damage. The sensor can be on the same flexible substrate with a narrow throat portion of the sensor between the inductor and the capacitor, Figure 1. The throat is of sufficient length to allow the capacitor to be appropriately placed within the container and the inductor placed outside the container. The throat is fed through the orifice in the container wall (e.g., fuel tank opening) and connects to the inductor and capacitor via electrical leads to form a closed circuit, Figure 2. Another embodiment is to have the inductor and capacitor fabricated as separate units. In this embodiment, the inductor is mounted external to the container, and the capacitor is mounted internal to the container, Figure 1. Electrical leads are fed through the orifice to connect the inductor and capacitor, Figure 2. When a container holding multiple sensors is made of a conductive material, an antenna can be placed internal to the container. An internal antenna allows all components of the sensors to reside inside the container. The antenna must be separated from the container wall s conductive surface. Additionally, the inductors must be maintained in a fixed position relative to and separated from the container

Nanogranular soft magnetic material and on-package integrated inductors

NASA Astrophysics Data System (ADS)

Li, Liangliang

2007-12-01

Integrated inductors used in electronic circuits are mainly spiral-shaped aluminum devices fabricated on Si chip. They have several disadvantages---large silicon area consumption, high DC resistance and high cost. An attractive approach to address these issues is directly integrating inductors into package substrates, which provide plenty of usage area, low resistance and low cost. The goals of this dissertation are designing and fabricating magnetic and air-core inductors with characteristic low resistance and high quality factor on package substrates. The research work includes three parts which are summarized below. First, the CoFeHfO nanogranular magnetic material developed on Si wafers and package substrates by pulsed DC reactive sputtering were investigated. On Si wafers, the optimized CoFeHfO film has soft magnetic properties. On printed circuit board (PCB) substrates, these magnetic properties degrade due to the rough surface. Surface planarization such as chemical-mechanical polishing can be applied on PCB substrates to reduce the surface roughness and hence improve these properties. Second, on-package inductors with small resistances and high quality factors were designed, fabricated, measured and analyzed. Air-core and magnetic inductors (20 design variations) were built on 8-inch PCB substrates. The DC resistances of these inductors are less than 12 mO, one of the lowest values ever reported. The maximum quality factors can be as large as ˜80 at around 1 GHz for the air-core inductors and ˜25 at 200 MHz for the magnetic inductors. Third, inductor simulation was carried out to study the effects of magnetic materials on the properties of inductors using the Ansoft HFSS software package. The measurement data for the permeability spectra of the CoFeHfO film and the tensor nature of the permeability were taken into account in the simulation. The simulation results matched the experimental data for the inductances, resistances and quality factors. This established an accurate method for modeling high-frequency magnetic devices. Using this method, an inductor with a closed magnetic core was studied by varying the geometry of the core and copper coil. It has been found that the inductance of this inductor depends strongly on whether the permeability of the magnetic core is isotropic or anisotropic.

Fabrication of Circuits on Flexible Substrates Using Conductive SU-8 for Sensing Applications

PubMed Central

Gerardo, Carlos D.; Cretu, Edmond; Rohling, Robert

2017-01-01

This article describes a new low-cost rapid microfabrication technology for high-density interconnects and passive devices on flexible substrates for sensing applications. Silver nanoparticles with an average size of 80 nm were used to create a conductive SU-8 mixture with a concentration of wt 25%. The patterned structures after hard baking have a sheet resistance of 11.17 Ω/☐. This conductive SU-8 was used to pattern planar inductors, capacitors and interconnection lines on flexible Kapton film. The conductive SU-8 structures were used as a seed layer for a subsequent electroplating process to increase the conductivity of the devices. Examples of inductors, resistor-capacitor (RC) and inductor-capacitor (LC) circuits, interconnection lines and a near-field communication (NFC) antenna are presented as a demonstration. As an example of high-resolution miniaturization, we fabricated microinductors having line widths of 5 μm. Mechanical bending tests were successful down to a 5 mm radius. To the best of the authors’ knowledge, this is the first report of conductive SU-8 used to fabricate such planar devices and the first on flexible substrates. This is a proof of concept that this fabrication approach can be used as an alternative for microfabrication of planar passive devices on flexible substrates. PMID:28629134

The fractionated dipole antenna: A new antenna for body imaging at 7 Tesla.

PubMed

Raaijmakers, Alexander J E; Italiaander, Michel; Voogt, Ingmar J; Luijten, Peter R; Hoogduin, Johannes M; Klomp, Dennis W J; van den Berg, Cornelis A T

2016-03-01

Dipole antennas in ultrahigh field MRI have demonstrated advantages over more conventional designs. In this study, the fractionated dipole antenna is presented: a dipole where the legs are split into segments that are interconnected by capacitors or inductors. A parameter study has been performed on dipole antenna length using numerical simulations. A subsequent simulation study investigates the optimal intersegment capacitor/inductor value. The resulting optimal design has been constructed and compared to a previous design, the single-side adapted dipole (SSAD) by simulations and measurements. An array of eight elements has been constructed for prostate imaging on four subjects (body mass index 20-27.5) using 8 × 2 kW amplifiers. For prostate imaging at 7T, lowest peak local specific-absorption rate (SAR) levels are achieved if the antenna is 30 cm or longer. A fractionated dipole antenna design with inductors between segments has been chosen to achieve even lower SAR levels and more homogeneous receive sensitivities. With the new design, good quality prostate images are acquired. SAR levels are reduced by 41% to 63% in comparison to the SSAD. Coupling levels are moderate (average nearest neighbor: -14.6 dB) for each subject and prostate B1+ levels range from 12 to 18 μT. © 2015 Wiley Periodicals, Inc.

Coupled and decoupled on-chip solenoid inductors with nanogranular magnetic cores

NASA Astrophysics Data System (ADS)

He, Yuhan; Wang, Luo; Wang, Yicheng; Zhang, Huaiwu; Peng, Dongliang; Bai, Feiming

2017-12-01

On-chip integrated solenoid inductors with multilayered nanogranular magnetic cores have been designed and fabricated on silicon wafers. Both decoupled and coupled inductors with multilayered magnetic cores were studied. For the decoupled inductor, an inductance of 14.2 nH or an equivalent inductance area density greater than 100 nH/mm2 was obtained, which is about 14 times of that of the air-core inductor, and the quality factor is 7.5 at 130 MHz. For the coupled inductor, an even higher peak quality factor of 17 was achieved at 300 MHz, however, the inductance area density decreased to 34 nH/mm2. The reason of the enhanced peak quality factor was attributed to less spike domains on the edge of the closure-loop shaped magnetic core, and therefore higher permeability and more uniform uniaxial anisotropy.

Effect of the Matching Circuit on the Electromechanical Characteristics of Sandwiched Piezoelectric Transducers.

PubMed

Lin, Shuyu; Xu, Jie

2017-02-10

The input electrical impedance behaves as a capacitive when a piezoelectric transducer is excited near its resonance frequency. In order to increase the energy transmission efficiency, a series or parallel inductor should be used to compensate the capacitive impedance of the piezoelectric transducer. In this paper, the effect of the series matching inductor on the electromechanical characteristics of the piezoelectric transducer is analyzed. The dependency of the resonance/anti-resonance frequency, the effective electromechanical coupling coefficient, the electrical quality factor and the electro-acoustical efficiency on the matching inductor is obtained. It is shown that apart from compensating the capacitive impedance of the piezoelectric transducer, the series matching inductor can also change the electromechanical characteristics of the piezoelectric transducer. When series matching inductor is increased, the resonance frequency is decreased and the anti-resonance unchanged; the effective electromechanical coupling coefficient is increased. For the electrical quality factor and the electroacoustic efficiency, the dependency on the matching inductor is different when the transducer is operated at the resonance and the anti-resonance frequency. The electromechanical characteristics of the piezoelectric transducer with series matching inductor are measured. It is shown that the theoretically predicted relationship between the electromechanical characteristics and the series matching inductor is in good agreement with the experimental results.

Effect of the Matching Circuit on the Electromechanical Characteristics of Sandwiched Piezoelectric Transducers

PubMed Central

Lin, Shuyu; Xu, Jie

2017-01-01

The input electrical impedance behaves as a capacitive when a piezoelectric transducer is excited near its resonance frequency. In order to increase the energy transmission efficiency, a series or parallel inductor should be used to compensate the capacitive impedance of the piezoelectric transducer. In this paper, the effect of the series matching inductor on the electromechanical characteristics of the piezoelectric transducer is analyzed. The dependency of the resonance/anti-resonance frequency, the effective electromechanical coupling coefficient, the electrical quality factor and the electro-acoustical efficiency on the matching inductor is obtained. It is shown that apart from compensating the capacitive impedance of the piezoelectric transducer, the series matching inductor can also change the electromechanical characteristics of the piezoelectric transducer. When series matching inductor is increased, the resonance frequency is decreased and the anti-resonance unchanged; the effective electromechanical coupling coefficient is increased. For the electrical quality factor and the electroacoustic efficiency, the dependency on the matching inductor is different when the transducer is operated at the resonance and the anti-resonance frequency. The electromechanical characteristics of the piezoelectric transducer with series matching inductor are measured. It is shown that the theoretically predicted relationship between the electromechanical characteristics and the series matching inductor is in good agreement with the experimental results. PMID:28208583

Two-inductor boost and buck converters

NASA Astrophysics Data System (ADS)

White, J. L.; Muldoon, W. J.

The derivation, analysis and design of a coupled inductor boost converter is presented. Aspects of the qualitative ac behavior of coupled inductor converters are discussed. Considerations for the design of the magnetics for such converters are addressed.

Bridgeless SEPIC PFC Converter for Multistring LED Driver

NASA Astrophysics Data System (ADS)

Jha, Aman; Singh, Bhim

2018-05-01

This paper deals with Power Factor Correction (PFC) in Low Voltage High Current (LVHC) multi-string light emitting diode (LED) using a bridgeless (BL) single ended primary inductance converter (SEPIC). This application is designed for large area LED lighting with illumination control. A multi-mode LED dimming technique is used for the lighting control. The BL-SEPIC PFC converter is used as a load emulator for high power factor. The regulated low voltage from flyback converter is a source power to the synchronous buck converters for multi-string LED driver and forced cooling system for LED junction. The BL-SEPIC PFC converter inductor design is based on Discontinuous Inductor Current Modes (DICM) which provides good PFC at low cost. Test results are found quite satisfactory for universal input AC (90-265 V). There is significant improvement in the power factor and input current Total Harmonic Distortion (THD) with good margin of harmonic limits for lighting IEC 61000-3-2 Class C.

Highly efficient maximum power point tracking using DC-DC coupled inductor single-ended primary inductance converter for photovoltaic power systems

NASA Astrophysics Data System (ADS)

Quamruzzaman, M.; Mohammad, Nur; Matin, M. A.; Alam, M. R.

2016-10-01

Solar photovoltaics (PVs) have nonlinear voltage-current characteristics, with a distinct maximum power point (MPP) depending on factors such as solar irradiance and operating temperature. To extract maximum power from the PV array at any environmental condition, DC-DC converters are usually used as MPP trackers. This paper presents the performance analysis of a coupled inductor single-ended primary inductance converter for maximum power point tracking (MPPT) in a PV system. A detailed model of the system has been designed and developed in MATLAB/Simulink. The performance evaluation has been conducted on the basis of stability, current ripple reduction and efficiency at different operating conditions. Simulation results show considerable ripple reduction in the input and output currents of the converter. Both the MPPT and converter efficiencies are significantly improved. The obtained simulation results validate the effectiveness and suitability of the converter model in MPPT and show reasonable agreement with the theoretical analysis.

Superconducting analog-to-digital converter with a triple-junction reversible flip-flop bidirectional counter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, G.S.

1993-07-13

A high-performance superconducting analog-to-digital converter is described, comprising: a bidirectional binary counter having n stages of triple-junction reversible flip-flops connected together in a cascade arrangement from the least significant bit (LSB) to the most significant bit (MSB) where n is the number of bits of the digital output, each triple-junction reversible flip-flop including first, second and third shunted Josephson tunnel junctions and a superconducting inductor connected in a bridge circuit, the Josephson junctions and the inductor forming upper and lower portions of the flip-flop, each reversible flip-flop being a bistable logic circuit in which the direction of the circulating currentmore » determines the state of the circuit; and means for applying an analog input current to the bidirectional counter; wherein the bidirectional counter algebraically counts incremental changes in the analog input current, increasing the binary count for positive incremental changes in the analog current and decreasing the binary count for negative incremental changes in the current, and wherein the counter does not require a gate bias, thus minimizing power dissipation.« less

Resonant paramagnetic enhancement of the thermal and zero-point Nyquist noise

NASA Astrophysics Data System (ADS)

França, H. M.; Santos, R. B. B.

1999-01-01

The interaction between a very thin macroscopic solenoid, and a single magnetic particle precessing in a external magnetic field B0, is described by taking into account the thermal and the zero-point fluctuations of stochastic electrodynamics. The inductor belongs to a RLC circuit without batteries and the random motion of the magnetic dipole generates in the solenoid a fluctuating current Idip( t), and a fluctuating voltage εdip( t), with spectral distribution quite different from the Nyquist noise. We show that the mean square value < Idip2> presents an enormous variation when the frequency of precession approaches the frequency of the circuit, but it is still much smaller than the Nyquist current in the circuit. However, we also show that < Idip2> can reach measurable values if the inductor is interacting with a macroscopic sample of magnetic particles (atoms or nuclei) which are close enough to its coils.

Air-Gapped Structures as Magnetic Elements for Use in Power Processing Systems. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Ohri, A. K.

1977-01-01

Methodical approaches to the design of inductors for use in LC filters and dc-to-dc converters using air gapped magnetic structures are presented. Methods for the analysis and design of full wave rectifier LC filter circuits operating with the inductor current in both the continuous conduction and the discontinuous conduction modes are also described. In the continuous conduction mode, linear circuit analysis techniques are employed, while in the case of the discontinuous mode, the method of analysis requires computer solutions of the piecewise linear differential equations which describe the filter in the time domain. Procedures for designing filter inductors using air gapped cores are presented. The first procedure requires digital computation to yield a design which is optimized in the sense of minimum core volume and minimum number of turns. The second procedure does not yield an optimized design as defined above, but the design can be obtained by hand calculations or with a small calculator. The third procedure is based on the use of specially prepared magnetic core data and provides an easy way to quickly reach a workable design.

Enhanced inductance in laminated multilayer magnetic planar inductor for sensitive magnetic field detection

NASA Astrophysics Data System (ADS)

Wang, Yao; Wen, Yumei; Song, Fapeng; Li, Ping; Yu, Shumin

2018-04-01

The authors reported laminated multilayer magnetic planar inductors for sensitive magnetic field detection, which consist of two serially connected sandwich planar inductors (i.e., FeCuNbSiB/micro planar coil/FeCuNbSiB/micro planar coil/FeCuNbSiB). When ac current is applied to coils, the greatly increased inductance by the incorporated high permeability magnetic material and enlarged mutual-inductance among coils significantly improve the sensor sensitivity to the dc magnetic field. The demagnetizing field is also found to affect the performance severely when the shape and the number of magnetic layers vary. The investigation indicates that the proposed laminate can provide an inductance ratio of 665% at the frequency of 1 kHz. By connecting the sensor with a capacitor, the sensor output with varying dc magnetic fields is obtained by tuning the resonant frequency shift. The study indicates that the proposed sensor can provide a sensitivity of about 3.57 kHz/Oe with a resolution of 28 nT between 2 Oe and 60 Oe, which outperforms most of the magnetic sensors with frequency shifting output.

Fast-responding short circuit protection system with self-reset for use in circuit supplied by DC power

NASA Technical Reports Server (NTRS)

Burns, Bradley M. (Inventor); Blalock, Norman N. (Inventor)

2011-01-01

A short circuit protection system includes an inductor, a switch, a voltage sensing circuit, and a controller. The switch and inductor are electrically coupled to be in series with one another. A voltage sensing circuit is coupled across the switch and the inductor. A controller, coupled to the voltage sensing circuit and the switch, opens the switch when a voltage at the output terminal of the inductor transitions from above a threshold voltage to below the threshold voltage. The controller closes the switch when the voltage at the output terminal of the inductor transitions from below the threshold voltage to above the threshold voltage.

Adjustable direct current and pulsed circuit fault current limiter

DOEpatents

Boenig, Heinrich J.; Schillig, Josef B.

2003-09-23

A fault current limiting system for direct current circuits and for pulsed power circuit. In the circuits, a current source biases a diode that is in series with the circuits' transmission line. If fault current in a circuit exceeds current from the current source biasing the diode open, the diode will cease conducting and route the fault current through the current source and an inductor. This limits the rate of rise and the peak value of the fault current.

Load characteristics of wireless power transfer system with different resonant types and resonator numbers

NASA Astrophysics Data System (ADS)

Zhang, Yiming; Zhao, Zhengming; Chen, Kainan; Fan, Jun

2017-05-01

Wireless Power Transfer (WPT) has been the research focus and applied in many fields. Normally power is transferred wirelessly to charge the battery, which requires specific load characteristics. The load characteristics are essential for the design and operation of the WPT system. This paper investigates the load characteristics of the WPT system with different resonant types and resonator numbers. It is found that in a WPT system with series or LCL resonance under a constant voltage source, the load characteristic is determined by the number of inductors. Even number of inductors results in a constant current characteristic and odd number constant voltage characteristic. Calculations, simulations, and experiments verify the analysis.

System and Method for Monitoring Piezoelectric Material Performance

NASA Technical Reports Server (NTRS)

Moses, Robert W. (Inventor); Fox, Christopher L. (Inventor); Fox, Melanie L. (Inventor); Chattin, Richard L. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor)

2007-01-01

A system and method are provided for monitoring performance capacity of a piezoelectric material that may form part of an actuator or sensor device. A switch is used to selectively electrically couple an inductor to the piezoelectric material to form an inductor-capacitor circuit. Resonance is induced in the inductor-capacitor circuit when the switch is operated to create the circuit. The resonance of the inductor-capacitor circuit is monitored with the frequency of the resonance being indicative of performance capacity of the device's piezoelectric material.

Planar Lithographed Superconducting LC Resonators for Frequency-Domain Multiplexed Readout Systems

NASA Astrophysics Data System (ADS)

Rotermund, K.; Barch, B.; Chapman, S.; Hattori, K.; Lee, A.; Palaio, N.; Shirley, I.; Suzuki, A.; Tran, C.

2016-07-01

Cosmic microwave background (CMB) polarization experiments are increasing the number of transition edge sensor (TES) bolometers to increase sensitivity. In order to maintain low thermal loading of the sub-Kelvin stage, the frequency-domain multiplexing (FDM) factor has to increase accordingly. FDM is achieved by placing TES bolometers in series with inductor-capacitor (LC) resonators, which select the readout frequency. The multiplexing factor can be raised with a large total readout bandwidth and small frequency spacing between channels. The inductance is kept constant to maintain a uniform readout bandwidth across detectors, while the maximum acceptable value is determined by bolometer stability. Current technology relies on commercially available ceramic chip capacitors. These have high scatter in their capacitance thereby requiring large frequency spacing. Furthermore, they have high equivalent series resistance (ESR) at higher frequencies and are time consuming and tedious to hand assemble via soldering. A solution lies in lithographed, planar spiral inductors (currently in use by some experiments) combined with interdigitated capacitors on a silicon (Si) substrate. To maintain reasonable device dimensions, we have reduced trace and gap widths of the LCs to 4 \\upmu m. We increased the inductance from 16 to 60 \\upmu H to achieve a higher packing density, a requirement for FDM systems with large multiplexing factors. Additionally, the Si substrate yields low ESR values across the entire frequency range and lithography makes mass production of LC pairs possible. We reduced mutual inductance between inductors by placing them in a checkerboard pattern with the capacitors, thereby increasing physical distances between adjacent inductors. We also reduce magnetic coupling of inductors with external sources by evaporating a superconducting ground plane onto the backside of the substrate. We report on the development of lithographed LCs in the 1-5 MHz range for use with FDM systems. These resonators will be used by CMB polarization experiments such as Polarbear-2, Simons Array, and SPT-3G. Existing FDM systems have multiplexing factors up to 16× . We report the extension to 40× , i.e., Polarbear-2, and 68× , i.e., SPT-3G. We present the design criteria of Polarbear-2's LC circuits, the fabrication techniques, and the testing. Concerns such as yield, accuracy in frequency, loss, and mutual inductance between spatially neighboring channels will be discussed.

A Low Cost Bluetooth Low Energy Transceiver for Wireless Sensor Network Applications with a Front-end Receiver-Matching Network-Reusing Power Amplifier Load Inductor.

PubMed

Liang, Zhen; Li, Bin; Huang, Mo; Zheng, Yanqi; Ye, Hui; Xu, Ken; Deng, Fangming

2017-04-19

In this work, a low cost Bluetooth Low Energy (BLE) transceiver for wireless sensor network (WSN) applications, with a receiver (RX)-matching network-reusing power amplifier (PA) load inductor, is presented. In order to decrease the die area, only two inductors were used in this work. Besides the one used in the voltage control oscillator (VCO), the PA load inductor was reused as the RX impedance matching component in the front-end. Proper controls have been applied to achieve high transmitter (TX) input impedance when the transceiver is in the receiving mode, and vice versa. This allows the TRX-switch/matching network integration without significant performance degradation. The RX adopted a low-IF structure and integrated a single-ended low noise amplifier (LNA), a current bleeding mixer, a 4th complex filter and a delta-sigma continuous time (CT) analog-to-digital converter (ADC). The TX employed a two-point PLL-based architecture with a non-linear PA. The RX achieved a sensitivity of -93 dBm and consumes 9.7 mW, while the TX achieved a 2.97% error vector magnitude (EVM) with 9.4 mW at 0 dBm output power. This design was fabricated in a 0.11 μm complementary metal oxide semiconductor (CMOS) technology and the front-end circuit only occupies 0.24 mm². The measurement results verify the effectiveness and applicability of the proposed BLE transceiver for WSN applications.

Three-dimensional coil inductor

DOEpatents

Bernhardt, Anthony F.; Malba, Vincent

2002-01-01

A three-dimensional coil inductor is disclosed. The inductor includes a substrate; a set of lower electrically conductive traces positioned on the substrate; a core placed over the lower traces; a set of side electrically conductive traces laid on the core and the lower traces; and a set of upper electrically conductive traces attached to the side traces so as to form the inductor. Fabrication of the inductor includes the steps of forming a set of lower traces on a substrate; positioning a core over the lower traces; forming a set of side traces on the core; connecting the side traces to the lower traces; forming a set of upper traces on the core; and connecting the upper traces to the side traces so as to form a coil structure.

An innovative high-power constant-current pulsed-arc power-supply for a high-density pulsed-arc-plasma ion-source using a LaB6-filament.

PubMed

Ueno, A; Oguri, H; Ikegami, K; Namekawa, Y; Ohkoshi, K; Tokuchi, A

2010-02-01

An innovative high-power constant-current (CC) pulsed-arc (PA) power-supply (PS) indispensable for a high-density PA plasma ion-source using a lanthanum hexaboride (LaB(6)) filament was devised by combining a constant-voltage (CV) PA-PS, which is composed of an insulated gate bipolar transistor (IGBT) switch, a CV direct-current (dc) PS and a 270 mF capacitor with a CC-PA-PS, which is composed of an IGBT-switch, a CC-dc-PS and a 400 microH inductor, through the inductor. The hybrid-CC-PA-PS succeeded in producing a flat arc-pulse with a peak power of 56 kW (400 A x 140 V) and a duty factor of more than 1.5% (600 micros x 25 Hz) for Japan Proton Accelerator Research Complex (J-PARC) H(-) ion-source stably. It also succeeded in shortening the 99% rising-time of the arc-pulse-current to about 20 micros and tilting up or down the arc-pulse-current arbitrarily and almost linearly by changing the setting voltage of its CV-dc-PS.

Improved battery charger for electric vehicles

NASA Technical Reports Server (NTRS)

Rippel, W. E.

1981-01-01

Polyphase version of single-phase "boost chopper" significantly reduces ripple and electromagnetic interference (EMI). Drive circuit of n-phase boost chopper incorporates n-phase duty-cycle generator; inductor, transistor, and diode compose chopper which can run on single-phase or three-phase alternating current or on direct current. Device retains compactness and power factors approaching unity, while improving efficiency.

Toroidal-Core Microinductors Biased by Permanent Magnets

NASA Technical Reports Server (NTRS)

Lieneweg, Udo; Blaes, Brent

2003-01-01

The designs of microscopic toroidal-core inductors in integrated circuits of DC-to-DC voltage converters would be modified, according to a proposal, by filling the gaps in the cores with permanent magnets that would apply bias fluxes (see figure). The magnitudes and polarities of the bias fluxes would be tailored to counteract the DC fluxes generated by the DC components of the currents in the inductor windings, such that it would be possible to either reduce the sizes of the cores or increase the AC components of the currents in the cores without incurring adverse effects. Reducing the sizes of the cores could save significant amounts of space on integrated circuits because relative to other integrated-circuit components, microinductors occupy large areas - of the order of a square millimeter each. An important consideration in the design of such an inductor is preventing magnetic saturation of the core at current levels up to the maximum anticipated operating current. The requirement to prevent saturation, as well as other requirements and constraints upon the design of the core are expressed by several equations based on the traditional magnetic-circuit approximation. The equations involve the core and gap dimensions and the magnetic-property parameters of the core and magnet materials. The equations show that, other things remaining equal, as the maximum current is increased, one must increase the size of the core to prevent the flux density from rising to the saturation level. By using a permanent bias flux to oppose the flux generated by the DC component of the current, one would reduce the net DC component of flux in the core, making it possible to reduce the core size needed to prevent the total flux density (sum of DC and AC components) from rising to the saturation level. Alternatively, one could take advantage of the reduction of the net DC component of flux by increasing the allowable AC component of flux and the corresponding AC component of current. In either case, permanent-magnet material and the slant (if any) and thickness of the gap must be chosen according to the equations to obtain the required bias flux. In modifying the design of the inductor, one must ensure that the inductance is not altered. The simplest way to preserve the original value of inductance would be to leave the gap dimensions unchanged and fill the gap with a permanent- magnet material that, fortuitously, would produce just the required bias flux. A more generally applicable alternative would be to partly fill either the original gap or a slightly enlarged gap with a suitable permanent-magnet material (thereby leaving a small residual gap) so that the reluctance of the resulting magnetic circuit would yield the desired inductance.

Op-amp gyrator simulates high Q inductor

NASA Technical Reports Server (NTRS)

Sutherland, W. C.

1977-01-01

Gyrator circuit consisting of dual operational amplifier and four resistors inverts impedance of capacitor to simulate inductor. Synthetic inductor has high Q factor, good stability, wide bandwidth, and easily determined value of inductance that is independent of frequency. It readily lends itself to integrated-circuit applications, including filter networks.

Inductors and Inductance-Resistance Networks.

ERIC Educational Resources Information Center

Kirwin, Gerald J.

This programed booklet presents ideas related to inductors and inductance--resistance networks. It is designed for the engineering student who is familiar with differential equations and electrical networks. A variety of cases are considered with the idea of developing in the student a broad acquaintance with the inductor response. The booklet is…

Ferrofluid-based Stretchable Magnetic Core Inductors

NASA Astrophysics Data System (ADS)

Lazarus, N.; Meyer, C. D.

2015-12-01

Magnetic materials are commonly used in inductor and transformer cores to increase inductance density. The emerging field of stretchable electronics poses a new challenge since typical magnetic cores are bulky, rigid and often brittle. This paper presents, for the first time, stretchable inductors incorporating ferrofluid as a liquid magnetic core. Ferrofluids, suspensions of nanoscale magnetic particles in a carrier liquid, provide enhanced magnetic permeability without changing the mechanical properties of the surrounding elastomer. The inductor tested in this work consisted of a liquid metal solenoid wrapped around a ferrofluid core in separate channels. The low frequency inductance was found to increase from 255 nH before fill to 390 nH after fill with ferrofluid, an increase of 52%. The inductor was also shown to survive uniaxial strains of up to 100%.

Reversing-counterpulse repetitive-pulse inductive storage circuit

DOEpatents

Honig, Emanuel M.

1987-01-01

A high-power reversing-counterpulse repetitive-pulse inductive storage and transfer circuit includes an opening switch, a main energy storage coil, a counterpulse capacitor and a small inductor. After counterpulsing the opening switch off, the counterpulse capacitor is recharged by the main energy storage coil before the load pulse is initiated. This gives the counterpulse capacitor sufficient energy for the next counterpulse operation, although the polarity of the capacitor's voltage must be reversed before that can occur. By using a current-zero switch as the counterpulse start switch, the capacitor is disconnected from the circuit (with a full charge) when the load pulse is initiated, preventing the capacitor from depleting its energy store by discharging through the load. After the load pulse is terminated by reclosing the main opening switch, the polarity of the counterpulse capacitor voltage is reversed by discharging the capacitor through a small inductor and interrupting the discharge current oscillation at zero current and peak reversed voltage. The circuit enables high-power, high-repetition-rate operation with reusable switches and features total control (pulse-to-pulse) over output pulse initiation, duration, repetition rate, and, to some extent, risetime.

Reversing-counterpulse repetitive-pulse inductive storage circuit

DOEpatents

Honig, E.M.

1984-06-05

A high power reversing-counterpulse repetitive-pulse inductive storage and transfer circuit includes an opening switch, a main energy storage coil, a counterpulse capacitor and a small inductor. After counterpulsing the opening switch off, the counterpulse capacitor is recharged by the main energy storage coil before the load pulse is initiated. This gives the counterpulse capacitor sufficient energy for the next counterpulse operation, although the polarity of the capacitor's voltage must be reversed before that can occur. By using a current-zero switch as the counterpulse start switch, the capacitor is disconnected from the circuit (with a full charge) when the load pulse is initiated, preventing the capacitor from depleting its energy store by discharging through the load. After the load pulse is terminated by reclosing the main opening switch, the polarity of the counterpulse capacitor voltage is reversed by discharging the capacitor through a small inductor and interrupting the discharge current oscillation at zero current and peak reversed voltage. The circuit enables high-power, high-repetition-rate operation with reusable switches and features total control (pulse-to-pulse) over output pulse initiation, duration, repetition rate, and, to some extent, risetime.

Characteristics of the boat inductor for keeping liquid metal in the suspended state

NASA Technical Reports Server (NTRS)

Fogel, A. A.; Siforova, T. A.; Mezdrogina, M. M.

1985-01-01

Characteristics of the boat inductor for keeping liquid metal in the suspended state are examined. Behavioral features of the liquid metal, and the suspension boundary of liquid metal in the lower position are discussed. It is concluded that the inductor can be used to crystallize metals in the suspended state.

Wide Temperature Magnetization Characteristics of Transverse Magnetically Annealed Amorphous Tapes for High Frequency Aerospace Magnetics

NASA Technical Reports Server (NTRS)

Niedra, Janis M.; Schwarze, Gene E.

1999-01-01

100 kHz magnetization properties of sample transverse magnetically annealed, cobalt-based amorphous and iron-based nanocrystalline tape wound magnetic cores are presented over the temperature range of -150 C to 150 C, at selected values of B(sub peak). Frequency resolved characteristics are given over the range of 50 kHz to 1 MHz, but at B(sub peak) = 0.1 T and 50 C only. Basic exciting winding current and induced voltage data were taken on bare toroidal cores, in a standard type measurement setup. A linear permeability model, which represents the core by a parallel L-R circuit, is used to interpret and present the magnetization characteristics and several figures of merit applicable to inductor materials are reviewed. The 100 kHz permeability thus derived decreases with increasing temperature for the Fe-based, nanocrystalline material, but increases roughly linearly with temperature for the two Co-based materials, as long as B(sub peak) is sufficiently low to avoid saturation effects. Due to the high permeabilities, rather low values of the 'quality factor' Q, from about 20 to below unity, were obtained over the frequency range of 50 kHz to 1 MHz (50 C, B(sub peak) = 0.1 T). Therefore these cores must be gapped in order to make up high Q or high current inductors. However, being rugged, low core loss materials with flat B-H loop characteristics, they may provide new solutions to specialty inductor applications.

Suppression of Instability of High Pressure DC Microplasma Operating in the Negative Differential Resistance (NDR) Regime

NASA Astrophysics Data System (ADS)

Mahamud, Rajib; Farouk, Tanvir I.

2015-09-01

Microplasma devices have been the subject of considerable interest and research during the last decade. In a DC system most of the operation regime of the plasma discharges studied fall in the ``abnormal,'' ``normal'' and ``corona'' modes - where a quasi-steady state is achieved. It is well known that even in a DC system the negative differential resistance (NDR) regime can trigger self pulsing discharges. These pulsations are initiated by the parasitic capacitance of the system hence governed by the response time of the power circuit. The circuit response time is required to be larger than the ion transit time to initiate the oscillations. In this present study a suppressor circuit element in the form of an inductor is used to restrain the plasma from switching to a self pulsing mode. It has been identified that the combined response time of the inductor and the plasma discharge (L/Rplasma) has to be larger than the power circuit time constant (RC) to achieve suppression. Inhibition of oscillation has been observed in both experiments and numerical simulations. The obtained voltage-current characteristics show that the inductor element extends the normal glow regime to lower current. Additional parametric simulations are conducted to map out a ``stable'' operation regime. The author would like to thank DARPA (ARO Grant No. W911NF1210007) and University of South Carolina (USC) for the financial support of the work.

Sub-100 μm scale on-chip inductors with CoZrTa for GHz applications

NASA Astrophysics Data System (ADS)

Xu, Wei; Wu, Hao; Gardner, Donald S.; Sinha, Saurabh; Dastagir, Tawab; Bakkaloglu, Bertan; Cao, Yu; Yu, Hongbin

2011-04-01

On-chip inductors with magnetic material are fabricated with complementary metal-oxide semiconductor processes. The inductors use copper metallization and amorphous CoZrTa thinfilms. Enhancements of 3.5X in inductance and 3X for the quality factor at frequencies as highas 3 GHz have been successfully demonstrated by using a continuous CoZrTa-ring structure in spiral inductors at the 100 μm scale. Further improvement of the frequency response of inductance up to 6 GHz was achieved by micro-patterning the magnetic film. The effect ofincreasing the film thickness on the performance of strip line inductors was measured and modeled. This work demonstrates significantly larger increases in inductance and quality factor atabove 1 GHz as compared to prior efforts, thereby making the added processing cost worthwhile.

A Low Temperature Co-fired Ceramics Manufactured Power Inductor Based on A Ternary Hybrid Material System

NASA Astrophysics Data System (ADS)

Xie, Yunsong; Chen, Ru

Low temperature co-fired ceramics (LTCC) is one of the most important techniques to produce circuits with high working frequency, multi-functionality and high integration. We have developed a methodology to enable a ternary hybrid material system being implemented into the LTCC manufacturing process. The co-firing sintering process can be divided into a densification and cooling process. In this method, a successful ternary hybrid material densification process is achieved by tuning the sintering profile of each material to match each other. The system integrity is maintained in the cooling process is obtained by develop a strong bonding at the interfaces of each materials. As a demonstration, we have construct a power inductor device made of the ternary material system including Ag, NiCuZn ferrite and non-magnetic ceramic. The power inductors well maintains its physical integrity after sintering. The microscopic images show no obvious sign of cracks or structural deformation. More importantly, despite the bonding between the ferrite and ceramic is enhanced by non-magnetic element diffusion, the undesired magnetic elements diffusion is effectively suppressed. The electric performance shows that the power handling capability is comparable to the current state of art device.

Spacecraft transformer and inductor design

NASA Technical Reports Server (NTRS)

Mclyman, W. T.

1977-01-01

The conversion process in spacecraft power electronics requires the use of magnetic components which frequently are the heaviest and bulkiest items in the conversion circuit. This handbook pertains to magnetic material selection, transformer and inductor design tradeoffs, transformer design, iron core dc inductor design, toroidal power core inductor design, window utilization factors, regulation, and temperature rise. Relationships are given which simplify and standardize the design of transformers and the analysis of the circuits in which they are used. The interactions of the various design parameters are also presented in simplified form so that tradeoffs and optimizations may easily be made.

Integration of planar transformer and/or planar inductor with power switches in power converter

DOEpatents

Chen, Kanghua; Ahmed, Sayeed; Zhu, Lizhi

2007-10-30

A power converter integrates at least one planar transformer comprising a multi-layer transformer substrate and/or at least one planar inductor comprising a multi-layer inductor substrate with a number of power semiconductor switches physically and thermally coupled to a heat sink via one or more multi-layer switch substrates.

Kinetic Inductance Memory Cell and Architecture for Superconducting Computers

NASA Astrophysics Data System (ADS)

Chen, George J.

Josephson memory devices typically use a superconducting loop containing one or more Josephson junctions to store information. The magnetic inductance of the loop in conjunction with the Josephson junctions provides multiple states to store data. This thesis shows that replacing the magnetic inductor in a memory cell with a kinetic inductor can lead to a smaller cell size. However, magnetic control of the cells is lost. Thus, a current-injection based architecture for a memory array has been designed to work around this problem. The isolation between memory cells that magnetic control provides is provided through resistors in this new architecture. However, these resistors allow leakage current to flow which ultimately limits the size of the array due to power considerations. A kinetic inductance memory array will be limited to 4K bits with a read access time of 320 ps for a 1 um linewidth technology. If a power decoder could be developed, the memory architecture could serve as the blueprint for a fast (<1 ns), large scale (>1 Mbit) superconducting memory array.

Pulsed thermionic converter study

NASA Technical Reports Server (NTRS)

1976-01-01

A nuclear electric propulsion concept using a thermionic reactor inductively coupled to a magnetoplasmadynamic accelerator (MPD arc jet) is described, and the results of preliminary analyses are presented. In this system, the MPD thruster operates intermittently at higher voltages and power levels than the thermionic generating unit. A typical thrust pulse from the MPD arc jet is characterized by power levels of 1 to 4 MWe, a duration of 1 msec, and a duty cycle of approximately 20%. The thermionic generating unit operates continuously but with a lower power level of approximately 0.4 MWe. Energy storage between thrust pulses is provided by building up a large current in an inductor using the output of the thermionic converter array. Periodically, the charging current is interrupted, and the energy stored in the magnetic field of the inductor is utilized for a short duration thrust pulse. The results of the preliminary analysis show that a coupling effectiveness of approximately 85 to 90% is feasible for a nominal 400 KWe system with an inductive unit suitable for a flight vehicle.

Surface-micromachined magnetic undulator with period length between 10μm and 1 mm for advanced light sources

NASA Astrophysics Data System (ADS)

Harrison, Jere; Joshi, Abhijeet; Lake, Jonathan; Candler, Rob; Musumeci, Pietro

2012-07-01

A technological gap exists between the μm-scale wiggling periods achieved using electromagnetic waves of high intensity laser pulses and the mm scale of permanent-magnet and superconducting undulators. In the sub-mm range, surface-micromachined soft-magnetic micro-electro-mechanical system inductors with integrated solenoidal coils have already experimentally demonstrated 100 to 500 mT field amplitude across air gaps as large as 15μm. Simulations indicate that magnetic fields as large as 1.5 T across 50μm inductor gaps are feasible. A simple rearranging of the yoke and pole geometry allows for fabrication of 10+ cm long undulator structures with period lengths between 12.5μm and 1 mm. Such undulators find application both in high average power spontaneous emission sources and, if used in combination with ultrahigh-brightness electron beams, could lead to the realization of low energy compact free-electron lasers. Challenges include electron energy broadening due to wakefields and Joule heating in the electromagnet.

Stretchable inductor with liquid magnetic core

NASA Astrophysics Data System (ADS)

Lazarus, N.; Meyer, C. D.

2016-03-01

Adding magnetic materials is a well-established method for improving performance of inductors. However, traditional magnetic cores are rigid and poorly suited for the emerging field of stretchable electronics, where highly deformable inductors are used to wirelessly couple power and data signals. In this work, stretchable inductors are demonstrated based on the use of ferrofluids, magnetic liquids based on distributed magnetic particles, to create a compliant magnetic core. Using a silicone molding technique to create multi-layer fluidic channels, a liquid metal solenoid is fabricated around a ferrofluid channel. An analytical model is developed for the effects of mechanical strain, followed by experimental verification using two different ferrofluids with different permeabilities. Adding ferrofluid was found to increase the unstrained inductance by up to 280% relative to a similar inductor with a non-magnetic silicone core, while retaining the ability to survive uniaxial strains up to 100%.

Load-Dependent Soft-Switching Method of Half-Bridge Current Doubler for High-Voltage Point-of-Load Converter in Data Center Power Supplies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Yutian; Yang, Fei; Tolbert, Leon M.

With the increased cloud computing and digital information storage, the energy requirement of data centers keeps increasing. A high-voltage point of load (HV POL) with an input series output parallel structure is proposed to convert 400 to 1 VDC within a single stage to increase the power conversion efficiency. The symmetrical controlled half-bridge current doubler is selected as the converter topology in the HV POL. A load-dependent soft-switching method has been proposed with an auxiliary circuit that includes inductor, diode, and MOSFETs so that the hard-switching issue of typical symmetrical controlled half-bridge converters is resolved. The operation principles of themore » proposed soft-switching half-bridge current doubler have been analyzed in detail. Then, the necessity of adjusting the timing with the loading in the proposed method is analyzed based on losses, and a controller is designed to realize the load-dependent operation. A lossless RCD current sensing method is used to sense the output inductor current value in the proposed load-dependent operation. In conclusion, experimental efficiency of a hardware prototype is provided to show that the proposed method can increase the converter's efficiency in both heavy- and light-load conditions.« less

Load-Dependent Soft-Switching Method of Half-Bridge Current Doubler for High-Voltage Point-of-Load Converter in Data Center Power Supplies

DOE PAGES

Cui, Yutian; Yang, Fei; Tolbert, Leon M.; ...

2016-06-14

With the increased cloud computing and digital information storage, the energy requirement of data centers keeps increasing. A high-voltage point of load (HV POL) with an input series output parallel structure is proposed to convert 400 to 1 VDC within a single stage to increase the power conversion efficiency. The symmetrical controlled half-bridge current doubler is selected as the converter topology in the HV POL. A load-dependent soft-switching method has been proposed with an auxiliary circuit that includes inductor, diode, and MOSFETs so that the hard-switching issue of typical symmetrical controlled half-bridge converters is resolved. The operation principles of themore » proposed soft-switching half-bridge current doubler have been analyzed in detail. Then, the necessity of adjusting the timing with the loading in the proposed method is analyzed based on losses, and a controller is designed to realize the load-dependent operation. A lossless RCD current sensing method is used to sense the output inductor current value in the proposed load-dependent operation. In conclusion, experimental efficiency of a hardware prototype is provided to show that the proposed method can increase the converter's efficiency in both heavy- and light-load conditions.« less

A Discrete-Time Average Model Based Predictive Control for Quasi-Z-Source Inverter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yushan; Abu-Rub, Haitham; Xue, Yaosuo

A discrete-time average model-based predictive control (DTA-MPC) is proposed for a quasi-Z-source inverter (qZSI). As a single-stage inverter topology, the qZSI regulates the dc-link voltage and the ac output voltage through the shoot-through (ST) duty cycle and the modulation index. Several feedback strategies have been dedicated to produce these two control variables, among which the most popular are the proportional–integral (PI)-based control and the conventional model-predictive control (MPC). However, in the former, there are tradeoffs between fast response and stability; the latter is robust, but at the cost of high calculation burden and variable switching frequency. Moreover, they require anmore » elaborated design or fine tuning of controller parameters. The proposed DTA-MPC predicts future behaviors of the ST duty cycle and modulation signals, based on the established discrete-time average model of the quasi-Z-source (qZS) inductor current, the qZS capacitor voltage, and load currents. The prediction actions are applied to the qZSI modulator in the next sampling instant, without the need of other controller parameters’ design. A constant switching frequency and significantly reduced computations are achieved with high performance. Transient responses and steady-state accuracy of the qZSI system under the proposed DTA-MPC are investigated and compared with the PI-based control and the conventional MPC. Simulation and experimental results verify the effectiveness of the proposed approach for the qZSI.« less

A Discrete-Time Average Model Based Predictive Control for Quasi-Z-Source Inverter

DOE PAGES

Liu, Yushan; Abu-Rub, Haitham; Xue, Yaosuo; ...

2017-12-25

A discrete-time average model-based predictive control (DTA-MPC) is proposed for a quasi-Z-source inverter (qZSI). As a single-stage inverter topology, the qZSI regulates the dc-link voltage and the ac output voltage through the shoot-through (ST) duty cycle and the modulation index. Several feedback strategies have been dedicated to produce these two control variables, among which the most popular are the proportional–integral (PI)-based control and the conventional model-predictive control (MPC). However, in the former, there are tradeoffs between fast response and stability; the latter is robust, but at the cost of high calculation burden and variable switching frequency. Moreover, they require anmore » elaborated design or fine tuning of controller parameters. The proposed DTA-MPC predicts future behaviors of the ST duty cycle and modulation signals, based on the established discrete-time average model of the quasi-Z-source (qZS) inductor current, the qZS capacitor voltage, and load currents. The prediction actions are applied to the qZSI modulator in the next sampling instant, without the need of other controller parameters’ design. A constant switching frequency and significantly reduced computations are achieved with high performance. Transient responses and steady-state accuracy of the qZSI system under the proposed DTA-MPC are investigated and compared with the PI-based control and the conventional MPC. Simulation and experimental results verify the effectiveness of the proposed approach for the qZSI.« less

High-performance flexible microwave passives on plastic

NASA Astrophysics Data System (ADS)

Ma, Zhenqiang; Seo, Jung-Hun; Cho, Sang June; Zhou, Weidong

2014-06-01

We report the demonstration of bendable inductors, capacitors and switches fabricated on a polyethylene terephthalate (PET) substrate that can operate at high microwave frequencies. By employing bendable dielectric and single crystalline semiconductor materials, spiral inductors and metal-insulator-metal (MIM) capacitors with high quality factors and high resonance frequencies and single-pole, single-throw (SPST) switches were archived. The effects of mechanical bending on the performance of inductors, capacitors and switches were also measured and analyzed. We further investigated the highest possible resonance frequencies and quality factors of inductors and capacitors and, high frequency responses and insertion loss. These demonstrations will lead to flexible radio-frequency and microwave systems in the future.

A wave shaping approach of ferrite inductors exhibiting hysteresis using orthogonal field bias

NASA Astrophysics Data System (ADS)

Adly, A. A.; Abd-El-Hafiz, S. K.; Mahgoub, A. O.

2018-05-01

Advances in power electronic systems have considerably contributed to a wide spectrum of applications. In most power electronic circuits, inductors play crucial functions. Utilization of ferrite cores becomes a must when large inductances are required. Nevertheless, this results in an additional complexity due to their hysteresis nature. Recently, an efficient approach for modeling vector hysteresis using tri-node Hopfield neural networks (HNNs) has been introduced. This paper presents a wave shaping approach using hollow cylindrical ferrite core inductors having axial and toroidal windings. The approach investigates the possibility of tuning the inductor permeability to minimize circuit harmonics. Details of the approach are given in the paper.

Integrated Inductors for RF Transmitters in CMOS/MEMS Smart Microsensor Systems

PubMed Central

Kim, Jong-Wan; Takao, Hidekuni; Sawada, Kazuaki; Ishida, Makoto

2007-01-01

This paper presents the integration of an inductor by complementary metal-oxide-semiconductor (CMOS) compatible processes for integrated smart microsensor systems that have been developed to monitor the motion and vital signs of humans in various environments. Integration of radio frequency transmitter (RF) technology with complementary metal-oxide-semiconductor/micro electro mechanical systems (CMOS/MEMS) microsensors is required to realize the wireless smart microsensors system. The essential RF components such as a voltage controlled RF-CMOS oscillator (VCO), spiral inductors for an LC resonator and an integrated antenna have been fabricated and evaluated experimentally. The fabricated RF transmitter and integrated antenna were packaged with subminiature series A (SMA) connectors, respectively. For the impedance (50 Ω) matching, a bonding wire type inductor was developed. In this paper, the design and fabrication of the bonding wire inductor for impedance matching is described. Integrated techniques for the RF transmitter by CMOS compatible processes have been successfully developed. After matching by inserting the bonding wire inductor between the on-chip integrated antenna and the VCO output, the measured emission power at distance of 5 m from RF transmitter was -37 dBm (0.2 μW).

Self-Paced Physics, Segments 37-40.

ERIC Educational Resources Information Center

New York Inst. of Tech., Old Westbury.

Four study segments of the Self-Paced Physics Course materials are presented in this eighth problems and solutions book used as a part of course assignments. The content is related to magnetic induction, Faraday's law, induced currents, Lenz's law, induced electromotive forces, time-varying magnetic fields, self-inductance, inductors,…

Low-volume aluminum and aluminum / titanium nitride bilayer lumped-element kinetic inductance detectors for far-infrared astronomy

NASA Astrophysics Data System (ADS)

Glenn, Jason; Fyhrie, Adalyn; Wheeler, Jordan; Day, Peter K.; Eom, Byeong H.; Leduc, Henry G.

2016-07-01

We present the design and characterization of low-volume, lumped-element aluminum kinetic inductance de- tectors for sensitive far-infrared astronomy observations. The lumped-element kinetic inductance detectors are comprised of meandered inductors that serve as radiation absorbers in parallel with interdigitated capacitors, forming high quality factor resonators. Low inductor volumes lead to low noise equivalent powers by raising quasiparticles densities, and hence responsivities, with respect to larger volumes. Low volumes are achieved with thin (20 nm), narrow (150 nm) inductors. The interdigitated capacitor architecture is designed to mitigate two-level system noise by lowering electric fields in the silicon substrate. Resonance frequencies are in the range of 190 to 500 MHz, with measured internal quality factors in excess of 1 x 105. In a prior incarnation, a titanium nitride layer on top of the aluminum served as a protective layer, but complicated the superconducting proper- ties. These results were reported previously. In the current incarnation, the aluminum layer is left bare with no titanium nitride over-layer. The results for these bare aluminum devices include a yield of 88%, frequency responsivity of 109 W-1, and noise equivalent power of 1 x 10-17 W Hz-1/2 for a 350μm array. There is no evidence for 1=f noise down to at least 200 mHz. The sensitivity is currently limited by white noise, very likely from stray light in the testbed; for this detector design, sensitivities limited by generation-recombination noise in a lower-background environment should be several orders of magnitude lower.

A low temperature co-fired ceramic power inductor manufactured using a glass-free ternary composite material system

NASA Astrophysics Data System (ADS)

Li, Yuanxun; Xie, Yunsong; Xie, Ru; Chen, Daming; Han, Likun; Su, Hua

2018-03-01

A glass-free ternary composite material system (CMS) manufactured employing the low temperature ( 890 ° C ) co-fired ceramic (LTCC) technique is reported. This ternary CMS consists of silver, NiCuZn ferrite, and Zn2SiO4 ceramic. The reported device fabricated from this ternary CMS is a power inductor with a nominal inductance of 1.0 μH. Three major highlights were achieved from the device and the material study. First, unlike most other LTCC methods, no glass is required to be added in either of the dielectric materials in order to co-fire the NiCuZn ferrite, Zn2SiO4 ceramic, and silver. Second, a successfully co-fired silver, NiCuZn, and Zn2SiO4 device can be achieved by optimizing the thermal shrinkage properties of both NiCuZn and Zn2SiO4, so that they have a very similar temperature shrinkage profile. We have also found that strong non-magnetic elemental diffusion occurs during the densification process, which further enhances the success rate of manufacturing co-fired devices. Last but not least, elemental mapping suggests that strong magnetic elemental diffusion between NiCuZn and Zn2SiO4 has been suppressed during the co-firing process. The investigation of electrical performance illustrates that while the ordinary binary CMS based power inductor can deal with 400 mA DC, the ternary CMS based power inductor is able to handle higher DC currents, 700 mA and 620 mA DC, according to both simulation and experiment demonstrations, respectively.

Reversing-counterpulse repetitive-pulse inductive storage circuit

DOEpatents

Honig, E.M.

1987-02-10

A high-power reversing-counterpulse repetitive-pulse inductive storage and transfer circuit includes an opening switch, a main energy storage coil, a counterpulse capacitor and a small inductor. After counterpulsing the opening switch off, the counterpulse capacitor is recharged by the main energy storage coil before the load pulse is initiated. This gives the counterpulse capacitor sufficient energy for the next counterpulse operation, although the polarity of the capacitor's voltage must be reversed before that can occur. By using a current-zero switch as the counterpulse start switch, the capacitor is disconnected from the circuit (with a full charge) when the load pulse is initiated, preventing the capacitor from depleting its energy store by discharging through the load. After the load pulse is terminated by reclosing the main opening switch, the polarity of the counterpulse capacitor voltage is reversed by discharging the capacitor through a small inductor and interrupting the discharge current oscillation at zero current and peak reversed voltage. The circuit enables high-power, high-repetition-rate operation with reusable switches and features total control (pulse-to-pulse) over output pulse initiation, duration, repetition rate, and, to some extent, risetime. 10 figs.

Workshop on Plasma Experiments in the Laboratory and in Space. Abstracts

DTIC Science & Technology

1991-01-01

The AMPTE IRM satellite revealed in the region of overlap between plasmaspheric and ring current plasmas a gra- dual decrease of cold plasna density...names UMKD generator, "Alive wine , or 4unipolar Inductor’ For space physics, the breakdown of this tid picture is a( Interest because it results in the

FET commutated current-FED inverter

NASA Technical Reports Server (NTRS)

Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)

1983-01-01

A shunt switch comprised of a field-effect transistor (Q.sub.1) is employed to commutate a current-fed inverter (10) using thyristors (SCR1, SCR2) or bijunction transistors (Q.sub.2, Q.sub.3) in a full bridge (1, 2, 3, 4) or half bridge (5, 6) and transformer (T.sub.1) configuration. In the case of thyristors, a tapped inverter (12) is employed to couple the inverter to a dc source to back bias the thyristors during commutation. Alternatively, a commutation power supply (20) may be employed for that purpse. Diodes (D.sub.1, D.sub.2) in series with some voltage dropping element (resistor R.sub.12 or resistors R.sub.1, R.sub.2 or Zener diodes D.sub.4, D.sub.5) are connected in parallel with the thyristors in the half bridge and transformer configuration to assure sharing the back bias voltage. A clamp circuit comprised of a winding (18) negatively coupled to the inductor and a diode (D.sub.3) return stored energy from the inductor to the power supply for efficient operation with buck or boost mode.

Complete passive vibration suppression using multi-layered piezoelectric element, inductor, and resistor

NASA Astrophysics Data System (ADS)

Yamada, Keisuke

2017-01-01

This paper describes passive technique for suppressing vibration in flexible structures using a multi-layered piezoelectric element, an inductor, and a resistor. The objective of using a multi-layered piezoelectric element is to increase its capacitance. A piezoelectric element with a large capacitance value does not require an active electrical circuit to simulate an inductor with a large inductance value. The effect of multi-layering of piezoelectric elements was theoretically analyzed through an equivalent transformation of a multi-layered piezoelectric element into a single-layered piezoelectric element. The governing equations were derived using this equivalent transformation. The effect of the resistances of the inductor and piezoelectric elements were considered because the sum of these resistances may exceed the optimum resistance. The performance of the passive vibration suppression using an LR circuit was compared to that of the method where a resistive circuit is used assuming that the sum of the resistances of the inductor and piezoelectric elements exceeds the optimum resistance. The effectiveness of the proposed method and theoretical analysis was verified through simulations and experiments.

On the use of new generation mobile phone (smart phone) for retrospective accident dosimetry

NASA Astrophysics Data System (ADS)

Lee, J. I.; Chang, I.; Pradhan, A. S.; Kim, J. L.; Kim, B. H.; Chung, K. S.

2015-11-01

Optically stimulated luminescence (OSL) characteristics of resistors, inductors and integrated-circuit (IC) chips, extracted from new generation smart phones, were investigated for the purpose of retrospective accident dosimetry. Inductor samples were found to exhibit OSL sensitivity about 5 times and 40 times higher than that of the resistors and the IC chips, respectively. On post-irradiation storage, the resistors exhibited a much higher OSL fading (about 80 % in 36 h as compared to the value 3 min after irradiation) than IC chips (about 20 % after 36 h) and inductors (about 50 % in 36 h). Higher OSL sensitivity, linear dose response (from 8.7 mGy up to 8.9 Gy) and acceptable fading make inductors more attractive for accident dosimetry than widely studied resistors.

Pulse switching for high energy lasers

NASA Technical Reports Server (NTRS)

Laudenslager, J. B.; Pacala, T. J. (Inventor)

1981-01-01

A saturable inductor switch for compressing the width and sharpening the rise time of high voltage pulses from a relatively slow rise time, high voltage generator to an electric discharge gas laser (EDGL) also provides a capability for efficient energy transfer from a high impedance primary source to an intermediate low impedance laser discharge network. The switch is positioned with respect to a capacitive storage device, such as a coaxial cable, so that when a charge build-up in the storage device reaches a predetermined level, saturation of the switch inductor releases or switches energy stored in the capactive storage device to the EDGL. Cascaded saturable inductor switches for providing output pulses having rise times of less than ten nanoseconds and a technique for magnetically biasing the saturable inductor switch are disclosed.

Alternator insulation evaluation tests

NASA Technical Reports Server (NTRS)

Penn, W. B.; Schaefer, R. F.; Balke, R. L.

1972-01-01

Tests were conducted to predict the remaining electrical insulation life of a 60 KW homopolar inductor alternator following completion of NASA turbo-alternator endurance tests for SNAP-8 space electrical power systems application. The insulation quality was established for two alternators following completion of these tests. A step-temperature aging test procedure was developed for insulation life prediction and applied to one of the two alternators. Armature winding insulation life of over 80,000 hours for an average winding temperature of 248 degrees C was predicted using the developed procedure.

Setting the Delay of the LTD Switch Firing Using Trigger Inductors

NASA Astrophysics Data System (ADS)

Alexeenko, V. M.; Sinebryukhov, V. A.; Kondratiev, S. S.; Volkov, S. N.; Kim, A. A.; Yakovlev, V. Yu.

2018-01-01

Simulation results are compared with experimental data to define the integral breakdown criterion for the spark gaps of the switches of the LTDs with oil insulation and to determine the influence of the inductance of the trigger inductor on the delay of the switch firing. The results confirm that the shape of the output square pulse produced by the oil-insulated LTDs can be corrected as required if the trigger inductors are used to trigger the cavity switches.

Temperature responsive transmitter

NASA Technical Reports Server (NTRS)

Kleinberg, Leonard L. (Inventor)

1987-01-01

A temperature responsive transmitter is provided in which frequency varies linearly with temperature. The transmitter includes two identically biased transistors connected in parallel. A capacitor, which reflects into the common bases to generate negative resistance effectively in parallel with the capacitor, is connected to the common emitters. A crystal is effectively in parallel with the capacitor and the negative resistance. Oscillations occur if the magnitude of the absolute value of the negative resistance is less than the positive resistive impedance of the capacitor and the inductance of the crystal. The crystal has a large linear temperature coefficient and a resonant frequency which is substantially less than the gain-bandwidth product of the transistors to ensure that the crystal primarily determines the frequency of oscillation. A high-Q tank circuit having an inductor and a capacitor is connected to the common collectors to increase the collector current flow which in turn enhances the radiation of the oscillator frequency by the inductor.

Overvoltage protection system for wireless power transfer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chambon, Paul H.; Jones, Perry T.; Miller, John M.

A wireless power transfer overvoltage protection system is provided. The system includes a resonant receiving circuit. The resonant receiving circuit includes an inductor, a resonant capacitor and a first switching device. The first switching device is connected the ends of the inductor. The first switching device has a first state in which the ends of the inductor are electrically coupled to each other through the first switching device, and a second state in which the inductor and resonant capacitor are capable of resonating. The system further includes a control module configured to control the first switching device to switching betweenmore » the first state and the second state when the resonant receiving circuit is charging a load and a preset condition is satisfied and otherwise, the first switching device is maintained in the first state.« less

Electronic constant current and current pulse signal generator for nuclear instrumentation testing

DOEpatents

Brown, R.A.

1994-04-19

Circuitry is described for testing the ability of an intermediate range nuclear instrument to detect and measure a constant current and a periodic current pulse. The invention simulates the resistance and capacitance of the signal connection of a nuclear instrument ion chamber detector and interconnecting cable. An LED flasher/oscillator illuminates an LED at a periodic rate established by a timing capacitor and circuitry internal to the flasher/oscillator. When the LED is on, a periodic current pulse is applied to the instrument. When the LED is off, a constant current is applied. An inductor opposes battery current flow when the LED is on. 1 figures.

Electronic constant current and current pulse signal generator for nuclear instrumentation testing

DOEpatents

Brown, Roger A.

1994-01-01

Circuitry for testing the ability of an intermediate range nuclear instrut to detect and measure a constant current and a periodic current pulse. The invention simulates the resistance and capacitance of the signal connection of a nuclear instrument ion chamber detector and interconnecting cable. An LED flasher/oscillator illuminates an LED at a periodic rate established by a timing capacitor and circuitry internal to the flasher/oscillator. When the LED is on, a periodic current pulse is applied to the instrument. When the LED is off, a constant current is applied. An inductor opposes battery current flow when the LED is on.

Transient Response of a Second Order System Using State Variables.

ERIC Educational Resources Information Center

LePage, Wilbur R.

This programed booklet is designed for the engineering student who is familiar with the techniques of integral calculus and electrical networks. The booklet teaches how to determine the current and voltages across a resistor, inductor, and capacitor after the switch in a network has been closed. This is a classical problem in engineering, the…

Soft ferrite cores characterization for integrated micro-inductors

NASA Astrophysics Data System (ADS)

Nguyen, Yen Mai; Lopez, Thomas; Laur, Jean-Pierre; Bourrier, David; Charlot, Samuel; Valdez-Nava, Zarel; Bley, Vincent; Combettes, Céline; Brunet, Magali

2013-12-01

Ferrite-based micro-inductors are proposed for hybrid integration on silicon for low-power medium frequency DC-DC converters. Due to their small coercive field and their high resistivity, soft ferrites are good candidates for a magnetic core working at moderate frequencies in the range of 5-10 MHz. We have studied several soft ferrites including commercial ferrite film and U70 and U200 homemade ferrites. The inductors are fabricated at wafer level using micromachining and assembling techniques. The proposed process is based on a sintered ferrite core placed in between thick electroplated copper windings. The low profile ferrite cores of 1.2 × 2.6 × 0.2 mm3 are produced by two methods from green tape-casted films and ferrite powder. This paper presents the magnetic characterization of the sintered ferrite films cut and printed in rectangular shape and sintered at different temperatures. The comparison is made in order to find out the best material for the core that can reach the required inductance (470 nH at 6 MHz) under 0.6A current DC bias and that generate the smallest losses. An inductance density of 285 nH/ mm2 up to 6 MHz was obtained for ESL 40011 cores that is much higher than the previously reported devices. The small size of our devices is also a prominent point.

A 25-Gbps high-sensitivity optical receiver with 10-Gbps photodiode using inductive input coupling for optical interconnects

NASA Astrophysics Data System (ADS)

Oku, Hideki; Narita, Kiyomi; Shiraishi, Takashi; Ide, Satoshi; Tanaka, Kazuhiro

2012-01-01

A 25-Gbps high-sensitivity optical receiver with a 10-Gbps photodiode (PD) using inductive input coupling has been demonstrated for optical interconnects. We introduced the inductive input coupling technique to achieve the 25-Gbps optical receiver using a 10-Gbps PD. We implemented an input inductor (Lin) between the PD and trans-impedance amplifier (TIA), and optimized inductance to enhance the bandwidth and reduce the input referred noise current through simulation with the RF PD-model. Near the resonance frequency of the tank circuit formed by PD capacitance, Lin, and TIA input capacitance, the PD photo-current through Lin into the TIA is enhanced. This resonance has the effects of enhancing the bandwidth at TIA input and reducing the input equivalent value of the noise current from TIA. We fabricated the 25-Gbps optical receiver with the 10-Gbps PD using an inductive input coupling technique. Due to the application of an inductor, the receiver bandwidth is enhanced from 10 GHz to 14.2 GHz. Thanks to this wide-band and low-noise performance, we were able to improve the sensitivity at an error rate of 1E-12 from non-error-free to -6.5 dBm. These results indicate that our technique is promising for cost-effective optical interconnects.

To enhance the efficiency of a power supply circuit by the use of Fe-P-B-Nb-type ultralow loss glassy metal core

NASA Astrophysics Data System (ADS)

Matsumoto, H.; Urata, A.; Yamada, Y.; Makino, A.

2009-04-01

The inductor in a power supply is required to be capable of dealing satisfactorily with the high-current supply and to improve the power loss characteristic. A novel glassy metal powder with a chemical composition Fe77P7B13Nb3 features both a high saturated magnetic flux density of 1.3 T and a low coercive force of 2.0 A/m, which has a stable amorphous structure suitable for glassy metal composite cores. Hence there is no magnetic saturation even under a high-current supply, and it is confirmed to have significantly low magnetic loss resulting from the low coercive force. As a result of using the glassy metal alloy Fe77P7B13Nb3 powder in an inductor core, we have achieved improvement in power supply efficiency by up to roughly 2.0%. Moreover, the reduction in the standby power requirement by the improvement in the power supply efficiency in the low load current case, where the core loss occupies a high ratio in the entire loss, can be expected. Additionally, heat generation in a core is suppressed by using the low loss powder, and it becomes easy to design a temperature rise in the entire power supply circuit.

Characterization of embroidered inductors

NASA Astrophysics Data System (ADS)

Roh, Jung-Sim; Chi, Yong-Seung; Lee, Jae-Hee; Nam, Sangwook; Kang, Tae Jin

2010-11-01

As the demand for wearable intelligent textile systems continues to expand, it is now essential to achieve a high-level of electronic circuit integration into textiles. By applying a commercial yarn manufacturing technique and a computer numerical control (CNC) embroidery process, metal composite embroidery yarns (MCEYs) comprised of three strands of fine metal filaments and polyester filaments, and embroidered circuits have been successfully produced. Using MCEYs, circular and square spiral inductors were embroidered on a textile substrate. Their inductive characteristics, i.e. inductance, self-resonance frequency, and quality factor, were investigated under three different environments, i.e. in free space, on a human body, and with a metal fabric ground. Their inductive characteristics could be easily modified by adjusting the circuit design. The validity of the MCEY inductors was demonstrated with Wheeler's formula and design equations for the MCEY inductors were proposed. When in contact with the human body, the self-resonance frequency of the circuit decreased but the inductance was not affected. Although the inductance and maximum quality factor decreased with a metal ground, the inductor gave a stable performance irrespective of the environment. The results also suggest that MCEY embroidery is a simple and eco-friendly process for producing flexible, light-weight, wearable circuitries in various designs.

The persistent current and energy spectrum on a driven mesoscopic LC-circuit with Josephson junction

NASA Astrophysics Data System (ADS)

Pahlavanias, Hassan

2018-03-01

The quantum theory for a mesoscopic electric circuit including a Josephson junction with charge discreteness is studied. By considering coupling energy of the mesoscopic capacitor in Josephson junction device, a Hamiltonian describing the dynamics of a quantum mesoscopic electric LC-circuit with charge discreteness is introduced. We first calculate the persistent current on a quantum driven ring including Josephson junction. Then we obtain the persistent current and energy spectrum of a quantum mesoscopic electrical circuit which includes capacitor, inductor, time-dependent external source and Josephson junction.

Magnetic Design Guidelines for Electronic Power Supplies.

DTIC Science & Technology

1986-09-30

henries ",= peak flux density in gauss d = wire (conductor) dia in mils CM = d2 = circular mi’s Irms = RMS current in amperes Idc = DC current in...component lac = RMS ac current in the inductor f = minimum frequency in hertz L = inductance in henries Then Eac 2 16.83 x 2, x 760 x .05 10 Eac 1 168.3 x 2...duty cycle x 1/f L inductance in henries *permeability in gauss/oersted H magnetizing force in oersteds ’. i g length of air gap in cm ic length of

Fuzzy Current-Mode Control and Stability Analysis

NASA Technical Reports Server (NTRS)

Kopasakis, George

2000-01-01

In this paper a current-mode control (CMC) methodology is developed for a buck converter by using a fuzzy logic controller. Conventional CMC methodologies are based on lead-lag compensation with voltage and inductor current feedback. In this paper the converter lead-lag compensation will be substituted with a fuzzy controller. A small-signal model of the fuzzy controller will also be developed in order to examine the stability properties of this buck converter control system. The paper develops an analytical approach, introducing fuzzy control into the area of CMC.

30-100-GHz inductors and transformers for millimeter-wave (Bi)CMOS integrated circuits

NASA Astrophysics Data System (ADS)

Dickson, T. O.; Lacroix, M.-A.; Boret, S.; Gloria, D.; Beerkens, R.; Voinigescu, S. P.

2005-01-01

Silicon planar and three-dimensional inductors and transformers were designed and characterized on-wafer up to 100 GHz. Self-resonance frequencies (SRFs) beyond 100 GHz were obtained, demonstrating for the first time that spiral structures are suitable for applications such as 60-GHz wireless local area network and 77-GHz automotive RADAR. Minimizing area over substrate is critical to achieving high SRF. A stacked transformer is reported with S21 of -2.5 dB at 50 GHz, and which offers improved performance and less area (30 μm × 30 μm) than planar transformers or microstrip couplers. A compact inductor model is described, along with a methodology for extracting model parameters from simulated or measured y-parameters. Millimeter-wave SiGe BiCMOS mixer and voltage-controlled-oscillator circuits employing spiral inductors are presented with better or comparable performance to previously reported transmission-line-based circuits.

Modelling of double air-bridged structured inductor implemented by a GaAs integrated passive device manufacturing process

NASA Astrophysics Data System (ADS)

Li, Yang; Yao, Zhao; Zhang, Chun-Wei; Fu, Xiao-Qian; Li, Zhi-Ming; Li, Nian-Qiang; Wang, Cong

2017-05-01

In order to provide excellent performance and show the development of a complicated structure in a module and system, this paper presents a double air-bridge-structured symmetrical differential inductor based on integrated passive device technology. Corresponding to the proposed complicated structure, a new manufacturing process fabricated on a high-resistivity GaAs substrate is described in detail. Frequency-independent physical models are presented with lump elements and the results of skin effect-based measurements. Finally, some key features of the inductor are compared; good agreement between the measurements and modeled circuit fully verifies the validity of the proposed modeling approach. Meanwhile, we also present a comparison of different coil turns for inductor performance. The proposed work can provide a good solution for the design, fabrication, modeling, and practical application of radio-frequency modules and systems.

A Passive EMI Filter with Access to the Ungrounded Motor Neutral Line-The Case that a General-Purpose Inverter is Directly Connected to a Three-Phase Grounded Voltage Source-

NASA Astrophysics Data System (ADS)

Doumoto, Takafumi; Akagi, Hirofumi

This paper proposes a small-sized passive EMI filter for the purpose of eliminating high-frequency shaft voltage and ground leakage current from an ac motor. The motor is driven by a general-purpose PWM inverter connected to a three-phase grounded voltage source. The passive EMI filter requires access to the ungrounded neutral point of the motor. This unique circuit configuration makes the common-mode inductor effective in reducing the high-frequency common-mode voltage generated by the PWM inverter with a carrier frequency of 15kHz. As a result, both high-frequency shaft voltage and ground leakage current can be eliminated very efficiently. However, the common-mode inductor may not play any role in reducing the low-frequency common-mode voltage generated by the diode rectifier, so that a low-frequency component still remains in the shaft voltage. Such a low-frequency shaft voltage may not produce any bad effect on motor bearings. The validity and effectiveness of the EMI filter is verified by experimental results obtained from a 200-V 5-kVA laboratory system.

A novel torsional exciter for modal vibration testing of large rotating machinery

NASA Astrophysics Data System (ADS)

Sihler, Christof

2006-10-01

A novel exciter for applying a dynamic torsional force to a rotating structure is presented in this paper. It has been developed at IPP in order to perform vibration tests with shaft assemblies of large flywheel generators (synchronous machines). The electromagnetic exciter (shaker) needs no fixture to the rotating shaft because the torque is applied by means of the stator winding of an electrical machine. Therefore, the exciter can most easily be applied in cases where a three-phase electrical machine (a motor or generator) is part of the shaft assembly. The oscillating power for the shaker is generated in a separate current-controlled DC circuit with an inductor acting as a buffer storage of magnetic energy. An AC component with adjustable frequency is superimposed on the inductor current in order to generate pulsating torques acting on the rotating shaft with the desired waveform and frequency. Since this torsional exciter does not require an external power source, can easily be installed (without contact to the rotating structure) and provides dynamic torsional forces which are sufficient for multi-megawatt applications, it is best suited for on-site tests of large rotating machinery.

Systems and methods for commutating inductor current using a matrix converter

DOEpatents

Ransom, Ray M; Kajouke, Lateef A; Perisic, Milun

2012-10-16

Systems and methods are provided for delivering current using a matrix converter in a vehicle. An electrical system comprises an AC interface, a first conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the first conversion module, and a control module coupled to the first conversion module. The control module is configured to operate the first conversion module in a bidirectional operating mode to commutate current bidirectionally. When a magnitude of the current through the inductive element is greater than a first threshold value, the control module operates the conversion module in a unidirectional operating mode, wherein current is commutated unidirectionally.

Integrating Magnetics for On-Chip Power: A Perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sullivan, CR; Harburg, DV; Qiu, JZ

Integration of efficient power converters requires technology for efficient, high-power on-chip inductors and transformers. Increases in switching frequency, facilitated by advances in circuit designs and silicon or wide-bandgap semiconductors, can enable miniaturization, but only if the magnetics technology works well at the higher frequencies. Technologies, geometries, and scaling of air-core and magnetic-core inductors and transformers are examined, and their potential for integration is discussed. Air-core inductors can use simpler fabrication, and increasing frequency can always be used to decrease their size, but magnetic cores can decrease the required thickness without requiring as high a frequency.

Caracterisation des mecanismes d'usure en cavitation de revetements HVOF a base de CaviTec

NASA Astrophysics Data System (ADS)

Lavigne, Sebastien

The increasing demand for high performance power conversion systems continuously pushes for improvement in efficiency and power density. This dissertation focuses on a topological effort to efficiently utilize the active and passive devices. In particular, a hybrid approach is adopted, where both capacitors and inductors are used in the voltage conversion and power transfer process. Conventional capacitor-based converters, called switched-capacitor (SC) converters, suffer from poor efficiency due to the inevitable charge redistribution process. With a strategic placement of one or more inductors, the charge redistribution loss can be eliminated by inductively charging/discharging the capacitors, a process called soft-charging operation. As a result, the capacitor size can be greatly reduced without reducing the efficiency. A general analytical framework is presented, which determines whether an arbitrary SC topology is able to achieve full soft-charging operation with a single inductor. For topologies that cannot, a split-phase control technique is introduced, which amends existing two-phase controls to completely eliminate the charge redistribution loss. In addition, alternative placements of inductors are explored to extend the family of hybrid converters. The hybrid converters can have two modes of operation, the fixed-ratio mode and pulse width modulated (PWM) mode. The fixed-conversion-ratio hybrid converters operate in a similar manner to that of a conventional SC converter, with the addition of a soft-charging inductor. The switching frequency of such converters can be adjusted to operate in either zero current switching (ZCS) mode or continuous conduction mode (CCM), which allows for the trade-off of switching loss and conduction loss. It is shown that the capacitor and inductor values can be selected to achieve a minimal passive component volume, which can be significantly smaller than that of a conventional SC converter or a magnetic-based converter. On the other hand, PWM-based hybrid converters generate a PWM rectangular wave as the terminal voltage to the inductor, similar to the operation of a buck converter. In contrast to conventional SC converters, such hybrid converters can achieve lossless and continuous regulation of the output voltage. Compared to buck converters, the required inductor is greatly reduced, as well as the switch stress. A 80-170 V input, 12-24 V output prototype PWM Dickson converter is implemented using GaN switches. The measured peak efficiency is 97%, and high efficiency can be maintained over the entire input and output operating range. In addition, the similarity between multilevel converters (for example, flying capacitor multilevel (FCML) converters) and the PWM-based hybrid SC converters is discussed. Both types of converters can be seen as a hybrid converter which uses both capacitors and inductors for energy transfer. A general framework to compare these converters, along with conventional buck converters, is proposed. In this framework, the power losses (including conduction loss and switching loss) are kept constant, while the total passive component volume is used as the figure of merit. Based on the principle of maximizing energy utilization of passive components, a 7-level FCML converter and an active energy buffer are designed and implemented for single phase dc-ac applications. In addition, the stand-alone system includes a start-up circuitry, EMC filter and auxiliary power supply. The enclosed box achieves a combined power density of 216 W/in3 and an efficiency of 97.4%, and compares favorably against the state-of-the-art designs under the same specification. To further improve the efficiency and power density, soft-switching techniques are investigated and applied on the hybrid converters. A zero voltage switching (ZVS) technique is introduced for both the fixed-ratio mode and the PWM mode operated hybrid converters. The previous hardware prototypes are modified for ZVS operation, and prove the feasibility of simultaneous soft-charging and soft-switching operation. Last but not the least, some of the practical issues associated with the hybrid converter are discussed, such as practical capacitor selection, capacitor voltage balancing and other circuit implementation challenges. Future work based on these topics is given. In summary, these hybrid converters are suited for applications where extreme efficiency and power density are critical. Through efficient utilization of active and passive devices, the hybrid topologies can offer a greater optimization opportunity and ability to take advantage of technology improvement than is possible with conventional designs.

Screen printed passive components for flexible power electronics

NASA Astrophysics Data System (ADS)

Ostfeld, Aminy E.; Deckman, Igal; Gaikwad, Abhinav M.; Lochner, Claire M.; Arias, Ana C.

2015-10-01

Additive and low-temperature printing processes enable the integration of diverse electronic devices, both power-supplying and power-consuming, on flexible substrates at low cost. Production of a complete electronic system from these devices, however, often requires power electronics to convert between the various operating voltages of the devices. Passive components—inductors, capacitors, and resistors—perform functions such as filtering, short-term energy storage, and voltage measurement, which are vital in power electronics and many other applications. In this paper, we present screen-printed inductors, capacitors, resistors and an RLC circuit on flexible plastic substrates, and report on the design process for minimization of inductor series resistance that enables their use in power electronics. Printed inductors and resistors are then incorporated into a step-up voltage regulator circuit. Organic light-emitting diodes and a flexible lithium ion battery are fabricated and the voltage regulator is used to power the diodes from the battery, demonstrating the potential of printed passive components to replace conventional surface-mount components in a DC-DC converter application.

Temperature Dependence of Thin Film Spiral Inductors on Alumina Over a Temperature Range of 25 to 475 C

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Jordan, Jennifer L.; Scardelletti, Maximilian C.

2010-01-01

In this paper, we present an analysis of inductors on an Alumina substrate over the temperature range of 25 to 475 C. Five sets of inductors, each set consisting of a 1.5, 2.5, 3.5, and a 4.5 turn inductor with different line width and spacing, were measured on a high temperature probe station from 10 MHz to 30 GHz. From these measured characteristics, it is shown that the inductance is nearly independent of temperature for low frequencies compared to the self resonant frequency, the parasitic capacitances are independent of temperature, and the resistance varies nearly linearly with temperature. These characteristics result in the self resonant frequency decreasing by only a few percent as the temperature is increased from 25 to 475 C, but the maximum quality factor decreases by a factor of 2 to 3. These observations based on measured data are confirmed through 2D simulations using Sonnet software.

Screen printed passive components for flexible power electronics

PubMed Central

Ostfeld, Aminy E.; Deckman, Igal; Gaikwad, Abhinav M.; Lochner, Claire M.; Arias, Ana C.

2015-01-01

Additive and low-temperature printing processes enable the integration of diverse electronic devices, both power-supplying and power-consuming, on flexible substrates at low cost. Production of a complete electronic system from these devices, however, often requires power electronics to convert between the various operating voltages of the devices. Passive components—inductors, capacitors, and resistors—perform functions such as filtering, short-term energy storage, and voltage measurement, which are vital in power electronics and many other applications. In this paper, we present screen-printed inductors, capacitors, resistors and an RLC circuit on flexible plastic substrates, and report on the design process for minimization of inductor series resistance that enables their use in power electronics. Printed inductors and resistors are then incorporated into a step-up voltage regulator circuit. Organic light-emitting diodes and a flexible lithium ion battery are fabricated and the voltage regulator is used to power the diodes from the battery, demonstrating the potential of printed passive components to replace conventional surface-mount components in a DC-DC converter application. PMID:26514331

Screen printed passive components for flexible power electronics.

PubMed

Ostfeld, Aminy E; Deckman, Igal; Gaikwad, Abhinav M; Lochner, Claire M; Arias, Ana C

2015-10-30

Additive and low-temperature printing processes enable the integration of diverse electronic devices, both power-supplying and power-consuming, on flexible substrates at low cost. Production of a complete electronic system from these devices, however, often requires power electronics to convert between the various operating voltages of the devices. Passive components-inductors, capacitors, and resistors-perform functions such as filtering, short-term energy storage, and voltage measurement, which are vital in power electronics and many other applications. In this paper, we present screen-printed inductors, capacitors, resistors and an RLC circuit on flexible plastic substrates, and report on the design process for minimization of inductor series resistance that enables their use in power electronics. Printed inductors and resistors are then incorporated into a step-up voltage regulator circuit. Organic light-emitting diodes and a flexible lithium ion battery are fabricated and the voltage regulator is used to power the diodes from the battery, demonstrating the potential of printed passive components to replace conventional surface-mount components in a DC-DC converter application.

NLCC controller for SEPIC-based micro-wind energy conversion system

NASA Astrophysics Data System (ADS)

Justin Nayagam, Brintha Jane; Sathi, Rama Reddy; Olimuthu, Divya

2017-04-01

The growth of the power industry is gaining greater momentum as the usage of the non-conventional energy sources that include fuel, solar, and wind energies, increases. Wind energy conversion systems (WECSs) are gaining more popularity and are expected to be able to control the power at the output. This paper describes the current control (CC), non-linear carrier charge control (NLCCC), and fuzzy logic control (FLC) applied to the single-ended primary inductor converter (SEPIC)-based WECS. The current controller has an inherent overcurrent protection with better line noise rejection. The pulses for the switch of the SEPIC are obtained by comparing the current flowing through it with the virtual current reference. FLC is also investigated for the micro-wind energy conversion system (μWECS), since it improves the damping characteristics of WECS over a wide range of operating points. This cannot attain the unity power factor rectification. In this paper, NLCCC is proposed for high-power factor rectifier-based SEPIC in continuous conduction mode (CCM) for μWECS. The proposed converter provides an output voltage with low input current ripple due to the presence of the inductor at the input side. By comparing the signal proportional to the integral of switch current with a periodic non-linear carrier wave, the duty ratio of the converter switch is determined for the NLCC controller. By selecting the shape of the periodic non-linear carrier wave the input-line current can be made to follow the input-line voltage. This work employs a parabolic carrier waveform generator. The output voltage is regulated for changes in the wind speed. The results obtained prove the effectiveness of the NLCC controller in improving the power factor.

A high efficiency 3 kW switchmode battery charger

NASA Technical Reports Server (NTRS)

Latos, T. S.; Bosack, D. J.

1982-01-01

This paper discusses the design approach and status of a high-efficiency switchmode battery charger designed to charge a 108 V battery from the 115 Vac line. The charger contains a transformer isolated boost chopper operating at 20 kHz. The boost inductor current is programmed to follow the ac line voltage such that high power factor operation and low line distortion are obtained.

Wide Temperature Characteristics of Transverse Magnetically Annealed Amorphous Tapes for High Frequency Aerospace Magnetics

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

1999-01-01

100 kHz core loss and magnetization properties of sample transverse magnetically annealed, cobalt-based amorphous and iron-based nanocrystalline tape wound magnetic cores are presented over the temperature range of -150 to 150 C, at selected values of B(sub peak). For B-fields not close to saturation, the core loss is not sensitive to temperature in this range and is as low as seen in the best MnZn power ferrites at their optimum temperatures. Frequency resolved characteristics are given over the range of 50 kHz to 1 MHz, at B(sub peak) = 0.1 T and 50 C only. A linear permeability model is used to interpret and present the magnetization characteristics and several figures of merit applicable to inductor materials arc reviewed. This linear modeling shows that, due to their high permeabilities, these cores must he gapped in order to make up high Q or high current inductors. However, they should serve well, as is, for high frequency, anti ratcheting transformer applications.

Linear transformer and primary low-inductance switch and capacitor modules for fast charging of PFL

NASA Astrophysics Data System (ADS)

Bykov, Yu A.; Krastelev, E. G.; Popov, G. V.; Sedin, A. A.; Feduschak, V. F.

2017-05-01

A step-up linear pulse transformer and a modular primary powering system were developed for fast (≈350 ns) charging of a pulse forming line (PFL) of a high-current electron accelerator. The linear transformer is assembled of a set of 20 inductors with circular ferromagnetic cores and one-turn primary windings. The secondary turn is formed by housing tube walls and a voltage adder with a film-glycerol insulation installed inside of the inductors. The primary powering system assembles 10 modules, each of them is a low-inductance site of two capacitors of 0,35 µF and one gas switch mounted at the same enclosure. The total stored energy is 5.5 kJ at the charging voltage of 40 kV. According to test results, the equivalent parameters at the output of the transformer are the next: a capacity - 17.5 nF, an inductance - 2 µH, a resistance - 3.2 Ohms.

Dynamic characteristics of a 20 kHz resonant power system - Fault identification and fault recovery

NASA Technical Reports Server (NTRS)

Wasynczuk, O.

1988-01-01

A detailed simulation of a dc inductor resonant driver and receiver is used to demonstrate the transient characteristics of a 20 kHz resonant power system during fault and overload conditions. The simulated system consists of a dc inductor resonant inverter (driver), a 50-meter transmission cable, and a dc inductor resonant receiver load. Of particular interest are the driver and receiver performance during fault and overload conditions and on the recovery characteristics following removal of the fault. The information gained from these studies sets the stage for further work in fault identification and autonomous power system control.

Dynamical investigation and parameter stability region analysis of a flywheel energy storage system in charging mode

NASA Astrophysics Data System (ADS)

Zhang, Wei-Ya; Li, Yong-Li; Chang, Xiao-Yong; Wang, Nan

2013-09-01

In this paper, the dynamic behavior analysis of the electromechanical coupling characteristics of a flywheel energy storage system (FESS) with a permanent magnet (PM) brushless direct-current (DC) motor (BLDCM) is studied. The Hopf bifurcation theory and nonlinear methods are used to investigate the generation process and mechanism of the coupled dynamic behavior for the average current controlled FESS in the charging mode. First, the universal nonlinear dynamic model of the FESS based on the BLDCM is derived. Then, for a 0.01 kWh/1.6 kW FESS platform in the Key Laboratory of the Smart Grid at Tianjin University, the phase trajectory of the FESS from a stable state towards chaos is presented using numerical and stroboscopic methods, and all dynamic behaviors of the system in this process are captured. The characteristics of the low-frequency oscillation and the mechanism of the Hopf bifurcation are investigated based on the Routh stability criterion and nonlinear dynamic theory. It is shown that the Hopf bifurcation is directly due to the loss of control over the inductor current, which is caused by the system control parameters exceeding certain ranges. This coupling nonlinear process of the FESS affects the stability of the motor running and the efficiency of energy transfer. In this paper, we investigate into the effects of control parameter change on the stability and the stability regions of these parameters based on the averaged-model approach. Furthermore, the effect of the quantization error in the digital control system is considered to modify the stability regions of the control parameters. Finally, these theoretical results are verified through platform experiments.

Module Eight: Induction; Basic Electricity and Electronics Individualized Learning System.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

The module covers in greater depth electromagnetic induction, its effects, and how it is used to advantage in electrical circuits; and the physical components, called inductors, designed to take advantage of the phenomenon of electromagnetic induction. This module is divided into four lessons: electromagnetism; inductors and flux density, inducing…

High voltage MOSFET switching circuit

DOEpatents

McEwan, Thomas E.

1994-01-01

The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

Position Sensor with Integrated Signal-Conditioning Electronics on a Printed Wiring Board

NASA Technical Reports Server (NTRS)

Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

2001-01-01

A position sensor, such as a rotary position sensor, includes the signal-conditioning electronics in the housing. The signal-conditioning electronics are disposed on a printed wiring board, which is assembled with another printed wiring board including the sensor windings to provide a sub-assembly. A mu-metal shield is interposed between the printed wiring boards to prevent magnetic interference. The sub-assembly is disposed in the sensor housing adjacent to an inductor board which turns on a shaft. The inductor board emanates an internally or externally generated excitation signal that induces a signal in the sensor windings. The induced signal represents the rotary position of the inductor board relative to the sensor winding board.

Problems in the Development of High-Power Turbogenerators with Superconducting Field Windings,

DTIC Science & Technology

1983-12-05

Both these constructions use a pulsating magnetic flux, which lowers the efficiency of the machine. In the case of rotating armature winding there is...Current pickup is accomplished with the aid of springs or flexible . connections. Calculations showed that with power 500 MW such a generator should...superconducting inductor a number of complicated technical problems appears. The main problem - the provision of strength and perfect heat insulation

Power supplies for dual-frequency induction melting of metals

NASA Astrophysics Data System (ADS)

Lusgin, V. I.; Koptyakov, A. S.; Petrov, A. U.; Zinovev, K. A.; Kamaev, D. A.

2018-02-01

The article discusses the benefits of multi frequency induction melting in the production of synthetic cast iron, structural (electric circuit) principles of dual frequency Power supplies of melting systems. The ways of electric power regulation of low frequency and high frequency components of the current in the inductor sections of furnace are demonstrated, namely power rescheduling at the metal melting stage, alloying stage and decarburizing of synthetic cast iron.

RF Telemetry System for an Implantable Bio-MEMS Sensor

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Hall, David G.; Miranda, Felix A.

2004-01-01

In this paper, a novel miniature inductor and a pick-up antenna for contact less powering and RF telemetry from implantable bio-MEMS sensors are presented. The design of the inductor and the pick-up antenna are discussed. In addition, the measured characteristics at the design frequency of 330 MHz have been shown.

High voltage MOSFET switching circuit

DOEpatents

McEwan, T.E.

1994-07-26

The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET. 2 figs.

Conduction-coupled Tesla transformer.

PubMed

Reed, J L

2015-03-01

A proof-of-principle Tesla transformer circuit is introduced. The new transformer exhibits the high voltage-high power output signal of shock-excited transformers. The circuit, with specification of proper circuit element values, is capable of obtaining extreme oscillatory voltages. The primary and secondary portions of the circuit communicate solely by conduction. The destructive arcing between the primary and secondary inductors in electromagnetically coupled transformers is ubiquitous. Flashover is eliminated in the new transformer as the high-voltage inductors do not interpenetrate and so do not possess an annular volume of electric field. The inductors are remote from one another. The high voltage secondary inductor is isolated in space, except for a base feed conductor, and obtains earth by its self-capacitance to the surroundings. Governing equations, for the ideal case of no damping, are developed from first principles. Experimental, theoretical, and circuit simulator data are presented for the new transformer. Commercial high-temperature superconductors are discussed as a means to eliminate the counter-intuitive damping due to small primary inductances in both the electromagnetic-coupled and new conduction-coupled transformers.

Skin effect suppression for Cu/CoZrNb multilayered inductor

NASA Astrophysics Data System (ADS)

Sato, Noriyuki; Endo, Yasushi; Yamaguchi, Masahiro

2012-04-01

The Cu/Co85Zr3Nb12 multilayer is studied as a conductor of a spiral inductor to suppress the skin effect at the 5 GHz range (matches IEEE 802.11 a standard) using negative-permeability in CoZrNb films beyond the ferromagnetic resonance frequency. The skin effect suppression becomes remarkable when the thickness of Cu in each period of the multilayer, tCu, is less than the skin depth of Cu at the targeting frequency. For the 5 GHz operation, tCu ≤ 750 nm. The resistance of the Cu/CoZrNb multilayered spiral inductor decreases as much as 8.7%, while keeping the same inductance of 1.1 nH as that of a similar air core. Accordingly, Q = 16. Therefore, the proposed method can contribute to realize a high-Q spiral inductor. We also study the potentially applicable frequency of this method. Given a soft magnetic material with Ms = 105 emu/cc and Hk = 5 Oe, the method can be applied at 700 MHz, the lowermost carrier frequency band for the 4th generation cellular phone system.

FEM analysis of magnetic flake composites

NASA Astrophysics Data System (ADS)

Claassen, J. H.

2009-07-01

A composite comprised of layered flake-like magnetic particles embedded in an insulating medium has been proposed as a low permeability, low loss core material. This would be an alternative to "distributed air gap" compressed powder cores that are widely used for inductors in power applications. Since the lowest loss metallic materials are manufactured in the form of very thin sheets, the particles after pulverizing would be in the form of flakes. The effective permeability and average core loss have been computed for model systems of flake composites in a two-dimensional approximation. The core loss is modeled by eddy current dissipation in the low-frequency limit, where the conductor thickness is much less than the skin depth. It is found that useful values of permeability should be obtained for a modest filling fraction of magnetic material, in contrast to the powder cores which require a value close to unity. The core loss will scale as the inverse of filling fraction, with a small additional enhancement due to perpendicular field components. It is thus expected that useful core materials may be attainable without the necessity of large compaction forces.

Rapid screening of potential autophagic inductor agents using mammalian cell lines.

PubMed

Martins, Waleska K; Severino, Divinomar; Souza, Cleidiane; Stolf, Beatriz S; Baptista, Maurício S

2013-06-01

Recent progress in understanding the molecular basis of autophagy has demonstrated its importance in several areas of human health. Affordable screening techniques with higher sensitivity and specificity to identify autophagy are, however, needed to move the field forward. In fact, only laborious and/or expensive methodologies such as electron microscopy, dye-staining of autophagic vesicles, and LC3-II immunoblotting or immunoassaying are available for autophagy identification. Aiming to fulfill this technical gap, we describe here the association of three widely used assays to determine cell viability - Crystal Violet staining (CVS), 3-[4, 5-dimethylthiaolyl]-2, 5-diphenyl-tetrazolium bromide (MTT) reduction, and neutral red uptake (NRU) - to predict autophagic cell death in vitro. The conceptual framework of the method is the superior uptake of NR in cells engaging in autophagy. NRU was then weighted by the average of MTT reduction and CVS allowing the calculation of autophagic arbitrary units (AAU), a numeric variable that correlated specifically with the autophagic cell death. The proposed strategy is very useful for drug discovery, allowing the investigation of potential autophagic inductor agents through a rapid screening using mammalian cell lines B16-F10, HaCaT, HeLa, MES-SA, and MES-SA/Dx5 in a unique single microplate. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Integrated Micro-scale Power Conversion

DTIC Science & Technology

2012-08-01

Micro Power Converters (μPC) Loads: Sources: μ-Power Converter (μPC) Thin-film battery Solar Cell Micro- fuel Cell Vibration Harvester...passive size • Hybrid integration with MEMS passives, particularly inductors Hybrid integration ARL focus Bubble Size = Volume [mm3] Industry Focus...Power converters survey Compiled by Bedair, Bashirullah Switched inductor (SI) Switched capacitor (SC) Resonant Resonat piezo Hybrid - SI / SC

An inductor-based converter with EMI reduction for low-voltage thermoelectric energy harvesting

NASA Astrophysics Data System (ADS)

Wang, Chuang; Zhao, Kai; Li, Zunchao

2017-07-01

This paper presents a self-powered inductor-based converter which harvests thermoelectric energy and boosts extremely low voltage to a typical voltage level for supplying body sensor nodes. Electromagnetic interference (EMI) of the converter is reduced by spreading spectrum of fundamental frequency and harmonics via pseudo-random modulation, which is obtained via combining the linear feedback shift register and digitally controlled oscillator. Besides, the methods, namely extracting energy near MPP and reducing the power dissipation, are employed to improve the power efficiency. The presented inductor-based converter is designed and verified in CSMC CMOS 0.18-µm 1P6M process. The results reveal that it achieves the high efficiency and EMI reduction at the same time.

Analysis of a PWM Resonant Buck Chopper for Use as a Ship Service Converter Module

DTIC Science & Technology

1999-01-01

zonal architecture [2] has a number of advantages over the current radial distribution architecture. The radial network includes generators supplying...Several representative topologies are considered in this section. The literature is replete with softswitching dc-dc converter topologies and control...differs from a conventional PWM buck by the addition of a resonant network consisting of inductor Lr, capacitor Q, an auxiliary switch Sr, an auxiliary

NDT of railway components using induction thermography

NASA Astrophysics Data System (ADS)

Netzelmann, U.; Walle, G.; Ehlen, A.; Lugin, S.; Finckbohner, M.; Bessert, S.

2016-02-01

Induction or eddy current thermography is used to detect surface cracks in ferritic steel. The technique is applied to detect surface cracks in rails from a moving test car. Cracks were detected at a train speed between 2 and 15 km/h. An automated demonstrator system for testing railway wheels after production is described. While the wheel is rotated, a robot guides the detection unit consisting of inductor and infrared camera over the surface.

Calculation and research of electrical characteristics of induction crucible furnaces with unmagnetized conductive crucible

NASA Astrophysics Data System (ADS)

Fedin, M. A.; Kuvaldin, A. B.; Kuleshov, A. O.; Zhmurko, I. Y.; Akhmetyanov, S. V.

2018-01-01

Calculation methods for induction crucible furnaces with a conductive crucible have been reviewed and compared. The calculation method of electrical and energy characteristics of furnaces with a conductive crucible has been developed and the example of the calculation is shown below. The calculation results are compared with experimental data. Dependences of electrical and power characteristics of the furnace on frequency, inductor current, geometric dimensions and temperature have been obtained.

Combination field chopper and battery charger

DOEpatents

Steigerwald, R.L.; Crouch, K.E.; Wilson, J.W.A.

1979-08-13

A power transistor used in a chopper circuit to control field excitation of a vehicle motor when in a power mode is also used to control charging current from an a-c to d-c rectifier to the vehicle battery when in a battery charging mode. Two isolating diodes and a small high frequency filter inductor are the only elements required in the chopper circuit to reconfigure the circuit for power or charging modes of operation.

Combination field chopper and battery charger

DOEpatents

Steigerwald, Robert L.; Crouch, Keith E.; Wilson, James W. A.

1981-01-01

A power transistor used in a chopper circuit to control field excitation of a vehicle motor when in a power mode is also used to control charging current from an a-c to d-c rectifier to the vehicle battery when in a battery charging mode. Two isolating diodes and a small high frequency filter inductor are the only elements required in the chopper circuit to reconfigure the circuit for power or charging modes of operation.

Impact of Electromagnetic Field upon Temperature Measurement of Induction Heated Charges

NASA Astrophysics Data System (ADS)

Smalcerz, A.; Przylucki, R.

2013-04-01

The use of thermoelements is a commonly applied method in industry and engineering. It provides a wide measurement range of temperature, a direct voltage signal from the transducer, low cost of the thermoelement, and its resistance to many unfavorable factors which occur in an industrial environment. Unfortunately, thermoelements may not be resistant to interferences of a strong electromagnetic field because of the nature and design of a transducer. Induction heating is the most commonly used type of heating, at present, for metals. In order to guarantee the correctness of the carried out heating process, it is essential to control the temperature of the heated element. The impact of a strong electromagnetic field upon the thermocouple temperature measurement of the inductively heated elements has been analyzed in this paper. The experiment includes dozens of measurements where the following parameters have been varied: frequency of the current which feeds the heating inductor, power supplied to the heating system, geometry of heat inductor, and the charge material and its geometrical dimensions. Interferences of the power-line frequency have been eliminated in part of the carried out measurements.

Perform Experiments on LINUS-O and LTX Imploding Liquid Liner Fusion Systems.

DTIC Science & Technology

1982-08-27

EXPERIMENTS .. .. .. ... 3 III. HOMOPOLAR GENERATOR/INDUCTOR POWER SUPPLY EXPERIMENTS. 11 IV. PLASMA SWITCH EXPERIMENTS. .. .. .. .... . ..... 18 V... homopolar generator (HPG) inductive load system. 0 Conduct an electromagnetic pulse (EMP) simulation demonstration using the NRL HPG/inductive storage...suggest solutions to the unstable flow problem, the research was suspended due to the program redirection. -10- IT III. HOMOPOLAR GENERATOR/INDUCTOR POWER

Improved power transfer to wearable systems through stretchable magnetic composites

NASA Astrophysics Data System (ADS)

Lazarus, N.; Bedair, S. S.

2016-05-01

The use of wireless power transfer is common in stretchable electronics since physical wiring can be easily destroyed as the system is stretched. This work presents the first demonstration of improved inductive power coupling to a stretchable system through the addition of a thin layer of ferroelastomeric material. A ferroelastomer, an elastomeric polymer loaded with magnetic particulates, has a permeability greater than one while retaining the ability to survive significant mechanical strains. A recently developed ferroelastomer composite based on sendust platelets within a soft silicone elastomer was incorporated into liquid metal stretchable inductors based on the liquid metal galinstan in fluidic channels. For a single-turn inductor, the maximum power transfer efficiency rises from 71 % with no backplane, to 81 % for a rigid ferrite backplane on the transmitter side alone, to 86 % with a ferroelastomer backplane on the receiver side as well. The coupling between a commercial wireless power transmitter coil with ferrite backplane to a five-turn liquid metal inductor was also investigated, finding an improvement in power transfer efficiency from 81 % with only a rigid backplane to 90 % with the addition of the ferroelastomer backplane. Both the single and multi-turn inductors were demonstrated surviving up to 50 % uniaxial applied strain.

Interferon system in women with genital papillomavirus infection receiving immunomodulatory therapy.

PubMed

Rogovskaya, S I; Zhdanov, A V; Loginova, N S; Faizullin, L Z; Prilepskaya, V N; Van'ko, L V; Sukhikh, G T

2002-11-01

The interferon system was studied in women with genital papillomavirus infection. In most patients the interferon system was activated, while the ability of lymphocytes to respond to inductors decreased. Laserotherapy and immunomodulatory therapy with larifan, ridostin, and viferon for 1 month normalized blood interferon concentration (39.4% patients) and interferon-gamma production by lymphocytes in response to inductors (87.9% patients). After laser monotherapy these parameters returned to normal only in 13.2 and 7.6% patients, respectively. Correlation and regression analyses showed that changes in the interferon system were synchronized after immunomodulatory therapy. These data indicate that immunomodulatory therapy produces a complex effect on the interferon system. Measurements of blood interferon level can be used to predict the effect of further treatment with interferon-gamma inductors.

Operating nanoliter scale NMR microcoils in a 1 tesla field.

PubMed

McDowell, Andrew F; Adolphi, Natalie L

2007-09-01

Microcoil probes enclosing sample volumes of 1.2, 3.3, 7.0, and 81 nanoliters are constructed as nuclear magnetic resonance (NMR) detectors for operation in a 1 tesla permanent magnet. The probes for the three smallest volumes utilize a novel auxiliary tuning inductor for which the design criteria are given. The signal-to-noise ratio (SNR) and line width of water samples are measured. Based on the measured DC resistance of the microcoils, together with the calculated radio frequency (RF) resistance of the tuning inductor, the SNR is calculated and shown to agree with the measured values. The details of the calculations indicate that the auxiliary inductor does not degrade the NMR probe performance. The diameter of the wire used to construct the microcoils is shown to affect the signal line widths.

Sliding mode control of direct coupled interleaved boost converter for fuel cell

NASA Astrophysics Data System (ADS)

Wang, W. Y.; Ding, Y. H.; Ke, X.; Ma, X.

2017-12-01

A three phase direct coupled interleaved boost converter (TP-DIBC) was recommended in this paper. This converter has a small unbalance current sharing among the branches of TP-DIBC. An adaptive control law sliding mode control (SMC) is designed for the TP-DIBC. The aim is to 1) reduce ripple output voltage, inductor current and regulate output voltage tightly 2) The total current carried by direct coupled interleaved boost converter (DIBC) must be equally shared between different parallel branches. The efficacy and robustness of the proposed TP-DIBC and adaptive SMC is confirmed via computer simulations using Matlab SimPower System Tools. The simulation result is in line with the expectation.

A Megawatt Power Module for Ship Service - Supplement. Volume 1: Program Technical Report

DTIC Science & Technology

2007-06-01

Alternator” otherwise known as an “AC Homopolar ” or “Synchronous Homopolar ” machine for this application. The various motor /generator machine...After reviewing alternative motor /generator technologies as discussed above, a Homopolar Inductor Alternator (HIA) was selected for the technology...integrated flywheel energy storage system with homopolar inductor motor /generator and high-frequency drive”, Industry Applications, IEEE Transactions on

Overpulse railgun energy recovery circuit

DOEpatents

Honig, Emanuel M.

1989-01-01

In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, an overpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

Counterpulse railgun energy recovery circuit

DOEpatents

Honig, Emanuel M.

1986-01-01

In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

Fabrication, characterization and comparison of composite magnetic materials for high efficiency integrated voltage regulators with embedded magnetic core micro-inductors

NASA Astrophysics Data System (ADS)

Bellaredj, Mohamed L. F.; Mueller, Sebastian; Davis, Anto K.; Mano, Yasuhiko; Kohl, Paul A.; Swaminathan, Madhavan

2017-11-01

High-efficiency integrated voltage regulators (IVRs) require the integration of power inductors, which have low loss and reduced size at very high frequency. The use of a magnetic material core can reduce significantly the inductor area and simultaneously increase the inductance. This paper focuses on the fabrication, characterization and modeling of nickel zinc (NiZn) ferrite and carbonyl iron powder (CIP)-epoxy magnetic composite materials, which are used as the magnetic core materials of embedded inductors in a printed wiring board (PWB) for a system in package (SIP) based buck type IVR. The fabricated composite materials and process are fully compatible with FR4 epoxy resin prepreg and laminate. For 85% weight loading of the magnetic powder (around 100 MHz at room temperature), the composite materials show a relative permeability of 7.5-8.1 for the NiZn ferrite composite and 5.2-5.6 for the CIP composite and a loss tangent value of 0.24-0.28 for the NiZn ferrite composite and 0.09-0.1 for the CIP-composite. The room temperature saturation flux density values are 0.1351 T and 0.5280 T for the NiZn ferrite and the CIP composites, respectively. The frequency dispersion parameters of the magnetic composites are modeled using a simplified Lorentz and Landau-Lifshitz-Gilbert equation for a Debye type relaxation. Embedded magnetic core solenoid inductors were designed based on the composite materials for the output filter of a high-efficiency SIP based buck type IVR. Evaluation of a SIP based buck type IVR with the designed inductors shows that it can reach peak efficiencies of 91.7% at 11 MHz for the NiZn ferrite-composite, 91.6% at 14 MHz for CIP-composite and 87.5% (NiZn ferrite-composite) and 87.3% (CIP-composite) efficiency at 100 MHz for a 1.7 V:1.05 V conversion. For a direct 5 V:1 V conversion using a stacked topology, a peak efficiency of 82% at 10 MHz and 72% efficiency at 100 MHz can be achieved for both materials.

Fast-scale non-linear distortion analysis of peak-current-controlled buck-boost inverters

NASA Astrophysics Data System (ADS)

Zhang, Hao; Dong, Shuai; Yi, Chuanzhi; Guan, Weimin

2018-02-01

This paper deals with fast-scale non-linear distortion behaviours including asymmetrical period-doubling bifurcation and zero-crossing distortion in peak-current-controlled buck-boost inverters. The underlying mechanisms of the fast-scale non-linear distortion behaviours in inverters are revealed. The folded bifurcation diagram is presented to analyse the asymmetrical phenomenon of fast-scale period-doubling bifurcation. In view of the effect of phase shift and current ripple, the analytical expressions for one pair of critical phase angles are derived by using the design-oriented geometrical current approach. It is shown that the phase shift between inductor current and capacitor voltage should be responsible for the zero-crossing distortion phenomenon. These results obtained here are useful to optimise the circuit design and improve the circuit performance.

User's manual: Computer-aided design programs for inductor-energy-storage dc-to-dc electronic power converters

NASA Technical Reports Server (NTRS)

Huffman, S.

1977-01-01

Detailed instructions on the use of two computer-aided-design programs for designing the energy storage inductor for single winding and two winding dc to dc converters are provided. Step by step procedures are given to illustrate the formatting of user input data. The procedures are illustrated by eight sample design problems which include the user input and the computer program output.

Multiple feedback control apparatus for power conditioning equipment

NASA Technical Reports Server (NTRS)

Biess, John (Inventor); Yu, Yuan (Inventor)

1977-01-01

An improved feedback control system to govern the cyclic operation of the power switch of a non-dissipative power conditioning equipment. The apparatus includes two or three control loops working in unison. The first causes the output DC level to be compared with a reference, and the error amplified for control purposes. The second utilizes the AC component of the voltage across the output filter inductor or the current through the output filter capacitor, and the third loop senses the output transients.

Low Temperature Operation of a Switching Power Converter

NASA Technical Reports Server (NTRS)

Anglada-Sanchez, Carlos R.; Perez-Feliciano, David; Ray, Biswajit

1997-01-01

The low temperature operation of a 48 W, 50 kHz, 36/12 V pulse width modulated (PWM) buck de-de power converter designed with standard commercially available components and devices is reported. The efficiency of the converter increased from 85.6% at room temperature (300 K) to 92.0% at liquid nitrogen temperature (77 K). The variation of power MOSFET, diode rectifier, and output filter inductor loss with temperature is discussed. Relevant current, voltage. and power waveforms are also included.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yalong; Jones, Edward A.; Wang, Fred

Arm inductor in a modular multilevel converter (MMC) is used to limit the circulating current and dc short circuit fault current. The circulating current in MMC is dominated by second-order harmonic, which can be largely reduced with circulating current suppressing control. By analyzing the mechanism of the circulating current suppressing control, it is found that the circulating current at switching frequency becomes the main harmonic when suppression control is implemented. Unlike the second-order harmonic that circulates only within the three phases, switching frequency harmonic also flows through the dc side and may further cause high-frequency dc voltage harmonic. This articlemore » develops the theoretical relationship between the arm inductance and switching frequency circulating current, which can be used to guide the arm inductance selection. The experimental results with a downscaled MMC prototype verify the existence of the switching frequency circulating current and its relationship with arm inductance.« less

Transport properties of nanocomposite and its simulation with L-R-C circuit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gangopadhyay, Arnab, E-mail: agangulyphysics@gmail.com; Sarkar, Aditi, E-mail: agangulyphysics@gmail.com; Sarkar, A., E-mail: agangulyphysics@gmail.com

2014-04-24

The nano particles are represented in this communication by L-R-C equivalent circuit. The dc current voltage characteristics (CVC) of the proposed circuit have simulated using Circuit-Maker ® 2000. Experimental investigation on ZnO nano-composite with capping material gum acacia shows similar CVC. NPs are represented by C-R combinations to manifest the Coulomb blockade effect of a quantum dot. The capping material is represented by an inductor along with a resistance in series. Nine NPs with capping matrix are simulated. The dc current voltage characteristics (CVC) and gross feature of polarization nature obtained by experiment and simulation study are consistent.

Design optimization of high frequency transformer with controlled leakage inductance for current fed dual active bridge converter

NASA Astrophysics Data System (ADS)

Jung, Tae-Uk; Kim, Myung-Hwan; Yoo, Jin-Hyung

2018-05-01

Current fed dual active bridge converters for photovoltaic generation may typically require a given leakage or extra inductance in order to provide proper control of the currents. Therefore, the many researches have been focused on the leakage inductance control of high frequency transformer to integrate an extra inductor. In this paper, an asymmetric winding arrangement to get the controlled leakage inductance for the high frequency transformer is proposed to improve the efficiency of the current fed dual active bridge converter. In order to accurate analysis, a coupled electromagnetic analysis model of transformer connected with high frequency switching circuit is used. A design optimization procedure for high efficiency is also presented using design analysis model, and it is verified by the experimental result.

E-beam high voltage switching power supply

DOEpatents

Shimer, D.W.; Lange, A.C.

1996-10-15

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 figs.

E-beam high voltage switching power supply

DOEpatents

Shimer, Daniel W.; Lange, Arnold C.

1996-01-01

A high-power power supply produces a controllable, constant high voltage put under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

High Step-Up DC—DC Converter for AC Photovoltaic Module with MPPT Control

NASA Astrophysics Data System (ADS)

Sundar, Govindasamy; Karthick, Narashiman; Rama Reddy, Sasi

2014-08-01

This paper presents the high gain step-up BOOST converter which is essential to step up the low output voltage from PV panel to the high voltage according to the requirement of the application. In this paper a high gain BOOST converter with coupled inductor technique is proposed with the MPPT control. Without extreme duty ratios and the numerous turns-ratios of a coupled inductor this converter achieves a high step-up voltage-conversion ratio and the leakage energy of the coupled inductor is efficiently recycled to the load. MPPT control used to extract the maximum power from PV panel by controlling the Duty ratio of the converter. The PV panel, BOOST converter and the MPPT are modeled using Sim Power System blocks in MATLAB/SIMULINK environment. The prototype model of the proposed converter has been implemented with the maximum measured efficiency is up to 95.4% and full-load efficiency is 93.1%.

Development of a physically-based planar inductors VHDL-AMS model for integrated power converter design

NASA Astrophysics Data System (ADS)

Ammouri, Aymen; Ben Salah, Walid; Khachroumi, Sofiane; Ben Salah, Tarek; Kourda, Ferid; Morel, Hervé

2014-05-01

Design of integrated power converters needs prototype-less approaches. Specific simulations are required for investigation and validation process. Simulation relies on active and passive device models. Models of planar devices, for instance, are still not available in power simulator tools. There is, thus, a specific limitation during the simulation process of integrated power systems. The paper focuses on the development of a physically-based planar inductor model and its validation inside a power converter during transient switching. The planar inductor model remains a complex device to model, particularly when the skin, the proximity and the parasitic capacitances effects are taken into account. Heterogeneous simulation scheme, including circuit and device models, is successfully implemented in VHDL-AMS language and simulated in Simplorer platform. The mixed simulation results has been favorably tested and compared with practical measurements. It is found that the multi-domain simulation results and measurements data are in close agreement.

RF performances of inductors integrated on localized p+-type porous silicon regions

PubMed Central

2012-01-01

To study the influence of localized porous silicon regions on radiofrequency performances of passive devices, inductors were integrated on localized porous silicon regions, full porous silicon sheet, bulk silicon and glass substrates. In this work, a novel strong, resistant fluoropolymer mask is introduced to localize the porous silicon on the silicon wafer. Then, the quality factors and resonant frequencies obtained with the different substrates are presented. A first comparison is done between the performances of inductors integrated on same-thickness localized and full porous silicon sheet layers. The effect of the silicon regions in the decrease of performances of localized porous silicon is discussed. Then, the study shows that the localized porous silicon substrate significantly reduces losses in comparison with high-resistivity silicon or highly doped silicon bulks. These results are promising for the integration of both passive and active devices on the same silicon/porous silicon hybrid substrate. PMID:23009746

Robust decentralized controller for minimizing coupling effect in single inductor multiple output DC-DC converter operating in continuous conduction mode.

PubMed

Medeiros, Renan Landau Paiva de; Barra, Walter; Bessa, Iury Valente de; Chaves Filho, João Edgar; Ayres, Florindo Antonio de Cavalho; Neves, Cleonor Crescêncio das

2018-02-01

This paper describes a novel robust decentralized control design methodology for a single inductor multiple output (SIMO) DC-DC converter. Based on a nominal multiple input multiple output (MIMO) plant model and performance requirements, a pairing input-output analysis is performed to select the suitable input to control each output aiming to attenuate the loop coupling. Thus, the plant uncertainty limits are selected and expressed in interval form with parameter values of the plant model. A single inductor dual output (SIDO) DC-DC buck converter board is developed for experimental tests. The experimental results show that the proposed methodology can maintain a desirable performance even in the presence of parametric uncertainties. Furthermore, the performance indexes calculated from experimental data show that the proposed methodology outperforms classical MIMO control techniques. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Multi-Channel Capacitive Sensor Arrays

PubMed Central

Wang, Bingnan; Long, Jiang; Teo, Koon Hoo

2016-01-01

In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved. PMID:26821023

Tunable acoustic metamaterial based on piezoelectric ceramic transducer

NASA Astrophysics Data System (ADS)

Zhu, Xiaohui; Qiao, Jing; Zhang, Guangyu; Zhou, Qiang; Wu, Yingdan; Li, Longqiu

2017-04-01

In this paper, a tunable metamaterial consisting of periodic layers of steel, polyurea and piezoelectric ceramic transducer (PZT) was presented. The PZT layer in this structure was connected to an inductor L. Transfer matrix method was used to calculate the band structure of the sample. It was observed that an extremely narrow stop band was induced by the PZT layer with inductor L. This narrow stop band was attributed to the resonance circuit constituted by the piezoelectric layer, for the piezoelectric layer with electrodes could be seen as a capacitor. Further, homogenization was used to calculate the effective elastic constants of the sample. Results showed that the effective parameters of this structure behaved negative in the narrow stop band. The location of the narrow stop band was in the charge of inductor L, which could be used to design acoustic filters or noise insulators by changing the parameters of structure.

Factors affecting energy deposition and expansion in single wire low current experiments

NASA Astrophysics Data System (ADS)

Duselis, Peter U.; Vaughan, Jeffrey A.; Kusse, Bruce R.

2004-08-01

Single wire experiments were performed on a low current pulse generator at Cornell University. A 220 nF capacitor charged to 15-25 kV was used to drive single wire experiments. The capacitor and wire holder were connected in series through an external variable inductor to control the current rise rate. This external series inductance was adjustable from 0.2 to 2 μH. When coupled with the range of charging voltages this results in current rise rates from 5 to 50 A/ns. The current heated the wire through liquid and vapor phases until plasma formed around the wire. Energy deposition and expansion rates were measured as functions of the current rise rate. These results indicated better energy deposition and higher expansion rates with faster current rise rates. Effects of the wire-electrode connection method and wire polarity were also studied.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart, Gary

The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high-temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high-temperature superconducting material used evolved from 1 st generation (1G) BSCCO-2212 melt cast bulk high-temperature superconductors to 2 nd generation (2G) YBCO-based high-temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology, that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. Amore » number of these modules are arranged in an m x n array to form the current-limiting matrix.« less

Unity power factor converter

NASA Technical Reports Server (NTRS)

Wester, Gene W. (Inventor)

1980-01-01

A unity power factor converter capable of effecting either inversion (dc-to-dc) or rectification (ac-to-dc), and capable of providing bilateral power control from a DC source (or load) through an AC transmission line to a DC load (or source) for power flow in either direction, is comprised of comparators for comparing the AC current i with an AC signal i.sub.ref (or its phase inversion) derived from the AC ports to generate control signals to operate a switch control circuit for high speed switching to shape the AC current waveform to a sine waveform, and synchronize it in phase and frequency with the AC voltage at the AC ports, by selectively switching the connections to a series inductor as required to increase or decrease the current i.

Direct current ballast circuit for metal halide lamp

NASA Technical Reports Server (NTRS)

Lutus, P. (Inventor)

1981-01-01

A direct current ballast circuit for a two electrode metal halide lamp is described. Said direct current ballast circuit includes a low voltage DC input and a high frequency power amplifier and power transformer for developing a high voltage output. The output voltage is rectified by diodes and filtered by inductor and capacitor to provide a regulated DC output through commutating diodes to one terminal of the lamp at the output terminal. A feedback path from the output of the filter capacitor through the bias resistor to power the high frequency circuit which includes the power amplifier and the power transformer for sustaining circuit operations during low voltage transients on the input DC supply is described. A current sensor connected to the output of the lamp through terminal for stabilizing lamp current following breakdown of the lamp is described.

An Optimal Current Observer for Predictive Current Controlled Buck DC-DC Converters

PubMed Central

Min, Run; Chen, Chen; Zhang, Xiaodong; Zou, Xuecheng; Tong, Qiaoling; Zhang, Qiao

2014-01-01

In digital current mode controlled DC-DC converters, conventional current sensors might not provide isolation at a minimized price, power loss and size. Therefore, a current observer which can be realized based on the digital circuit itself, is a possible substitute. However, the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage. In this paper, an optimal current observer is proposed. It achieves the highest observation accuracy by compensating for all the known parasitic parameters. By employing the optimal current observer-based predictive current controller, a buck converter is implemented. The converter has a convergently and accurately observed inductor current, and shows preferable transient response than the conventional voltage mode controlled converter. Besides, costs, power loss and size are minimized since the strategy requires no additional hardware for current sensing. The effectiveness of the proposed optimal current observer is demonstrated experimentally. PMID:24854061

Comparison of magnetic probe calibration at nano and millitesla magnitudes

NASA Astrophysics Data System (ADS)

Pahl, Ryan A.; Rovey, Joshua L.; Pommerenke, David J.

2014-01-01

Magnetic field probes are invaluable diagnostics for pulsed inductive plasma devices where field magnitudes on the order of tenths of tesla or larger are common. Typical methods of providing a broadband calibration of dot{{B}} probes involve either a Helmholtz coil driven by a function generator or a network analyzer. Both calibration methods typically produce field magnitudes of tens of microtesla or less, at least three and as many as six orders of magnitude lower than their intended use. This calibration factor is then assumed constant regardless of magnetic field magnitude and the effects of experimental setup are ignored. This work quantifies the variation in calibration factor observed when calibrating magnetic field probes in low field magnitudes. Calibration of two dot{{B}} probe designs as functions of frequency and field magnitude are presented. The first dot{{B}} probe design is the most commonly used design and is constructed from two hand-wound inductors in a differential configuration. The second probe uses surface mounted inductors in a differential configuration with balanced shielding to further reduce common mode noise. Calibration factors are determined experimentally using an 80.4 mm radius Helmholtz coil in two separate configurations over a frequency range of 100-1000 kHz. A conventional low magnitude calibration using a vector network analyzer produced a field magnitude of 158 nT and yielded calibration factors of 15 663 ± 1.7% and 4920 ± 0.6% {T}/{V {s}} at 457 kHz for the surface mounted and hand-wound probes, respectively. A relevant magnitude calibration using a pulsed-power setup with field magnitudes of 8.7-354 mT yielded calibration factors of 14 615 ± 0.3% and 4507 ± 0.4% {T}/{V {s}} at 457 kHz for the surface mounted inductor and hand-wound probe, respectively. Low-magnitude calibration resulted in a larger calibration factor, with an average difference of 9.7% for the surface mounted probe and 12.0% for the hand-wound probe. The maximum difference between relevant and low magnitude tests was 21.5%.

The P3 Power Generation System for Advanced Missile Defense Applications

DTIC Science & Technology

2008-11-01

circuit. This increased the output power to the load resistor . The inductor couples with the piezo element to form an electrical LC tuned circuit and...of RMS power was generated with an efficiency of 40 % when an inductor of 250 mH was connected in series to a 100 ohm resistor . From power density...per cycle for generating electrical energy in a piezo -crystal membrane. Steady-state heat transfer measurements have been made previously with a

Application of genetic algorithm in modeling on-wafer inductors for up to 110 Ghz

NASA Astrophysics Data System (ADS)

Liu, Nianhong; Fu, Jun; Liu, Hui; Cui, Wenpu; Liu, Zhihong; Liu, Linlin; Zhou, Wei; Wang, Quan; Guo, Ao

2018-05-01

In this work, the genetic algorithm has been introducted into parameter extraction for on-wafer inductors for up to 110 GHz millimeter-wave operations, and nine independent parameters of the equivalent circuit model are optimized together. With the genetic algorithm, the model with the optimized parameters gives a better fitting accuracy than the preliminary parameters without optimization. Especially, the fitting accuracy of the Q value achieves a significant improvement after the optimization.

Magnetic Material Assessment of a Novel Ultra-High Step-Up Converter with Single Semiconductor Switch and Galvanic Isolation for Fuel-Cell Power System.

PubMed

Shen, Chih-Lung; Liou, Heng

2017-11-15

In this paper, a novel step-up converter is proposed, which has the particular features of single semiconductor switch, ultra-high conversion ratio, galvanic isolation, and easy control. Therefore, the proposed converter is suitable for the applications of fuel-cell power system. Coupled inductors and switched capacitors are incorporated in the converter to obtain an ultra-high voltage ratio that is much higher than that of a conventional high step-up converter. Even if the turns ratio of coupled inductor and duty ratio are only to be 1 and 0.5, respectively, the converter can readily achieve a voltage gain of up to 18. Owing to this outstanding performance, it can also be applied to any other low voltage source for voltage boosting. In the power stage, only one active switch is used to handle the converter operation. In addition, the leakage energy of the two couple inductors can be totally recycled without any snubber, which simplifies the control mechanism and improves the conversion efficiency. Magnetic material dominates the conversion performance of the converter. Different types of iron cores are discussed for the possibility to serve as a coupled inductor. A 200 W prototype with 400 V output voltage is built to validate the proposed converter. In measurement, it indicates that the highest efficiency can be up to 94%.

Magnetic Material Assessment of a Novel Ultra-High Step-Up Converter with Single Semiconductor Switch and Galvanic Isolation for Fuel-Cell Power System

PubMed Central

Shen, Chih-Lung; Liou, Heng

2017-01-01

In this paper, a novel step-up converter is proposed, which has the particular features of single semiconductor switch, ultra-high conversion ratio, galvanic isolation, and easy control. Therefore, the proposed converter is suitable for the applications of fuel-cell power system. Coupled inductors and switched capacitors are incorporated in the converter to obtain an ultra-high voltage ratio that is much higher than that of a conventional high step-up converter. Even if the turns ratio of coupled inductor and duty ratio are only to be 1 and 0.5, respectively, the converter can readily achieve a voltage gain of up to 18. Owing to this outstanding performance, it can also be applied to any other low voltage source for voltage boosting. In the power stage, only one active switch is used to handle the converter operation. In addition, the leakage energy of the two couple inductors can be totally recycled without any snubber, which simplifies the control mechanism and improves the conversion efficiency. Magnetic material dominates the conversion performance of the converter. Different types of iron cores are discussed for the possibility to serve as a coupled inductor. A 200 W prototype with 400 V output voltage is built to validate the proposed converter. In measurement, it indicates that the highest efficiency can be up to 94%. PMID:29140282

Improved Transient and Steady-State Performances of Series Resonant ZCS High-Frequency Inverter-Coupled Voltage Multiplier Converter with Dual Mode PFM Control Scheme

NASA Astrophysics Data System (ADS)

Chu, Enhui; Gamage, Laknath; Ishitobi, Manabu; Hiraki, Eiji; Nakaoka, Mutsuo

The A variety of switched-mode high voltage DC power supplies using voltage-fed type or current-fed type high-frequency transformer resonant inverters using MOS gate bipolar power transistors; IGBTs have been recently developed so far for a medical-use X-ray high power generator. In general, the high voltage high power X-ray generator using voltage-fed high frequency inverter with a high voltage transformer link has to meet some performances such as (i) short rising period in start transient of X-ray tube voltage (ii) no overshoot transient response in tube voltage, (iii) minimized voltage ripple in periodic steady-state under extremely wide load variations and filament heater current fluctuation conditions of the X-ray tube. This paper presents two lossless inductor snubber-assisted series resonant zero current soft switching high-frequency inverter using a diode-capacitor ladder type voltage multiplier called Cockcroft-Walton circuit, which is effectively implemented for a high DC voltage X-ray power generator. This DC high voltage generator which incorporates pulse frequency modulated series resonant inverter using IGBT power module packages is based on the operation principle of zero current soft switching commutation scheme under discontinuous resonant current and continuous resonant current transition modes. This series capacitor compensated for transformer resonant power converter with a high frequency transformer linked voltage boost multiplier can efficiently work a novel selectively-changed dual mode PFM control scheme in order to improve the start transient and steady-state response characteristics and can completely achieve stable zero current soft switching commutation tube filament current dependent for wide load parameter setting values with the aid of two lossless inductor snubbers. It is proved on the basis of simulation and experimental results in which a simple and low cost control implementation based on selectively-changed dual-mode PFM for high-voltage X-ray DC-DC power converter with a voltage multiplier strategy has some specified voltage pattern tracking voltage response performances under rapid rising time and no overshoot in start transient tube voltage as well as the minimized steady-state voltage ripple in tube voltage.

Digital computer simulation of inductor-energy-storage dc-to-dc converters with closed-loop regulators

NASA Technical Reports Server (NTRS)

Ohri, A. K.; Owen, H. A.; Wilson, T. G.; Rodriguez, G. E.

1974-01-01

The simulation of converter-controller combinations by means of a flexible digital computer program which produces output to a graphic display is discussed. The procedure is an alternative to mathematical analysis of converter systems. The types of computer programming involved in the simulation are described. Schematic diagrams, state equations, and output equations are displayed for four basic forms of inductor-energy-storage dc to dc converters. Mathematical models are developed to show the relationship of the parameters.

Vacuum arc plasma thrusters with inductive energy storage driver

NASA Technical Reports Server (NTRS)

Krishnan, Mahadevan (Inventor)

2009-01-01

A plasma thruster with a cylindrical inner and cylindrical outer electrode generates plasma particles from the application of energy stored in an inductor to a surface suitable for the formation of a plasma and expansion of plasma particles. The plasma production results in the generation of charged particles suitable for generating a reaction force, and the charged particles are guided by a magnetic field produced by the same inductor used to store the energy used to form the plasma.

High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

DOEpatents

Sanchez, Robert O.; Gunewardena, Shelton; Masi, James V.

2007-11-27

An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

DOEpatents

Sanchez, Robert O.; Gunewardena, Shelton; Masi, James V.

2005-03-29

An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

Influence of material uncertainties on the RLC parameters of wound inductors modeled using the finite element method

NASA Astrophysics Data System (ADS)

Lossa, Geoffrey; Deblecker, Olivier; Grève, Zacharie De

2018-05-01

In this work, we highlight the influence of the material uncertainties (magnetic permeability, electric conductivity of a Mn-Zn ferrite core, and electric permittivity of wire insulation) on the RLC parameters of a wound inductor extracted from the finite element method. To that end, the finite element method is embedded in a Monte Carlo simulation. We show that considering mentioned different material properties as real random variables, leads to significant variations in the distributions of the RLC parameters.

Evaluation of 95 gpm Inductors for Aqueous Film Forming Foam,

DTIC Science & Technology

1984-04-30

AQUEOUS FILM FORMING FOAM BACKGROUND/INTRODUCTION Early History The use of Aqueous Film Forming Foam ( AFFF ...vadIdniybybok46141 SECURITY CLASSIFICATION~ OF THIS PAGE 11. TITL (Include Secuit Cuaif~los) EVALUATION 0F795 GPM INDUCTORS FOR AQUEOUS FILM FORMING ...AD-A141 242 EVALUATION OF 95 GPM INDUCORG SEOR AQUEOUS FIL FORMING 1/GAM U) HUGHES ASSOCI A F S NC KEN S INO ON M0AD A14 24 RN GIE ETAL 3 00PR

Active energy recovery clamping circuit to improve the performance of power converters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitaker, Bret; Barkley, Adam

2017-05-09

A regenerative clamping circuit for a power converter using clamping diodes to transfer charge to a clamping capacitor and a regenerative converter to transfer charge out of the clamping capacitor back to the power supply input connection. The regenerative converter uses a switch connected to the midpoint of a series connected inductor and capacitor. The ends of the inductor and capacitor series are connected across the terminals of the power supply to be in parallel with the power supply.

Railguns

NASA Astrophysics Data System (ADS)

Marshall, R. A.

Descriptions are given of the following railgun systems: the fast-capacitor/inductor system, the slow-capacitor/inductance system, the homopolar generator/inductor system, the distributed energy store system, and the flux compressor powered railgun. Attention is also given to the inverse railgun flux compressor, where the piston is driven between the rails along which the inverted chevron armature slides. The development of the railgun since World War II is surveyed. It is noted that the most pressing need at present is for cheaper, simpler energy stores to couple to the railguns.

Comparative Analyses of Multi-Pulse Phase Controlled Rectifiers in Continuous Conduction Mode with a Two-Pole LC Output Filter for Surface Ship DC Applications

DTIC Science & Technology

2013-03-01

for this sub-mode, the minimum inductor current occurs at an angle 3 3t  (where 3 60    referenced to  ), as shown in Figure 13. 24...can be rewritten as    sin cos cosb b b ApA B      . (73) Grouping similar terms, yields  sin cosb b ApA B         , (74...where the fundamental frequency and each harmonic component are displayed graphically in a bar chart format as shown in Figure 25. The total current

High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs

DOEpatents

Shimer, D.W.; Lange, A.C.

1995-05-23

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.

High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs

DOEpatents

Shimer, Daniel W.; Lange, Arnold C.

1995-01-01

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Minimizing the total harmonic distortion for a 3 kW, 20 kHz ac to dc converter using SPICE

NASA Technical Reports Server (NTRS)

Lollar, Louis F.; Kapustka, Robert E.

1988-01-01

This paper describes the SPICE model of a transformer-rectified-filter (TRF) circuit and the Micro-CAP (Microcomputer Circuit Analysis Program) model and their application. The models were used to develop an actual circuit with reduced input current THD. The SPICE analysis consistently predicted the THD improvements in actual circuits as various designs were attempted. In an effort to predict and verify load regulation, the incorporation of saturable inductor models significantly improved the fidelity of the TRF circuit output voltage.

Circulating Current Suppressing Control’s Impact on Arm Inductance Selection for Modular Multilevel Converter

DOE PAGES

Li, Yalong; Jones, Edward A.; Wang, Fred

2016-10-13

Arm inductor in a modular multilevel converter (MMC) is used to limit the circulating current and dc short circuit fault current. The circulating current in MMC is dominated by second-order harmonic, which can be largely reduced with circulating current suppressing control. By analyzing the mechanism of the circulating current suppressing control, it is found that the circulating current at switching frequency becomes the main harmonic when suppression control is implemented. Unlike the second-order harmonic that circulates only within the three phases, switching frequency harmonic also flows through the dc side and may further cause high-frequency dc voltage harmonic. This articlemore » develops the theoretical relationship between the arm inductance and switching frequency circulating current, which can be used to guide the arm inductance selection. The experimental results with a downscaled MMC prototype verify the existence of the switching frequency circulating current and its relationship with arm inductance.« less

Improved L-C resonant decay technique for Q measurement of quasilinear power inductors: New results for MPP and ferrite powdered cores

NASA Technical Reports Server (NTRS)

Niedra, Janis M.; Gerber, Scott S.

1995-01-01

The L-C resonant decay technique for measuring circuit Q or losses is improved by eliminating the switch from the inductor-capacitor loop. A MOSFET switch is used instead to momentarily connect the resonant circuit to an existing voltage source, which itself is gated off during the decay transient. Very reproducible, low duty cycle data could be taken this way over a dynamic voltage range of at least 10:1. Circuit Q is computed from a polynomial fit to the sequence of the decaying voltage maxima. This method was applied to measure the losses at 60 kHz in inductors having loose powder cores of moly permalloy and an Mn-Zn power ferrite. After the copper and capacitor losses are separated out, the resulting specific core loss is shown to be roughly as expected for the MPP powder, but anomalously high for the ferrite powder. Possible causes are mentioned.

3D Magnetic field modeling of a new superconducting synchronous machine using reluctance network method

NASA Astrophysics Data System (ADS)

Kelouaz, Moussa; Ouazir, Youcef; Hadjout, Larbi; Mezani, Smail; Lubin, Thiery; Berger, Kévin; Lévêque, Jean

2018-05-01

In this paper a new superconducting inductor topology intended for synchronous machine is presented. The studied machine has a standard 3-phase armature and a new kind of 2-poles inductor (claw-pole structure) excited by two coaxial superconducting coils. The air-gap spatial variation of the radial flux density is obtained by inserting a superconducting bulk, which deviates the magnetic field due to the coils. The complex geometry of this inductor usually needs 3D finite elements (FEM) for its analysis. However, to avoid a long computational time inherent to 3D FEM, we propose in this work an alternative modeling, which uses a 3D meshed reluctance network. The results obtained with the developed model are compared to 3D FEM computations as well as to measurements carried out on a laboratory prototype. Finally, a 3D FEM study of the shielding properties of the superconducting screen demonstrates the suitability of using a diamagnetic-like model of the superconducting screen.

Reduced size dual band pass filters for RFID applications with excellent bandpass/bandstop characteristics

NASA Astrophysics Data System (ADS)

Abdalla, M. A.; Choudhary, D. Kumar; Chaudhary, R. Kumar

2018-02-01

This paper presents the design of two reduced size dual-band metamaterial bandpass filters and its simulation followed by measurements of proposed filters. These filters are supporting different frequency bands and primarily could be utilize in radio frequency identification (RFID) application. The filter includes three cells in which two are symmetrical and both inductively coupled with the third cell which is present in between them. In the proposed designs, three different metamaterial composite right/left handed (CRLH) cell resonators have been analysed for compactness. The CRLH cell consists of an interdigital capacitor, a stub/meander line/spiral inductor and a via to connect the top of the structure and ground plane. Finally, the proposed dual band bandpass filters (using meander line and spiral inductor) are showing size reduction by 65% and 50% (with 25% operating frequency reduction), respectively, in comparison with reference filter using stub inductor. More than 30 dB attenuation has been achieved between the two passbands.

The 10 kW power electronics for hydrogen arcjets

NASA Technical Reports Server (NTRS)

Hamley, John A.; Pinero, Luis R.; Hill, Gerald M.

1992-01-01

A combination of emerging mission considerations such as 'launch on schedule', resource limitations, and the development of higher power spacecraft busses has resulted in renewed interest in high power hydrogen arcjet systems with specific impulses greater than 1000 s for Earth-space orbit transfer and maneuver applications. Solar electric propulsion systems with about 10 kW of power appear to offer payload benefits at acceptable trip times. This work outlines the design and development of 10 kW hydrogen arcjet power electronics and results of arcjet integration testing. The power electronics incorporated a full bridge switching topology similar to that employed in state of the art 5 kW power electronics, and the output filter included an output current averaging inductor with an integral pulse generation winding for arcjet ignition. Phase shifted, pulse width modulation with current mode control was used to regulate the current delivered to arcjet, and a low inductance power stage minimized switching transients. Hybrid power Metal Oxide Semiconductor Field Effect Transistors were used to minimize conduction losses. Switching losses were minimized using a fast response, optically isolated, totem-pole gate drive circuit. The input bus voltage for the unit was 150 V, with a maximum output voltage of 225 V. The switching frequency of 20 kHz was a compromise between mass savings and higher efficiency. Power conversion efficiencies in excess of 0.94 were demonstrated, along with steady state load current regulation of 1 percent. The power electronics were successfully integrated with a 10 kW laboratory hydrogen arcjet, and reliable, nondestructive starts and transitions to steady state operation were demonstrated. The estimated specific mass for a flight packaged unit was 2 kg/kW.

Directly writing resistor, inductor and capacitor to composite functional circuits: a super-simple way for alternative electronics.

PubMed

Gao, Yunxia; Li, Haiyan; Liu, Jing

2013-01-01

The current strategies for making electronic devices are generally time, water, material and energy consuming. Here, the direct writing of composite functional circuits through comprehensive use of GaIn10-based liquid metal inks and matching material is proposed and investigated, which is a rather easy going and cost effective electronics fabrication way compared with the conventional approaches. Owing to its excellent adhesion and electrical properties, the liquid metal ink was demonstrated as a generalist in directly making various basic electronic components such as planar resistor, inductor and capacitor or their combination and thus composing circuits with expected electrical functions. For a precise control of the geometric sizes of the writing, a mask with a designed pattern was employed and demonstrated. Mechanisms for justifying the chemical components of the inks and the magnitudes of the target electronic elements so as to compose various practical circuits were disclosed. Fundamental tests on the electrical components including capacitor and inductor directly written on paper with working time up to 48 h and elevated temperature demonstrated their good stability and potential widespread adaptability especially when used in some high frequency circuits. As the first proof-of-concept experiment, a typical functional oscillating circuit including an integrated chip of 74HC04 with a supply voltage of 5 V, a capacitor of 10 nF and two resistors of 5 kΩ and 1 kΩ respectively was directly composed on paper through integrating specific electrical elements together, which presented an oscillation frequency of 8.8 kHz. The present method significantly extends the roles of the metal ink in recent works serving as only a single electrical conductor or interconnecting wires. It opens the way for directly writing out complex functional circuits or devices on different substrates. Such circuit composition strategy has generalized purpose and can be extended to more areas, even daily pervasive electronics.

Nanosecond bipolar pulse generators for bioelectrics.

PubMed

Xiao, Shu; Zhou, Chunrong; Yang, Enbo; Rajulapati, Sambasiva R

2018-04-26

Biological effects caused by a nanosecond pulse, such as cell membrane permeabilization, peripheral nerve excitation and cell blebbing, can be reduced or cancelled by applying another pulse of reversed polarity. Depending on the degree of cancellation, the pulse interval of these two pulses can be as long as dozens of microseconds. The cancellation effect diminishes as the pulse duration increases. To study the cancellation effect and potentially utilize it in electrotherapy, nanosecond bipolar pulse generators must be made available. An overview of the generators is given in this paper. A pulse forming line (PFL) that is matched at one end and shorted at the other end allows a bipolar pulse to be produced, but no delay can be inserted between the phases. Another generator employs a combination of a resistor, an inductor and a capacitor to form an RLC resonant circuit so that a bipolar pulse with a decaying magnitude can be generated. A third generator is a converter, which converts an existing unipolar pulse to a bipolar pulse. This is done by inserting an inductor in a transmission line. The first phase of the bipolar pulse is provided by the unipolar pulse's rising phase. The second phase is formed during the fall time of the unipolar pulse, when the inductor, which was previously charged during the flat part of the unipolar pulse, discharges its current to the load. The fourth type of generator uses multiple MOSFET switches stacked to turn on a pre-charged, bipolar RC network. This approach is the most flexible in that it can generate multiphasic pulses that have different amplitudes, delays, and durations. However, it may not be suitable for producing short nanosecond pulses (<100 ns), whereas the PFL approach and the RLC approach with gas switches are used for this range. Thus, each generator has its own advantages and applicable range. Copyright © 2018 Elsevier B.V. All rights reserved.

Directly Writing Resistor, Inductor and Capacitor to Composite Functional Circuits: A Super-Simple Way for Alternative Electronics

PubMed Central

Gao, Yunxia; Li, Haiyan; Liu, Jing

2013-01-01

Background The current strategies for making electronic devices are generally time, water, material and energy consuming. Here, the direct writing of composite functional circuits through comprehensive use of GaIn10-based liquid metal inks and matching material is proposed and investigated, which is a rather easy going and cost effective electronics fabrication way compared with the conventional approaches. Methods Owing to its excellent adhesion and electrical properties, the liquid metal ink was demonstrated as a generalist in directly making various basic electronic components such as planar resistor, inductor and capacitor or their combination and thus composing circuits with expected electrical functions. For a precise control of the geometric sizes of the writing, a mask with a designed pattern was employed and demonstrated. Mechanisms for justifying the chemical components of the inks and the magnitudes of the target electronic elements so as to compose various practical circuits were disclosed. Results Fundamental tests on the electrical components including capacitor and inductor directly written on paper with working time up to 48 h and elevated temperature demonstrated their good stability and potential widespread adaptability especially when used in some high frequency circuits. As the first proof-of-concept experiment, a typical functional oscillating circuit including an integrated chip of 74HC04 with a supply voltage of 5 V, a capacitor of 10 nF and two resistors of 5 kΩ and 1 kΩ respectively was directly composed on paper through integrating specific electrical elements together, which presented an oscillation frequency of 8.8 kHz. Conclusions The present method significantly extends the roles of the metal ink in recent works serving as only a single electrical conductor or interconnecting wires. It opens the way for directly writing out complex functional circuits or devices on different substrates. Such circuit composition strategy has generalized purpose and can be extended to more areas, even daily pervasive electronics. PMID:23936349

Performance and Characterization of Magnetic Penetration Thermometer Devices for X-Ray Spectroscopy

NASA Technical Reports Server (NTRS)

Porst, J. -P.; Adams, J. S.; Bandler, S. R.; Balvin, M.; Busch, S. E.; Denis, K. L.; Kelly, D.; Nagler, P.; Sadleir, J. E.; Seidel, G. M.;

Counterpulse railgun energy recovery circuit

DOEpatents

Honig, E.M.

1984-09-28

The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

Overpulse railgun energy recovery circuit

DOEpatents

Honig, E.M.

1984-09-28

The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, an overpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

An improved low-voltage ride-through performance of DFIG based wind plant using stator dynamic composite fault current limiter.

PubMed

Gayen, P K; Chatterjee, D; Goswami, S K

2016-05-01

In this paper, an enhanced low-voltage ride-through (LVRT) performance of a grid connected doubly fed induction generator (DFIG) has been presented with the usage of stator dynamic composite fault current limiter (SDCFCL). This protection circuit comprises of a suitable series resistor-inductor combination and parallel bidirectional semiconductor switch. The SDCFCL facilitates double benefits such as reduction of rotor induced open circuit voltage due to increased value of stator total inductance and concurrent increase of rotor impedance. Both effects will limit rotor circuit over current and over voltage situation more secured way in comparison to the conventional scheme like the dynamic rotor current limiter (RCL) during any type of fault situation. The proposed concept is validated through the simulation study of the grid integrated 2.0MW DFIG. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

A soft-switching coupled inductor bidirectional DC-DC converter with high-conversion ratio

NASA Astrophysics Data System (ADS)

Chao, Kuei-Hsiang; Jheng, Yi-Cing

2018-01-01

A soft-switching bidirectional DC-DC converter is presented herein as a way to improve the conversion efficiency of a photovoltaic (PV) system. Adoption of coupled inductors enables the presented converter not only to provide a high-conversion ratio but also to suppress the transient surge voltage via the release of the energy stored in leakage flux of the coupled inductors, and the cost can kept down consequently. A combined use of a switching mechanism and an auxiliary resonant branch enables the converter to successfully perform zero-voltage switching operations on the main switches and improves the efficiency accordingly. It was testified by experiments that our proposed converter works relatively efficiently in full-load working range. Additionally, the framework of the converter intended for testifying has high-conversion ratio. The results of a test, where a generating system using PV module array coupled with batteries as energy storage device was used as the low-voltage input side, and DC link was used as high-voltage side, demonstrated our proposed converter framework with high-conversion ratio on both high-voltage and low-voltage sides.

Research on spacecraft electrical power conversion

NASA Technical Reports Server (NTRS)

Wilson, T. G.

1974-01-01

The steady state characteristics and starting behavior of some widely used self-oscillating magnetically coupled square wave inverters were studied and the development of LC-tuned square wave inverters is reported. An analysis on high amplitude voltage spikes which occur in dc-to-square-wave parallel converters shows the importance of various circuit parameters for inverter design and for the suppression of spikes. A computerized simulation of an inductor energy storage dc-to-dc converter with closed loop regulators and of a preregulating current step-up converter are detailed. Work continued on the computer aided design of two-winding energy storage dc-to-dc converters.

An Inductorless Self-Controlled Rectifier for Piezoelectric Energy Harvesting

PubMed Central

Lu, Shaohua; Boussaid, Farid

2015-01-01

This paper presents a high-efficiency inductorless self-controlled rectifier for piezoelectric energy harvesting. High efficiency is achieved by discharging the piezoelectric device (PD) capacitance each time the current produced by the PD changes polarity. This is achieved automatically without the use of delay lines, thereby making the proposed circuit compatible with any type of PD. In addition, the proposed rectifier alleviates the need for an inductor, making it suitable for on-chip integration. Reported experimental results show that the proposed rectifier can harvest up to 3.9 times more energy than a full wave bridge rectifier. PMID:26610492

An Inductorless Self-Controlled Rectifier for Piezoelectric Energy Harvesting.

PubMed

Lu, Shaohua; Boussaid, Farid

2015-11-19

This paper presents a high-efficiency inductorless self-controlled rectifier for piezoelectric energy harvesting. High efficiency is achieved by discharging the piezoelectric device (PD) capacitance each time the current produced by the PD changes polarity. This is achieved automatically without the use of delay lines, thereby making the proposed circuit compatible with any type of PD. In addition, the proposed rectifier alleviates the need for an inductor, making it suitable for on-chip integration. Reported experimental results show that the proposed rectifier can harvest up to 3.9 times more energy than a full wave bridge rectifier.

Direct reading inductance meter

NASA Technical Reports Server (NTRS)

Kolby, R. B. (Inventor)

1977-01-01

A direct reading inductance meter comprised of a crystal oscillator and an LC tuned oscillator is presented. The oscillators function respectively to generate a reference frequency, f(r), and to generate an initial frequency, f(0), which when mixed produce a difference equal to zero. Upon connecting an inductor of small unknown value in the LC circuit to change its resonant frequency to f(x), a difference frequency (f(r)-f(x)) is produced that is very nearly a linear function of the inductance of the inductor. The difference frequency is measured and displayed on a linear scale in units of inductance.

Analysis of high voltage step-up nonisolated DC-DC boost converters

NASA Astrophysics Data System (ADS)

Alisson Alencar Freitas, Antônio; Lessa Tofoli, Fernando; Junior, Edilson Mineiro Sá; Daher, Sergio; Antunes, Fernando Luiz Marcelo

2016-05-01

A high voltage step-up nonisolated DC-DC converter based on coupled inductors suitable to photovoltaic (PV) systems applications is proposed in this paper. Considering that numerous approaches exist to extend the voltage conversion ratio of DC-DC converters that do not use transformers, a detailed comparison is also presented among the proposed converter and other popular topologies such as the conventional boost converter and the quadratic boost converter. The qualitative analysis of the coupled-inductor-based topology is developed so that a design procedure can be obtained, from which an experimental prototype is implemented to validate the theoretical assumptions.

Power electronics for low power arcjets

NASA Technical Reports Server (NTRS)

Hamley, John A.; Hill, Gerald M.

1991-01-01

In anticipation of the needs of future light-weight, low-power spacecraft, arcjet power electronics in the 100 to 400 W operating range were developed. Limited spacecraft power and thermal control capacity of these small spacecraft emphasized the need for high efficiency. Power topologies similar to those in the higher 2 kW and 5 to 30 kW power range were implemented, including a four transistor bridge switching circuit, current mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter. Electromagnetic compatibility requirements were not considered in this work, and control power for the converter was derived from AC mains. Addition of input filters and control power converters would result in an efficiency of on the order of 90 percent for a flight unit. Due to the developmental nature of arcjet systems at this power level, the exact nature of the thruster/power processor interface was not quantified. Output regulation and current ripple requirements of 1 and 20 percent respectively, as well as starting techniques, were derived from the characteristics of the 2 kW system but an open circuit voltage in excess of 175 V was specified. Arcjet integration tests were performed, resulting in successful starts and stable arcjet operation at power levels as low as 240 W with simulated hydrazine propellants.

A simplified controller and detailed dynamics of constant off-time peak current control

NASA Astrophysics Data System (ADS)

Van den Bossche, Alex; Dimitrova, Ekaterina; Valchev, Vencislav; Feradov, Firgan

2017-09-01

A fast and reliable current control is often the base of power electronic converters. The traditional constant frequency peak control is unstable above 50 % duty ratio. In contrast, the constant off-time peak current control (COTCC) is unconditionally stable and fast, so it is worth analyzing it. Another feature of the COTCC is that one can combine a current control together with a current protection. The time dynamics show a zero-transient response, even when the inductor changes in a wide range. It can also be modeled as a special transfer function for all frequencies. The article shows also that it can be implemented in a simple analog circuit using a wide temperature range IC, such as the LM2903, which is compatible with PV conversion and automotive temperature range. Experiments are done using a 3 kW step-up converter. A drawback is still that the principle does not easily fit in usual digital controllers up to now.

Design and implementation of co-operative control strategy for hybrid AC/DC microgrids

NASA Astrophysics Data System (ADS)

Mahmud, Rasel

This thesis is mainly divided in two major sections: 1) Modeling and control of AC microgrid, DC microgrid, Hybrid AC/DC microgrid using distributed co-operative control, and 2) Development of a four bus laboratory prototype of an AC microgrid system. At first, a distributed cooperative control (DCC) for a DC microgrid considering the state-of-charge (SoC) of the batteries in a typical plug-in-electric-vehicle (PEV) is developed. In DC microgrids, this methodology is developed to assist the load sharing amongst the distributed generation units (DGs), according to their ratings with improved voltage regulation. Subsequently, a DCC based control algorithm for AC microgrid is also investigated to improve the performance of AC microgrid in terms of power sharing among the DGs, voltage regulation and frequency deviation. The results validate the advantages of the proposed methodology as compared to traditional droop control of AC microgrid. The DCC-based control methodology for AC microgrid and DC microgrid are further expanded to develop a DCC-based power management algorithm for hybrid AC/DC microgrid. The developed algorithm for hybrid microgrid controls the power flow through the interfacing converter (IC) between the AC and DC microgrids. This will facilitate the power sharing between the DGs according to their power ratings. Moreover, it enables the fixed scheduled power delivery at different operating conditions, while maintaining good voltage regulation and improved frequency profile. The second section provides a detailed explanation and step-by-step design and development of an AC/DC microgrid testbed. Controllers for the three-phase inverters are designed and tested on different generation units along with their corresponding inductor-capacitor-inductor (LCL) filters to eliminate the switching frequency harmonics. Electric power distribution line models are developed to form the microgrid network topology. Voltage and current sensors are placed in the proper positions to achieve a full visibility over the microgrid. A running average filter (RAF) based enhanced phase-locked-loop (EPLL) is designed and implemented to extract frequency and phase angle information. A PLL-based synchronizing scheme is also developed to synchronize the DGs to the microgrid. The developed laboratory prototype runs on dSpace platform for real time data acquisition, communication and controller implementation.

Frequency-tunable superconducting resonators via nonlinear kinetic inductance

NASA Astrophysics Data System (ADS)

Vissers, M. R.; Hubmayr, J.; Sandberg, M.; Chaudhuri, S.; Bockstiegel, C.; Gao, J.

2015-08-01

We have designed, fabricated, and tested a frequency-tunable high-Q superconducting resonator made from a niobium titanium nitride film. The frequency tunability is achieved by injecting a DC through a current-directing circuit into the nonlinear inductor whose kinetic inductance is current-dependent. We have demonstrated continuous tuning of the resonance frequency in a 180 MHz frequency range around 4.5 GHz while maintaining the high internal quality factor Qi > 180 000. This device may serve as a tunable filter and find applications in superconducting quantum computing and measurement. It also provides a useful tool to study the nonlinear response of a superconductor. In addition, it may be developed into techniques for measurement of the complex impedance of a superconductor at its transition temperature and for readout of transition-edge sensors.

The ringer - An efficient, high repetition rate circuit for electromagnetic launchers

NASA Astrophysics Data System (ADS)

Giorgi, D.; Helava, H.; Lindner, K.; Long, J.; Zucker, O.

1989-01-01

The Meatgrinder is an efficient, current-multiplying circuit which can be used to optimize the energy transfer to various electromagnetic gun configurations. The authors present a simple variant of the Meatgrinder circuit which permits a first-order current profiling into the gun and recovery of the inductive energy in the barrel at a high repetition rate. The circuit is basically a one-stage Meatgrinder which utilizes the ringing of the energy storage capacitor (less than 40 percent reversal) to perform the opening switch function and a solid-state diode as the crowbar switch between the two mutually coupled inductors. With resonant charging, this results in a completely passive, high-repetiton-rate electromagnetic-gun power supply. Since most of the barrel energy is recovered, a railgun with negligible muzzle flash can be realized.

Auxiliary quasi-resonant dc tank electrical power converter

DOEpatents

Peng, Fang Z.

2006-10-24

An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention taught in U.S. Pat. No. 6,111,770, herein incorporated by reference. The present invention provides faster current charging to the resonant inductor, thus minimizing delay time of the pulse width modulation (PWM) due to the soft-switching process. The new AQRDCT converter includes three tank capacitors or power supplies to achieve the faster current charging and minimize the soft-switching time delay. The new AQRDCT converter further includes a voltage balancing circuit to charge and discharge the three tank capacitors so that additional isolated power supplies from the utility line are not needed. A voltage clamping circuit is also included for clamping voltage surge due to the reverse recovery of diodes.

Load insensitive electrical device. [power converters for supplying direct current at one voltage from a source at another voltage

NASA Technical Reports Server (NTRS)

Schwarz, F. C. (Inventor)

1974-01-01

A class of power converters is described for supplying direct current at one voltage from a source at another voltage. It includes a simple passive circuit arrangement of solid-state switches, inductors, and capacitors by which the output voltage of the converter tends to remain constant in spite of changes in load. The switches are sensitive to the current flowing in the circuit and are employed to permit the charging of capacitance devices in accordance with the load requirements. Because solid-state switches (such as SCR's) may be used with relatively high voltage and because of the inherent efficiency of the invention that permits relatively high switching frequencies, power supplies built in accordance with the invention, together with their associated cabling, can be substantially lighter in weight for a given output power level and efficiency of operation than systems of the prior art.

Detector Powering in the 21st Century Why stay stuck with the Good old 20th Century methods?

NASA Astrophysics Data System (ADS)

Dhawan, Satish; Sumner, Richard

Future Collider Physics Detectors are envisioned with large granularity but we have a power delivery problem unless we fill a large fraction of the detector volume with copper conductors. LHC detector electronics is powered by transporting direct current over distances of 30 to 150 meters. This is how Thomas Alva Edison powered his light bulb. For example, CMS ECAL uses 50 kiloamps at 2.5 volts, supplied over a cable set with a transmission efficiency of only 30%. The transmission loss becomes waste heat in the detector that has to be removed. We have been exploring methods to transmit the DC power at higher voltage (low current), reducing to the final low voltage (high current) using DC-DC converters. These converters must operate in high magnetic fields and high radiation levels. This requires rad hard components and non-magnetic (air core) inductors.

Alternating current circuit theory and pulsed NMR (Nuclear Magnetic Resonance)

NASA Astrophysics Data System (ADS)

Gerstein, B. C.

1987-06-01

Pulsed NMR, by definition, deals with time varying excitations. These excitations, supplied by resonant circuits which provide a pulse of radiofrequency (frequencies in the megahertz region) power to a resonant circuit containing, among other things, a coil of wire, or inductor, in which a sample under investigation is placed for purposes of the nuclear magnetic resonance experiment. There are therefore two features of the pulse NMR experiment. First is the fact that we have available a source of continuous wave (CW) alternating current at some angular frequency, omega, measured in radians per second. This source is generally supplied by an ultrastable device called a frequency synthesizer. The second feature of the pulsed NMR experiment is that the sample is not continuously irradiated, but a pulse of radiofrequency oscillation is applied to the sample. This report discusses alternating current theory, resonant circuits and the equipment used in this experiment.

Triple Hybrid Energy Harvesting Interface Electronics

NASA Astrophysics Data System (ADS)

Uluşan, H.; Chamanian, S.; Pathirana, W. M. P. R.; Zorlu, Ö.; Muhtaroğlu, A.; Külah, H.

2016-11-01

This study presents a novel triple hybrid system that combines simultaneously generated power from thermoelectric (TE), vibration-based electromagnetic (EM) and piezoelectric (PZT) harvesters for a relatively high power supply capability. In the proposed solution each harvesting source utilizes a distinct power management circuit that generates a DC voltage suitable for combining the three parallel supplies. The circuits are designed and implemented in 180 nm standard CMOS technology, and are terminated with a schottky diode to avoid reverse current flow. The harvested AC signal from the EM harvester is rectified with a self-powered AC-DC doubler, which utilizes active diode structures to minimize the forward- bias voltage drop. The PZT interface electronics utilizes a negative voltage converter as the first stage, followed by synchronous power extraction and DC-to-DC conversion through internal switches, and an external inductor. The ultra-low voltage DC power harvested by the TE generator is stepped up through a charge-pump driven by an LC oscillator with fully- integrated center-tapped differential inductors. Test results indicate that hybrid energy harvesting circuit provides more than 1 V output for load resistances higher than 100 kΩ (10 μW) where the stand-alone harvesting circuits are not able to reach 1 V output. This is the first hybrid harvester circuit that simultaneously extracts energy from three independent sources, and delivers a single DC output.

Development of a Massive, Highly Multiplexible, Phonon-Mediated Particle Detector Using Kinetic Inductance Detectors

NASA Astrophysics Data System (ADS)

Chang, Y.-Y.; Cornell, B.; Aralis, T.; Bumble, B.; Golwala, S. R.

2018-04-01

We present a status update on the development of a phonon-mediated particle detector using kinetic inductance detector (KID). The design is intended for O(1) kg substrate, using O(102) KIDs on a single readout line, to image the athermal phonon distribution at < 1 mm position resolution and O(10) eV energy resolution. The design specification is set by the need to improve position reconstruction fidelity while maintaining low energy threshold for future rare-event searches such as for low-mass dark matter. We report on the design, which shows negligible crosstalk and > 95% inductor current uniformity, using the coplanar waveguide feedline, ground shield, and a new class of KIDs with symmetric coplanar stripline (sCPS) inductor. The multiplexing is designed upon the frequency-geometry relation we develop for the sCPS KIDs. We introduce the fabrications of the Nb RF assessment prototypes and the high phonon collection efficiency Al-Nb devices. We achieve ≲ 0.07% frequency displacement on a 80-KID RF assessment prototype, and the result indicates that we may place more than 180 resonances in our 0.4 GHz readout band with minimal frequency misordering. The coupling quality factors are ˜ 105 as designed. Finally, we update our work in progress in fabricating the O(102) KID, bi-material, O(1) kg detectors, and the expected position and energy resolutions.

Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems

NASA Astrophysics Data System (ADS)

Béthoux, O.; Cathelin, J.

2010-12-01

Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the rated power whereas conventional boost efficiency barely achieves 91.5% in the same operating conditions.

Soft-matter capacitors and inductors for hyperelastic strain sensing and stretchable electronics

NASA Astrophysics Data System (ADS)

Fassler, A.; Majidi, C.

2013-05-01

We introduce a family of soft-matter capacitors and inductors composed of microchannels of liquid-phase gallium-indium-tin alloy (galinstan) embedded in a soft silicone elastomer (Ecoflex® 00-30). In contrast to conventional (rigid) electronics, these circuit elements remain electronically functional even when stretched to several times their natural length. As the surrounding elastomer stretches, the capacitance and inductance of the embedded liquid channels change monotonically. Using a custom-built loading apparatus, we experimentally measure relative changes in capacitance and inductance as a function of stretch in three directions. These experimental relationships are consistent with theoretical predictions that we derive with finite elasticity kinematics.

Stress insensitive multilayer chip inductor with ferrite core

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vishwas, B.; Madhuri, W., E-mail: madhuriw12@gmail.com; Rao, N. Madhusudan

2015-06-24

Mg{sub 0.25}Cu{sub 0.25}Zn{sub 0.5}Fe{sub 2}O{sub 4} is synthesized by sol gel auto combustion technique. The obtained ferrite powder is finally sintered in a microwave furnace at 850°C. Multilayer chip inductor (MLCI) of two layers is prepared by screen printing technique. The sintered ferrite is characterized by X-ray diffraction. The frequency response of dielectric constant is studied in the frequency range of 100Hz to 5MHz. Dielectric polarization is discussed in the light of Maxwell-Wagner interfacial polarization. The prepared MLCI is studied for stress sensitivity in the range of 0 to 8 MPa.

Nanoscale displacement sensing using microfabricated variable-inductance planar coils

NASA Astrophysics Data System (ADS)

Coskun, M. Bulut; Thotahewa, Kasun; Ying, York-Sing; Yuce, Mehmet; Neild, Adrian; Alan, Tuncay

2013-09-01

Microfabricated spiral inductors were employed for nanoscale displacement detection, suitable for use in implantable pressure sensor applications. We developed a variable inductor sensor consisting of two coaxially positioned planar coils connected in series to a measurement circuit. The devices were characterized by varying the air gap between the coils hence changing the inductance, while a Colpitts oscillator readout was used to obtain corresponding frequencies. Our approach shows significant advantages over existing methodologies combining a displacement resolution of 17 nm and low hysteresis (0.15%) in a 1 × 1 mm2 device. We show that resolution could be further improved by shrinking the device's lateral dimensions.

Method of controlling switching of a multiphase inductor-converter bridge

DOEpatents

Kustom, Robert L.; Fuja, Raymond E.

1981-01-01

In an inductor-convertor circuit for transferring electrical energy between a storage coil and a load coil using a storage thyristor bridge, a load thyristor bridge, and a set of commutating capacitors, operation is improved by a method of changing the rate of delivery of energy in a given direction. The change in rate corresponds to a predetermined change in phase angle between the load bridge and the storage bridge and comprises changing the phase of the bridge by two steps, each equal to half the predetermined change and occurring 180.degree. apart. The method assures commutation and minimizes imbalances that lead otherwise to overvoltages.

Number Codes Readable by Magnetic-Field-Response Recorders

NASA Technical Reports Server (NTRS)

Woodard, Stanley E.; Taylor,Bryant D.

2009-01-01

A method of encoding and reading numbers incorporates some of the features of conventional optical bar coding and radio-frequency identification (RFID) tagging, but overcomes some of the disadvantages of both: (1) Unlike in conventional optical bar coding, numbers can be read without having a line of sight to a tag; and (2) the tag circuitry is simpler than the circuitry used in conventional RFID. The method is based largely on the principles described in Magnetic-Field-Response Measurement-Acquisition System (LAR-16908), NASA Tech Briefs, Vol. 30, No. 6 (June 2006) page 28. To recapitulate: A noncontact system includes a monitoring unit that acquires measurements from sensors at distances of the order of several meters. Each sensor is a passive radio-frequency (RF) resonant circuit in the form of one or more inductor(s) and capacitor(s). The monitoring unit a handheld unit denoted a magnetic field response recorder (MFRR) generates an RF magnetic field that excites oscillations in the resonant circuits resulting in the sensors responding with their own radiated magnetic field. The resonance frequency of each sensor is made to differ significantly from that of the other sensors to facilitate distinction among the responses of different sensors. The MFRR measures selected aspects of the sensor responses: in a typical application, the sensors are designed so that their resonance frequencies vary somewhat with the sensed physical quantities and, accordingly, the MFRR measures the resonance frequencies and variations thereof as indications of those quantities. In the present method, the resonance circuits are not used as sensors. Instead, the circuits are made to resonate at fixed frequencies that correspond to digits to be encoded. The number-encoding scheme is best explained by means of examples in which each resonant circuit consists of a spiral trace inductor electrically connected to a set of parallel-connected capacitors in the form of interdigitated electrode pairs (see figure). The inductor and capacitor(s) in each resonant circuit can be fabricated as a patterned thin metal film by means of established metal-deposition and -patterning techniques. The capacitance and, hence, the resonance frequency, depends on the number of interdigitated electrodes connected to the inductor. In a similar manner, sets of electrodes could be used.

Electronics Demonstrated for Low- Temperature Operation

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Hammond, Ahmad; Gerber, Scott S.

2000-01-01

The operation of electronic systems at cryogenic temperatures is anticipated for many NASA spacecraft, such as planetary explorers and deep space probes. For example, an unheated interplanetary probe launched to explore the rings of Saturn would experience an average temperature near Saturn of about 183 C. Electronics capable of low-temperature operation in the harsh deep space environment also would help improve circuit performance, increase system efficiency, and reduce payload development and launch costs. An ongoing research and development program on low-temperature electronics at the NASA Glenn Research Center at Lewis Field is focusing on the design of efficient power systems that can survive and exploit the advantages of low-temperature environments. The targeted systems, which are mission driven, include converters, inverters, controls, digital circuits, and special-purpose circuits. Initial development efforts successfully demonstrated the low-temperature operation and cold-restart of several direct-current/direct-current (dc/dc) converters based on different types of circuit design, some with superconducting inductors. The table lists some of these dc/dc converters with their properties, and the photograph shows a high-voltage, high-power dc/dc converter designed for an ion propulsion system for low-temperature operation. The development efforts of advanced electronic systems and the supporting technologies for low-temperature operation are being carried out in-house and through collaboration with other Government agencies, industry, and academia. The Low Temperature Electronics Program supports missions and development programs at NASA s Jet Propulsion Laboratory and Goddard Space Flight Center. The developed technologies will be transferred to commercial end users for applications such as satellite infrared sensors and medical diagnostic equipment.

Nonlinear analysis of a family of LC tuned inverters. [dc to square wave circuits for power conditioning

NASA Technical Reports Server (NTRS)

Lee, F. C. Y.; Wilson, T. G.

1974-01-01

A family of four dc-to-square-wave LC tuned inverters are analyzed using singular point. Limit cycles and waveshape characteristics are given for three modes of oscillation: quasi-harmonic, relaxation, and discontinuous. An inverter in which the avalanche breakdown of the transistor emitter-to-base junction occurs is discussed and the starting characteristics of this family of inverters are presented. The LC tuned inverters are shown to belong to a family of inverters with a common equivalent circuit consisting of only three 'series' elements: a five-segment piecewise-linear current-controlled resistor, linear inductor, and linear capacitor.

Repetitive switching for an electromagnetic rail gun

NASA Astrophysics Data System (ADS)

Gruden, J. M.

1983-12-01

Previous testing on a repetitive opening switch for inductive energy storage has proved the feasibility of the rotary switch concept. The concept consists of a rotating copper disk (rotor) with a pie-shaped insulator section and brushes which slide along each of the rotor surfaces. While on top of the copper surface, the brushes and rotor conduct current allowing the energy storage inductor to charge. When the brushes slide onto the insulator section, the current cannot pass through the rotor and is diverted into the load. This study investigates two new brush designs and a rotor modification designed to improve the current commutating capabilities of the switch. One brush design (fringe fiber) employs carbon fibers on the leading and trailing edge of the brush to increase the resistive commutating action as the switch opens and closes. The other brush design uses fingers to conduct current to the rotor surface, effectively increasing the number of brush contact points. The rotor modification was the placement of tungsten inserts at the copper-insulator interfaces.

Highly Deformable Liquid Embedded Soft-Matter Capacitors and Inductors for Stretchable Electronics

NASA Astrophysics Data System (ADS)

Fassler, Andrew; Majidi, Carmel

2013-03-01

We have developed a family of soft-matter capacitors and inductors that can be stretched to several times their natural length. These circuit elements are composed of microchannels of a liquid-phase Gallium-Indium-Tin alloy (Galinstan) embedded in a soft silicone elastomer (Ecoflex® 00-30). As the elastomer stretches, the embedded liquid channels deform, causing the capacitance and inductance to change monotonically. The relative changes in capacitance and inductance are experimentally measured as a function of stretch in three directions. The relationships found show potential for these devices to be used as strain sensors and tunable electronic filters. Additionally, theoretical predictions derived using finite elasticity kinematics are consistent with these experimentally found relationships.

High power solid state laser modulator

DOEpatents

Birx, Daniel L.; Ball, Don G.; Cook, Edward G.

2004-04-27

A multi-stage magnetic modulator provides a pulse train of .+-.40 kV electrical pulses at a 5-7 kHz repetition rate to a metal vapor laser. A fractional turn transformer steps up the voltage by a factor of 80 to 1 and magnetic pulse compression is used to reduce the pulse width of the pulse train. The transformer is fabricated utilizing a rod and plate stack type of construction to achieve a high packing factor. The pulses are controlled by an SCR stack where a plurality of SCRs are electrically connected in parallel, each SCR electrically connected to a saturable inductor, all saturable inductors being wound on the same core of magnetic material for enhanced power handling characteristics.

Effect of preheating on fatigue resistance of gears in spin induction coil hardening process

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Aggarwal, M. L.

2018-02-01

Spin hardening inductors are typically used for fine-sized teeth gear geometry. With the proper selection of several design parameters, only the gear teeth can be case surface hardened without affecting the other surface of gear. Preheating may be done to reach an adapted high austenitizing temperature in the root circle to avoid overheating of the tooth tip during final heating. The effect of preheating of gear on control of compressive residual stresses and case hardening has been experimentally discussed in this paper. Present work is about analysing single frequency mode, preheat hardening treatment and compressive residual stresses field for hardening process of spur gear using spin hardening inductors.

Near Field Radiation Characteristics of Implantable Square Spiral Chip Inductor Antennas for Bio-Sensors

NASA Technical Reports Server (NTRS)

Nessel, James A.; Simons, Rainee N.; Miranda, Felix A.

2007-01-01

The near field radiation characteristics of implantable Square Spiral Chip Inductor Antennas (SSCIA) for Bio-Sensors have been measured. Our results indicate that the measured near field relative signal strength of these antennas agrees with simulated results and confirm that in the near field region the radiation field is fairly uniform in all directions. The effects of parameters such as ground-plane, number of turns and microstrip-gap width on the performance of the SSCIA are presented. Furthermore, the SSCIA antenna with serrated ground plane produce a broad radiation pattern, with a relative signal strength detectable at distances within the range of operation of hand-held devices for self-diagnosis.

Method of controlling switching of a multiphase inductor-converter bridge. [Patent application

DOEpatents

Kustom, R.L.; Fuja, R.E.

In an inductor-convertor circuit for transferring electrical energy between a storage coil and a load coil through a storage thyristor bridge, a load thyristor bridge, and a set of commutating capacitors, operation is improved by a method of changing the rate of delivery of energy in a given direction. The change in rate corresponds to a predetermined change in phase angle between the load bridge and the storage bridge, and comprises changing the phase of the bridge by two steps, each equal to half the predetermined change and occurring 180/sup 0/ apart. The method assures commutation and minimizes imbalances that lead otherwise to overvoltages. 11 figures.

Frequency-tunable superconducting resonators via nonlinear kinetic inductance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vissers, M. R.; Hubmayr, J.; Sandberg, M.

2015-08-10

We have designed, fabricated, and tested a frequency-tunable high-Q superconducting resonator made from a niobium titanium nitride film. The frequency tunability is achieved by injecting a DC through a current-directing circuit into the nonlinear inductor whose kinetic inductance is current-dependent. We have demonstrated continuous tuning of the resonance frequency in a 180 MHz frequency range around 4.5 GHz while maintaining the high internal quality factor Q{sub i} > 180 000. This device may serve as a tunable filter and find applications in superconducting quantum computing and measurement. It also provides a useful tool to study the nonlinear response of a superconductor. In addition,more » it may be developed into techniques for measurement of the complex impedance of a superconductor at its transition temperature and for readout of transition-edge sensors.« less

Performance of High-frequency High-flux Magnetic Cores at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Gerber, Scott S.; Hammoud, Ahmad; Elbuluk, Malik E.; Patterson, Richard L.

2002-01-01

Three magnetic powder cores and one ferrite core, which are commonly used in inductor and transformer design for switch mode power supplies, were selected for investigation at cryogenic temperatures. The powder cores are Molypermalloy Core (MPC), High Flux Core (HFC), and Kool Mu Core (KMC). The performance of four inductors utilizing these cores has been evaluated as a function of temperature from 20 C to -180 C. All cores were wound with the same wire type and gauge to obtain equal values of inductance at room temperature. Each inductor was evaluated in terms of its inductance, quality (Q) factor, resistance, and dynamic hysteresis characteristics (B-H loop) as a function of temperature and frequency. Both sinusoidal and square wave excitations were used in these investigations. Measured data obtained on the inductance showed that both the MPC and the HFC cores maintain a constant inductance value, whereas with the KMC and ferrite core hold a steady value in inductance with frequency but decrease as temperature is decreased. All cores exhibited dependency, with varying degrees, in their quality factor and resistance on test frequency and temperature. Except for the ferrite, all cores exhibited good stability in the investigated properties with temperature as well as frequency. Details of the experimental procedures and test results are presented and discussed in the paper.

Antigen induced inhibition of autoimmune response to rat male accessory glands: role of thymocytes on the efferent phase of the suppression.

PubMed

Ferro, M E; Romero-Piffiguer, M; Rivero, V; Yranzo-Volonte, N; Correa, S; Riera, C M

1991-01-01

In the present study, we report that Cy-sensitive, MRAG-adherent spleen mononuclear (SpM) inductor-phase T suppressor (Ts) cells obtained from rats pretreated with low doses of a purified fraction (FI) of rat male accessory gland antigens (RAG) are mainly OX19+ and W3/25+. Furthermore, thymocytes from rats pretreated with FI of RAG restore the suppression of the autoimmune response to RAG autoantigens in irradiated recipients of SpM inductor-phase Ts cells. In contrast, thymocytes from rats pretreated with rat heart saline extract (unrelated antigen) did not recuperate the suppression of the autoimmune response detected by macrophage migration inhibitory factor (MIF) and delayed-type hypersensitivity. The suppressor thymocytes did not directly exert their inhibitory effect because they were not effective to suppress the autoimmune response to RAG autoantigens when irradiated recipients did not receive SpM inductor-phase Ts cells. The effect of these thymocytes was found in PNA--but not in PNA+ thymic cell population. The perithymic injection of Toxoplasma gondii did block their suppressor activity. The present report clearly shows an active participation of thymus in the efferent phase of the suppressor circuit that controls the autoimmune response to MRAG. The implications of these findings are discussed.

5 CFR 532.313 - Private sector industries.

Code of Federal Regulations, 2010 CFR

2010-01-01

... electrical signals. 335311 Power, distribution, and specialty transformer manufacturing. 48531 Taxi service... Electronic coil, transformer, and other inductor manufacturing. 334417 Electronic connector manufacturing...

Multiple frequency bioelectrical impedance analysis: a cross-validation study of the inductor circuit and Cole models.

PubMed

Ward, L; Cornish, B H; Paton, N I; Thomas, B J

1999-11-01

It has been proposed that multiple frequency bioelectrical impedance models of the human body should include an inductive property for the circulatory system, the inductor circuit model (ICM), and that such a model, when coupled with a new method of data analysis, can improve the predictive power of multiple frequency bioelectrical impedance analysis (MFBIA). This hypothesis was tested using MFBIA measurements and gold standard measures of total body and extracellular water volumes in a cross-validation study in two subject groups (viz. controls and HIV). The MFBIA measurements were analysed using the current, widely accepted Cole model and the alternative ICM model which includes an inductive component. Correlations in the range 0.75 to 0.92 (for TBW) and 0.46 to 0.79 (for ECW) for impedance quotients versus gold standard measures within the subject groups were observed. These decreased, to as low as r = 0.50 for TBW and r = 0.29 for ECW, when the derived algorithms were applied to the alternative subject group. These results suggest that lack of portability of MFBIA algorithms between subject groups is not due to an inadequacy of the analogue circuit model per se but is possibly due more to fundamental flaws in the principles associated with its application. These include assuming a constant proportionality of body segment geometries and tissue fluid resistivities. This study has also demonstrated that this inadequacy cannot be overcome by simply introducing an inductive component into the analogue electrical circuit.

CRYOGENIC MAGNETS

DOEpatents

Post, R.F.; Taylor, C.E.

1963-05-21

A cryogenic magnet coil is described for generating magnetic fields of the order of 100,000 gauss with a minimum expenditure of energy lost in resistive heating of the coil inductors and energy lost irreversibly in running the coil refrigeration plant. The cryogenic coil comprises a coil conductor for generating a magnetic field upon energization with electrical current, and refrigeration means disposed in heat conductive relation to the coil conductor for cooling to a low temperature. A substantial reduction in the power requirements for generating these magnetic fields is attained by scaling the field generating coil to large size and particular dimensions for a particular conductor, and operating the coil at a particular optimum temperature commensurate with minimum overall power requirements. (AEC)

String resistance detector

NASA Technical Reports Server (NTRS)

Hall, A. Daniel (Inventor); Davies, Francis J. (Inventor)

2007-01-01

Method and system are disclosed for determining individual string resistance in a network of strings when the current through a parallel connected string is unknown and when the voltage across a series connected string is unknown. The method/system of the invention involves connecting one or more frequency-varying impedance components with known electrical characteristics to each string and applying a frequency-varying input signal to the network of strings. The frequency-varying impedance components may be one or more capacitors, inductors, or both, and are selected so that each string is uniquely identifiable in the output signal resulting from the frequency-varying input signal. Numerical methods, such as non-linear regression, may then be used to resolve the resistance associated with each string.

Quality engineering tools focused on high power LED driver design using boost power stages in switch mode

NASA Astrophysics Data System (ADS)

Ileana, Ioan; Risteiu, Mircea; Marc, Gheorghe

2016-12-01

This paper is a part of our research dedicated to high power LED lamps designing. The boost-up selected technology wants to meet driver producers' tendency in the frame of efficiency and disturbances constrains. In our work we used modeling and simulation tools for implementing scenarios of the driver work when some controlling functions are executed (output voltage/ current versus input voltage and fixed switching frequency, input and output electric power transfer versus switching frequency, transient inductor voltage analysis, and transient out capacitor analysis). Some electrical and thermal stress conditions are also analyzed. Based on these aspects, a high reliable power LED driver has been designed.

AC application of second generation HTS wire

NASA Astrophysics Data System (ADS)

Thieme, C. L. H.; Gagnon, K.; Voccio, J.; Aized, D.; Claassen, J.

2008-02-01

For the production of Second Generation (2G) YBCO High Temperature Superconductor wire American Superconductor uses a wide-strip MOD-YBCO/RABiTSTM process, a low-cost approach for commercial manufacturing. It can be engineered with a high degree of flexibility to manufacture practical 2G conductors with architectures and properties tailored for specific applications and operating conditions. For ac applications conductor and coil design can be geared towards low hysteretic losses. For applications which experience high frequency ac fields, the stabilizer needs to be adjusted for low eddy current losses. For these applications a stainless-steel laminate is used. An example is a Low Pass Filter Inductor which was developed and built in this work.

Vacuum arc plasma thrusters with inductive energy storage driver

NASA Technical Reports Server (NTRS)

Schein, Jochen (Inventor); Gerhan, Andrew N. (Inventor); Woo, Robyn L. (Inventor); Au, Michael Y. (Inventor); Krishnan, Mahadevan (Inventor)

2004-01-01

An apparatus for producing a vacuum arc plasma source device using a low mass, compact inductive energy storage circuit powered by a low voltage DC supply acts as a vacuum arc plasma thruster. An inductor is charged through a switch, subsequently the switch is opened and a voltage spike of Ldi/dt is produced initiating plasma across a resistive path separating anode and cathode. The plasma is subsequently maintained by energy stored in the inductor. Plasma is produced from cathode material, which allows for any electrically conductive material to be used. A planar structure, a tubular structure, and a coaxial structure allow for consumption of cathode material feed and thereby long lifetime of the thruster for long durations of time.

Toroid cavity/coil NMR multi-detector

DOEpatents

Gerald, II, Rex E.; Meadows, Alexander D.; Gregar, Joseph S.; Rathke, Jerome W.

2007-09-18

An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

Resonance-induced sensitivity enhancement method for conductivity sensors

NASA Technical Reports Server (NTRS)

Tai, Yu-Chong (Inventor); Shih, Chi-yuan (Inventor); Li, Wei (Inventor); Zheng, Siyang (Inventor)

2009-01-01

Methods and systems for improving the sensitivity of a variety of conductivity sensing devices, in particular capacitively-coupled contactless conductivity detectors. A parallel inductor is added to the conductivity sensor. The sensor with the parallel inductor is operated at a resonant frequency of the equivalent circuit model. At the resonant frequency, parasitic capacitances that are either in series or in parallel with the conductance (and possibly a series resistance) is substantially removed from the equivalent circuit, leaving a purely resistive impedance. An appreciably higher sensor sensitivity results. Experimental verification shows that sensitivity improvements of the order of 10,000-fold are possible. Examples of detecting particulates with high precision by application of the apparatus and methods of operation are described.

Scheme for rapid adjustment of network impedance

DOEpatents

Vithayathil, John J.

1991-01-01

A static controlled reactance device is inserted in series with an AC electric power transmission line to adjust its transfer impedance. An inductor (reactor) is serially connected with two back-to-back connected thyristors which control the conduction period and hence the effective reactance of the inductor. Additional reactive elements are provided in parallel with the thyristor controlled reactor to filter harmonics and to obtain required range of variable reactance. Alternatively, the static controlled reactance device discussed above may be connected to the secondary winding of a series transformer having its primary winding connected in series to the transmission line. In a three phase transmission system, the controlled reactance device may be connected in delta configuration on the secondary side of the series transformer to eliminate triplen harmonics.

Spiral Chip Implantable Radiator and Printed Loop External Receptor for RF Telemetry in Bio-Sensor Systems

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Hall, David G.; Miranda, Felix A.

2004-01-01

The paper describes the operation of a patented wireless RF telemetry system, consisting of a bio-MEMS implantable sensor and an external hand held unit, operating over the frequency range of few hundreds of MHz. A MEMS capacitive pressure sensor integrated with a miniature inductor/antenna together constitute the implantable sensor. Signal processing circuits collocated with a printed loop antenna together form the hand held unit, capable of inductively powering and also receiving the telemetry signals from the sensor. The paper in addition, demonstrates a technique to enhance the quality factor and inductance of the inductor in the presence of a lower ground plane and also presents the radiation characteristics of the loop antenna.

Bidirectional converter for high-efficiency fuel cell powertrain

NASA Astrophysics Data System (ADS)

Fardoun, Abbas A.; Ismail, Esam H.; Sabzali, Ahmad J.; Al-Saffar, Mustafa A.

2014-03-01

In this paper, a new wide conversion ratio step-up and step-down converter is presented. The proposed converter is derived from the conventional Single Ended Primary Inductor Converter (SEPIC) topology and it is integrated with a capacitor-diode voltage multiplier, which offers a simple structure, reduced electromagnetic interference (EMI), and reduced semiconductors' voltage stresses. Other advantages include: continuous input and output current, extended step-up and step-down voltage conversion ratio without extreme low or high duty-cycle, simple control circuitry, and near-zero input and output ripple currents compared to other converter topologies. The low charging/discharging current ripple and wide gain features result in a longer life-span and lower cost of the energy storage battery system. In addition, the "near-zero" ripple capability improves the fuel cell durability. Theoretical analysis results obtained with the proposed structure are compared with other bi-direction converter topologies. Simulation and experimental results are presented to verify the performance of the proposed bi-directional converter.

Lithographed Superconducting Resonator Development for Next-Generation Frequency Multiplexing Readout of Transition-Edge Sensors

NASA Astrophysics Data System (ADS)

Faramarzi, F.; De Haan, T.; Kusaka, A.; Lee, A.; Neuhauser, B.; Plambeck, R.; Raum, C.; Suzuki, A.; Westbrook, B.

2018-03-01

Ground-based cosmic microwave background (CMB) experiments are undergoing a period of exponential growth. Current experiments are observing with 1000-10,000 detectors, and the next-generation experiment (CMB stage 4) is proposing to deploy approximately 500,000 detectors. This order of magnitude increase in detector count will require a new approach for readout electronics. We have developed superconducting resonators for next-generation frequency-domain multiplexing (fMUX) readout architecture. Our goal is to reduce the physical size of resonators, such that resonators and detectors can eventually be integrated on a single wafer. To reduce the size of these resonators, we have designed spiral inductors and interdigitated capacitors that resonate around 10-100 MHz, an order of magnitude higher frequency compared to current fMUX readout systems. The higher frequency leads to a wider bandwidth and would enable higher multiplexing factor than the current ˜ 50 detectors per readout channel. We will report on the simulation, fabrication method, characterization technique, and measurement of quality factor of these resonators.

Push-pull switching power amplifier

NASA Technical Reports Server (NTRS)

Cuk, Slobodan M. (Inventor)

1980-01-01

A true push-pull switching power amplifier is disclosed utilizing two dc-to-dc converters. Each converter is comprised of two inductances, one inductance in series with a DC source and the other inductor in series with the output load, and an electrical energy transferring device with storage capability, namely storage capacitance, with suitable switching means between the inductances to obtain DC level conversion, where the switching means allows bidirectional current (and power) flow, and the switching means of one dc-to-dc converter is driven by the complement of a square-wave switching signal for the other dc-to-dc converter for true push-pull operation. For reduction of current ripple, the inductances in each of the two converters may be coupled, and with proper design of the coupling, the ripple can be reduced to zero at either the input or the output, but preferably the output.

Study of the electromagnetic characteristics of multiple HTSPPT modules based on the configuration of toroidal structure for inductive pulsed power supply

NASA Astrophysics Data System (ADS)

Zhang, Cunshan; Zheng, Xinxin; Li, Haitao; Li, Zhenmei; Zhang, Tao; Jiao, Can

2018-04-01

High temperature superconducting pulsed power transformer (HTSPPT) is an important device for pulsed power supplies. It consists of a superconducting primary and a normal conducting secondary, which is used for energy storage and current amplification. The critical current density, the energy storage, and the coupling coefficient are three main performance indexes. They are affected by the geometry parameters of HTSPPT modules, such as the height and the width of the superconducting coils. In addition, the hoop stress of the HTSPPT coils is limited by the maximum tensile strength of high temperature superconducting (HTS) tapes. In this paper, Bi-2223/Ag HTS tapes are selected as the wire of primary inductor and the toroidal structure model is selected for multiple HTSPPT modules. The relationships between the geometry parameters of HTSPPT modules and the electrical performance are studied.

Power conditioning unit for photovoltaic power systems

NASA Astrophysics Data System (ADS)

Beghin, G.; Nguyen Phuoc, V. T.

Operational features and components of a power conditioning unit for interconnecting solar cell module powers with a utility grid are outlined. The two-stage unit first modifies the voltage to desired levels on an internal dc link, then inverts the current in 2 power transformers connected to a vector summation control to neutralize harmonic distortion up to the 11th harmonic. The system operates in parallel with the grid with extra inductors to absorb line-to-line voltage and phase differences, and permits peak power use from the PV array. Reactive power is gained internally, and a power system controller monitors voltages, frequencies, and currents. A booster preregulator adjusts the input voltage from the array to provide voltage regulation for the inverter, and can commutate 450 amps. A total harmonic distortion of less than 5 percent is claimed, with a rating of 5 kVA, 50/60 Hz, 3-phase, and 4-wire.

Pulsar Magnetohydrodynamic Winds

NASA Astrophysics Data System (ADS)

Okamoto, Isao; Sigalo, Friday B.

2006-12-01

The acceleration and collimation/decollimation of relativistic magnetocentrifugal winds are discussed concerning a cold plasma from a strongly magnetized, rapidly rotating neutron star in a steady axisymmetric state based on ideal magnetohydrodynamics. There exist unipolar inductors associated with the field line angular frequency, α, at the magnetospheric base surface, SB, with a huge potential difference between the poles and the equator, which drive electric current through the pulsar magnetosphere. Any ``current line'' must emanate from one terminal of the unipolar inductor and return to the other, converting the Poynting flux to the kinetic flux of the wind at finite distances. In a plausible field structure satisfying the transfield force-balance equation, the fast surface, SF, must exist somewhere between the subasymptotic and asymptotic domains, i.e., at the innermost point along each field line of the asymptotic domain of \\varpaA2/\\varpi2 ≪ 1, where \\varpiA is the Alfvénic axial distance. The criticality condition at SF yields the Lorentz factor, γF = μ\\varepsilon1/3, and the angular momentum flux, β, as the eigenvalues in terms of the field line angular velocity, α, the mass flux per unit flux tube, η, and one of the Bernoulli integrals, μδ, which are assumed to be specifiable as the boundary conditions at SB. The other Bernoulli integral, μɛ, is related to μδ as μɛ = μδ[1-(α2\\varpiA2/c2)]-1, and both μɛ and \\varpiA2 are eigenvalues to be determined by the criticality condition at SF. Ongoing MHD acceleration is possible in the superfast domain. This fact may be helpful in resolving a discrepancy between the wind theory and the Crab-nebula model. It is argued that the ``anti-collimation theorem'' holds for relativistic winds, based on the curvature of field streamlines determined by the transfield force balance. The ``theorem'' combines with the ``current-closure condition'' as a global condition in the wind zone to produce a two-component ``quasi-conical'' field structure as one of the basic properties of MHD outflows of centrifugal origin in the pulsar magnetosphere.

Direct Current Contamination of Kilohertz Frequency Alternating Current Waveforms

PubMed Central

Franke, Manfred; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

2014-01-01

Kilohertz Frequency Alternating Current (KHFAC) waveforms are being evaluated in a variety of physiological settings because of their potential to modulate neural activity uniquely when compared to frequencies in the sub-kilohertz range. However, the use of waveforms in this frequency range presents some unique challenges regarding the generator output. In this study we explored the possibility of undesirable contamination of the KHFAC waveforms by direct current (DC). We evaluated current- and voltage-controlled KHFAC waveform generators in configurations that included a capacitive coupling between generator and electrode, a resistive coupling and combinations of capacitive with inductive coupling. Our results demonstrate that both voltage- and current-controlled signal generators can unintentionally add DC-contamination to a KHFAC signal, and that capacitive coupling is not always sufficient to eliminate this contamination. We furthermore demonstrated that high value inductors, placed in parallel with the electrode, can be effective in eliminating DC-contamination irrespective of the type of stimulator, reducing the DC contamination to less than 1 μA. This study highlights the importance of carefully designing the electronic setup used in KHFAC studies and suggests specific testing that should be performed and reported in all studies that assess the neural response to KHFAC waveforms. PMID:24820914

A Passive EMI Filter with Access to the Ungrounded Motor Neutral Line-Its Effect on Eliminating Leakage Current from the Inverter Heat Sink-

NASA Astrophysics Data System (ADS)

Doumoto, Takafumi; Akagi, Hirofumi

This paper deals with a leakage current flowing out of the heat sink of a voltage-source PWM inverter. The heat-sink leakage current is caused by a steep change in the common-mode voltage produced by the inverter. It flows through parasitic capacitors between the heat sink and power semiconductor devices when no EMI filter is connected. Experimental results reveal that the heat-sink leakage current flows not into the supply side, but into the motor side. These understandings succeed in describing an equivalent common-mode circuit taking the parasitic capacitors into account. The authors have proposed a passive EMI filter that is unique in access to the ungrounded motor neutral line. It is discussed from this equivalent circuit that the passive EMI filter is effective in preventing the leakage current from flowing. Moreover, installation of another small-sized common-mode inductor at the ac side of the diode rectifier prevents the leakage current from flowing into the supply side. Experimental results obtained from a 200-V, 3.7-kW laboratory system confirm the effectiveness and viability of the EMI filter.

Inductor-Free Wireless Energy Delivery via Maxwell's Displacement Current from an Electrodeless Triboelectric Nanogenerator.

PubMed

Cao, Xia; Zhang, Meng; Huang, Jinrong; Jiang, Tao; Zou, Jingdian; Wang, Ning; Wang, Zhong Lin

2018-02-01

Wireless power delivery has been a dream technology for applications in medical science, security, radio frequency identification (RFID), and the internet of things, and is usually based on induction coils and/or antenna. Here, a new approach is demonstrated for wireless power delivery by using the Maxwell's displacement current generated by an electrodeless triboelectric nanogenerator (TENG) that directly harvests ambient mechanical energy. A rotary electrodeless TENG is fabricated using the contact and sliding mode with a segmented structure. Due to the leakage of electric field between the segments during relative rotation, the generated Maxwell's displacement current in free space is collected by metal collectors. At a gap distance of 3 cm, the output wireless current density and voltage can reach 7 µA cm -2 and 65 V, respectively. A larger rotary electrodeless TENG and flexible wearable electrodeless TENG are demonstrated to power light-emitting diodes (LEDs) through wireless energy delivery. This innovative discovery opens a new avenue for noncontact, wireless energy transmission for applications in portable and wearable electronics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A digital prediction algorithm for a single-phase boost PFC

NASA Astrophysics Data System (ADS)

Qing, Wang; Ning, Chen; Weifeng, Sun; Shengli, Lu; Longxing, Shi

2012-12-01

A novel digital control algorithm for digital control power factor correction is presented, which is called the prediction algorithm and has a feature of a higher PF (power factor) with lower total harmonic distortion, and a faster dynamic response with the change of the input voltage or load current. For a certain system, based on the current system state parameters, the prediction algorithm can estimate the track of the output voltage and the inductor current at the next switching cycle and get a set of optimized control sequences to perfectly track the trajectory of input voltage. The proposed prediction algorithm is verified at different conditions, and computer simulation and experimental results under multi-situations confirm the effectiveness of the prediction algorithm. Under the circumstances that the input voltage is in the range of 90-265 V and the load current in the range of 20%-100%, the PF value is larger than 0.998. The startup and the recovery times respectively are about 0.1 s and 0.02 s without overshoot. The experimental results also verify the validity of the proposed method.

The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission.

PubMed

Kiani, Mehdi; Ghovanloo, Maysam

2012-09-01

Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor ( Q ) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory.

Ferroresonant flux coupled battery charger

NASA Technical Reports Server (NTRS)

McLyman, Colonel W. T. (Inventor)

1987-01-01

A battery charger for incorporation into an electric-powered vehicle is disclosed. The charger includes a ferroresonant voltage-regulating circuit for providing an output voltage proportional to the frequency of an input AC voltage. A high frequency converter converts a DC voltage supplied, for example, from a rectifier connected to a standard AC outlet, to a controlled frequency AC voltage which is supplied to the input of the ferroresonant circuit. The ferroresonant circuit includes an output, a saturable core transformer connected across the output, and a first linear inductor and a capacitor connected in series across the saturable core transformer and tuned to resonate at the third harmonic of the AC voltage from the high frequency converter. The ferroresonant circuit further includes a second linear inductor connected between the input of the ferroresonant circuit and the saturable core transformer. The output voltage from the ferroresonant circuit is rectified and applied across a pair of output terminals adapted to be connected to the battery to be charged. A feedback circuit compares the voltage across the output terminals with a reference voltage and controls the frequency of the AC voltage produced by the high frequency converter to maintain the voltage across the output terminals at a predetermined value. The second linear inductor provides a highly reactive load in the event of a fault across the output terminals to render the charger short-circuit proof.

The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission

PubMed Central

Kiani, Mehdi; Ghovanloo, Maysam

2014-01-01

Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor (Q) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory. PMID:24683368

Magnetic-Field-Response Measurement-Acquisition System

NASA Technical Reports Server (NTRS)

Woodward, Stanley E.; Shams, Qamar A.; Fox, Robert L.; Taylor, Bryant D.

2006-01-01

A measurement-acquisition system uses magnetic fields to power sensors and to acquire measurements from sensors. The system alleviates many shortcomings of traditional measurement-acquisition systems, which include a finite number of measurement channels, weight penalty associated with wires, use limited to a single type of measurement, wire degradation due to wear or chemical decay, and the logistics needed to add new sensors. Eliminating wiring for acquiring measurements can alleviate potential hazards associated with wires, such as damaged wires becoming ignition sources due to arcing. The sensors are designed as electrically passive inductive-capacitive or passive inductive-capacitive-resistive circuits that produce magnetic-field-responses. One or more electrical parameters (inductance, capacitance, and resistance) of each sensor can be variable and corresponds to a measured physical state of interest. The magnetic-field- response attributes (frequency, amplitude, and bandwidth) of the inductor correspond to the states of physical properties for which each sensor measures. For each sensor, the measurement-acquisition system produces a series of increasing magnetic-field harmonics within a frequency range dedicated to that sensor. For each harmonic, an antenna electrically coupled to an oscillating current (the frequency of which is that of the harmonic) produces an oscillating magnetic field. Faraday induction via the harmonic magnetic fields produces an electromotive force and therefore a current in the sensor. Once electrically active, the sensor produces its own harmonic magnetic field as the inductor stores and releases magnetic energy. The antenna of the measurement- acquisition system is switched from a transmitting to a receiving mode to acquire the magnetic-field response of the sensor. The rectified amplitude of the received response is compared to previous responses to prior transmitted harmonics, to ascertain if the measurement system has detected a response inflection. The "transmit-receive-compare" of sequential harmonics is repeated until the inflection is identified. The harmonic producing the amplitude inflection is the sensor resonant frequency. Resonant frequency and response amplitude are stored and then correlated to calibration data.

Silicon MOS inductor

DOEpatents

Balberg, Isaac

1981-01-01

A device made of amorphous silicon which exhibits inductive properties at certain voltage biases and in certain frequency ranges in described. Devices of the type described can be made in integrated circuit form.

Regenerative flywheel storage system, volume 2

NASA Astrophysics Data System (ADS)

1980-06-01

A vehicle propulsion system was simulated on a digital computer in order to determine the optimum system operating strategies and to establish a calculated range improvement over a nonregenerative, all electric vehicle. Fabrication of the inductor motor, the flywheel, the power conditioner, and the system control are described. Test results of the system operating over the SAE J227a Schedule D driving cycle are given and are compared to the calculated value. The flywheel energy storage system consists of a solid rotor, synchronous, inductor type, flywheel drive machine electrically coupled to a dc battery electric propulsion system through a load commutated inverter. The motor/alternator unit is coupled mechanically to a small steel flywheel which provides a portion of the vehicle's accelerating energy and regenerates the vehicle's braking energy.

Spurious-Mode Control of Same-Phase Drive-Type Ultrasonic Motor

NASA Astrophysics Data System (ADS)

Aoyagi, Manabu; Watanabe, Hiroyuki; Tomikawa, Yoshiro; Takano, Takehiro

2002-05-01

A same-phase drive-type ultrasonic motor requires a single power source for its operation. In particular, self-oscillation driving is useful for driving a small ultrasonic motor. This type of ultrasonic motor has a spurious mode close to the operation frequency on its stator vibrator. The spurious vibration mode affects the oscillation frequency of a self-oscillation drive circuit. Hence the spurious vibration mode should be restrained or moved away from the neighborhood of the operation frequency. In this paper, we report that an inductor connected at an electrical control terminal provided on standby electrodes for the reverse rotation operation controls only the spurious vibration mode. The effect of an inductor connected at the control terminal was clarified by the simulation of an equivalent circuit and some experiments.

Correlation between tunability and anisotropy in magnetoelectric voltage tunable inductor (VTI).

PubMed

Yan, Yongke; Geng, Liwei D; Zhang, Lujie; Gao, Xiangyu; Gollapudi, Sreenivasulu; Song, Hyun-Cheol; Dong, Shuxiang; Sanghadasa, Mohan; Ngo, Khai; Wang, Yu U; Priya, Shashank

2017-11-22

Electric field modulation of magnetic properties via magnetoelectric coupling in composite materials is of fundamental and technological importance for realizing tunable energy efficient electronics. Here we provide foundational analysis on magnetoelectric voltage tunable inductor (VTI) that exhibits extremely large inductance tunability of up to 1150% under moderate electric fields. This field dependence of inductance arises from the change of permeability, which correlates with the stress dependence of magnetic anisotropy. Through combination of analytical models that were validated by experimental results, comprehensive understanding of various anisotropies on the tunability of VTI is provided. Results indicate that inclusion of magnetic materials with low magnetocrystalline anisotropy is one of the most effective ways to achieve high VTI tunability. This study opens pathway towards design of tunable circuit components that exhibit field-dependent electronic behavior.

System and Method for Detecting Cracks and their Location

NASA Technical Reports Server (NTRS)

Woodward, Stanley E. (Inventor); Shams, Qamar A. (Inventor)

2007-01-01

A system and method are provided for detecting cracks and their location in a structure. A circuit coupled to a structure has capacitive strain sensors coupled sequentially and in parallel to one another. When excited by a variable magnetic field, the circuit has a resonant frequency that is different for unstrained and strained states. In terms of strained states, the resonant frequency is indicative of a region of the circuit that is experiencing strain induced by strain in a region of the structure in proximity to the region of the circuit. An inductor is electrically coupled to one end of each circuit. A magnetic field response recorder wirelessly transmits the variable magnetic field to the inductor and senses the resonant frequency of the circuit so-excited by the variable magnetic field.

Mid-infrared plasmonic inductors: Enhancing inductance with meandering lines

PubMed Central

Torres, Víctor; Ortuño, Rubén; Rodríguez-Ulibarri, Pablo; Griol, Amadeu; Martínez, Alejandro; Navarro-Cía, Miguel; Beruete, Miguel; Sorolla, Mario

2014-01-01

We present a mid-infrared inductor that when applied to an extraordinary transmission hole array produces a strong redshift of the resonant peak accompanied by an unprecedented enlargement of the operation bandwidth. The importance of the result is twofold: from a fundamental viewpoint, the direct applicability of equivalent circuit concepts borrowed from microwaves is demonstrated, in frequencies as high as 17 THz upholding unification of plasmonics and microwave concepts and allowing for a simplification of structure design and analysis; in practical terms, a broadband funnelling of infrared radiation with fractional bandwidth and efficiency as high as 97% and 48%, respectively, is achieved through an area less than one hundredth the squared wavelength, which leads to an impressive accessible strong field localization that may be of great interest in sensing applications. PMID:24393839

Modélisation du champ magnétique d'un propulseur M.H.D. annulaire

NASA Astrophysics Data System (ADS)

Kom, C. H.; Brunet, Y.

1995-01-01

Stray fields have to be as small as possible to reduce the magnetic signature of the vessel in M.H.D. propulsion where the magnetic field has to be very high. The calculation of the magnetic field of an angular M.H.D. thruster is presented. The field is produced by a distribution of superconducting magnets in the shape of sectors. An analytical formulation of the field can be used in the active zone, outside the coil ends. An analytical method using a Fourier development of the current sheets is employed for an inductor in cylindrical sectors, and a direct method is used for a massive inductor. Numerical and analytical results are compared. Pour des raisons de discrétion, les champs de fuite doivent être minimisés en propulsion M.H.D. où les champs magnétiques doivent être intenses. Le calcul du champ magnétique d'un propulseur M.H.D. naval annulaire, constitué de secteurs inducteurs supraconducteurs est représenté. Dans la zone active, hors des têtes de bobines, une formulation analytique peut être utilisée. Une méthode analytique utilisant le développemment en série de Fourier du courant est adoptée pour les industeurs cylindriques, et une méthode directe pour les inducteurs massifs. Les résultats numériques sont comparés à ceux obtenus avec un logiciel d'éléments finis 2D.

New highly linear tunable transconductor circuits with low number of MOS transistors

NASA Astrophysics Data System (ADS)

Yucel, Firat; Yuce, Erkan

2016-08-01

In this article, two new highly linear tunable transconductor circuits are proposed. The transconductors employ only six MOS transistors operated in saturation region. The second transconductor is derived from the first one with a slight modification. Transconductance of both transconductors can be tuned by a control voltage. Both of the transconductors do not need any additional bias voltages and currents. Another important feature of the transconductors is their high input and output impedances for cascadability with other circuits. Besides, total harmonic distortions are less than 1.5% for both transconductors. A positive lossless grounded inductor simulator with a grounded capacitor is given as an application example of the transconductors. Simulation and experimental test results are included to show effectiveness of the proposed circuits.

Testing military grade magnetics (transformers, inductors and coils).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Engineers and designers are constantly searching for test methods to qualify or 'prove-in' new designs. In the High Reliability world of military parts, design test, qualification tests, in process tests and product characteristic tests, become even more important. The use of in process and function tests has been adopted as a way of demonstrating that parts will operate correctly and survive its 'use' environments. This paper discusses various types of tests to qualify the magnetic components - the current carrying capability of coils, a next assembly 'as used' test, a corona test and inductance at temperature test. Each of thesemore » tests addresses a different potential failure on a component. The entire process from design to implementation is described.« less

Compact orthogonal NMR field sensor

DOEpatents

Gerald, II, Rex E.; Rathke, Jerome W [Homer Glen, IL

2009-02-03

A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

Enhancing Induction Coil Reliability

NASA Astrophysics Data System (ADS)

Kreter, K.; Goldstein, R.; Yakey, C.; Nemkov, V.

2014-12-01

In induction hardening, thermal fatigue is one of the main copper failure modes of induction heat treating coils. There have been papers published that describe this failure mode and others that describe some good design practices. The variables previously identified as the sources of thermal fatigue include radiation from the part surface, frequency, current, concentrator losses, water pressure and coil wall thickness. However, there is very little quantitative data on the factors that influence thermal fatigue in induction coils is available in the public domain. By using finite element analysis software this study analyzes the effect of common design variables of inductor cooling, and quantifies the relative importance of these variables. A comprehensive case study for a single shot induction coil with Fluxtrol A concentrator applied is used for the analysis.

A Comparison of Various magnetic thin films for the application of microscale magnetic components

NASA Astrophysics Data System (ADS)

Flynn, David; Desmulliez, Marc

2006-04-01

A novel method to manufacture and assemble a microinductor that is based on flipchip bonding is described in this paper. The fabricated inductors have an inductance ranging from 0.3 µH to 180 µH. An optimum Q-factor of 14 was attained at 1MHz. Cobalt-Copper-iron cores maintained a constant inductance across a 1 kHz-1MHz bandwidth. The thin film laminate minimizes the eddy current loss and the hysteresis loss was negligible. Impedance increases linearly with frequency indicating that parasitic capacitance effects in this frequency range are negligible. The microinductor operated at an efficiency of 92% at 1MHz achieving a power density of 3.75 W/mm3.

49 CFR 236.529 - Roadway element inductor; height and distance from rail.

Code of Federal Regulations, 2011 CFR

2011-10-01

... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and Instructions...

49 CFR 236.529 - Roadway element inductor; height and distance from rail.

Code of Federal Regulations, 2010 CFR

2010-10-01

... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and Instructions...

Developments in space power components for power management and distribution

NASA Technical Reports Server (NTRS)

Renz, D. D.

1984-01-01

Advanced power electronic components development for space applications is discussed. The components described include transformers, inductors, semiconductor devices such as transistors and diodes, remote power controllers, and transmission lines.

Analysis of non-destructive current simulators of flux compression generators.

PubMed

O'Connor, K A; Curry, R D

2014-06-01

Development and evaluation of power conditioning systems and high power microwave components often used with flux compression generators (FCGs) requires repeated testing and characterization. In an effort to minimize the cost and time required for testing with explosive generators, non-destructive simulators of an FCG's output current have been developed. Flux compression generators and simulators of FCGs are unique pulsed power sources in that the current waveform exhibits a quasi-exponential increasing rate at which the current rises. Accurately reproducing the quasi-exponential current waveform of a FCG can be important in designing electroexplosive opening switches and other power conditioning components that are dependent on the integral of current action and the rate of energy dissipation. Three versions of FCG simulators have been developed that include an inductive network with decreasing impedance in time. A primary difference between these simulators is the voltage source driving them. It is shown that a capacitor-inductor-capacitor network driving a constant or decreasing inductive load can produce the desired high-order derivatives of the load current to replicate a quasi-exponential waveform. The operation of the FCG simulators is reviewed and described mathematically for the first time to aid in the design of new simulators. Experimental and calculated results of two recent simulators are reported with recommendations for future designs.

49 CFR 236.532 - Strap iron inductor; use restricted.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Roadway § 236.532 Strap iron...

49 CFR 236.532 - Strap iron inductor; use restricted.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Roadway § 236.532 Strap iron...

Estimated power quality for line commutated photovoltaic residential system

NASA Astrophysics Data System (ADS)

McNeill, B. W.; Mirza, M. A.

1983-10-01

A residential photovoltaic system using a line commutated inverter is modeled using a single diode model for the solar cells and a four switch model for the inverter. The model predicts power factor and total harmonic distortion as a function of solar radiation, array voltage, inverter output voltage, and inverter filter capacitor and inductor size. The model was run using parameter values appropriate for the John F. Long PV System and the predicted results compared well with measured results from the system. The model shows that improvements in total harmonic distortion are made at the expense of the power factor. The harmonic distortion is least when the inverter is operating at just continuous conduction. The total harmonic distortion can be kept to less than 0.17 all day if a variable inductor is used in the inverter's input filters.

Dielectric and diamagnetic susceptibilities near percolative superconductor-insulator transitions.

PubMed

Loh, Yen Lee; Karki, Pragalv

2017-10-25

Coarse-grained superconductor-insulator composites exhibit a superconductor-insulator transition governed by classical percolation, which should be describable by networks of inductors and capacitors. We study several classes of random inductor-capacitor networks on square lattices. We present a unifying framework for defining electric and magnetic response functions, and we extend the Frank-Lobb bond-propagation algorithm to compute these quantities by network reduction. We confirm that the superfluid stiffness scales approximately as [Formula: see text] as the superconducting bond fraction p approaches the percolation threshold p c . We find that the diamagnetic susceptibility scales as [Formula: see text] below percolation, and as [Formula: see text] above percolation. For models lacking self-capacitances, the electric susceptibility scales as [Formula: see text]. Including a self-capacitance on each node changes the critical behavior to approximately [Formula: see text].

Prediction of multiple resonance characteristics by an extended resistor-inductor-capacitor circuit model for plasmonic metamaterials absorbers in infrared.

PubMed

Xu, Xiaolun; Li, Yongqian; Wang, Binbin; Zhou, Zili

2015-10-01

The resonance characteristics of plasmonic metamaterials absorbers (PMAs) are strongly dependent on geometric parameters. A resistor-inductor-capacitor (RLC) circuit model has been extended to predict the resonance wavelengths and the bandwidths of multiple magnetic polaritons modes in PMAs. For a typical metallic-dielectric-metallic structure absorber working in the infrared region, the developed model describes the correlation between the resonance characteristics and the dimensional sizes. In particular, the RLC model is suitable for not only the fundamental resonance mode, but also for the second- and third-order resonance modes. The prediction of the resonance characteristics agrees fairly well with those calculated by the finite-difference time-domain simulation and the experimental results. The developed RLC model enables the facilitation of designing multi-band PMAs for infrared radiation detectors and thermal emitters.

Body Fluids Monitor

NASA Technical Reports Server (NTRS)

Siconolfi, Steven F. (Inventor)

2000-01-01

Method and apparatus are described for determining volumes of body fluids in a subject using bioelectrical response spectroscopy. The human body is represented using an electrical circuit. Intra-cellular water is represented by a resistor in series with a capacitor; extra-cellular water is represented by a resistor in series with two parallel inductors. The parallel inductors represent the resistance due to vascular fluids. An alternating, low amperage, multifrequency signal is applied to determine a subject's impedance and resistance. From these data, statistical regression is used to determine a 1% impedance where the subject's impedance changes by no more than 1% over a 25 kHz interval. Circuit component, of the human body circuit are determined based on the 1% impedance. Equations for calculating total body water, extra-cellular water, total blood volume, and plasma volume are developed based on the circuit components.

Protection layers on a superconducting microwave resonator toward a hybrid quantum system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jongmin, E-mail: jongmin.lee@sandia.gov; Sandia National Laboratories, Albuquerque, New Mexico 87123; Park, Dong Hun, E-mail: leomac@umd.edu

2015-10-07

We propose a protection scheme of a superconducting microwave resonator to realize a hybrid quantum system, where cold neutral atoms are coupled with a single microwave photon through magnetic dipole interaction at an interface inductor. The evanescent field atom trap, such as a waveguide/nanofiber atom trap, brings both surface-scattered photons and absorption-induced broadband blackbody radiation which result in quasiparticles and a low quality factor at the resonator. A proposed multiband protection layer consists of pairs of two dielectric layers and a thin nanogrid conductive dielectric layer above the interface inductor. We show numerical simulations of quality factors and reflection/absorption spectra,more » indicating that the proposed multilayer structure can protect a lumped-element microwave resonator from optical photons and blackbody radiation while maintaining a reasonably high quality factor.« less

Stabilizing Rabi oscillation of a charge qubit via the atomic clock technique

NASA Astrophysics Data System (ADS)

Yu, Deshui; Landra, Alessandro; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer

2018-02-01

We propose a superconducting circuit-atom hybrid, where the Rabi oscillation of single excess Cooper pair in the island is stabilized via the common atomic clock technique. The noise in the superconducting circuit is mapped onto the voltage source which biases the Cooper-pair box via an inductor and a gate capacitor. The fast fluctuations of the gate charge are significantly suppressed by an inductor-capacitor resonator, leading to a long-relaxation-time Rabi oscillation. More importantly, the residual low-frequency fluctuations are further reduced by using the general feedback-control method, in which the voltage bias is stabilized via continuously measuring the dc-Stark-shift-induced atomic Ramsey signal. The stability and coherence time of the resulting charge-qubit Rabi oscillation are both enhanced. The principal structure of this Cooper-pair-box oscillator is studied in detail.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elizondo-Decanini, Juan M.

Short pulse neutron generators are described herein. In a general embodiment, the short pulse neutron generator includes a Blumlein structure. The Blumlein structure includes a first conductive plate, a second conductive plate, a third conductive plate, at least one of an inductor or a resistor, a switch, and a dielectric material. The first conductive plate is positioned relative to the second conductive plate such that a gap separates these plates. A vacuum chamber is positioned in the gap, and an ion source is positioned to emit ions in the vacuum chamber. The third conductive plate is electrically grounded, and themore » switch is operable to electrically connect and disconnect the second conductive plate and the third conductive plate. The at least one of the resistor or the inductor is coupled to the first conductive plate and the second conductive plate.« less

Models for Multimegawatt Space Power Systems

DTIC Science & Technology

1990-06-01

devices such as batteries, flywheels, and large, cryogenic inductors. Turbines with generators, thermionics, thermoelectrics, alkali metal...NTCA Weapons Laboratory Kirtland AFB, NM 87117 C. Perry Bankston California Institute of Technology Jet Propulsion Laboratory 4800 Oak Grove

Direct current contamination of kilohertz frequency alternating current waveforms.

PubMed

Franke, Manfred; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

2014-07-30

Kilohertz frequency alternating current (KHFAC) waveforms are being evaluated in a variety of physiological settings because of their potential to modulate neural activity uniquely when compared to frequencies in the sub-kilohertz range. However, the use of waveforms in this frequency range presents some unique challenges regarding the generator output. In this study we explored the possibility of undesirable contamination of the KHFAC waveforms by direct current (DC). We evaluated current- and voltage-controlled KHFAC waveform generators in configurations that included a capacitive coupling between generator and electrode, a resistive coupling and combinations of capacitive with inductive coupling. Our results demonstrate that both voltage- and current-controlled signal generators can unintentionally add DC-contamination to a KHFAC signal, and that capacitive coupling is not always sufficient to eliminate this contamination. We furthermore demonstrated that high value inductors, placed in parallel with the electrode, can be effective in eliminating DC-contamination irrespective of the type of stimulator, reducing the DC contamination to less than 1 μA. This study highlights the importance of carefully designing the electronic setup used in KHFAC studies and suggests specific testing that should be performed and reported in all studies that assess the neural response to KHFAC waveforms. Published by Elsevier B.V.

Inverting Quasi-Resonant Switched-Capacitor Bidirectional Converter and Its Application to Battery Equalization

NASA Astrophysics Data System (ADS)

Lee, Yuang-Shung; Chiu, Yin-Yuan; Cheng, Ming-Wang; Ko, Yi-Pin; Hsiao, Sung-Hsin

The proposed quasi-resonant (QR) zero current switching (ZCS) switched-capacitor (SC) converter is a new type of bidirectional power flow control conversion scheme. The proposed converter is able to provide voltage conversion ratios from -3/-{1 \\over 3} (triple-mode/trisection-mode) to -n/-{1 \\over n} (-n-mode/-{1 \\over n}-mode) by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse power flow control schemes. It possesses the advantages of low switching losses and current stress in this QR ZCS SC converter. The principle of operation, theoretical analysis of the proposed triple-mode/trisection-mode bidirectional power conversion scheme is described in detail with circuit model analysis. Simulation and experimental studies are carried out to verify the performance of the proposed inverting type ZCS SC QR bidirectional converter. The proposed converters can be applied to battery equalization for battery management system (BMS).

Apparatus for Teaching Physics.

ERIC Educational Resources Information Center

Gottlieb, Herbert H., Ed.

1981-01-01

Describes: (1) a variable inductor suitable for an inductance-capacitance bridge consisting of a fixed cylindrical solenoid and a moveable solenoid; (2) long-range apparatus for demonstrating falling bodies; and (3) an apparatus using two lasers to demonstrate ray optics. (SK)

Rotary Power Transformer and Inverter Circuit

NASA Technical Reports Server (NTRS)

Mclyman, C. W. T.; Bridgeforth, A. O.

1985-01-01

Noise lower than with sliprings. Rotary transformer transfers electric power across rotary joint. No wearing contacts, no contact noise, and no contamination from lubricants or wear debris. Because additional inductor not required, size and complexity of circuit reduced considerably.

The experimental-theoretical model of the jet HF induction discharge of atmospheric pressure

NASA Astrophysics Data System (ADS)

Gainullin, R.; Kirpichnikov, A.

2017-11-01

The paper considers theexperimental-theoretical model devised to determine the regularities of the quasi-stationary electromagnetic field structure of the HFI discharge burning in the inductor of finite dimensions at atmospheric pressure.

Electronic switching circuit uses complementary non-linear components

NASA Technical Reports Server (NTRS)

Zucker, O. S.

1972-01-01

Inherent switching properties of saturable inductors and storage diodes are combined to perform large variety of electronic functions, such as pulse shaping, gating, and multiplexing. Passive elements replace active switching devices in generation of complex waveforms.

Wireless Fluid Level Measuring System

NASA Technical Reports Server (NTRS)

Taylor, Bryant D. (Inventor); Woodard, Stanley E. (Inventor)

2007-01-01

A level-sensing probe positioned in a tank is divided into sections with each section including (i) a fluid-level capacitive sensor disposed along the length thereof, (ii) an inductor electrically coupled to the capacitive sensor, (iii) a sensor antenna positioned for inductive coupling to the inductor, and (iv) an electrical conductor coupled to the sensor antenna. An electrically non-conductive housing accessible from a position outside of the tank houses antennas arrayed in a pattern. Each antenna is electrically coupled to the electrical conductor from a corresponding one of the sections. A magnetic field response recorder has a measurement head with transceiving antennas arrayed therein to correspond to the pattern of the housing's antennas. When a measurement is to be taken, the measurement head is mechanically coupled to the housing so that each housing antenna is substantially aligned with a specific one of the transceiving antennas.

Regenerative flywheel energy storage system. Volume 3: Life cycle and cost-benefit analysis of a battery-flywheel electric car

NASA Astrophysics Data System (ADS)

1980-06-01

Fabrication of the inductor motor, the flywheel, the power conditioner, and the system control is described. Test results of the system operating over the SAE j227a Schedule D driving cycle are given and are compared to the calculated value. The flywheel energy storage system consists of a solid rotor, synchronous, inductor-type, flywheel drive machine electrically coupled to a dc battery electric propulsion system through a load-commutated inverter. The motor/alernator unit is coupled mechanically to a small steel flywheel which provides a portion of the vehicle's accelerating energy and regenerates the vehicle's braking energy. Laboratory simulation of the electric vehicle propulsion system included a 108 volt, lead-acid battery bank and a separately excited dc propulsion motor coupled to a flywheel and generator which simulate the vehicle's inertia and losses.

RF-MEMS tunable interdigitated capacitor and fixed spiral inductor for band pass filter applications

NASA Astrophysics Data System (ADS)

Bade, Ladon Ahmed; Dennis, John Ojur; Khir, M. Haris Md; Wen, Wong Peng

2016-11-01

This research presents the tunable Radio Frequency Micro Electromechanical Systems (RF-MEMS) coupled band-pass filter (BPF), which possess a wide tuning range and constructed by using the Chebyshev fourth degree equivalent circuit consisting of fixed inductors and interdigitated tunable capacitors. The suggested method was authenticated by designing a new tunable BPF with a 100% tuning range from 3.1 GHz to 4.9 GHz. The Metal Multi-User MEMS Process (Metal MUMPs) was involved in the process of design of this band-pass filter. It aimed to achieve the reconfiguration of frequencies and show high efficiency of RF in the applications that using Ultra Wide Band (UWB) such as wireless sensor networks. The RF performance of this filter was found to be very satisfactory due to its simple fabrication. Moreover, it showed less insertion loss of around 4 dB and high return loss of around 20 dB.

ESS Smelting Technology

NASA Astrophysics Data System (ADS)

Erasmus, L. J.; Fourie, L. J.

2017-02-01

The envirosteel smelter is a rectangular furnace with a large free board volume and multiple channel inductors mounted below the hearth. The raw materials are charged against the back wall forming an inclined heap sloping toward the front long wall. The feed blend is spread in thin layers over the surface of the heap and is heated by exposure to radiation from the free board. Reducing conditions in the top layer of the heap permit gas-solid reduction. Metal, in the hearth of the furnace, flows into the channel inductor where it is heated. The heated metal flows back against the front long wall to under the heap. The bottom of the heap is continuously melted by energy transferred from the metal layer. The two off-gas ducts are located in the short end walls. The combustion air is heated to around 800°C by a furnace gas in an external heat exchanger.

Understanding efficiency limits of dielectric elastomer driver circuitry

NASA Astrophysics Data System (ADS)

Lo, Ho Cheong; Calius, Emilio; Anderson, Iain

2013-04-01

Dielectric elastomers (DEs) can theoretically operate at efficiencies greater than that of electromagnetics. This is due to their unique mode of operation which involves charging and discharging a capacitive load at a few kilovolts (typically 1kV-4kV). Efficient recovery of the electrical energy stored in the capacitance of the DE is essential in achieving favourable efficiencies as actuators or generators. This is not a trivial problem because the DE acts as a voltage source with a low capacity and a large output resistance. These properties are not ideal for a power source, and will reduce the performance of any power conditioning circuit utilizing inductors or transformers. This paper briefly explores how circuit parameters affect the performance of a simple inductor circuit used to transfer energy from a DE to another capacitor. These parameters must be taken into account when designing the driving circuitry to maximize performance.

Integration of Thermal Energy Harvesting in Semi-Active Piezoelectric Shunt-Damping Systems

NASA Astrophysics Data System (ADS)

Lubieniecki, Michał; Uhl, Tadeusz

2015-01-01

The opportunities to energize a broad range of devices by use of energy available almost anywhere and in many forms are almost unlimited. A major advantage of energy harvesting is the manufacture of small autonomous electronic devices with no need for power supply and maintenance. Shunt damping circuits, although unfavorably affected by the size and mass of bulky coil inductors, started to base on synthetic inductors losing their passivity. In this paper we report a study of the feasibility of powering shunt damping circuits by use of thermal energy otherwise irrevocably lost from a bearing. The heat generated in the bearing is converted thermoelectrically into electric energy which is then used to power synthetic inductance circuitry. We show that the power demand of such circuit can be satisfied by use of a thermoelectric generator paired with a moderately loaded bearing.

Induction melter apparatus

DOEpatents

Roach, Jay A [Idaho Falls, ID; Richardson, John G [Idaho Falls, ID; Raivo, Brian D [Idaho Falls, ID; Soelberg, Nicholas R [Idaho Falls, ID

2008-06-17

Apparatus and methods of operation are provided for a cold-crucible-induction melter for vitrifying waste wherein a single induction power supply may be used to effect a selected thermal distribution by independently energizing at least two inductors. Also, a bottom drain assembly may be heated by an inductor and may include an electrically resistive heater. The bottom drain assembly may be cooled to solidify molten material passing therethrough to prevent discharge of molten material therefrom. Configurations are provided wherein the induction flux skin depth substantially corresponds with the central longitudinal axis of the crucible. Further, the drain tube may be positioned within the induction flux skin depth in relation to material within the crucible or may be substantially aligned with a direction of flow of molten material within the crucible. An improved head design including four shells forming thermal radiation shields and at least two gas-cooled plenums is also disclosed.

Operating an induction melter apparatus

DOEpatents

Roach, Jay A.; Richardson, John G.; Raivo, Brian D.; Soelberg, Nicholas R.

2006-01-31

Apparatus and methods of operation are provided for a cold-crucible-induction melter for vitrifying waste wherein a single induction power supply may be used to effect a selected thermal distribution by independently energizing at least two inductors. Also, a bottom drain assembly may be heated by an inductor and may include an electrically resistive heater. The bottom drain assembly may be cooled to solidify molten material passing therethrough to prevent discharge of molten material therefrom. Configurations are provided wherein the induction flux skin depth substantially corresponds with the central longitudinal axis of the crucible. Further, the drain tube may be positioned within the induction flux skin depth in relation to material within the crucible or may be substantially aligned with a direction of flow of molten material within the crucible. An improved head design including four shells forming thermal radiation shields and at least two gas-cooled plenums is also disclosed.

Modulational Instability in a Pair of Non-identical Coupled Nonlinear Electrical Transmission Lines

NASA Astrophysics Data System (ADS)

Eric, Tala-Tebue; Aurelien, Kenfack-Jiotsa; Marius Hervé, Tatchou-Ntemfack; Timoléon Crépin, Kofané

2013-07-01

In this work, we investigate the dynamics of modulated waves non-identical coupled nonlinear transmission lines. Traditional methods for avoiding mode mixing in identical coupled nonlinear electrical lines consist of adding the same number of linear inductors in each branch. Adding linear inductors in a single line leads to asymmetric coupled nonlinear electrical transmission lines which propagate the signal and the mode mixing. On one hand, the difference between the two lines induced the fission for only one mode of propagation. This fission is influenced by the amplitude of the signal and the amount of the input energy as well; it also narrows the width of the input pulse soliton, leading to a possible increasing of the bit rate. On the other hand, the dissymmetry of the two lines converts the network into a good amplifier for the ω_ mode which corresponds to the regime admitting low frequencies.

Development of an Algorithm for Automatic Analysis of the Impedance Spectrum Based on a Measurement Model

NASA Astrophysics Data System (ADS)

Kobayashi, Kiyoshi; Suzuki, Tohru S.

2018-03-01

A new algorithm for the automatic estimation of an equivalent circuit and the subsequent parameter optimization is developed by combining the data-mining concept and complex least-squares method. In this algorithm, the program generates an initial equivalent-circuit model based on the sampling data and then attempts to optimize the parameters. The basic hypothesis is that the measured impedance spectrum can be reproduced by the sum of the partial-impedance spectra presented by the resistor, inductor, resistor connected in parallel to a capacitor, and resistor connected in parallel to an inductor. The adequacy of the model is determined by using a simple artificial-intelligence function, which is applied to the output function of the Levenberg-Marquardt module. From the iteration of model modifications, the program finds an adequate equivalent-circuit model without any user input to the equivalent-circuit model.

Design and test hardware for a solar array switching unit

NASA Technical Reports Server (NTRS)

Patil, A. R.; Cho, B. H.; Sable, D.; Lee, F. C.

1992-01-01

This paper describes the control of a pulse width modulated (PWM) type sequential shunt switching unit (SSU) for spacecraft applications. It is found that the solar cell output capacitance has a significant impact on SSU design. Shorting of this cell capacitance by the PWM switch causes input current surges. These surges are minimized by the use of a series filter inductor. The system with a filter is analyzed for ripple and the control to output-voltage transfer function. Stable closed loop design considerations are discussed. The results are supported by modeling and measurements of loop gain and of closed-loop bus impedance on test hardware for NASA's 120 V Earth Observation System (EOS). The analysis and modeling are also applicable to NASA's 160 V Space Station power system.

Strong coercivity reduction and high initial permeability in NiCoP coated BaFe12O19-polystyrene bilayer composite

NASA Astrophysics Data System (ADS)

Hamad, Mahmoud A.; El-Sayed, Adly H.; Hemeda, O. M.; Tawfik, A.

2016-03-01

Soft-magnetic NiCoP coated hard-magnetic M-type ferrite BaFe12O19 (BaM)-polystyrene (PS) bilayer composite film was successfully synthesized. X-ray diffraction peaks exhibited no change in the structure of BaM after coating with PS. The NiCoP coated BaM-PS composite exhibited a wasp-waisted magnetic hysteretic loop with remarkable reduction in the coercivity, remanence and squareness with respect to BaM-PS, which is useful for the core of a magnetic switching device to control currents so large that they are unmanageable. Moreover, the initial permeability measurement exhibits initial permeability of around 100 000 and thermal stability up to 558 K, which is good for flux-amplifying components of smaller inductors.

Series Connected Converter for Control of Multi-Bus Spacecraft Power Utility

NASA Technical Reports Server (NTRS)

Beach, Raymond F. (Inventor); Brush, Andy (Inventor)

1997-01-01

The invention provides a power system using series connected regulators. Power from a source, such as a solar array, is processed through the regulators and provided to corresponding buses used to charge a battery and supply loads. The regulators employ a bypass loop around a DC-DC converter. The bypass loop connects a hot input of the converter to a return output, preferably though an inductor. Part of the current from the source passes through the bypass loop to the power bus. The converter bucks or boosts the voltage from the source to maintain the desired voltage at the bus. Thus, only part of the power is processed through the converter. The converter can also be used without the bypass loop to provide isolation. All of the converters can be substantially identical.

Current sheet characteristics of a parallel-plate electromagnetic plasma accelerator operated in gas-prefilled mode

NASA Astrophysics Data System (ADS)

Liu, Shuai; Huang, Yizhi; Guo, Haishan; Lin, Tianyu; Huang, Dong; Yang, Lanjun

2018-05-01

The axial characteristics of a current sheet in a parallel-plate electromagnetic plasma accelerator operated in gas-prefilled mode are reported. The accelerator is powered by a fourteen stage pulse forming network. The capacitor and inductor in each stage are 1.5 μF and 300 nH, respectively, and yield a damped oscillation square wave of current with a pulse width of 20.6 μs. Magnetic probes and photodiodes are placed at various axial positions to measure the behavior of the current sheet. Both magnetic probe and photodiode signals reveal a secondary breakdown when the current reverses the direction. An increase in the discharge current amplitude and a decrease in pressure lead to a decrease in the current shedding factor. The current sheet velocity and thickness are nearly constant during the run-down phase under the first half-period of the current. The current sheet thicknesses are typically in the range of 25 mm to 40 mm. The current sheet velocities are in the range of 10 km/s to 45 km/s when the discharge current is between 10 kA and 55 kA and the gas prefill pressure is between 30 Pa and 800 Pa. The experimental velocities are about 75% to 90% of the theoretical velocities calculated with the current shedding factor. One reason for this could be that the idealized snowplow analysis model ignores the surface drag force.

Two-port network analysis and modeling of a balanced armature receiver.

PubMed

Kim, Noori; Allen, Jont B

2013-07-01

Models for acoustic transducers, such as loudspeakers, mastoid bone-drivers, hearing-aid receivers, etc., are critical elements in many acoustic applications. Acoustic transducers employ two-port models to convert between acoustic and electromagnetic signals. This study analyzes a widely-used commercial hearing-aid receiver ED series, manufactured by Knowles Electronics, Inc. Electromagnetic transducer modeling must consider two key elements: a semi-inductor and a gyrator. The semi-inductor accounts for electromagnetic eddy-currents, the 'skin effect' of a conductor (Vanderkooy, 1989), while the gyrator (McMillan, 1946; Tellegen, 1948) accounts for the anti-reciprocity characteristic [Lenz's law (Hunt, 1954, p. 113)]. Aside from Hunt (1954), no publications we know of have included the gyrator element in their electromagnetic transducer models. The most prevalent method of transducer modeling evokes the mobility method, an ideal transformer instead of a gyrator followed by the dual of the mechanical circuit (Beranek, 1954). The mobility approach greatly complicates the analysis. The present study proposes a novel, simplified and rigorous receiver model. Hunt's two-port parameters, the electrical impedance Ze(s), acoustic impedance Za(s) and electro-acoustic transduction coefficient Ta(s), are calculated using ABCD and impedance matrix methods (Van Valkenburg, 1964). The results from electrical input impedance measurements Zin(s), which vary with given acoustical loads, are used in the calculation (Weece and Allen, 2010). The hearing-aid receiver transducer model is designed based on energy transformation flow [electric→ mechanic→ acoustic]. The model has been verified with electrical input impedance, diaphragm velocity in vacuo, and output pressure measurements. This receiver model is suitable for designing most electromagnetic transducers and it can ultimately improve the design of hearing-aid devices by providing a simplified yet accurate, physically motivated analysis. This article is part of a special issue entitled "MEMRO 2012". Published by Elsevier B.V.

A triple hybrid micropower generator with simultaneous multi-mode energy harvesting

NASA Astrophysics Data System (ADS)

Uluşan, H.; Chamanian, S.; Pathirana, W. P. M. R.; Zorlu, Ö.; Muhtaroğlu, A.; Külah, H.

2018-01-01

This study presents a triple hybrid energy harvesting system that combines harvested power from thermoelectric (TE), vibration-based electromagnetic (EM) and piezoelectric (PZT) harvesters into a single DC supply. A power management circuit is designed and implemented in 180 nm standard CMOS technology based on the distinct requirements of each harvester, and is terminated with a Schottky diode to avoid reverse current flow. The system topology hence supports simultaneous power generation and delivery from low and high frequency vibrations as well as temperature differences in the environment. The ultra-low DC voltage harvested from TE generator is boosted with a cross-coupled charge-pump driven by an LC oscillator with fully-integrated center-tapped differential inductors. The EM harvester output was rectified with a self-powered and low drop-out AC/DC doubler circuit. The PZT interface electronics benefits from peak-to-peak cycle of the harvested voltage through a negative voltage converter followed by synchronous power extraction and DC-to-DC conversion through internal switches, and an external inductor. The hybrid system was tested with a wearable in-house EM energy harvester placed wrist of a jogger, a commercial low volume PZT harvester, and DC supply as the TE generator output. The system generates more than 1.2 V output for load resistances higher than 50 kΩ, which corresponds to 24 μW to power wearable sensors. Simultaneous multi-mode operation achieves higher voltage and power compared to stand-alone harvesting circuits, and generates up to 110 μW of output power. This is the first hybrid harvester circuit that simultaneously extracts energy from three independent sources, and delivers a single DC output.

Optimized MPPT-based converter for TEG energy harvester to power wireless sensor and monitoring system in nuclear power plant

NASA Astrophysics Data System (ADS)

Xing, Shaoxu; Anakok, Isil; Zuo, Lei

2017-04-01

Accidents like Fukushima Disasters push people to improve the monitoring systems for the nuclear power plants. Thus, various types of energy harvesters are designed to power these systems and the Thermoelectric Generator (TEG) energy harvester is one of them. In order to enhance the amount of harvested power and the system efficiency, the power management stage needs to be carefully designed. In this paper, a power converter with optimized Maximum Power Point Tracking (MPPT) is proposed for the TEG Energy Harvester to power the wireless sensor network in nuclear power plant. The TEG Energy Harvester is installed on the coolant pipe of the nuclear plant and harvests energy from its heat energy while the power converter with optimized MPPT can make the TEG Energy Harvester output the maximum power, quickly response to the voltage change and provide sufficient energy for wireless sensor system to monitor the operation of the nuclear power plant. Due to the special characteristics of the Single-Ended Primary Inductor Converter (SEPIC) when it is working in the Discontinuous Inductor Current Mode (DICM) and Continuous Conduction Mode (CCM), the MPPT method presented in this paper would be able to control the converter to achieve the maximum output power in any working conditions of the TEG system with a simple circuit. The optimized MPPT algorithm will significantly reduce the cost and simplify the system as well as achieve a good performance. Experiment test results have shown that, comparing to a fixed- duty-cycle SEPIC which is specifically designed for the working on the secondary coolant loop in nuclear power plant, the optimized MPPT algorithm increased the output power by 55%.

Analysis of spacecraft battery charger systems

NASA Astrophysics Data System (ADS)

Kim, Seong J.; Cho, Bo H.

In spacecraft battery charger systems, switching regulators are widely used for bus voltage regulation, charge current regulation, and peak power tracking. Small-signal dynamic characteristics of the battery charging subsystem of direct energy transfer (DET) and peak power tracking (PPT) systems are analyzed to facilitate design of the control loop for optimum performance and stability. Control loop designs of the charger in various modes of operation are discussed. Analyses are verified through simulations. It is shown that when the charger operates in the bus voltage regulation mode, the control-to-voltage transfer function has a negative DC gain and two LHP zeros in both the DET and PPT systems. The control-to-inductor current transfer function also has a negative DC gain and a RHP zero. Thus, in the current-mode control, the current loop can no longer be used to stabilize the system. When the system operates in the charge current regulation mode, the charger operates with a fixed duty cycle which is determined by the regulated bus voltage and the battery voltage. Without an input filter, the converter becomes a first-order system. When the peak power tracker is inactive, the operating point of the solar array output moves to the voltage source region. Thus, the solar array behaves as a stiff voltage source to a constant power load.

A 3.2-GHz fully integrated low-phase noise CMOS VCO with self-biasing current source for the IEEE 802.11a/hiperLAN WLAN standard

NASA Astrophysics Data System (ADS)

Quemada, C.; Adin, I.; Bistue, G.; Berenguer, R.; Mendizabal, J.

2005-06-01

A 3.3V, fully integrated 3.2-GHz voltage-controlled oscillator (VCO) is designed in a 0.18μm CMOS technology for the IEE 802.11a/HiperLAN WLAN standard for the UNII band from 5.15 to 5.35 GHz. The VCO is tunable between 2.85 GHz and 3.31 GHz. NMOS architecture with self-biasing current of the tank source is chosen. A startup circuit has been employed to avoid zero initial current. Current variation is lower than 1% for voltage supply variations of 10%. The use of a self-biasing current source in the tank provides a greater safety in the transconductance value and allows running along more extreme point operation The designed VCO displays a phase noise and output power of -98dBc/Hz (at 100 KHz offset frequency) and 0dBm respectively. This phase noise has been obtained with inductors of 2.2nH and quality factor of 12 at 3.2 GHz, and P-N junction varactors whose quality factor is estimated to exceed 40 at 3.2 GHz. These passive components have been fabricated, measured and modeled previously. The core of the VCO consumes 33mW DC power.

Design and dSpace interfacing of current fed high gain dc to dc boost converter for low voltage applications

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Debraj; Das, Subhrajit; Arunkumar, G.; Elangovan, D.; Ragunath, G.

2017-11-01

In this paper a current fed interleaved DC - DC boost converter which has an isolated topology and used for high voltage step up is proposed. A basic DC to DC boost converter converts uncontrolled DC voltage into controlled DC voltage of higher magnitude. Whereas this topology has the advantages of lower input current ripple, lesser output voltage, lesser stress on switches, faster transient response, improved reliability and much lesser electromagnetic emission over the conventional DC to DC boost converter. Most important benefit of this interleaved DC to DC boost converter is much higher efficiency. The input current is divided into two paths, substantially ohmic loss (I2R) and inductor ac loss gets reduced and finally the system achieves much higher efficiency. With recent mandates on energy saving interleaved DC to DC boost converter may be used as a very powerful tool to maintain good power density keeping the input current manageable. Higher efficiency also allows higher switching frequency and as a result the topology becomes more compact and cost friendly. The proposed topology boosts 48v DC to 200 V DC. Switching frequency is 100 kHz and PSIM 9.1 Platform has been used for the simulation.

Dependence of Initial Oxygen Concentration on Ozone Yield Using Inductive Energy Storage System Pulsed Power Generator

NASA Astrophysics Data System (ADS)

Go, Tomio; Tanaka, Yasushi; Yamazaki, Nobuyuki; Mukaigawa, Seiji; Takaki, Koichi; Fujiwara, Tamiya

Dependence of initial oxygen concentration on ozone yield using streamer discharge reactor driven by an inductive energy storage system pulsed power generator is described in this paper. Fast recovery type diodes were employed as semiconductor opening switch to interrupt a circuit current within 100 ns. This rapid current change produced high-voltage short pulse between a secondary energy storage inductor. The repetitive high-voltage short pulse was applied to a 1 mm diameter center wire electrode placed in a cylindrical pulse corona reactor. The streamer discharge successfully occurred between the center wire electrode and an outer cylinder ground electrode of 2 cm inner diameter. The ozone was produced with the streamer discharge and increased with increasing pulse repetition rate. The ozone yield changed in proportion to initial oxygen concentration contained in the injected gas mixture at 800 ns forward pumping time of the current. However, the decrease of the ozone yield by decreasing oxygen concentration in the gas mixture at 180 ns forward pumping time of the current was lower than the decrease at 800 ns forward pumping time of the current. This dependence of the initial oxygen concentration on ozone yield at 180 ns forward pumping time is similar to that of dielectric barrier discharge reactor.

Radio aneurysm coils for noninvasive detection of cerebral embolization failures: a preliminary study.

PubMed

Mohammadi, Abdolreza Rashidi; Chen, Keqin; Ali, Mohamed Sultan Mohamed; Takahata, Kenichi

2011-12-15

The rupture of a cerebral aneurysm is the most common cause of subarachnoid hemorrhage. Endovascular embolization of the aneurysms by implantation of Guglielmi detachable coils (GDC) has become a major treatment approach in the prevention of a rupture. Implantation of the coils induces formation of tissues over the coils, embolizing the aneurysm. However, blood entry into the coiled aneurysm often occurs due to failures in the embolization process. Current diagnostic methods used for aneurysms, such as X-ray angiography and computer tomography, are ineffective for continuous monitoring of the disease and require extremely expensive equipment. Here we present a novel technique for wireless monitoring of cerebral aneurysms using implanted embolization coils as radiofrequency resonant sensors that detect the blood entry. The experiments show that commonly used embolization coils could be utilized as electrical inductors or antennas. As the blood flows into a coil-implanted aneurysm, parasitic capacitance of the coil is modified because of the difference in permittivity between the blood and the tissues grown around the coil, resulting in a change in the coil's resonant frequency. The resonances of platinum GDC-like coils embedded in aneurysm models are detected to show average responses of 224-819 MHz/ml to saline injected into the models. This preliminary demonstration indicates a new possibility in the use of implanted GDC as a wireless sensor for embolization failures, the first step toward realizing long-term, noninvasive, and cost-effective remote monitoring of cerebral aneurysms treated with coil embolization. Copyright © 2011 Elsevier B.V. All rights reserved.

A PWM Buck Converter With Load-Adaptive Power Transistor Scaling Scheme Using Analog-Digital Hybrid Control for High Energy Efficiency in Implantable Biomedical Systems.

PubMed

Park, Sung-Yun; Cho, Jihyun; Lee, Kyuseok; Yoon, Euisik

2015-12-01

We report a pulse width modulation (PWM) buck converter that is able to achieve a power conversion efficiency (PCE) of > 80% in light loads 100 μA) for implantable biomedical systems. In order to achieve a high PCE for the given light loads, the buck converter adaptively reconfigures the size of power PMOS and NMOS transistors and their gate drivers in accordance with load currents, while operating at a fixed frequency of 1 MHz. The buck converter employs the analog-digital hybrid control scheme for coarse/fine adjustment of power transistors. The coarse digital control generates an approximate duty cycle necessary for driving a given load and selects an appropriate width of power transistors to minimize redundant power dissipation. The fine analog control provides the final tuning of the duty cycle to compensate for the error from the coarse digital control. The mode switching between the analog and digital controls is accomplished by a mode arbiter which estimates the average of duty cycles for the given load condition from limit cycle oscillations (LCO) induced by coarse adjustment. The fabricated buck converter achieved a peak efficiency of 86.3% at 1.4 mA and > 80% efficiency for a wide range of load conditions from 45 μA to 4.1 mA, while generating 1 V output from 2.5-3.3 V supply. The converter occupies 0.375 mm(2) in 0.18 μm CMOS processes and requires two external components: 1.2 μF capacitor and 6.8 μH inductor.

Repetitive Series Interrupter II.

DTIC Science & Technology

1977-07-01

nated by other authorized documents. The citation of trade names and names of manufacturers is this report is not to be construed as official... intergrating inductor Magnet circuit load resistance Pulse-forming network load resistance Fault network load resistance Time delay between TUT fire and

49 CFR 236.527 - Roadway element insulation resistance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Roadway element insulation resistance. 236.527 Section 236.527 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... element insulation resistance. Insulation resistance between roadway inductor and ground shall be...

49 CFR 236.527 - Roadway element insulation resistance.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Roadway element insulation resistance. 236.527 Section 236.527 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... element insulation resistance. Insulation resistance between roadway inductor and ground shall be...

49 CFR 236.527 - Roadway element insulation resistance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Roadway element insulation resistance. 236.527 Section 236.527 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... element insulation resistance. Insulation resistance between roadway inductor and ground shall be...

Energy-Saving Inverter

NASA Technical Reports Server (NTRS)

Rippel, W. E.; Edwards, D. B.

1984-01-01

Commutation by field-effect transistor allows more efficient operation. High voltage field-effect transistor (FET) controls silicon controlled rectifiers (SCR's). Circuit requires only one capacitor and one inductor in commutation circuit: simpler, more efficient, and more economical than conventional inverters. Adaptable to dc-to-dc converters.

49 CFR 236.744 - Element, roadway.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Element, roadway. 236.744 Section 236.744 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... signal system, such as electric circuit, inductor, or trip arm to which the locomotive apparatus of such...

Healing of the bone with anti-fracture drugs.

PubMed

Vannucci, Letizia; Brandi, Maria Luisa

2016-12-01

Fracture healing is a complex physiological process. As impaired fracture healing is more frequent in osteoporotic subjects, anti-osteoporotic drugs could have some impact on this process. Areas covered: We reviewed the current literature to evaluate the effects of these drugs on fracture healing and their potential role in supporting this process, especially when impaired. A PubMed/Medline search was undertaken combining the terms 'fracture healing', 'anti-resorptive drugs', 'anabolic agents', 'anti-osteoporotic drugs'. Expert opinion: As clinical evidence on the role of anti-osteoporotic drugs in the process of fracture healing consists mainly of case reports or studies with a relatively small number of patients, large randomized clinical trials are needed in order to extend to the human setting the promising results on these agents as inductors or co-adjuvants of bone healing derived from animal studies.

Monolithic quasi-sliding-mode controller for SIDO buck converter with a self-adaptive free-wheeling current level

NASA Astrophysics Data System (ADS)

Xiaobo, Wu; Qing, Liu; Menglian, Zhao; Mingyang, Chen

2013-01-01

An analog implementation of a novel fixed-frequency quasi-sliding-mode controller for single-inductor dual-output (SIDO) buck converter in pseudo-continuous conduction mode (PCCM) with a self-adaptive freewheeling current level (SFCL) is presented. Both small and large signal variations around the operation point are considered to achieve better transient response so as to reduce the cross-regulation of this SIDO buck converter. Moreover, an internal integral loop is added to suppress the steady-state regulation error introduced by conventional PWM-based sliding mode controllers. Instead of keeping it as a constant value, the free-wheeling current level varies according to the load condition to maintain high power efficiency and less cross-regulation at the same time. To verify the feasibility of the proposed controller, an SIDO buck converter with two regulated output voltages, 1.8 V and 3.3 V, is designed and fabricated in HEJIAN 0.35 μm CMOS process. Simulation and experiment results show that the transient time of this SIDO buck converter drops to 10 μs while the cross-regulation is reduced to 0.057 mV/mA, when its first load changes from 50 to 100 mA.

Methodology for Wide Band-Gap Device Dynamic Characterization

DOE PAGES

Zhang, Zheyu; Guo, Ben; Wang, Fei Fred; ...

2017-01-19

Here, the double pulse test (DPT) is a widely accepted method to evaluate the dynamic behavior of power devices. Considering the high switching-speed capability of wide band-gap devices, the test results are very sensitive to the alignment of voltage and current (V-I) measurements. Also, because of the shoot-through current induced by Cdv/dt (i.e., cross-talk), the switching losses of the nonoperating switch device in a phase-leg must be considered in addition to the operating device. This paper summarizes the key issues of the DPT, including components and layout design, measurement considerations, grounding effects, and data processing. Additionally, a practical method ismore » proposed for phase-leg switching loss evaluation by calculating the difference between the input energy supplied by a dc capacitor and the output energy stored in a load inductor. Based on a phase-leg power module built with 1200-V/50-A SiC MOSFETs, the test results show that this method can accurately evaluate the switching loss of both the upper and lower switches by detecting only one switching current and voltage, and it is immune to V-I timing misalignment errors.« less

Study of the generator/motor operation of induction machines in a high frequency link space power system

NASA Technical Reports Server (NTRS)

Lipo, Thomas A.; Sood, Pradeep K.

1987-01-01

Static power conversion systems have traditionally utilized dc current or voltage source links for converting power from one ac or dc form to another since it readily achieves the temporary energy storage required to decouple the input from the output. Such links, however, result in bulky dc capacitors and/or inductors and lead to relatively high losses in the converters due to stresses on the semiconductor switches. The feasibility of utilizing a high frequency sinusoidal voltage link to accomplish the energy storage and decoupling function is examined. In particular, a type of resonant six pulse bridge interface converter is proposed which utilizes zero voltage switching principles to minimize switching losses and uses an easy to implement technique for pulse density modulation to control the amplitude, frequency, and the waveshape of the synthesized low frequency voltage or current. Adaptation of the proposed topology for power conversion to single-phase ac and dc voltage or current outputs is shown to be straight forward. The feasibility of the proposed power circuit and control technique for both active and passive loads are verified by means of simulation and experiment.

Nanolaminated Permalloy Core for High-Flux, High-Frequency Ultracompact Power Conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, J; Kim, M; Galle, P

2013-09-01

Metallic magnetic materials have desirable magnetic properties, including high permeability, and high saturation flux density, when compared with their ferrite counterparts. However, eddy-current losses preclude their use in many switching converter applications, due to the challenge of simultaneously achieving sufficiently thin laminations such that eddy currents are suppressed (e.g., 500 nm-1 mu m for megahertz frequencies), while simultaneously achieving overall core thicknesses such that substantial power can be handled. A CMOS-compatible fabrication process based on robot-assisted sequential electrodeposition followed by selective chemical etching has been developed for the realization of a core of substantial overall thickness (tens to hundreds ofmore » micrometers) comprised of multiple, stacked permalloy (Ni80Fe20) nanolaminations. Tests of toroidal inductors with nanolaminated cores showed negligible eddy-current loss relative to total core loss even at a peak flux density of 0.5 T in the megahertz frequency range. To illustrate the use of these cores, a buck power converter topology is implemented with switching frequencies of 1-2 MHz. Power conversion efficiency greater than 85% with peak operating flux density of 0.3-0.5 T in the core and converter output power level exceeding 5 W was achieved.« less

Teaching of Inductive and Capacitive Reactance.

ERIC Educational Resources Information Center

MacInnes, I.; Jeffrey, W. S.

1983-01-01

Discusses how understanding mechanical systems and their graphic representation can be of value when teaching inductive and capacitive reactance, in particular, the response of inductors and capacitors to an alternating potential difference. Suggests that mechanical systems be taught, not just before introducing reactance but earlier in the…

Effect of a Second, Parallel Capacitor on the Performance of a Pulse Inductive Plasma Thruster

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Balla, Joseph V.

2010-01-01

Pulsed inductive plasma accelerators are electrodeless space propulsion devices where a capacitor is charged to an initial voltage and is then discharged through an inductive coil that couples energy into the propellant, ionizing and accelerating it to produce thrust. A model that employs a set of circuit equations (as illustrated in Fig. 1a) coupled to a one-dimensional momentum equation has been previously used by Lovberg and Dailey [1] and Polzin et al. [2-4] to model the plasma acceleration process in pulsed inductive thrusters. In this paper an extra capacitor, inductor, and resistor are added to the system in the manner illustrated in the schematic shown in Fig. 1b. If the second capacitor has a smaller value than the initially charged capacitor, it can serve to increase the current rise rate through the inductive coil. Increasing the current rise rate should serve to better ionize the propellant. The equation of motion is solved to find the effect of an increased current rise rate on the acceleration process. We examine the tradeoffs between enhancing the breakdown process (increasing current rise rate) and altering the plasma acceleration process. These results provide insight into the performance of modified circuits in an inductive thruster, revealing how this design permutation can affect an inductive thruster's performance.

Wireless Capacitive Pressure Sensor Operating up to 400 Celcius from 0 to 100 psi Utilizing Power Scavenging

NASA Technical Reports Server (NTRS)

Scardelletti, Maximilian C.; Ponchak, George E.; Harsh, Kevin; Mackey, Jonathan A.; Meredith, Roger D.; Zorman, Christian A.; Beheim, Glenn M.; Dynys, Frederick W.; Hunter, Gary W.

2014-01-01

In this paper, a wireless capacitive pressure sensor developed for the health monitoring of aircraft engines has been demonstrated. The sensing system is composed of a Clapp-type oscillator that operates at 131 MHz. The Clapp oscillator is fabricated on a alumina substrate and consists of a Cree SiC (silicon carbide) MESFET (Metal Semiconductor Field Effect Transistors), this film inductor, Compex chip capacitors and Sporian Microsystem capacitive pressure sensor. The resonant tank circuit within the oscillator is made up of the pressure sensor and a spiral thin film inductor, which is used to magnetically couple the wireless pressure sensor signal to a coil antenna placed over 1 meter away. 75% of the power used to bias the sensing system is generated from thermoelectric power modules. The wireless pressure sensor is operational at room temperature through 400 C from 0 to 100 psi and exhibits a frequency shift of over 600 kHz.

Design trade-off between spatial resolution and power consumption in CMOS biosensor circuit based on millimeter-wave LC oscillator array

NASA Astrophysics Data System (ADS)

Matsunaga, Maya; Kobayashi, Atsuki; Nakazato, Kazuo; Niitsu, Kiichi

2018-03-01

In this paper, we describe a trade-off between spatial resolution and power consumption in an LC oscillator-based CMOS biosensor, which can detect biomolecules by observing the resonance frequency shift due to changes in the complex permittivity of the biomolecules. The optimal operating frequency and improvement in the image resolution of the sensor output require a reduction in the size of the inductor. However, it is necessary to increase the transconductance of the cross-coupling transistor to achieve the oscillation condition, although the power consumption increases. We confirmed the trade-off between the spatial resolution and the power consumption of this sensor using SPICE simulation. A test chip was fabricated using a 65 nm CMOS process, and the transition in the peak frequency and the power consumption were measured. When the outer diameter of the inductor was 46 µm, the power consumption was 31.2 mW, which matched well with the simulation results.

Study of the effect of distance and misalignment between magnetically coupled coils for wireless power transfer in intraocular pressure measurement.

PubMed

Rendon-Nava, Adrian E; Díaz-Méndez, J Alejandro; Nino-de-Rivera, Luis; Calleja-Arriaga, Wilfrido; Gil-Carrasco, Felix; Díaz-Alonso, Daniela

2014-01-01

An analysis of the effect of distance and alignment between two magnetically coupled coils for wireless power transfer in intraocular pressure measurement is presented. For measurement purposes, a system was fabricated consisting of an external device, which is a Maxwell-Wien bridge circuit variation, in charge of transferring energy to a biomedical implant and reading data from it. The biomedical implant is an RLC tank circuit, encapsulated by a polyimide coating. Power transfer was done by magnetic induction coupling method, by placing one of the inductors of the Maxwell-Wien bridge circuit and the inductor of the implant in close proximity. The Maxwell-Wien bridge circuit was biased with a 10 MHz sinusoidal signal. The analysis presented in this paper proves that wireless transmission of power for intraocular pressure measurement is feasible with the measurement system proposed. In order to have a proper inductive coupling link, special care must be taken when placing the two coils in proximity to avoid misalignment between them.

Dielectric and diamagnetic susceptibilities near percolative superconductor-insulator transitions

NASA Astrophysics Data System (ADS)

Loh, Yen Lee; Karki, Pragalv

2017-10-01

Coarse-grained superconductor-insulator composites exhibit a superconductor-insulator transition governed by classical percolation, which should be describable by networks of inductors and capacitors. We study several classes of random inductor-capacitor networks on square lattices. We present a unifying framework for defining electric and magnetic response functions, and we extend the Frank-Lobb bond-propagation algorithm to compute these quantities by network reduction. We confirm that the superfluid stiffness scales approximately as ( p-p_c){\\hspace{0pt}}1.3 as the superconducting bond fraction p approaches the percolation threshold p c . We find that the diamagnetic susceptibility scales as ( p_c-p){\\hspace{0pt}}-1.3 below percolation, and as L2 ( p-p_c){\\hspace{0pt}}1.3 above percolation. For models lacking self-capacitances, the electric susceptibility scales as ( p_c-p){\\hspace{0pt}}-1.3 . Including a self-capacitance on each node changes the critical behavior to approximately ( p_c-p){\\hspace{0pt}}-2.52 .

Design and Analysis of a Micromachined LC Low Pass Filter For 2.4GHz Application

NASA Astrophysics Data System (ADS)

Saroj, Samruddhi R.; Rathee, Vishal R.; Pande, Rajesh S.

2018-02-01

This paper reports design and analysis of a passive low pass filter with cut-off frequency of 2.4 GHz using MEMS (Micro Electro-Mechanical Systems) technology. The passive components such as suspended spiral inductors and metal-insulator-metal (MIM) capacitor are arranged in T network form to implement LC low pass filter design. This design employs a simple approach of suspension thereby reducing parasitic losses to eliminate the performance degrading effects caused by integrating an off-chip inductor in the filter circuit proposed to be developed on a low cost silicon substrate using RF-MEMS components. The filter occupies only 2.1 mm x 0.66 mm die area and is designed using micro-strip transmission line placed on a silicon substrate. The design is implemented in High Frequency Structural Simulator (HFSS) software and fabrication flow is proposed for its implementation. The simulated results show that the design has an insertion loss of -4.98 dB and return loss of -2.60dB.

Model of lightning strike to a steel reinforce structure using PSpice

NASA Astrophysics Data System (ADS)

Koone, Neil; Condren, Brian

2003-03-01

Surges and arcs from lightning can pose hazards to personnel and sensitive equipment and processes. Steel reinforcement in structures can act as a Faraday cage mitigating lightning effects. Knowing a structure's response to a lightning strike allows hazards associated with lightning to be analyzed. A model of lightning's response in a steel reinforced structure has been developed using PSpice (a commercial circuit simulation). Segments of rebar are modeled as inductors and resistors in series. A program has been written to take architectural information of a steel reinforced structure and "build" a circuit network that is analogous to the network of reinforcement in a facility. A severe current waveform (simulating a 99th percentile lightning strike), modeled as a current source, is introduced in the circuit network, and potential differences within the structure are determined using PSpice. A visual three-dimensional model of the facility displays the voltage distribution across the structure using color to indicate the potential difference relative to the floor. Clear air arcing distances can be calculated from the voltage distribution using a conservative value for the dielectric breakdown strength of air.

Series resonance inverter with triggered vacuum gaps

NASA Astrophysics Data System (ADS)

Damstra, Geert C.; Zhang, X.

1994-05-01

Series resonance inverters based on semi-conductor switching elements are well-known and have a wide range of application, mainly for lower voltages. For high voltage application many switching elements have to be put in series to obtain sufficient blocking voltage. Voltage grinding and multiple gate control elements are needed. There is much experience with the triggered vacuum gaps as high voltage/high current single shot elements, for example in reignition circuits for synthetic circuit breaker tests. These elements have a blocking voltage of 50 - 100 kV and are triggerable by a light fiber control device. A prototype inverter has been developed that generates 0.1 Hz, 30 kV AC voltages with a flat top for tests on cables and capacitors of many micro farads fed from a low voltage supply of about 600 V. Only two TVG elements are needed to switch the resonant circuit alternatively on the positive or negative supply. The resonant circuit itself consists of the capacitance of the testobject and a high quality inductor that determines the frequency and the peak current of the voltage reversing process.

Summary of EM launcher experiments performed at LLNL

NASA Astrophysics Data System (ADS)

Hawke, R. S.; Nellis, W. J.; Newman, G. H.; Rego, J.; Susoeff, A. R.

1986-11-01

Performance results for three railguns are summarized. The system used a helium gas-driven injector and railgun launcher to accelerate 1- and 4-g polycarbonate projectiles intact up to 6.6 and 3.0 km/sc, respectively. A 625 kJ capacitor bank powered the railgun, and an adjustable inductor provided pulse shaping and peak current control. Operation in hard and soft vacuum was reliably achieved. The diagnostic system measured the projectile position and launch velocity, verified that the projectile was launched intact in the desired direction, and identified system components where improvements could enhance performance. Flash X-ray radiography measured velocity and verified that projectiles were intact. Pre-launch projectile travel along the axis of the launcher without tilt was recorded with flash radiographs and impact impressions or holes in witness plates. The sysem performed as expected up to 4-5 km/sec but below expectations at higher velocities. Diagnostics suggest that the decreased performance was probably cuased by the restriking of a second arc in the breech of the railgun, which shunted the current from the propulsive arc.

The frequency-domain method of calculation for the pulsed electromagnetic field in a conductive ferromagnetic plate

NASA Astrophysics Data System (ADS)

Nosov, G. V.; Kuleshova, E. O.; Lefebvre, S.; Plyusnin, A. A.; Tokmashev, D. M.

2017-02-01

The technique for parameters determination of magnetic skin effect on ferromagnetic plate at a specified pulse of magnetic field intensity on the plate surface is proposed. It is based on a frequency-domain method and could be applied for a pulsing transformer, a dynamoelectric pulse generator and a commutating inductor that contains an imbricated core. Due to this technique, such plate parameters as specific heat loss energy, the average power of this energy and the plate temperature raise, the magnetic flux attenuation factor and the plate q-factor could be calculated. These parameters depend on the steel type, the amplitude, the rms value, the duration and the form of the magnetic field intensity impulse on the plate surface. The plate thickness is defined by the value of the flux attenuation factor and the plate q-factor that should be maximal. The reliability of the proposed technique is built on a common frequency-domain usage applicable for pulse transient study under zero boundary conditions of the electric circuit and the conformity of obtained results with the sinusoidal steady-state mode.

Using hot lab to increase pre-service physics teacher’s critical thinking skills related to the topic of RLC circuit

NASA Astrophysics Data System (ADS)

Malik, A.; Setiawan, A.; Suhandi, A.; Permanasari, A.; Samsudin, A.; Safitri, D.; Lisdiani, S. A. S.; Sapriadil, S.; Hermita, N.

2018-05-01

This research purposes to explore the used of Higher Order Thinking Laboratory (HOT-Lab) in enhancing the critical thinking skills of pre-service teachers related to the topic of Resistors, Inductors, Capacitor (RLC circuit). This study utilised a quasi-experiment method with Pretest-Posttest Control Group design. The sample of the study was 60 students that were divided into two groups covering in experiment and control group, consists of 30 students. The instrument for measuring critical thinking skills is essay test. Data has been analyzed using normalized gain average, effect size, and t-test. The results show that students’ critical thinking skills using the HOT Lab are higher than the verification lab. Using HOT-lab was implemented in the form of activity in the laboratory can improve high-order thinking skills. Hence, it was concluded that the use of HOT Lab had a greater impact on improving students’ critical thinking skills on RLC topic. Finally, HOT Lab can be used for other physics topics.

LC Circuits for Diagnosing Embedded Piezoelectric Devices

NASA Technical Reports Server (NTRS)

Chattin, Richard L.; Fox, Robert Lee; Moses, Robert W.; Shams, Qamar A.

2005-01-01

A recently invented method of nonintrusively detecting faults in piezoelectric devices involves measurement of the resonance frequencies of inductor capacitor (LC) resonant circuits. The method is intended especially to enable diagnosis of piezoelectric sensors, actuators, and sensor/actuators that are embedded in structures and/or are components of multilayer composite material structures.

Solar-Powered Supply Is Light and Reliable

NASA Technical Reports Server (NTRS)

Willis, A. E.; Garrett, H.; Matheney, J.

1982-01-01

DC supply originally intended for use in solar-powered spacecraft propulsion is lightweight and very reliable. Operates from 100-200 volt output of solar panels to produce 11 different dc voltages, with total demand of 3,138 watts. With exception of specially wound inductors and transformers, system uses readily available components.

Efficient/reliable dc-to-dc inverter circuit

NASA Technical Reports Server (NTRS)

Pasciutti, E. R.

1970-01-01

Feedback loop, which contains an inductor in series with a saturable reactor, is added to a standard inverter circuit to permit the inverter power transistors to be switched in a controlled and efficient manner. This inverter is applicable where the power source has either high or low impedance properties.

Charge-pump voltage converter

DOEpatents

Brainard, John P [Albuquerque, NM; Christenson, Todd R [Albuquerque, NM

2009-11-03

A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

Modification of graphene oxide films by radiofrequency N2 plasma

NASA Astrophysics Data System (ADS)

Neustroev, E. P.; Burtseva, E. K.; Soloviev, B. D.; Prokopiev, A. R.; Popov, V. I.; Timofeev, V. B.

2018-04-01

The effect of treatment in nitrogen plasma on the properties of partially reduced graphene oxide (rGO) was studied. A comparison is made between two different sample locations in the reaction chamber. It is shown that in the case when rGO films were turned towards the inductor of the plasma system, the etching rate is much higher. Effective nitrogen functionalization of rGO was established in the second position, when the rGO films were turned in the opposite direction. In this case, the nitrogen content increases to 5 at% of the initial value. The change in the current-voltage characteristics is observed under illumination, which is independent of the wavelength. On and off daylight changes the resistance to 30% of the initial value. The magnitude of the photocurrent increases depending on the applied voltage. The effect is most noticeable for thin rGO films 10-15 nm in thickness.

A High Voltage Ratio and Low Ripple Interleaved DC-DC Converter for Fuel Cell Applications

PubMed Central

Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

2012-01-01

This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters. PMID:23365536

Switch failure diagnosis based on inductor current observation for boost converters

NASA Astrophysics Data System (ADS)

Jamshidpour, E.; Poure, P.; Saadate, S.

2016-09-01

Face to the growing number of applications using DC-DC power converters, the improvement of their reliability is subject to an increasing number of studies. Especially in safety critical applications, designing fault-tolerant converters is becoming mandatory. In this paper, a switch fault-tolerant DC-DC converter is studied. First, some of the fastest Fault Detection Algorithms (FDAs) are recalled. Then, a fast switch FDA is proposed which can detect both types of failures; open circuit fault as well as short circuit fault can be detected in less than one switching period. Second, a fault-tolerant converter which can be reconfigured under those types of fault is introduced. Hardware-In-the-Loop (HIL) results and experimental validations are given to verify the validity of the proposed switch fault-tolerant approach in the case of a single switch DC-DC boost converter with one redundant switch.

Polarization-multiplexed 2×2 phosphor-LED wireless light communication without using analog equalization and optical blue filter

NASA Astrophysics Data System (ADS)

Yeh, C. H.; Chen, H. Y.; Liu, Y. L.; Chow, C. W.

2015-01-01

We propose and experimentally demonstrate a 380 (2×190) Mbps phosphor-light-emitting-diode (LED) based visible light communication (VLC) system by using 2×2 polarization-multiplexing design for in-building access applications. To the best of our knowledge, this is the first time of employing polarization-multiplexing to achieve a high VLC transmission capacity by using phosphor-based white-LED without optical blue filter. Besides, utilizing the optimum resistor-inductor-capacity (RLC) bias-tee design, it can not only perform the function of combining the direct-current (DC) and the electrical data signal, but also act as a simple LED-Tx circuit. No optical blue filter and complicated post-equalization are required at the Rx. Here, the orthogonal-frequency-division-multiplexing (OFDM) quadrature-amplitude-modulation (QAM) with bit-loading is employed to enhance the transmission data rate.

Design of a dual sensor probe array for internal field measurement in Versatile Experiment Spherical Torusa)

NASA Astrophysics Data System (ADS)

Jeong-hun, Yang; Chung, Kyoung-Jae; An, YoungHwa; Jung, Bong Ki; Jo, Jong Gab; Hwang, Y. S.

2012-10-01

A dual sensor probe array is designed and constructed for internal magnetic field measurement at Versatile Experiment Spherical Torus (VEST) at the Seoul National University. Simultaneous use of Hall sensors and chip inductors allows cross-calibration among the measurements and compensation for each other's weaknesses while their small sizes are expected to cause only mild plasma perturbations. Calibration of the dual sensor probe array, using a Helmholtz coil, shows good sensitivity for the magnetic field measurement of the VEST. Prior to Ohmic start-up, the magnetic field structure inside the vacuum chamber is measured by using the calibrated probe array. The dual sensor probe array is expected to be useful in analyzing the temporal magnetic field structure change during the magnetic reconnection and in reconstruction of the current profile during the discharge of the VEST device.

A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

PubMed

Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

2012-01-01

This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

Integrating DC/DC Conversion with Possible Reconfiguration within Submodule Solar Photovoltaic Systems

NASA Astrophysics Data System (ADS)

Huang, Peter Jen-Hung

This research first proposes a method to merge photovoltaic (PV) cells or PV panels within the internal components DC-DC converters. The purpose of this merged structure is to reconfigure the PV modules between series and parallel connections using high switching frequencies (hundreds of kHz). This leads to multi-levels of voltages and currents that become applied to the output filter of the converter. Further, this research introduces a concept of a switching cell that utilizes the reconfiguration of series and parallel connections in DC-DC converters. The switching occurs at high switching frequency and the switches can be integrated to be within the solar panels or in between the solar cells. The concept is generalized and applied to basic buck and boost topologies. As examples of the new types of converters: reconfigurable PV-buck and PV-boost converter topologies are presented. It is also possible to create other reconfigurable power converters: non-isolated and isolated topologies. Analysis, simulation and experimental verification for the reconfigurable PV-buck and PV-boost converters are presented extensively to illustrate proof of concept. Benefits and drawbacks of the new approach are discussed. The second part of this research proposes to utilize the internal solar cell capacitance and internal solar module wire parasitic inductances to replace the input capacitor and filter inductor in boost derived DC-DC converters for energy harvesting applications. High switching frequency (MHz) hard switched and resonant boost converters are proposed. Their analysis, simulation and experimental prototypes are presented. A specific proof-of-concept application is especially tested for foldable PV panels, which are known for their high internal wire inductance. The experimental converters successfully boost solar module voltage without adding any external input capacitance or filter inductor. Benefits and drawbacks of new proposed PV submodule integrated boost converters are discussed.

Inductive Non-Contact Position Sensor

NASA Technical Reports Server (NTRS)

Youngquist, Robert; Garcia, Alyssa; Simmons, Stephen

2010-01-01

Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter's windows. In this hardware, a mirror is translated such that its position corresponds to the defect's depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is preferable because the mirror is internal to the optical system and thus accessible. Based on requirements supplied by the window inspectors, the depth of the defects needs to be measured over a range of 200 microns with a resolution of about 100 nm and an accuracy of about 400 nm. These same requirements then apply to measuring the position of the mirror, and in addition, since this is a scanning system, a response time of about 10 ms is needed. A market search was conducted and no sensor that met these requirements that also fit into the available housing volume (less than one cubic inch) was found, so a novel sensor configuration was constructed to meet the requirements. This new sensor generates a nearly linearly varying magnetic field over a small region of space, which can easily be sampled, resulting in a voltage proportional to position. Experiments were done with a range of inductor values, drive voltages, drive frequencies, and inductor shapes. A rough mathematical model was developed for the device that, in most aspects, describes how it operates and what electrical parameters should be chosen for best performance. The final configuration met all the requirements, yielding a small rugged sensor that was easy to use and had nanometer resolution over more than the 200-micron range required. The inductive position sensor is a compact device (potentially as small as 2 cubic centimeters), which offers nanometer-position resolution over a demonstrated range of nearly 1 mm. One of its advantages is the simplicity of its electrical design. Also, the sensor resolution is nearly uniform across its operational range, which is in contrast to eddy current and capacitive sensors whose sensitivity is dependent upon position.

Microstructuring of Nickel Thin Films and Property Modification of Nickel Oxide Films by Pulsed Laser Irradiation

NASA Astrophysics Data System (ADS)

Itapu, Srikanth

In recent years, low-cost and high-performance compact integrated circuit (IC) components have begun to play a significant role in enhancing circuit performance. One of many such components include on-chip inductors which often consume large area for moderate inductance (L) values and have relatively low-quality factor (Q). Besides reducing the physical circuitry of IC components, enhanced L and Q are also required in radio-frequency (RF) applications. Various approaches to overcome such limitations have been explored in recent years, such as incorporating magnetic materials, laminating and patterning ferromagnetic thin films, utilizing in-plane and out-of-plane anisotropy to enhance magnetic fields, patterning ground shields, fabricating multi-layers of magnetic thin film, etc. In this dissertation, we report on the possibility of forming microbump structures on films of magnetic metals, such as nickel (Ni), by single-pulse localized laser irradiation. Microstructuring on various metal films have been studied and different theoretical models have been proposed in recent years. We identified laser, geometry, and film quality conditions under which fabrication of such microstructures is possible and then examined this technique as a method to improve/enhance the L and Q of on-chip spiral inductors. The nanosecond pulsed-laser irradiation technique offers the advantage of localized thermal heating, noncontact nature and high throughput as compared to conventional microstructuring methods. In order to exploit the advantages of laser microstructuring, we modeled an inductor stack with copper as inductor layer over a silica substrate. Various ferromagnetic thin film materials (Ni, Co, Fe, ferrite, permalloy) were introduced and studied as a function of thickness and material properties. The microstructuring was then modeled as equivalent hemispherical structures and studied in detail as a function of microstructure density and diameter of the microstructure. A significant increase in L and Q was observed due to the ferromagnetic material as well as the microstructuring. To verify the simulated results, a 0.8cm x 1 cm inductor stack consisting of Ni/SiO2/Cu on glass substrate is fabricated and laser assisted microstructuring is performed on Ni thin film deposited by sputtering and evaporation. For Ni film deposited by RF sputtering, a grain structure with a fine network of inter-grain gaps (or cracks) were observed from the SEM images. These inter-grain gaps result in poor heat conduction laterally and vertically, thus hindering the microbump formation. Hence, smooth Ni films were obtained by vacuum evaporation. The continuous nature of the film material (vs voids and cracks in the sputtered film case) resulted in radially symmetric thermal expansion and deformation the amount of which can be controlled (within certain limits) by the laser pulse energy. Hence, for the inductor stack with evaporated Ni thin film, a 7% increase in L and 9% increase in Q is observed when microstructuring is performed on 12% of the total inductor area. For a further increase in the microstructuring to 19 % of the total inductor area, a 9% increae in L and 10% increase in Q is observed. Similarly, recent studies indicate an exciting research in wide bandgap transition metal oxide semiconductors such as NiO to enhance room temperature ferromagnetism for multiferroic devices, supercapacitor application and resistive switching. Dopants such Cu, Li enhance the p-type conductivity of NiO films and have been studied extensively, both theoretically and experimentally. Hence, the effect of ultraviolet (UV) laser irradiation on the structural, electrical, and optical properties of nickel oxide (NiOx) thin films, deposited by reactive sputtering of nickel in an oxygen containing atmosphere was studied. It was found that the conduction type can be changed from p-type to n-type and the resistivity decreased as the number of laser pulses is increased. The as-deposited films are polycrystalline, while laser irradiation renders the films amorphous. The observed transition from O-rich NiOx as-deposited films to Ni-rich laser- irradiated NiOx can be significant to resistive switching and other applications. The band gap of the as-deposited and the laser irradiated NiOx films was obtained from spectroscopic ellipsometry measurements and was found to slightly increase upon laser irradiation. It was also observed that the surface roughness increases slightly. Doping NiO with transition metals such as Fe, Zr and lanthanide metals such as La were studied experimentally, but no theoretical analysis has been investigated in knowing the vacancy and interstitial behavior in doped NiO. In this dissertation, we study the effect of doping transition metals belonging to the nickel family, i.e. Pd and Pt on the properties of NiO. An equivalent model to mimic the effects of laser irradiation on the native defects of NiO was also developed by studying the Ni16O16 in a 32 cell structure. A comprehensive study of varying the doping concentration in NiO was performed as a result of which the density of states (DOS) calculations revealed a decrease in the bandgap of Pd-doped NiO from 3.8eV for 3% Pd doping to 2.5eV for 20% Pd in NiO. Similarly, for the case of Pt-doped NiO, a decrease in the bandgap from 2.5 eV for 3% Pt doping to 2eV for 20% Pt doping is observed. The substitution of Ni3+ ions in NiO by Pd3+ and Pt3+ ions respectively, results in a decrease in the lattice constant as compared to undoped NiO.

Direct-reading inductance meter

NASA Technical Reports Server (NTRS)

Kolbly, R. B.

1977-01-01

Meter indicates from 30 nH to 3 micro H. Reference inductor of 15 micro H is made by winding 50 turns of Number 26 Formvar wire on Micrometal type 50-2 (or equivalent) core. Circuit eliminates requirement for complex instrument compensation prior to taking coil inductance measurement and thus is as easy to operate as common ohmmeter.

High speed multiwire photon camera

NASA Technical Reports Server (NTRS)

Lacy, Jeffrey L. (Inventor)

1991-01-01

An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occuring during the readout window.

High speed multiwire photon camera

NASA Technical Reports Server (NTRS)

Lacy, Jeffrey L. (Inventor)

1989-01-01

An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occurring during the readout window.

The possible social representations of astronomy by students from integrated high school

NASA Astrophysics Data System (ADS)

Barbosa, J. I. L.; Voelzke, M. R.

2017-12-01

In this paper, we present the possible Social Representations, which students of the Integrated High School of the Federal Institute of Alagoas (IFAL) have on the term inductor Astronomy, as well as identifying how they were probably elaborated. Therefore, in agreement with Moscovici (2010) is used the Theory of Social Representations.

On-Chip Out-of-Plane High-Q Inductors

DTIC Science & Technology

2002-01-01

and leaves the substrate available for circuits. Magnetic forces [2] and the surface tension of a molten dot of solder [3] or polymer [4] have been...and P. Renaud, "High aspect ratio planar coils embedded in SU8 photoepoxy for MEMS applications," Tech. Digest Eurosensors XII, Southampton, Sep. 13-16

Thermoacoustic inductor for heavy oil extraction

NASA Astrophysics Data System (ADS)

Tyncherov, K. T.; Mukhametshin, V. Sh; Paderin, M. G.; Selivanova, M. V.; Shokurov, I. V.; Almukhametova, E. M.

2018-03-01

The problem of enhancing heavy oil reservoir performance is a matter of relevance for many years. Among the technologies aimed at solving this problem, the technology of the bottom-hole and well casing heating is the most interesting. This is a real possibility to transform thickened hydrocarbon into a recoverable state, as well as to solve the tasks of cleaning the borehole from asphaltenes, resins, and paraffin sediments. In both cases, the borehole area is generally warmed up and the product is then pumped out by the known techniques. The type of the equipment, the way of the well operation, the stage of reservoir development, physical and chemical properties of paraffin sediments, etc. are taken into consideration. In the article, basing on the electromagnetic induction method and the Joule effect, the advantages of induction heating compared to the traditional resistive and steam methods are presented. It is shown that under the induction exposure, the heat is not focused on the apparatus, but on heating the oily product. Basing on the method, a thermoacoustic inductor with unique technical characteristics has been developed.

Prostaglandin E2 induces expression of P-selectin (CD62P) on cultured human umbilical vein endothelial cells and enhances endothelial binding of CD4-T-cells.

PubMed

Hailer, N P; Oppermann, E; Leckel, K; Cinatl, J; Markus, B H; Blaheta, R A

2000-07-15

Interaction of endothelial P-selectin with sialyl Lewis(x)-glycoprotein or P-selectin glycoprotein ligand (PSGL)-1 on leukocytes represents an early step in leukocyte recruitment. Redistribution of P-selectin to the endothelial cell surface occurs rapidly after challenge with several proinflammatory agents, for example, histamine, leucopterins, or lipopolysaccharide. We present evidence that prostaglandin E2 (PGE2) is an efficient inductor of surface P-selectin on cultured human umbilical vein endothelial cells (HUVEC). The increase in P-selectin-immunoreactivity coincided with redistribution of cytoplasmic P-selectin-reactive granulae to the endothelial cell surface, as visualized by confocal laser microscopic examination. CD4-T-cell adhesion to PGE2-stimulated HUVEC was also enhanced by a factor of 4, and blocking mAb directed against the binding site of P-selectin almost completely abrogated this increase in CD4-T-cell adhesion. In summary, our findings show that liberation of PGE2 is an important inductor of P-selectin surface expression on endothelial cells, resulting in enhanced recruitment of inflammatory cells.

Adaptive synchronized switch damping on an inductor: a self-tuning switching law

NASA Astrophysics Data System (ADS)

Kelley, Christopher R.; Kauffman, Jeffrey L.

2017-03-01

Synchronized switch damping (SSD) techniques exploit low-power switching between passive circuits connected to piezoelectric material to reduce structural vibration. In the classical implementation of SSD, the piezoelectric material remains in an open circuit for the majority of the vibration cycle and switches briefly to a shunt circuit at every displacement extremum. Recent research indicates that this switch timing is only optimal for excitation exactly at resonance and points to more general optimal switch criteria based on the phase of the displacement and the system parameters. This work proposes a self-tuning approach that implements the more general optimal switch timing for synchronized switch damping on an inductor (SSDI) without needing any knowledge of the system parameters. The law involves a gradient-based search optimization that is robust to noise and uncertainties in the system. Testing of a physical implementation confirms this law successfully adapts to the frequency and parameters of the system. Overall, the adaptive SSDI controller provides better off-resonance steady-state vibration reduction than classical SSDI while matching performance at resonance.

Trap Design and Construction for High-Power Multinuclear Magnetic Resonance Experiments

PubMed Central

Rispoli, Joseph V.; Dimitrov, Ivan E.; Cheshkov, Sergey; Malloy, Craig; Wright, Steven M.; McDougall, Mary P.

2016-01-01

Performing multinuclear experiments requires one or more radiofrequency (RF) coils operating at both the proton and second-nucleus frequencies; however, inductive coupling between coils must be mitigated to retain proton sensitivity and coil tuning stability. The inclusion of trap circuits simplifies placement of multinuclear RF coils while maintaining inter-element isolation. Of the commonly investigated non-proton nuclei, perhaps the most technically demanding is carbon-13, particularly when applying a proton decoupling scheme to improve the resulting spectra. This work presents experimental data for trap circuits withstanding high-power broadband proton decoupling of carbon-13 at 7 T. The advantages and challenges of building trap circuits with various inductor and capacitor components are discussed. Multiple trap designs are evaluated on the bench and utilized on an RF coil at 7 T to detect broadband proton-decoupled carbon-13 spectra from a lipid phantom. A particular trap design, built from a coaxial stub inductor and high-voltage ceramic chip capacitors, is highlighted owing to both its performance and adaptability for planar array coil elements with diverse spatial orientations. PMID:28529464

Design and implementation of improved LsCpLp resonant circuit for power supply for high-power electromagnetic acoustic transducer excitation

NASA Astrophysics Data System (ADS)

Zao, Yongming; Ouyang, Qi; Chen, Jiawei; Zhang, Xinglan; Hou, Shuaicheng

2017-08-01

This paper investigates the design and implementation of an improved series-parallel inductor-capacitor-inductor (LsCpLp) resonant circuit power supply for excitation of electromagnetic acoustic transducers (EMATs). The main advantage of the proposed resonant circuit is the absence of a high-permeability dynamic transformer. A high-frequency pulsating voltage gain can be achieved through a double resonance phenomenon. Both resonant tailing behavior and higher harmonics are suppressed by the improved resonant circuit, which also contributes to the generation of ultrasonic waves. Additionally, the proposed circuit can realize impedance matching and can also optimize the transduction efficiency. The complete design and implementation procedure for the power supply is described and has been validated by implementation of the proposed power supply to drive a portable EMAT. The circuit simulation results show close agreement with the experimental results and thus confirm the validity of the proposed topology. The proposed circuit is suitable for use as a portable EMAT excitation power supply that is fed by a low-voltage source.

SiGe BiCMOS manufacturing platform for mmWave applications

NASA Astrophysics Data System (ADS)

Kar-Roy, Arjun; Howard, David; Preisler, Edward; Racanelli, Marco; Chaudhry, Samir; Blaschke, Volker

2010-10-01

TowerJazz offers high volume manufacturable commercial SiGe BiCMOS technology platforms to address the mmWave market. In this paper, first, the SiGe BiCMOS process technology platforms such as SBC18 and SBC13 are described. These manufacturing platforms integrate 200 GHz fT/fMAX SiGe NPN with deep trench isolation into 0.18μm and 0.13μm node CMOS processes along with high density 5.6fF/μm2 stacked MIM capacitors, high value polysilicon resistors, high-Q metal resistors, lateral PNP transistors, and triple well isolation using deep n-well for mixed-signal integration, and, multiple varactors and compact high-Q inductors for RF needs. Second, design enablement tools that maximize performance and lowers costs and time to market such as scalable PSP and HICUM models, statistical and Xsigma models, reliability modeling tools, process control model tools, inductor toolbox and transmission line models are described. Finally, demonstrations in silicon for mmWave applications in the areas of optical networking, mobile broadband, phased array radar, collision avoidance radar and W-band imaging are listed.

Structural modulation of silver complexes and their distinctive catalytic properties.

PubMed

Zhao, Yue; Chen, Kai; Fan, Jian; Okamura, Taka-aki; Lu, Yi; Luo, Li; Sun, Wei-Yin

2014-02-07

A family of silver(I) complexes, [Ag2(L)2(OOCCF3)2] (1), [Ag(L)0.5(OOCCF3)] (2), [Ag(L)2](OOCCF3)(H2O)2 (3), was obtained by reactions of 4,4'-di(2-oxazolinyl)biphenyl (L) and AgOOCCF3 in different reaction media. Compound 1 has a 1D chain structure with alternative connections between the Ag(I) and L ligand. When the crystal nucleation inductor, pyrazine, was added into the reaction system, complex 2 was isolated with no pyrazine observed in its structure. In 2, the 1D inorganic chains formed by Ag(I) cations and OOCCF3(-) anions were connected by the L ligand to produce a 2D network. When a different inductor, imidazole, was added into the reaction system, 3 with (4,4) topology was synthesized, and again no imidazole was found in 3. When 1-3 were used as catalysts for cycloaddition reactions between imino esters and methyl acrylate, 3 affords the highest yield, in which the particular size of the channels in 3 led to its selective catalytic performance.

Phasor Domain Steady-State Modeling and Design of the DC–DC Modular Multilevel Converter

DOE PAGES

Yang, Heng; Qin, Jiangchao; Debnath, Suman; ...

2016-01-06

The DC-DC Modular Multilevel Converter (MMC), which originated from the AC-DC MMC, is an attractive converter topology for interconnection of medium-/high-voltage DC grids. This paper presents design considerations for the DC-DC MMC to achieve high efficiency and reduced component sizes. A steady-state mathematical model of the DC-DC MMC in the phasor-domain is developed. Based on the developed model, a design approach is proposed to size the components and to select the operating frequency of the converter to satisfy a set of design constraints while achieving high efficiency. The design approach includes sizing of the arm inductor, Sub-Module (SM) capacitor, andmore » phase filtering inductor along with the selection of AC operating frequency of the converter. The accuracy of the developed model and the effectiveness of the design approach are validated based on the simulation studies in the PSCAD/EMTDC software environment. The analysis and developments of this paper can be used as a guideline for design of the DC-DC MMC.« less

Silicon controlled rectifier polyphase bridge inverter commutated with gate-turn-off thyristor

NASA Technical Reports Server (NTRS)

Edwards, Dean B. (Inventor); Rippel, Wally E. (Inventor)

1986-01-01

A polyphase SCR inverter (10) having N switching poles, each comprised of two SCR switches (1A, 1B; 2A, 2B . . . NA, NB) and two diodes (D1B; D1B; D2A, D2B . . . DNA, DNB) in series opposition with saturable reactors (L1A, L1B; L2A, L2B . . . LNA, LNB) connecting the junctions between the SCR switches and diodes to an output terminal (1, 2 . . . 3) is commutated with only one GTO thyristor (16) connected between the common negative terminal of a dc source and a tap of a series inductor (14) connected to the positive terminal of the dc source. A clamp winding (22) and diode (24) are provided, as is a snubber (18) which may have its capacitance (c) sized for maximum load current divided into a plurality of capacitors (C.sub.1, C.sub.2 . . . C.sub.N), each in series with an SCR switch S.sub.1, S.sub.2 . . . S.sub.N). The total capacitance may be selected by activating selected switches as a function of load current. A resistor 28 and SCR switch 26 shunt reverse current when the load acts as a generator, such as a motor while braking.

A Single-Phase Current Source Solar Inverter with Constant Instantaneous Power, Improved Reliability, and Reduced-Size DC-Link Filter

NASA Astrophysics Data System (ADS)

Bush, Craig R.

This dissertation presents a novel current source converter topology that is primarily intended for single-phase photovoltaic (PV) applications. In comparison with the existing PV inverter technology, the salient features of the proposed topology are: a) the low frequency (double of line frequency) ripple that is common to single-phase inverters is greatly reduced; b) the absence of low frequency ripple enables significantly reduced size pass components to achieve necessary DC-link stiffness and c) improved maximum power point tracking (MPPT) performance is readily achieved due to the tightened current ripple even with reduced-size passive components. The proposed topology does not utilize any electrolytic capacitors. Instead an inductor is used as the DC-link filter and reliable AC film capacitors are utilized for the filter and auxiliary capacitor. The proposed topology has a life expectancy on par with PV panels. The proposed modulation technique can be used for any current source inverter where an unbalanced three-phase operation is desires such as active filters and power controllers. The proposed topology is ready for the next phase of microgrid and power system controllers in that it accepts reactive power commands. This work presents the proposed topology and its working principle supported by with numerical verifications and hardware results. Conclusions and future work are also presented.

Modular Coils with Low Hydrogen Content Especially for MRI of Dry Solids.

PubMed

Eichhorn, Timon; Ludwig, Ute; Fischer, Elmar; Gröbner, Jens; Göpper, Michael; Eisenbeiss, Anne-Katrin; Flügge, Tabea; Hennig, Jürgen; von Elverfeldt, Dominik; Hövener, Jan-Bernd

2015-01-01

Recent advances have enabled fast magnetic resonance imaging (MRI) of solid materials. This development has opened up new applications for MRI, but, at the same time, uncovered new challenges. Previously, MRI-invisible materials like the housing of MRI detection coils are now readily depicted and either cause artifacts or lead to a decreased image resolution. In this contribution, we present versatile, multi-nuclear single and dual-tune MRI coils that stand out by (1) a low hydrogen content for high-resolution MRI of dry solids without artifacts; (2) a modular approach with exchangeable inductors of variable volumes to optimally enclose the given object; (3) low cost and low manufacturing effort that is associated with the modular approach; (4) accurate sample placement in the coil outside of the bore, and (5) a wide, single- or dual-tune frequency range that covers several nuclei and enables multinuclear MRI without moving the sample. The inductors of the coils were constructed from self-supporting copper sheets to avoid all plastic materials within or around the resonator. The components that were mounted at a distance from the inductor, including the circuit board, coaxial cable and holder were manufactured from polytetrafluoroethylene. Residual hydrogen signal was sufficiently well suppressed to allow 1H-MRI of dry solids with a minimum field of view that was smaller than the sensitive volume of the coil. The SNR was found to be comparable but somewhat lower with respect to commercial, proton-rich quadrature coils, and higher with respect to a linearly-polarized commercial coil. The potential of the setup presented was exemplified by 1H/23Na high-resolution zero echo time (ZTE) MRI of a model solution and a dried human molar at 9.4 T. A full 3D image dataset of the tooth was obtained, rich in contrast and similar to the resolution of standard cone-beam computed tomography.

Modular Coils with Low Hydrogen Content Especially for MRI of Dry Solids

PubMed Central

Fischer, Elmar; Gröbner, Jens; Göpper, Michael; Eisenbeiss, Anne-Katrin; Flügge, Tabea; Hennig, Jürgen; von Elverfeldt, Dominik; Hövener, Jan-Bernd

2015-01-01

Introduction Recent advances have enabled fast magnetic resonance imaging (MRI) of solid materials. This development has opened up new applications for MRI, but, at the same time, uncovered new challenges. Previously, MRI-invisible materials like the housing of MRI detection coils are now readily depicted and either cause artifacts or lead to a decreased image resolution. In this contribution, we present versatile, multi-nuclear single and dual-tune MRI coils that stand out by (1) a low hydrogen content for high-resolution MRI of dry solids without artifacts; (2) a modular approach with exchangeable inductors of variable volumes to optimally enclose the given object; (3) low cost and low manufacturing effort that is associated with the modular approach; (4) accurate sample placement in the coil outside of the bore, and (5) a wide, single- or dual-tune frequency range that covers several nuclei and enables multinuclear MRI without moving the sample. Materials and Methods The inductors of the coils were constructed from self-supporting copper sheets to avoid all plastic materials within or around the resonator. The components that were mounted at a distance from the inductor, including the circuit board, coaxial cable and holder were manufactured from polytetrafluoroethylene. Results and Conclusion Residual hydrogen signal was sufficiently well suppressed to allow 1H-MRI of dry solids with a minimum field of view that was smaller than the sensitive volume of the coil. The SNR was found to be comparable but somewhat lower with respect to commercial, proton-rich quadrature coils, and higher with respect to a linearly-polarized commercial coil. The potential of the setup presented was exemplified by 1H / 23Na high-resolution zero echo time (ZTE) MRI of a model solution and a dried human molar at 9.4 T. A full 3D image dataset of the tooth was obtained, rich in contrast and similar to the resolution of standard cone-beam computed tomography. PMID:26496192

Noise Figure Optimization of Fully Integrated Inductively Degenerated Silicon Germanium HBT LNAs

NASA Astrophysics Data System (ADS)

Ibrahim, Mohamed Farhat

Silicon germanium (SiGe) heterojunction bipolar transistors (HBTs) have the properties of producing very low noise and high gain over a wide bandwidth. Because of these properties, SiGe HBTs have continually improved and now compete with InP and GaAs HEMTs for low-noise amplification. This thesis investigates the theoretical characterizations and optimizations of SiGe HBT low noise amplifiers (LNAs) for low-noise low-power applications, using SiGe BiCMOS (bipolar complementary metal-oxide-semiconductor) technology. The theoretical characterization of SiGe HBT transistors is investigated by a comprehensive study of the DC and small-signal transistor modeling. Based on a selected small-signal model, a noise model for the SiGe HBT transistor is produced. This noise model is used to build a cascode inductively degenerated SiGe HBT LNA circuit. The noise figure (NF) equation for this LNA is derived. This NF equation shows better than 94.4% agreement with the simulation results. With the small-signal model verification, a new analytical method for optimizing the noise figure of the SiGe HBT LNA circuits is presented. The novelty feature of this optimization is the inclusion of the noise contributions of the base inductor parasitic resistance, the emitter inductor parasitic resistance and the bond-wire inductor parasitic resistances. The optimization is performed by reducing the number of design variables as possible. This improved theoretical optimization results in LNA designs that achieve better noise figure performance compared to previously published results in bipolar and BiCMOS technologies. Different design constraints are discussed for the LNA optimization techniques. Three different LNAs are designed. The three designs are fully integrated and fabricated in a single chip to achieve a fully monolithic realization. The LNA designs are experimentally verified. The low noise design produced a NF of 1.5dB, S21 of 15dB, and power consumption of 15mW. The three LNA designs occupied 1.4mum 2 in 130 nm BiCMOS technology.

Variable dual-frequency electrostatic wave launcher for plasma applications.

PubMed

Jorns, Benjamin; Sorenson, Robert; Choueiri, Edgar

2011-12-01

A variable tuning system is presented for launching two electrostatic waves concurrently in a magnetized plasma. The purpose of this system is to satisfy the wave launching requirements for plasma applications where maximal power must be coupled into two carefully tuned electrostatic waves while minimizing erosion to the launching antenna. Two parallel LC traps with fixed inductors and variable capacitors are used to provide an impedance match between a two-wave source and a loop antenna placed outside the plasma. Equivalent circuit analysis is then employed to derive an analytical expression for the normalized, average magnetic flux density produced by the antenna in this system as a function of capacitance and frequency. It is found with this metric that the wave launcher can couple to electrostatic modes at two variable frequencies concurrently while attenuating noise from the source signal at undesired frequencies. An example based on an experiment for plasma heating with two electrostatic waves is used to demonstrate a procedure for tailoring the wave launcher to accommodate the frequency range and flux densities of a specific two-wave application. This example is also used to illustrate a method based on averaging over wave frequencies for evaluating the overall efficacy of the system. The wave launcher is shown to be particularly effective for the illustrative example--generating magnetic flux densities in excess of 50% of the ideal case at two variable frequencies concurrently--with a high adaptability to a number of plasma dynamics and heating applications.

Time-dependent quantum transport and power-law decay of the transient current in a nano-relay and nano-oscillator

NASA Astrophysics Data System (ADS)

Cuansing, Eduardo C.; Liang, Gengchiau

2011-10-01

Time-dependent nonequilibrium Green's functions are used to study electron transport properties in a device consisting of two linear chain leads and a time-dependent interlead coupling that is switched on non-adiabatically. We derive a numerically exact expression for the particle current and examine its characteristics as it evolves in time from the transient regime to the long-time steady-state regime. We find that just after switch-on, the current initially overshoots the expected long-time steady-state value, oscillates and decays as a power law, and eventually settles to a steady-state value consistent with the value calculated using the Landauer formula. The power-law parameters depend on the values of the applied bias voltage, the strength of the couplings, and the speed of the switch-on. In particular, the oscillating transient current decays away longer for lower bias voltages. Furthermore, the power-law decay nature of the current suggests an equivalent series resistor-inductor-capacitor circuit wherein all of the components have time-dependent properties. Such dynamical resistive, inductive, and capacitive influences are generic in nano-circuits where dynamical switches are incorporated. We also examine the characteristics of the dynamical current in a nano-oscillator modeled by introducing a sinusoidally modulated interlead coupling between the two leads. We find that the current does not strictly follow the sinusoidal form of the coupling. In particular, the maximum current does not occur during times when the leads are exactly aligned. Instead, the times when the maximum current occurs depend on the values of the bias potential, nearest-neighbor coupling, and the interlead coupling.

Relating the Stored Magnetic Energy of a Parallel-Plate Inductor to the Work of External Forces

ERIC Educational Resources Information Center

Gauthier, N.

2007-01-01

Idealized models are often used in introductory physics courses. For one, such models involve simple mathematics, which is a definite plus since complex mathematical manipulations quickly become an obstacle rather than a tool for a beginner. Idealized models facilitate a student's understanding and grasp of a given physical phenomenon, yet they…

Dissipation, Voltage Profile and Levy Dragon in a Special Ladder Network

ERIC Educational Resources Information Center

Ucak, C.

2009-01-01

A ladder network constructed by an elementary two-terminal network consisting of a parallel resistor-inductor block in series with a parallel resistor-capacitor block sometimes is said to have a non-dispersive dissipative response. This special ladder network is created iteratively by replacing the elementary two-terminal network in place of the…

Radio frequency telemetry system for sensors and actuators

NASA Technical Reports Server (NTRS)

Simons, Rainee N. (Inventor); Miranda, Felix A. (Inventor)

2003-01-01

The present invention discloses and teaches apparatus for combining Radio Frequency (RF) technology with novel micro-inductor antennas and signal processing circuits for RF telemetry of real time, measured data, from microelectromechanical system (MEMS) sensors, through electromagnetic coupling with a remote powering/receiving device. Such technology has many applications, but is especially useful in the biomedical area.

Radio Frequency Telemetry System for Sensors and Actuators

NASA Technical Reports Server (NTRS)

Simons, Rainee N. (Inventor); Miranda, Felix A. (Inventor)

2003-01-01

The present invention discloses and teaches apparatus for combining Radio Frequency (RF) technology with novel micro-inductor antennas and signal processing circuits for RF telemetry of real time, measured data, from microelectromechanical system (MEMS) sensors, through electromagnetic coupling with a remote poweringheceiving device. Such technology has many applications, but is especially useful in the biomedical area.

Repetitive resonant railgun power supply

DOEpatents

Honig, E.M.; Nunnally, W.C.

1985-06-19

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

A Reaction that Takes Place in Beakers but not in Conical Flasks

ERIC Educational Resources Information Center

White, Colin; Ophardt, Charles

2004-01-01

Inductors are substances that undergo a reaction and in so doing markedly accelerate or induce a simultaneous reaction. An experiment showing a reaction involving the oxidation of iodide to iodine by chromium (VI) found to be slow in the absence of acid, but which proceeded rapidly when iron (II) was induced is demonstrated.

Repetitive resonant railgun power supply

DOEpatents

Honig, Emanuel M.; Nunnally, William C.

1988-01-01

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

The Elusive Memristor: Properties of Basic Electrical Circuits

ERIC Educational Resources Information Center

Joglekar, Yogesh N.; Wolf, Stephen J.

2009-01-01

We present an introduction to and a tutorial on the properties of the recently discovered ideal circuit element, a memristor. By definition, a memristor M relates the charge "q" and the magnetic flux [phi] in a circuit and complements a resistor R, a capacitor C and an inductor L as an ingredient of ideal electrical circuits. The properties of…

Jet in jet in M87

NASA Astrophysics Data System (ADS)

Sob'yanin, Denis Nikolaevich

2017-11-01

New high-resolution Very Long Baseline Interferometer observations of the prominent jet in the M87 radio galaxy show a persistent triple-ridge structure of the transverse 15-GHz profile with a previously unobserved ultra-narrow central ridge. This radio structure can reflect the intrinsic structure of the jet, so that the jet as a whole consists of two embedded coaxial jets. A relativistic magnetohydrodynamic model is considered in which an inner jet is placed inside a hollow outer jet and the electromagnetic fields, pressures and other physical quantities are found. The entire jet is connected to the central engine that plays the role of a unipolar inductor generating voltage between the jets and providing opposite electric currents, and the charge neutrality and current closure together with the electromagnetic fields between the jets can contribute to the jet stabilization. The constant voltage is responsible for the similar widening laws observed for the inner and outer jets. This jet-in-jet structure can indicate simultaneous operation of two different jet-launching mechanisms, one relating to the central supermassive black hole and the other to the surrounding accretion disc. An inferred magnetic field of 80 G at the base is sufficient to provide the observed jet luminosity.

PSpice Model of Lightning Strike to a Steel Reinforced Structure

NASA Astrophysics Data System (ADS)

Koone, Neil; Condren, Brian

2003-12-01

Surges and arcs from lightning can pose hazards to personnel and sensitive equipment, and processes. Steel reinforcement in structures can act as a Faraday cage mitigating lightning effects. Knowing a structure's response to a lightning strike allows hazards associated with lightning to be analyzed. A model of lightning's response in a steel reinforced structure has been developed using PSpice (a commercial circuit simulation). Segments of rebar are modeled as inductors and resistors in series. A program has been written to take architectural information of a steel reinforced structure and "build" a circuit network that is analogous to the network of reinforcement in a facility. A severe current waveform (simulating a 99th percentile lightning strike), modeled as a current source, is introduced in the circuit network, and potential differences within the structure are determined using PSpice. A visual three-dimensional model of the facility displays the voltage distribution across the structure using color to indicate the potential difference relative to the floor. Clear air arcing distances can be calculated from the voltage distribution using a conservative value for the dielectric breakdown strength of air. Potential validation tests for the model will be presented.

A complete electrical shock hazard classification system and its application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordon, Lloyd; Cartelli, Laura; Graham, Nicole

Current electrical safety standards evolved to address the hazards of 60-Hz power that are faced primarily by electricians, linemen, and others performing facility and utility work. As a result, this leaves a substantial gap in the management of electrical hazards in Research and Development (R&D) and specialized high voltage and high power equipment. We find substantial use of direct current (dc) electrical energy, and the use of capacitors, inductors, batteries, and radiofrequency (RF) power. The electrical hazards of these forms of electricity and their systems are different than for 50/60 Hz power. This paper proposes a method of classifying allmore » of the electrical shock hazards found in all types of R&D and utilization equipment. Examples of the variation of these hazards from NFPA 70E include (a) high voltage can be harmless, if the available current is sufficiently low, (b) low voltage can be harmful if the available current/power is high, (c) high voltage capacitor hazards are unique and include severe reflex action, affects on the heart, and tissue damage, and (d) arc flash hazard analysis for dc and capacitor systems are not provided in existing standards. This work has led to a comprehensive electrical hazard classification system that is based on various research conducted over the past 100 years, on analysis of such systems in R&D, and on decades of experience. Lastly, the new comprehensive electrical shock hazard classification system uses a combination of voltage, shock current available, fault current available, power, energy, and waveform to classify all forms of electrical hazards.« less

A complete electrical shock hazard classification system and its application

DOE PAGES

Gordon, Lloyd; Cartelli, Laura; Graham, Nicole

2018-02-08

Current electrical safety standards evolved to address the hazards of 60-Hz power that are faced primarily by electricians, linemen, and others performing facility and utility work. As a result, this leaves a substantial gap in the management of electrical hazards in Research and Development (R&D) and specialized high voltage and high power equipment. We find substantial use of direct current (dc) electrical energy, and the use of capacitors, inductors, batteries, and radiofrequency (RF) power. The electrical hazards of these forms of electricity and their systems are different than for 50/60 Hz power. This paper proposes a method of classifying allmore » of the electrical shock hazards found in all types of R&D and utilization equipment. Examples of the variation of these hazards from NFPA 70E include (a) high voltage can be harmless, if the available current is sufficiently low, (b) low voltage can be harmful if the available current/power is high, (c) high voltage capacitor hazards are unique and include severe reflex action, affects on the heart, and tissue damage, and (d) arc flash hazard analysis for dc and capacitor systems are not provided in existing standards. This work has led to a comprehensive electrical hazard classification system that is based on various research conducted over the past 100 years, on analysis of such systems in R&D, and on decades of experience. Lastly, the new comprehensive electrical shock hazard classification system uses a combination of voltage, shock current available, fault current available, power, energy, and waveform to classify all forms of electrical hazards.« less

Application of the double relaxation oscillation superconducting quantum interference device sensor to micro-tesla 1H nuclear magnetic resonance experiments

NASA Astrophysics Data System (ADS)

Kang, Chan Seok; Kim, Kiwoong; Lee, Seong-Joo; Hwang, Seong-min; Kim, Jin-Mok; Yu, Kwon Kyu; Kwon, Hyukchan; Lee, Sang Kil; Lee, Yong-Ho

2011-09-01

We developed an ultra-low field (ULF)-nuclear magnetic resonance (NMR) measurement system capable of working with a measurement field (Bm) of several micro-tesla and performed basic NMR studies with a double relaxation oscillation superconducting quantum interference device (DROS) instead of conventional dc-SQUIDs. DROS is a SQUID sensor utilizing a relaxation oscillation between a dc-SQUID and a relaxation circuit; the new unit consists of an inductor and a resistor, and is connected in parallel with the SQUID. DROS has a 10 times larger flux-to-voltage transfer coefficient (˜mV/ϕ0) than that of the dc-SQUID, and this large transfer coefficient enables the acquisition of the SQUID signal with a simple flux-locked-loop (FLL) circuit using room temperature pre-amplifiers. The DROS second-order gradiometer showed average field noise of 9.2 μϕ0/√Hz in a magnetically shielded room (MSR). In addition, a current limiter formed of a Josephson junction array was put in a flux-transformer of DROS to prevent excessive currents that can be generated from the high pre-polarization field (Bp). Using this system, we measured an 1H NMR signal in water under 2.8 μT Bm field and reconstructed a one-dimensional MR image from the 1H NMR signal under a gradient field BG of 4.09 nT/mm. In addition, we confirmed that the ULF-NMR system can measure the NMR signal in the presence of metal without any distortion by measuring the NMR signal of a sample wrapped with metal. Lastly, we have measured the scalar J-coupling of trimethylphosphate and were able to confirm a clear doublet NMR signal with the coupling strength J3[P,H] = 10.4 ± 0.8 Hz. Finally, because the existing ULF-NMR/MRI studies were almost all performed with dc-SQUID based systems, we constructed a dc-SQUID-based ULF-NMR system in addition to the DROS based system and compared the characteristics of the two different systems by operating the two systems under identical experimental conditions.

Wireless Displacement Sensing of Micromachined Spiral-Coil Actuator Using Resonant Frequency Tracking

PubMed Central

Ali, Mohamed Sultan Mohamed; AbuZaiter, Alaa; Schlosser, Colin; Bycraft, Brad; Takahata, Kenichi

2014-01-01

This paper reports a method that enables real-time displacement monitoring and control of micromachined resonant-type actuators using wireless radiofrequency (RF). The method is applied to an out-of-plane, spiral-coil microactuator based on shape-memory-alloy (SMA). The SMA spiral coil forms an inductor-capacitor resonant circuit that is excited using external RF magnetic fields to thermally actuate the coil. The actuation causes a shift in the circuit's resonance as the coil is displaced vertically, which is wirelessly monitored through an external antenna to track the displacements. Controlled actuation and displacement monitoring using the developed method is demonstrated with the microfabricated device. The device exhibits a frequency sensitivity to displacement of 10 kHz/μm or more for a full out-of-plane travel range of 466 μm and an average actuation velocity of up to 155 μm/s. The method described permits the actuator to have a self-sensing function that is passively operated, thereby eliminating the need for separate sensors and batteries on the device, thus realizing precise control while attaining a high level of miniaturization in the device. PMID:25014100

Regulation of a lightweight high efficiency capacitator diode voltage multiplier dc-dc converter

NASA Technical Reports Server (NTRS)

Harrigill, W. T., Jr.; Myers, I. T.

1976-01-01

A method for the regulation of a capacitor diode voltage multiplier dc-dc converter has been developed which has only minor penalties in weight and efficiency. An auxiliary inductor is used, which only handles a fraction of the total power, to control the output voltage through a pulse width modulation method in a buck boost circuit.

EMP Preferred Test Procedures. Revision

DTIC Science & Technology

1977-02-01

r _ -P ~PREFERRED TEST PROCEDURES,r- -Hnbo -Tkeltted Elec-ront’c Parts) .... . ITR Projs.E6230,E6261, J.E. Bridges W.C. Emberson V.P. Nanda DNA QQ-72...Connectors Surface Transfer Impedance Shielded Enclosures Surface Transfer Admittance Shielded Rooms E- Field Shielding Conduits Effectiveness Resistor Damage H... Field Shielding Capacitor Damage Effectiveness Inductor Damage Conduit Couplers Transformer Damage Capacitor Characterization Resistor

A novel compact low impedance Marx generator with quasi-rectangular pulse output

NASA Astrophysics Data System (ADS)

Liu, Hongwei; Jiang, Ping; Yuan, Jianqiang; Wang, Lingyun; Ma, Xun; Xie, Weiping

2018-04-01

In this paper, a novel low impedance compact Marx generator with near-square pulse output based on the Fourier theory is developed. Compared with the traditional Marx generator, capacitors with different capacity have been used. It can generate a high-voltage quasi-rectangular pulse with a width of 100 ns at low impedance load, and it also has high energy density and power density. The generator consists of 16 modules. Each module comprises an integrative single-ended plastic case capacitor with a nominal value of 54 nF, four ceramic capacitors with a nominal value of 1.5 nF, a gas switch, a charging inductor, a grounding inductor, and insulators which provide mechanical support for all elements. In the module, different discharge periods from different capacitors add to the main circuit to form a quasi-rectangular pulse. The design process of the generator is analyzed, and the test results are provided here. The generator achieved pulse output with a rise time of 32 ns, pulse width of 120 ns, flat-topped width (95%-95%) of 50 ns, voltage of 550 kV, and power of 20 GW.

Control of nanoparticle agglomeration through variation of the time-temperature profile in chemical vapor synthesis

NASA Astrophysics Data System (ADS)

Djenadic, Ruzica; Winterer, Markus

2017-02-01

The influence of the time-temperature history on the characteristics of nanoparticles such as size, degree of agglomeration, or crystallinity is investigated for chemical vapor synthesis (CVS). A simple reaction-coagulation-sintering model is used to describe the CVS process, and the results of the model are compared to experimental data. Nanocrystalline titania is used as model material. Titania nanoparticles are generated from titanium-tetraisopropoxide (TTIP) in a hot-wall reactor. Pure anatase particles and mixtures of anatase, rutile (up to 11 vol.%), and brookite (up to 29 vol.%) with primary particle sizes from 1.7 nm to 10.5 nm and agglomerate particle sizes from 24.3 nm to 55.6 nm are formed depending on the particle time-temperature history. An inductively heated furnace with variable inductor geometry is used as a novel system to control the time-temperature profile in the reactor externally covering a large wall temperature range from 873 K to 2023 K. An appropriate choice of inductor geometry, i.e. time-temperature profile, can significantly reduce the degree of agglomeration. Other particle characteristics such as crystallinity are also substantially influenced by the time-temperature profile.

Magnetically switched power supply system for lasers

NASA Technical Reports Server (NTRS)

Pacala, Thomas J. (Inventor)

1987-01-01

A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse generating circuit is coupled to the laser for generating a high voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser.

Nanofluidic Transistor Circuits

NASA Astrophysics Data System (ADS)

Chang, Hsueh-Chia; Cheng, Li-Jing; Yan, Yu; Slouka, Zdenek; Senapati, Satyajyoti

2012-02-01

Non-equilibrium ion/fluid transport physics across on-chip membranes/nanopores is used to construct rectifying, hysteretic, oscillatory, excitatory and inhibitory nanofluidic elements. Analogs to linear resistors, capacitors, inductors and constant-phase elements were reported earlier (Chang and Yossifon, BMF 2009). Nonlinear rectifier is designed by introducing intra-membrane conductivity gradient and by asymmetric external depletion with a reverse rectification (Yossifon and Chang, PRL, PRE, Europhys Lett 2009-2011). Gating phenomenon is introduced by functionalizing polyelectrolytes whose conformation is field/pH sensitive (Wang, Chang and Zhu, Macromolecules 2010). Surface ion depletion can drive Rubinstein's microvortex instability (Chang, Yossifon and Demekhin, Annual Rev of Fluid Mech, 2012) or Onsager-Wien's water dissociation phenomenon, leading to two distinct overlimiting I-V features. Bipolar membranes exhibit an S-hysteresis due to water dissociation (Cheng and Chang, BMF 2011). Coupling the hysteretic diode with some linear elements result in autonomous ion current oscillations, which undergo classical transitions to chaos. Our integrated nanofluidic circuits are used for molecular sensing, protein separation/concentration, electrospray etc.

Silane surface modification effects on the electromagnetic properties of phosphatized iron-based SMCs

NASA Astrophysics Data System (ADS)

Fan, Liang-Fang; Hsiang, Hsing-I.; Hung, Jia-Jing

2018-03-01

It is difficult to achieve homogeneous phosphatized iron powder dispersion in organic resins during the preparation of soft magnetic composites (SMCs). Inhomogeneous iron powder mixing in organic resins generally leads to the formation of micro-structural defects in SMCs and hence causes the magnetic properties to become worse. Phosphatized iron powder dispersion in organic resins can be improved by coating the phosphatized iron powder surfaces with a coupling agent. This study investigated the (3-aminopropyl) triethoxysilane (APTES) surface modification effects on the electromagnetic properties of phosphatized iron-based soft magnetic composites (SMCs). The results showed that the phosphatized iron powder surface can be modified using APTES to improve the phosphatized iron powder and epoxy resin compatibility and hence enhance phosphate iron powder epoxy mixing. The tensile strength, initial permeability, rated current under DC-bias superposition and magnetic loss in SMCs prepared using phosphatized iron powders can be effectively improved using APTES surface modification, which provides a promising candidate for power chip inductor applications.

Power-Quality Improvement in PFC Bridgeless SEPIC-Fed BLDC Motor Drive

NASA Astrophysics Data System (ADS)

Singh, Bhim; Bist, Vashist

2013-06-01

This article presents a design of a power factor correction (PFC)-based brushless DC (BLDC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the voltage source inverter (VSI) feeding BLDC motor using a single voltage sensor. A front-end bridgeless single-ended primary inductance converter (SEPIC) is used for DC link voltage control and PFC operation. A bridgeless SEPIC is designed to operate in discontinuous inductor current mode (DICM) thus utilizing a simple control scheme of voltage follower. An electronic commutation of BLDC motor is used for VSI to operate in a low-frequency operation for reduced switching losses in the VSI. Moreover, a bridgeless topology offers less conduction losses due to absence of diode bridge rectifier for further increasing the efficiency. The proposed BLDC motor drive is designed to operate over a wide range of speed control with an improved power-quality at the AC mains under the recommended international power-quality standards such as IEC 61000-3-2.

Modeling, numerical simulation, and nonlinear dynamic behavior analysis of PV microgrid-connected inverter with capacitance catastrophe

NASA Astrophysics Data System (ADS)

Li, Sichen; Liao, Zhixian; Luo, Xiaoshu; Wei, Duqu; Jiang, Pinqun; Jiang, Qinghong

2018-02-01

The value of the output capacitance (C) should be carefully considered when designing a photovoltaic (PV) inverter since it can cause distortion in the working state of the circuit, and the circuit produces nonlinear dynamic behavior. According to Kirchhoff’s laws and the characteristics of an ideal operational amplifier for a strict piecewise linear state equation, a circuit simulation model is constructed to study the system parameters (time, C) for the current passing through an inductor with an inductance of L and the voltage across the capacitor with a capacitance of C. The developed simulation model uses Runge-Kutta methods to solve the state equations. This study focuses on predicting the fault of the circuit from the two aspects of the harmonic distortion and simulation results. Moreover, the presented model is also used to research the working state of the system in the case of a load capacitance catastrophe. The nonlinear dynamic behaviors in the inverter are simulated and verified.

Submicrosecond linear pulse transformer for 800 kV voltage with modular low-inductance primary power supply

NASA Astrophysics Data System (ADS)

Bykov, Yu. A.; Krastelev, E. G.; Popov, G. V.; Sedin, A. A.; Feduschak, V. F.

2016-12-01

A pulsed power source with voltage amplitude up to 800 kV for fast charging (350-400 ns) of the forming line of a high-current nanosecond accelerator is developed. The source includes capacitive energy storage and a linear pulse transformer. The linear transformer consists of a set of 20 inductors with circular ferromagnetic cores surrounded by primary windings inside of which a common stock adder of voltage with film-glycerol insulation is placed. The primary energy storage consists of ten modules, each of which is a low-inductance assembly of two capacitors with a capacitance of 0.35 μF and one gas switch mounted in the same frame. The total energy stored in capacitors is 5.5 kJ at the operating voltage of 40 kV. According to test results, the parameters of the equivalent circuit of the source are the following: shock capacitance = 17.5 nF, inductance = 2 μH, resistance = 3.2 Ω.

Submicrosecond linear pulse transformer for 800 kV voltage with modular low-inductance primary power supply

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bykov, Yu. A.; Krastelev, E. G., E-mail: ekrastelev@yandex.ru; Popov, G. V.

A pulsed power source with voltage amplitude up to 800 kV for fast charging (350–400 ns) of the forming line of a high-current nanosecond accelerator is developed. The source includes capacitive energy storage and a linear pulse transformer. The linear transformer consists of a set of 20 inductors with circular ferromagnetic cores surrounded by primary windings inside of which a common stock adder of voltage with film-glycerol insulation is placed. The primary energy storage consists of ten modules, each of which is a low-inductance assembly of two capacitors with a capacitance of 0.35 μF and one gas switch mounted inmore » the same frame. The total energy stored in capacitors is 5.5 kJ at the operating voltage of 40 kV. According to test results, the parameters of the equivalent circuit of the source are the following: shock capacitance = 17.5 nF, inductance = 2 μH, resistance = 3.2 Ω.« less

Morphological, Raman, electrical and dielectric properties of rare earth doped X-type hexagonal ferrites

NASA Astrophysics Data System (ADS)

Majeed, Abdul; Khan, Muhammad Azhar; ur Raheem, Faseeh; Ahmad, Iftikhar; Akhtar, Majid Niaz; Warsi, Muhammad Farooq

2016-12-01

The influence of rare-earth metals (La, Nd, Gd, Tb, Dy) on morphology, Raman, electrical and dielectric properties of Ba2NiCoRExFe28-xO46 ferrites were studied. The scanning electron microscopy (SEM) exhibited the platelet like structure of these hexagonal ferrites. The surface morphology indicated the formation of ferrite grains in the nano-regime scale. The bands obtained at lower wave number may be attributed to the metal-oxygen vibration at octahedral site which confirm the development of hexagonal phase of these ferrites. The resonance peaks were observed in dielectric constant, dielectric loss factor and quality factor versus frequency graphs. These dielectric parameters indicate that these ferrites nano-materials are potential candidates in the high frequency applications. The enhancement in DC electric resistivity from 2.48×108 to 1.20×109 Ω cm indicates that the prepared materials are beneficial for decreasing the eddy current losses at high frequencies and for the fabrication of multilayer chip inductor (MLCI) devices.

Developments of Highly Multiplexed, Multi-chroic Pixels for Balloon-Borne Platforms

NASA Astrophysics Data System (ADS)

Aubin, F.; Hanany, S.; Johnson, B. R.; Lee, A.; Suzuki, A.; Westbrook, B.; Young, K.

2018-02-01

We present our work to develop and characterize low thermal conductance bolometers that are part of sinuous antenna multi-chroic pixels (SAMP). We use longer, thinner and meandered bolometer legs to achieve 9 pW/K thermal conductance bolometers. We also discuss the development of inductor-capacitor chips operated at 4 K to extend the multiplexing factor of the frequency domain multiplexing to 105, an increase of 60% compared to the factor currently demonstrated for this readout system. This technology development is motivated by EBEX-IDS, a balloon-borne polarimeter designed to characterize the polarization of foregrounds and to detect the primordial gravity waves through their B-mode signature on the polarization of the cosmic microwave background. EBEX-IDS will operate 20,562 transition edge sensor bolometers spread over 7 frequency bands between 150 and 360 GHz. Balloon and satellite platforms enable observations at frequencies inaccessible from the ground and with higher instantaneous sensitivity. This development improves the readiness of the SAMP and frequency domain readout technologies for future satellite applications.

Measurement of low temperature plasma properties using non-invasive impedance measurements

NASA Astrophysics Data System (ADS)

Gillman, Eric; Amatucci, Bill; Tejero, Erik; Blackwell, David

2017-10-01

A plasma discharge can be modeled electrically as a combination of capacitors, resistors, and inductors. The plasma, much like an RLC circuit, will have resonances at particular frequencies. The location in frequency space of these resonances provides information about the plasma parameters. These resonances can be detected using impedance measurements, where the AC impedance of the plasma is measured by sweeping the frequency of an AC voltage applied to a sensor and determining the magnitude and phase of the measured current. In this work, an electrode used to sustain a glow discharge is also used as an impedance probe. The novelty of this method is that insertion of a physical probe, which can introduce perturbation and/or contamination, is not necessary. This non-invasive impedance probe method is used to measure the plasma discharge density in various regimes of plasma operation. Experimental results are compared to the basic circuit model results. The potential applications of this diagnostic method and regimes over which this measurement method is valid will be discussed.

Chapter 11.2: Inverters, Power Optimizers, and Microinverters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deline, Christopher A

Inverters span a wide range of sizes, topologies, and connection voltages: from utility-scale megawatt inverters to string inverters. Switch-mode power conversion relies on high frequency chopping of DC signal to periodically charge and discharge energy storage elements, such as inductors and capacitors. Additional circuit components are required to address practical issues in inverters such as voltage ripple and harmonic distortion. Inverters are beginning to incorporate components with a bandgap above should be 3 eV, such as SiC and GaN. Photovoltaic (PV) modules respond dynamically to changing temperature and irradiation conditions. Thus, maximum DC power extraction requires periodic adjustment of themore » PV voltage and current operating point. An inverter's total efficiency is measured by the product of its conversion efficiency and the maximum-power-point tracking (MPPT) efficiency. This chapter lists the primary functions of inverters that include auxiliary capabilities, such as monitoring of DC and AC performance, and other error reporting.« less

Electrochemical Solution Growth of Magnetic Nitrides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monson, Todd C.; Pearce, Charles

Magnetic nitrides, if manufactured in bulk form, would provide designers of transformers and inductors with a new class of better performing and affordable soft magnetic materials. According to experimental results from thin films and/or theoretical calculations, magnetic nitrides would have magnetic moments well in excess of current state of the art soft magnets. Furthermore, magnetic nitrides would have higher resistivities than current transformer core materials and therefore not require the use of laminates of inactive material to limit eddy current losses. However, almost all of the magnetic nitrides have been elusive except in difficult to reproduce thin films or asmore » inclusions in another material. Now, through its ability to reduce atmospheric nitrogen, the electrochemical solution growth (ESG) technique can bring highly sought after (and previously inaccessible) new magnetic nitrides into existence in bulk form. This method utilizes a molten salt as a solvent to solubilize metal cations and nitrogen ions produced electrochemically and form nitrogen compounds. Unlike other growth methods, the scalable ESG process can sustain high growth rates (~mm/hr) even under reasonable operating conditions (atmospheric pressure and 500 °C). Ultimately, this translates into a high throughput, low cost, manufacturing process. The ESG process has already been used successfully to grow high quality GaN. Below, the experimental results of an exploratory express LDRD project to access the viability of the ESG technique to grow magnetic nitrides will be presented.« less

Measurement of collective dynamical mass of Dirac fermions in graphene.

PubMed

Yoon, Hosang; Forsythe, Carlos; Wang, Lei; Tombros, Nikolaos; Watanabe, Kenji; Taniguchi, Takashi; Hone, James; Kim, Philip; Ham, Donhee

2014-08-01

Individual electrons in graphene behave as massless quasiparticles. Unexpectedly, it is inferred from plasmonic investigations that electrons in graphene must exhibit a non-zero mass when collectively excited. The inertial acceleration of the electron collective mass is essential to explain the behaviour of plasmons in this material, and may be directly measured by accelerating it with a time-varying voltage and quantifying the phase delay of the resulting current. This voltage-current phase relation would manifest as a kinetic inductance, representing the reluctance of the collective mass to accelerate. However, at optical (infrared) frequencies, phase measurements of current are generally difficult, and, at microwave frequencies, the inertial phase delay has been buried under electron scattering. Therefore, to date, the collective mass in graphene has defied unequivocal measurement. Here, we directly and precisely measure the kinetic inductance, and therefore the collective mass, by combining device engineering that reduces electron scattering and sensitive microwave phase measurements. Specifically, the encapsulation of graphene between hexagonal boron nitride layers, one-dimensional edge contacts and a proximate top gate configured as microwave ground together enable the inertial phase delay to be resolved from the electron scattering. Beside its fundamental importance, the kinetic inductance is found to be orders of magnitude larger than the magnetic inductance, which may be utilized to miniaturize radiofrequency integrated circuits. Moreover, its bias dependency heralds a solid-state voltage-controlled inductor to complement the prevalent voltage-controlled capacitor.

Slow wave structures integrated with ferromagnetic and ferro-electric thin films for smart RF applications

NASA Astrophysics Data System (ADS)

Rahman, B. M. Farid

Modern communications systems are following a common trend to increase the operational frequency, level of integration and number of frequency bands. Although 90-95% components in a cell phone are passives which take 80% of the total board area. High performance RF passive components play limited role and are desired towards this technological advancement. Slow wave structure is one of the most promising candidates to design compact RF and mm-Wave passive components. Slow wave structures are the specially designed transmission line realized by placing the alternate narrow and wide signal conductors in order to reduce the physical size of the components. This dissertation reports multiband slow wave structures integrated with ferromagnetic and ferroelectric thin films and their RF applications. A comparative study on different types of coplanar wave-guide (CPW) slow wave structures (SWS) has been demonstrated for the first time. Slow wave structures with various shapes have been investigated and optimized with various signal conductor shapes, ground conductor shapes and pitch of the sections. Novel techniques i.e. the use of the defected ground structure and the different signal conductor length has been implemented to achieve higher slow wave effect with minimum loss. The measured results have shown the reduction of size over 43.47% and 37.54% in the expense of only 0.27dB and 0.102dB insertion loss respectively which can reduce the area of a designed branch line coupler by 68% and 61% accordingly. Permalloy (Py) is patterned on top of the developed SWS for the first time to further increase the slow wave effect and provide tunable inductance value. High frequency applications of Py are limited by its ferro-magnetic resonance frequency since the inductance value decreases beyond that. Sub-micrometer patterning of Py has increased FMR frequency until 6.3GHz and 3.2GHz by introducing the shape anisotropy. For the SWS with patterned Py, the size of the quarter wavelength has been reduced from 14.86mm to 4.7mm at 2GHz. DC current which is the most convenient and available tuning parameter in a practical circuit board has been used, the developed SWS can function as quarter wave transmission line from 2GHz to 1.80GHz (i.e. 10%). Lead Zirconium Titanate (PZT) is grown and patterned on top of the section with standard sol-gel method to increase capacitance value. The inter digit capacitor type structure along with PZT thin film has been adopted and results showed capacitance value increment by 36%. An electric field between signal and ground has been applied to change the polarization of the thin film which resulted in a tuning of center frequency by 15% (1.75GHz to 2GHz). In addition, a novel approach has been implemented by integrating both the ferromagnetic and the ferroelectric thin films simultaneously to achieve higher slow wave effect, wider tuning range and smaller variation in Characteristics Impedance. The size of the final structure for a quarter wavelengths has been reduced from 14.86mm to 3.98mm while the center frequency has been tuned from 2GHz to 1.5GHz (i.e. 25%). Tunable RF applications of the ferro-magnetic thin films are also demonstrated as a DC current band pass filter, tunable noise suppressor and meander line inductor. A well designed frequency tunable band pass filter (BPF) is implemented at 4GHz with patterned Permalloy. The pass band frequency of a band pass filter has been tuned from 4GHz to 4.02GHz by applying a DC current. The suppression frequency of the developed noise suppressor is tuned from 4.8GHz to 6GHz and 4GHz to 6GHz by changing the aspect ratio of the Py bars and the gap in between them. Moreover, a novel way of tuning the stop band frequency of the noise suppressor by using an external direct current changed the suppression frequency from 6GHz to 4.3GHz. A pass band loss of 1.5%, less than 2° transmitted signal phase distortion, and 3 dB extra return loss of the designed noise suppressor showed the promise the noise suppressors. The increase in the number of turns of a meander line inductor has increased the inductance density from 2565nH/m to 3396nH/m while application of the patterned Py has increased the inductance density from 2565nH/m to 3060nH/m. The tuning of the meander line inductor has been performed by applying DC current until the FMR frequency 4.51GHz.

Exploratory Research and Development of Microwave Filters in Silicon Technology

DTIC Science & Technology

2013-09-25

admittance Gout . The equivalent model for the active inductor with parasitic components is also shown in Fig. 9. The values of the equivalent model are...minimizing the output admittance Gout . 23 B. Transconductor Design ID1 ID2 VS Rcomp VDD VDD Vc VG-vin/2VG+vin/2 vin M5 M3 M4 M1 M2 Fig. 10

Detección de compuestos inductores de aborto en acículas de enebro (Juniperus communis) y suero de vacas abortadas en los montes de la Rioja

USDA-ARS?s Scientific Manuscript database

Over recent years, there have been observed in several cattle farms within the region of the Sierra de Cameros (La Rioja) mountains, reproductive alterations consisting of pre-mature births and birth of dead calves or calves of reduced viability. After laboratory examination of several cases with ne...

Integrated power passives

NASA Technical Reports Server (NTRS)

Xie, Huikai (Inventor); Ngo, Khai D. T. (Inventor)

2013-01-01

A multi-layer film-stack and method for forming the multilayer film-stack is given where a series of alternating layers of conducting and dielectric materials are deposited such that the conducting layers can be selectively addressed. The use of the method to form integratable high capacitance density capacitors and complete the formation of an integrated power system-on-a-chip device including transistors, conductors, inductors, and capacitors is also given.

[Immune diagnostics of disorders in the IFN-alpha/NK-cell system in patients with frequently recurrent herpes simplex].

PubMed

Karsonova, A V; Shulzhenko, A E; Karaulov, A V

2014-01-01

Study of features of NK-cell response to the effect of recombinant IFN-alpha in complex with evaluation of the ability to synthesize inherent IFN-alpha in patients with frequently recurrent herpes simplex (FRHS). 48 patients with genital (n = 31), labial (n = 10) and mixed localization (n = 7) FRHS diagnosis were observed. 31 healthy donors composed the control group. MC were cultivated in the presence of a recombinant human IFN-alpha2b at the concentration of 10, 100 and 1000 U/ml for 24 hours. NK-cell response to the effect of IFN-alpha was evaluated after 24 hours using flow cytometry by degranulation reaction and in the NK-activity test. IFN-alpha synthesis was evaluated in HSV-1, HSV-2 and Newcastle disease virus stimulated cell supernatants by EIA method. Patients with FRHS were established to be a heterogeneous group by parameters in the IFN-alpha/NK-cell cytotoxicity system. 2 types of NK-cell response to the stimulation by recombinant IFN-alpha were identified. Type A is characterized by a decrease of NK-cell response to IFN-alpha in the remission phase and does not have this defect in the exacerbation phase. Synthesis of inherent IFN-alpha in response to viral inductors for type A was comparable with the response in healthy donors in both phases. On the contrary type B having normal sensitivity of NK-cells to IFN-alpha in the remission phase is characterized by a decrease of this parameter in the exacerbation phase for more than 3 times. Synthesis of inherent IFN-alpha in response to viral inductors during type B is increased in the remission phase and decreased in the exacerbation phase. During immune-correcting therapy of FRHS a personalized approach taking into account features of NK-cell response to IFN-alpha is necessary, because types A and B have principal differences by cytotoxicity parameters of NK-cells and their change under the effect of IFN-alpha, as well as by parameters of IFN-alpha synthesis in response to viral inductors at various phases of the clinical process.

Particle Acceleration in Dissipative Pulsar Magnetospheres

NASA Technical Reports Server (NTRS)

Kazanas, Z.; Kalapotharakos, C.; Harding, A.; Contopoulos, I.

2012-01-01

Pulsar magnetospheres represent unipolar inductor-type electrical circuits at which an EM potential across the polar cap (due to the rotation of their magnetic field) drives currents that run in and out of the polar cap and close at infinity. An estimate ofthe magnitude of this current can be obtained by dividing the potential induced across the polar cap V approx = B(sub O) R(sub O)(Omega R(sub O)/c)(exp 2) by the impedance of free space Z approx eq 4 pi/c; the resulting polar cap current density is close to $n {GJ} c$ where $n_{GJ}$ is the Goldreich-Julian (GJ) charge density. This argument suggests that even at current densities close to the GJ one, pulsar magnetospheres have a significant component of electric field $E_{parallel}$, parallel to the magnetic field, a condition necessary for particle acceleration and the production of radiation. We present the magnetic and electric field structures as well as the currents, charge densities, spin down rates and potential drops along the magnetic field lines of pulsar magnetospheres which do not obey the ideal MHD condition $E cdot B = 0$. By relating the current density along the poloidal field lines to the parallel electric field via a kind of Ohm's law $J = sigma E_{parallel}$ we study the structure of these magnetospheres as a function of the conductivity $sigma$. We find that for $sigma gg OmegaS the solution tends to the (ideal) Force-Free one and to the Vacuum one for $sigma 11 OmegaS. Finally, we present dissipative magnetospheric solutions with spatially variable $sigma$ that supports various microphysical properties and are compatible with the observations.

Printing Electronic Components from Copper-Infused Ink and Thermoplastic Mediums

NASA Astrophysics Data System (ADS)

Flowers, Patrick F.

The demand for printable electronics has sharply increased in recent years and is projected to continue to rise. Unfortunately, electronic materials which are suitable for desired applications while being compatible with available printing techniques are still often lacking. This thesis addresses two such challenging areas. In the realm of two-dimensional ink-based printing of electronics, a major barrier to the realization of printable computers that can run programs is the lack of a solution-coatable non-volatile memory with performance metrics comparable to silicon-based devices. To address this deficiency, I developed a nonvolatile memory based on Cu-SiO2 core-shell nanowires that can be printed from solution and exhibits on-off ratios of 106, switching speeds of 50 ns, a low operating voltage of 2 V, and operates for at least 104 cycles without failure. Each of these metrics is similar to or better than Flash memory (the write speed is 20 times faster than Flash). Memory architectures based on the individual memory cells demonstrated here could enable the printing of the more complex, embedded computing devices that are expected to make up an internet of things. Recently, the exploration of three-dimensional printing techniques to fabricate electronic materials began. A suitable general-purpose conductive thermoplastic filament was not available, however. In this work I examine the current state of conductive thermoplastic filaments, including a newly-released highly conductive filament that my lab has produced which we call Electrifi. I focus on the use of dual-material fused filament fabrication (FFF) to 3D print electronic components (conductive traces, resistors, capacitors, inductors) and circuits (a fully-printed high-pass filter). The resistivity of traces printed from conductive thermoplastic filaments made with carbon-black, graphene, and copper as conductive fillers was found to be 12, 0.78, and 0.014 ohm cm, respectively, enabling the creation of resistors with resistances spanning 3 orders of magnitude. The carbon black and graphene filaments were brittle and fractured easily, but the copper-based filament could be bent at least 500 times with little change in its resistance. Impedance measurements made on the thermoplastic filaments demonstrate that the copper-based filament had an impedance similar to a conductive PCB trace at 1 MHz. Dual material 3D printing was used to fabricate a variety of inductors and capacitors with properties that could be predictably tuned by modifying either the geometry of the components, or the materials used to fabricate the components. These resistors, capacitors, and inductors were combined to create a fully 3D printed high-pass filter with properties comparable to its conventional counterparts. The relatively low impedance of the copper-based filament enable its use to 3D print a receiver coil for wireless power transfer. We also demonstrate the ability to embed and connect surface mounted components in 3D printed objects with a low-cost ($1,000 in parts), open source dual-material 3D printer. This work thus demonstrates the potential for FFF 3D printing to create complex, three-dimensional circuits composed of either embedded or fully-printed electronic components.

Integrating Nano-patterned Ferromagnetic and Ferroelectric Thin Films for Electrically Tunable RF Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Tengxing; Peng, Yujia; Jiang, Wei

Tunable radio frequency (RF) components are pivotal elements in frequency-agile and multifunctional systems. However, there is a technical barrier to achieve miniaturized fully electrically tunable RF components. This paper provides and demonstrates the efficacy of a first unique design methodology in developing fully electrically tunable RF components by integrating ferromagnetic (e.g., Permalloy) and ferroelectric (e.g., Lead Zirconate Titanate: PZT) thin films patterns. Permalloy thin film has been patterned in nanometer scale to improve its ferromagnetic resonance frequency (FMR) for RF applications. Tunable inductors are developed with the utilization of different thickness of Permalloy thin film, which show over 50% incrementmore » in inductance and over 4% in tunability with DC current. More tunability can be achieved with multiple layers of Permalloy thin film and optimized thickness. A fully electrically tunable slow wave RF transmission line with simultaneously variable inductance and capacitance density has been implemented and thoroughly investigated for the first time. Measured results show that a fixed phase shift of 90° can be achieved from 1.5 GHz to 1.85 GHz continuously by applying external DC current from 0 to 200 mA and external DC voltage from 0 to 15 Volts, respectively.« less

Integrating Nano-patterned Ferromagnetic and Ferroelectric Thin Films for Electrically Tunable RF Applications

DOE PAGES

Wang, Tengxing; Peng, Yujia; Jiang, Wei; ...

2016-10-31

Tunable radio frequency (RF) components are pivotal elements in frequency-agile and multifunctional systems. However, there is a technical barrier to achieve miniaturized fully electrically tunable RF components. This paper provides and demonstrates the efficacy of a first unique design methodology in developing fully electrically tunable RF components by integrating ferromagnetic (e.g., Permalloy) and ferroelectric (e.g., Lead Zirconate Titanate: PZT) thin films patterns. Permalloy thin film has been patterned in nanometer scale to improve its ferromagnetic resonance frequency (FMR) for RF applications. Tunable inductors are developed with the utilization of different thickness of Permalloy thin film, which show over 50% incrementmore » in inductance and over 4% in tunability with DC current. More tunability can be achieved with multiple layers of Permalloy thin film and optimized thickness. A fully electrically tunable slow wave RF transmission line with simultaneously variable inductance and capacitance density has been implemented and thoroughly investigated for the first time. Measured results show that a fixed phase shift of 90° can be achieved from 1.5 GHz to 1.85 GHz continuously by applying external DC current from 0 to 200 mA and external DC voltage from 0 to 15 Volts, respectively.« less

Magnetically Delayed Low-Pressure Gas Discharge Switching

DTIC Science & Technology

1993-06-01

the gap, minimizes this effect. It is this version of the low- pressure switch that we are presently studying. Our magnetically delayed low... pressure switch (MDLPS) test-stand was built primarily to support the long-pulse, relativistic klystron (RK) and free electron laser (FEL) work at... pressure switch and compared the performance with and without the saturable inductor. A comparison of typi- cal closure properties is shown in Fig

Reconfigurable Analog PDE computation for Baseband and RFComputation

DTIC Science & Technology

2017-03-01

waveguiding PDEs. One-dimensional ladder topologies enable linear delays, linear-phase analog filters , as well as analog beamforming, potentially at RF...performance. This discussion focuses on ODE / PDE analog computation available in SoC FPAA structures. One such computation is a ladder filter (Fig...Implementation of a one-dimensional ladder filter for computing inductor (L) and capacitor (C) lines. These components can be implemented in CABs or as

1 GHz, 200 C, SiC MESFET Clapp Oscillator

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Schwartz, Zachary D.

2005-01-01

A SiC Clapp oscillator frabricated on an alumina substrate with chip capacitors and spiral inductors is designed for high temperature operation at 1 gigahertz. The oscillator operated from 30 to 200 C with an output power of 21.8 dBm at 1 gigahertz and 200 C. The efficiency at 200 C is 15 percent. The frequency variation over the temperature range is less than 0.5 percent.

[Immunomodulators in Therapy of Respiratory Infections].

PubMed

Isakov, V A; Isakov, D V

2014-01-01

Viral infections provoke dysbalance in the interferon system and inhibition of the cellular and phagocytic responses of the host. Long-term persistence of pathogenic viruses and bacteria induce atopy and could aggravate chronic respiratory diseases. The up-to-date classification of immunomodulators is described. High efficacy of interferon inductors, such as cycloferon and some others as auxiliary means in therapy or prophylaxis (immunorehabilitation) of viral respiratory infections in adults and children was shown.

[Immunomodulators with an 8-azasteroid structure as inducers of liver cytochrome P-450].

PubMed

Kuz'mitskiĭ, B B; Dad'kov, I G; Mashkovich, A E; Stoma, O V; Slepneva, L M

1990-01-01

Two structural analogues of D-homo-8-azasteroids, both an immunostimulant and an immunodepressant, are inductors of the liver cytochrome P-450 in animals. This capability was shown by means of both a decrease of the hexenal sleep duration in the pharmacological test and an increase of the quantity of cytochrome P-450 and the rate of N-demethylation of aminopyrine in the biochemical assays.

Study of the longitudinal space charge compensation and longitudinal instability of the ferrite inductive inserts in the Los Alamos Proton Storage Ring

NASA Astrophysics Data System (ADS)

Beltran, Chris

Future high intensity synchrotrons will have a large space charge effect. It has been demonstrated in the Proton Storage Ring (PSR) at the Los Alamos National Laboratory (LANL) that ferrite inductive inserts can be used to compensate for the longitudinal space charge effect. However, simply installing ferrite inductors in the PSR led to longitudinal instabilities that were not tolerable. It was proposed that heating the ferrite would change the material properties in such a way as to reduce the instability. This proposal was tested in the PSR, and found to be true. This dissertation investigates and describes the complex permeability of the ferrite at room temperature and at an elevated temperature. The derived complex permeability is then used to obtain an impedance at the two temperatures. The impedance is used to determine the amount of space charge compensation supplied by the inductors and predict the growth time and frequency range of the longitudinal instability. The impedance is verified by comparing the experimental growth time and frequency range of the longitudinal instability to theoretical and computer simulated growth times and frequency ranges of the longitudinal instability. Lastly, an approach to mitigating the longitudinal instability that does not involve heating the ferrite is explored.

Demonstration of a Packaged Capacitive Pressure Sensor System Suitable for Jet Turbofan Engine Health Monitoring

NASA Technical Reports Server (NTRS)

Scardelletti, Maximilian C.; Jordan, Jennifer L.; Meredith, Roger D.; Harsh, Kevin; Pilant, Evan; Usrey, Michael W.; Beheim, Glenn M.; Hunter, Gary W.; Zorman, Christian A.

2016-01-01

In this paper, the development and characterization of a packaged pressure sensor system suitable for jet engine health monitoring is demonstrated. The sensing system operates from 97 to 117 MHz over a pressure range from 0 to 350 psi and a temperature range from 25 to 500 deg. The sensing system consists of a Clapp-type oscillator that is fabricated on an alumina substrate and is comprised of a Cree SiC MESFET, MIM capacitors, a wire-wound inductor, chip resistors and a SiCN capacitive pressure sensor. The pressure sensor is located in the LC tank circuit of the oscillator so that a change in pressure causes a change in capacitance, thus changing the resonant frequency of the sensing system. The chip resistors, wire-wound inductors and MIM capacitors have all been characterized at temperature and operational frequency, and perform with less than 5% variance in electrical performance. The measured capacitive pressure sensing system agrees very well with simulated results. The packaged pressure sensing system is specifically designed to measure the pressure on a jet turbofan engine. The packaged system can be installed by way of borescope plug adaptor fitted to a borescope port exposed to the gas path of a turbofan engine.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Youngho; Hur, Kyeon; Kang, Yong

This study investigates the emerging harmonic stability concerns to be addressed by grid planners in generation interconnection studies, owing to the increased adoption of renewable energy resources connected to the grid via power electronic converters. The wideband and high-frequency electromagnetic transient (EMT) characteristics of these converter-interfaced generators (CIGs) and their interaction with the grid impedance are not accurately captured in the typical dynamic studies conducted by grid planners. This paper thus identifies the desired components to be studied and subsequently develops a practical process for integrating a new CIG into a grid with the existing CIGs. The steps of thismore » process are as follows: the impedance equation of a CIG using its control dynamics and an interface filter to the grid, for example, an LCL filter (inductor-capacitor-inductor type), is developed; an equivalent impedance model including the existing CIGs nearby and the grid observed from the point of common coupling are derived; the system stability for credible operating scenarios is assessed. Detailed EMT simulations validate the accuracy of the impedance models and stability assessment for various connection scenarios. Here, by complementing the conventional EMT simulation studies, the proposed analytical approach enables grid planners to identify critical design parameters for seamlessly integrating a new CIG and ensuring the reliability of the grid.« less

Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer.

PubMed

Babij, Michał; Kowalski, Zbigniew W; Nitsch, Karol; Silberring, Jerzy; Gotszalk, Teodor

2014-05-01

The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet.

Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babij, Michał; Kowalski, Zbigniew W., E-mail: zbigniew.w.kowalski@pwr.wroc.pl; Nitsch, Karol

The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with themore » absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet.« less

[Investigation of a new highly porous hydroxyapatite matrix for obliterating open mastoid cavities - application in guinea pigs bulla].

PubMed

Punke, C; Zehlicke, T; Boltze, C; Pau, H W

2009-04-01

Many different techniques for obliterating open mastoid cavity have been described. The results after the application of alloplastic materials like Hydroxyapatite and Tricalciumphosphate were poor due to long-lasting resorption. Extrusion of those materials has been described. We investigated the applicability of a new high-porosity ceramic for obliterating large open mastoid cavities and tested it in an animal model (bulla of guinea pig). A highly porous matrix (NanoBone) bone-inductor fabricated in a sol-gel-technique was administered unilaterally into the opened bullae of 30 guinea pigs. In each animal the opposite bulla was filled with Bio-Oss, a bone substitute consisting of a portion of mineral bovine bone. Histological evaluations were performed 1, 2, 3, 4, 5 and 12 weeks after the implantation. After the initial phase with an inflammatory reaction creating a loose granulation tissue, we observed the formation of trabeculare bone within the fourth week in both groups. From the fifth week on we found osteoclasts on the surface of NanoBone and Bio-Oss with consecutive degradation of both materials. In our animal model study we found beneficial properties of the used bone-inductors NanoBone and Bio-Oss for obliterating open mastoid cavities.

Conflicts in the operating theatre.

PubMed

Booij, Leo H D J

2007-04-01

Quality and safety of healthcare depend on team performance. Conflicts decrease team performance. A number of studied factors involved in the development and solution of conflicts are discussed. An operating team consists of individuals, with specific roles requiring specific expertise and skills, performing interdependent tasks with patient treatment as a common goal. Teams are prone to conflicts: a dispute, disagreement or difference of opinion related to patient management, requiring some decision or action. Many factors determine the character of the conflicts, and these vary between different countries, hospitals and teams. Factors include culture, professional social status, personality of members, etc. Conflicts can induce innovation, but can also result in job dissatisfaction. They even can affect the functioning of the hospital. On average, four conflicts can be observed per operation, which are mostly solved immediately. Communication in an open atmosphere is a major issue in dealing with conflicts. If conflicts are unresolved they grow into relationship conflicts, which are difficult to handle. Understanding the factors that contribute to the conflict is important for mediators. Most conflicts arise about theatre management, case acceptation, unexpected changes in the team or incapability of one of its members. There are many possible inductors of conflicts. Conflicts should be immediately resolved by open communication and respectful discussion.

Auxiliary resonant DC tank converter

DOEpatents

Peng, Fang Z.

2000-01-01

An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

Improved high power/high frequency inductor

NASA Technical Reports Server (NTRS)

Mclyman, W. T. (Inventor)

1990-01-01

A toroidal core is mounted on an alignment disc having uniformly distributed circumferential notches or holes therein. Wire is then wound about the toroidal core in a uniform pattern defined by the notches or holes. Prior to winding, the wire may be placed within shrink tubing. The shrink tubing is then wound about the alignment disc and core and then heat-shrunk to positively retain the wire in the uniform position on the toroidal core.

[Up-to-date approach to treatment of inflammatory infections in the maxillofacial region].

PubMed

Romantsov, M G; Kovalevskiĭ, M A; Iaremenko, A I; Grigorian, S S; Kovalenko, A L

2009-01-01

Cycloferon, a prospective interferon inductor, and the mechanism of its action were characterized. Its formulation for external use as liniment was developed. The pharmacotherapeutic effect of the drug in the treatment of paradontitis was shown. The drug efficacy in herpetic lesions of the mouth and lips mucosa was observed. The use of cycloferon in the treatment of the buccal mucosa affections in HIV-infected subjects was substantiated.

Laser Ablated Pure Non-Crystalline Co Thin Films for Inductors for Ultra-High Frequencies

DTIC Science & Technology

2001-04-01

Applications of Ferromagnetic and Optical Materials, Storage and Magnetoelectronics: Symposia Held in San Francisco , California, U.S.A. on April 16-20...V. Madurga, J. Vergara , C. Favieres Departamento de Ffsica. Universidad Paiblica de Navarra. Campus Arrosadfa. E-31006 Pamplona. Spain. ABSTRACT Non...Y. Hiroshima, T. Ishiguro, I. Urata, H. Ohta, M. Tohogi, Y. Ichinose. I. Appl. Phys. 79, 3572 (1996). 8. V. Madurga, J. Vergara , I.P. Landazhlbal

Development of High Resistive and High Magnetization Soft Thin Film and Fabrication of Thin Film Inductors

DTIC Science & Technology

2004-11-01

properties of Co- doped ZnO nanocluster films", .J. of Appl. Phys. in press, 2005 2. Presentations (contributed): Conference Contributions: 1) Y. Qiang...gigahertz band applications. The effects of substrates bias, sputter parameters, and seed-layer have thoroughly been investigated. The magnetic...Adequate properties of soft magnetic thin film were evaluated by an analytical calculation [1] to meet the requirement for gigahertz band thin-film

Proceedings of the International Cryocoolers Conference (6th) Held in Plymouth, Massachusetts on October 25-26, 1990. Volume 2

DTIC Science & Technology

1991-01-01

Pulse - Tube Cryocooler , BJ. Huang, L.T. Lee and C .W . Lu ................................................... 77 Pulse Tube Cooler Modeling . G.M...resistors, inductors and pulse generators. The design combines on one chip a test circuit and a sampler, which allows high frequency testing without...tube7 provides the opportunity to simplify the design and dispense with the reciprocating displacer shown in Figure 3. The superrniniaturised pulse

[Possibilities of magnetotherapy in stabilization of visual function in patients with glaucoma].

PubMed

Bisvas Shutanto Kumar; Listopadova, N A

1996-01-01

Courses of magnetotherapy (MT) using ATOS device with 33 mT magnetic field induction were administered to 31 patients (43 eyes) with primary open-angle glaucoma with compensated intraocular pressure. The operation mode was intermittent, with 1.0 to 1.5 Hz field rotation frequency by 6 radii. The procedure is administered to a patient in a sitting posture with magnetic inductor held before the eye. The duration of a session is 10 min, a course consists of 10 sessions. Untreated eyes (n = 15) of the same patients were examined for control. The patients were examined before and 4 to 5 months after MT course. Vision acuity improved by 0.16 diopters, on an average, in 29 eyes (96.7%) out of 30 with vision acuity below 1.0 before treatment. Visocontrastometry was carried out using Visokontrastometer-DT device with spatial frequency range from 0.4 to 19 cycle/degree (12 frequencies) and 125 x 125 monitor. The orientation of lattices was horizontal and vertical. The contrasts ranged from 0.03 to 0.9 (12 levels). MT brought about an improvement of spatial contrast sensitivity by at least 7 values of 12 levels in 22 (84.6%) out of 26 eyes and was unchanged in 4 eyes. Visual field was examined using Humphry automated analyzer. A 120-point threshold test was used. After a course of MT, visual field deficit decreased by at least 10% in 31 (72%) out of 43 eyes, increased in 3, and was unchanged in 9 eyes; on an average, visual field deficit decreased by 22.4% vs. the initial value. After 4 to 5 months the changes in the vision acuity and visual field deficit were negligible. In controls these parameters did not appreciably change over the entire follow-up period.

Convergent cross-mapping and pairwise asymmetric inference.

PubMed

McCracken, James M; Weigel, Robert S

2014-12-01

Convergent cross-mapping (CCM) is a technique for computing specific kinds of correlations between sets of times series. It was introduced by Sugihara et al. [Science 338, 496 (2012).] and is reported to be "a necessary condition for causation" capable of distinguishing causality from standard correlation. We show that the relationships between CCM correlations proposed by Sugihara et al. do not, in general, agree with intuitive concepts of "driving" and as such should not be considered indicative of causality. It is shown that the fact that the CCM algorithm implies causality is a function of system parameters for simple linear and nonlinear systems. For example, in a circuit containing a single resistor and inductor, both voltage and current can be identified as the driver depending on the frequency of the source voltage. It is shown that the CCM algorithm, however, can be modified to identify relationships between pairs of time series that are consistent with intuition for the considered example systems for which CCM causality analysis provided nonintuitive driver identifications. This modification of the CCM algorithm is introduced as "pairwise asymmetric inference" (PAI) and examples of its use are presented.

Model-Based Dead Time Optimization for Voltage-Source Converters Utilizing Silicon Carbide Semiconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Zheyu; Lu, Haifeng; Costinett, Daniel J.

Dead time significantly affects the reliability, power quality, and efficiency of voltage-source converters. For silicon carbide (SiC) devices, considering the high sensitivity of turn-off time to the operating conditions (> 5× difference between light load and full load) and characteristics of inductive loads (> 2× difference between motor load and inductor), as well as large additional energy loss induced by the freewheeling diode conduction during the superfluous dead time (~15% of the switching loss), then the traditional fixed dead time setting becomes inappropriate. This paper introduces an approach to adaptively regulate the dead time considering the current operating condition andmore » load characteristics via synthesizing online monitored turn-off switching parameters in the microcontroller with an embedded preset optimization model. Here, based on a buck converter built with 1200-V SiC MOSFETs, the experimental results show that the proposed method is able to ensure reliability and reduce power loss by 12% at full load and 18.2% at light load (8% of the full load in this case study).« less

Model-Based Dead Time Optimization for Voltage-Source Converters Utilizing Silicon Carbide Semiconductors

DOE PAGES

Zhang, Zheyu; Lu, Haifeng; Costinett, Daniel J.; ...

2016-12-29

Dead time significantly affects the reliability, power quality, and efficiency of voltage-source converters. For silicon carbide (SiC) devices, considering the high sensitivity of turn-off time to the operating conditions (> 5× difference between light load and full load) and characteristics of inductive loads (> 2× difference between motor load and inductor), as well as large additional energy loss induced by the freewheeling diode conduction during the superfluous dead time (~15% of the switching loss), then the traditional fixed dead time setting becomes inappropriate. This paper introduces an approach to adaptively regulate the dead time considering the current operating condition andmore » load characteristics via synthesizing online monitored turn-off switching parameters in the microcontroller with an embedded preset optimization model. Here, based on a buck converter built with 1200-V SiC MOSFETs, the experimental results show that the proposed method is able to ensure reliability and reduce power loss by 12% at full load and 18.2% at light load (8% of the full load in this case study).« less

Effect of neodymium substitution on the electric and dielectric properties of Mn-Ni-Zn ferrite

NASA Astrophysics Data System (ADS)

Agami, W. R.

2018-04-01

Ferrite samples of Mn0.5Ni0.1Zn0.4NdxFe2-xO4 (x = 0.0, 0.01, 0.02, 0.05, 0.075 and 0.1) have been prepared by usual ceramic method. The temperature and composition dependences of the dc electric resistivity (ρdc) were studied. The frequency and composition dependences of the ac electric resistivity (ρac) and dielectric parameters (dielectric constant ε' and dielectric loss ε'') have been investigated. ρdc was found to decrease with temperature for all samples while it increases with increasing Nd3+ concentration. On the other hand, ρac and the dielectric properties were found to decrease with increasing the frequency while ρac increases and both ε' and ε'' decrease with increasing Nd3+ concentration. These results were explained by the Maxwell-Wagner two-layer model and Koops's theory. The improvement in dc and ac electric resistivities shows that these prepared materials are valid for decreasing the eddy current losses at high frequencies, so they can be used in the fabrication of multilayer chip inductor (MLCI) devices.

Electromagnetic Launch Technology Assessment. Scientific Basis and Unified Treatment: Forces and Electromechanical Power Conversion (Analytical and Numerical Methods),

DTIC Science & Technology

1990-06-01

on simple railgun accelerators andI homopolar generators. Complex rotating flux compressors would drastically improve the performance of EM launchers...velocities. If this is the direction of improvement, then energies stored in the electric trains built with linear electric motors in Japan and Western I...laboratories which had power supplies 3 already built for other programs ( homopolar generators in conjunction with an inductor and an opening switch

Design and Performance Evaluation of a 200 deg C Interleaved Boost Converter (Preprint)

DTIC Science & Technology

2012-09-01

applications in which longer life operation is desired, SiC die are brazed in metal TO-257 hermetic packages, which do provide superior high temperature ...reliability. Optimization of a high temperature X-perm core based coupled inductor architecture, in terms of ac flux balancing and dc flux cancellation...by ~60% due to the rapid decline in X7R capacitance at the high temperature extreme. The results obtained during this study suggest that the

Plastic welder

NASA Technical Reports Server (NTRS)

Buckley, J. D.; Fox, R. L.; Swain, R. J.

1980-01-01

Low-cost, self-contained, portable welder joins plastic parts by induction heating. Welder is useable in any atmosphere or in vacuum and with most types of thermoplastic; plastic components can be joined in situ. Device is applicable to aerospace industry and in automobile, furniture, and construction industries. Power requirements are easily met by battery or solar energy. In welder, toroidal inductor transfers magnetic flux through thermoplastic to screen. Heated screen causes plastic surface on either side to melt and flow into it to form joint.

Biochemical markers for the assessment of aquatic environment contamination

PubMed Central

Havelková, Marcela; Randák, Tomáš; Blahová, Jana; Slatinská, Iveta; Svobodová, Zdeňka

2008-01-01

The need for assessment of aquatic ecosystem contamination and of its impact on water dwelling organisms was developed in response to rising aquatic environmental pollution. In this field study, liver enzymes of phase I and phase II of xenobiotic transformation, namely cytochrome P450, ethoxyresorufin-O-deethylase, glutathione-S-transferase and tripeptide glutathione were used to assess the contamination of the aquatic environment at different rivers in the Czech Republic. The indicator species selected was the male chub (Leuciscus cephalus L.) and male brown trout (Salmo trutta fario). Chemical analyses included also the assessment of the most important inductors of previously mentioned biochemical markers. The major inductors of monitored biomarkers are industrial contaminants which belong to a large group of organic pollutants (PCB, PAH, PCDD/F, DDT, HCH, HCB and OCS), persistent in the environment. Four different groups of river basins were assessed: the River Tichá Orlice and its tributary the Kralický brook; important tributaries of the River Elbe (the rivers Orlice, Chrudimka, Cidlina, Jizera, Vltava, Ohře and Bílina); major rivers in the Czech Republic (the rivers Lužnice, Otava, Sázava, Berounka, Vltava, Labe, Ohře, Svratka, Dyje, Morava and Odra) and the River Vltava. The use of the biochemical markers together with chemical analyses seems to be an effective way to monitor the quality of aquatic environment. PMID:21218108

Intelligent telemetric stent for wireless monitoring of intravascular pressure and its in vivo testing.

PubMed

Chen, Xing; Brox, Daniel; Assadsangabi, Babak; Hsiang, York; Takahata, Kenichi

2014-10-01

This paper reports a sensor-integrated telemetric stent targeted at wireless detection and monitoring of restenosis, a common vascular complication induced by stent implantation. The developed "smart" stent incorporates the design and fabrication approaches that raise the practicality of the device, being tested in an in vivo study that validates its operating principle. The stent is produced to have a gold-coated helical-like structure that serves as a high-performance inductor/antenna and integrated with a novel capacitive pressure sensor chip, all based on medical-grade stainless steel. The stent device forms an inductor-capacitor resonant tank that enables radio-frequency (RF) wireless pressure sensing in an operating frequency range of 30-80 MHz. With an overall length of 20 mm, the device is designed to be compatible with standard balloon catheters and necessary crimping process. The balloon-expanded devices are characterized in saline and blood to determine selective coating of passivation layer, Parylene C, with tailored thicknesses in order to maximize both RF and sensing abilities. In vitro testing of the devices reveals a frequency sensitivity up to 146 ppm/mmHg over a pressure range of 250 mmHg. Tests in pig models show wireless detection of device's resonance and frequency response to variations in local blood pressure, the targeted function of the device.

Impedance-Based Stability Analysis in Grid Interconnection Impact Study Owing to the Increased Adoption of Converter-Interfaced Generators

DOE PAGES

Cho, Youngho; Hur, Kyeon; Kang, Yong; ...

2017-09-08

This study investigates the emerging harmonic stability concerns to be addressed by grid planners in generation interconnection studies, owing to the increased adoption of renewable energy resources connected to the grid via power electronic converters. The wideband and high-frequency electromagnetic transient (EMT) characteristics of these converter-interfaced generators (CIGs) and their interaction with the grid impedance are not accurately captured in the typical dynamic studies conducted by grid planners. This paper thus identifies the desired components to be studied and subsequently develops a practical process for integrating a new CIG into a grid with the existing CIGs. The steps of thismore » process are as follows: the impedance equation of a CIG using its control dynamics and an interface filter to the grid, for example, an LCL filter (inductor-capacitor-inductor type), is developed; an equivalent impedance model including the existing CIGs nearby and the grid observed from the point of common coupling are derived; the system stability for credible operating scenarios is assessed. Detailed EMT simulations validate the accuracy of the impedance models and stability assessment for various connection scenarios. Here, by complementing the conventional EMT simulation studies, the proposed analytical approach enables grid planners to identify critical design parameters for seamlessly integrating a new CIG and ensuring the reliability of the grid.« less

A two layer hermetic-like coating process for on-wafer encapsulation of GaAs MMIC`s

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaleta, T.; Varmazis, C.; Carney, J.P.

1995-12-31

The authors have developed a low-cost, manufacturable, 2-layer coating process for on-wafer encapsulation of GaAs MMICs. This packaging approach takes advantage of the low dielectric permittivity of polymers such as Benzocyclobutene (BCB) and the sealing properties of ceramics such as SiC to provide both mechanical protection to MMICs during handling and also hermetic-like equivalence to moisture with predictable changes in the electrical performance of the coated MMICs. The effects of coatings on FET parameters, spiral inductors and a two stage X-Band LNA have been investigated. Results on FETs indicate that the internode capacitances Cgs and Cgd exhibited the same incrementalmore » change of 0.035 pF/mm (3 and 25 % increase respectively), while Cds changed by 0.051 pF/mm (27% increase) with very minimal changes in the other FET parameters. The only observed change in spiral inductors was a 112% increase in Cp from 0.006 pF to 0.013 pF. The LNA exhibited a 1 GHz shift in frequency response from 7 to 11 GHz to 6 to 11 GHz with no substantial changes in gain and noise figure. Preliminary reliability investigations on coated devices did not show any failures after 150 hours in autoclave (120C, 100% humidity).« less

A Self-Adaptive Capacitive Compensation Technique for Body Channel Communication.

PubMed

Mao, Jingna; Yang, Huazhong; Lian, Yong; Zhao, Bo

2017-10-01

In wireless body area network, capacitive-coupling body channel communication (CC-BCC) has the potential to attain better energy efficiency over conventional wireless communication schemes. The CC-BCC scheme utilizes the human body as the forward signal transmission medium, reducing the path loss in wireless body-centric communications. However, the backward path is formed by the coupling capacitance between the ground electrodes (GEs) of transmitter (Tx) and receiver (Rx), which increases the path loss and results in a body posture dependent backward impedance. Conventional methods use a fixed inductor to resonate with the backward capacitor to compensate the path loss, while it's not effective in compensating the variable backward impedance induced by the body movements. In this paper, we propose a self-adaptive capacitive compensation (SACC) technique to address such a problem. A backward distance detector is introduced to estimate the distance between two GEs of Tx and Rx, and a backward capacitance model is built to calculate the backward capacitance. The calculated backward capacitance at varying body posture is compensated by a digitally controlled tunable inductor (DCTI). The proposed SACC technique is validated by a prototype CC-BCC system, and measurements are taken on human subjects. The measurement results show that 9dB-16 dB channel enhancement can be achieved at a backward path distance of 1 cm-10 cm.

[Pharmacological analysis of the effect of natural double-helical nucleic acids on the detoxifying function of the liver].

PubMed

Masycheva, V I; Morozova, E N; Nadolinnaia, I G

1988-10-01

The effect of interferon inductors i.e. double stranded RNAs from S. cerevisiae and phage F6 on the liver detoxicating function was studied on noninbred albino mice. The liver detoxicating function was tested by duration of hexenal sleep. It was shown that intraperitoneal administration of the yeast and phage RNAs in doses of 1/5 LD50 for three times led to increasing of the narcotic sleep duration in the animals by 65 and 207 per cent, respectively. The effect was of the dose-dependent nature. The doses not inducing reliable inhibition of hexenal metabolism were equal to 1/10 LD50 for the yeast dsRNA and 1/27 LD50 for the phage dsRNA. The inhibitory effect of the dsRNAs was retained for 2-3 days after discontinuation of the drug use. When the dsRNAs were administered simultaneously with nembutal, an inductor of the liver microsomal enzymes, the dsRNAs eliminated its inducing effect. Simultaneous administration of alpha-tocopherol lowered the dsRNA effect on hexenal metabolism. The findings suggested that the dsRNA inhibitory effect on the liver detoxicating function was grounded on the mechanisms associated with inhibition of syntheses and activation of lipid peroxidation specific of the monooxygenase system under the action of the dsRNAs.

Longitudinal space charge compensation at PSR

NASA Astrophysics Data System (ADS)

Neri, Filippo

1998-11-01

The longitudinal space-charge force in neutron spallation source compressor ring or other high intensity proton storage rings can be compensated by introducing an insert in the ring. The effect of the inductor is to cancel all or part of the space charge potential, because it is capacitive. The Proton Storage Ring at Los Alamos National Laboratory is a compressor ring used to produce short pulses of spallation neutrons. Inductive inserts design for space charge compensation at the Los Alamos Proton Storage Ring is described.

Ultra-short pulse generator

DOEpatents

McEwan, T.E.

1993-12-28

An inexpensive pulse generating circuit is disclosed that generates ultra-short, 200 picosecond, and high voltage 100 kW, pulses suitable for wideband radar and other wideband applications. The circuit implements a nonlinear transmission line with series inductors and variable capacitors coupled to ground made from reverse biased diodes to sharpen and increase the amplitude of a high-voltage power MOSFET driver input pulse until it causes non-destructive transit time breakdown in a final avalanche shock wave diode, which increases and sharpens the pulse even more. 5 figures.

[Isolation and purification of Mn-peroxidase from Azospirillum brasilense Sp245].

PubMed

Kupriashina, M A; Selivanov, N Iu; Nikitina, V E

2012-01-01

Homogenous Mn-peroxidase of a 26-fold purity grade was isolated from a culture of Azospirillum brasilense Sp245 cultivated on a medium containing 0.1 mM pyrocatechol. The molecular weight of the enzyme is 43 kD as revealed by electrophoresis in SDS-PAAG. It was shown that the use of pyrocatechol and 2,2'-azino-bis(3-ethylbenzotiazoline-6-sulfonate) at concentrations of 0.1 and I mM as inductors increased the Mn-peroxidase activity by a factor of 3.

Advanced YBCO-Coated Conductors for Use on Air Platforms (Postprint)

DTIC Science & Technology

2007-06-01

for example, the Navy has programs on both homopolar and synchronous superconducting motors to drive the future all-electric ship.6 Westinghouse has...syn- chronous, homopolar , inductor-type alternator with a stationary HTS coil, solid rotor forging, and conven- tional stator; refer to Fig. 1. This is...Denial,’’ III-Vs Rev., 17 [5] 10 (2004). 6. D. U. Gubser, ‘‘Superconducting Motors and Generators for Naval Appli- cations,’’ Physica C, 392–396 1192

In vitro effect of short peptides on expression of interleukin-2 gene in splenocytes.

PubMed

Kazakova, T B; Barabanova, S V; Khavinson, V Kh; Glushikhina, M S; Parkhomenko, E P; Malinin, V V; Korneva, E A

2002-06-01

Synthetic peptides Vilon (Lys-Glu), Epithalon (Ala-Glu-Asp-Gly), and Cortagen (Ala-Glu-Asp-Pro) in vitro activated interleukin-2 mRNA synthesis in splenocytes from CBA mice in the absence of specific inductors. The intensity of interleukin-2 mRNA synthesis in splenocytes depended on the type, concentration, and duration of treatment with the peptides. Vilon and Epithalon were most potent, while Cortagen produced a less pronounced effect on interleukin-2 mRNA synthesis.