System-level integrated circuit (SLIC) development for phased array antenna applications

NASA Technical Reports Server (NTRS)

Shalkhauser, K. A.; Raquet, C. A.

1991-01-01

A microwave/millimeter wave system-level integrated circuit (SLIC) being developed for use in phased array antenna applications is described. The program goal is to design, fabricate, test, and deliver an advanced integrated circuit that merges radio frequency (RF) monolithic microwave integrated circuit (MMIC) technologies with digital, photonic, and analog circuitry that provide control, support, and interface functions. As a whole, the SLIC will offer improvements in RF device performance, uniformity, and stability while enabling accurate, rapid, repeatable control of the RF signal. Furthermore, the SLIC program addresses issues relating to insertion of solid state devices into antenna systems, such as the reduction in number of bias, control, and signal lines. Program goals, approach, and status are discussed.

Three phase power factor controller

NASA Technical Reports Server (NTRS)

Nola, F. J. (Inventor)

1984-01-01

A power control circuit for a three phase induction motor is described. Power factors for the three phases are summed to provide a control signal, and this control signal is particularly filtered and then employed to control the duty cycle of each phase of input power to the motor.

Solid state control system for oil well bailer pump

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

Senghaas, K. A.; Senghaas, P.

1985-05-14

A solid state switching controller for use with various types of oil well bailer pumps. Individually programmable steps with lockouts provide multiple mutual exclusivity between various circuit operations. A trickle charge battery system powers the control circuits. A tank overflow float protects against oil spillage. An automatic production rate adjustment circuit is provided which increases cycle time in proportion to the rate of production. The circuit includes a low power voltage detector for disabling the control circuits until the line voltage is acceptable. A three-phase power and control system with an isolation transformer for the controls avoids unreliable ground connections.more » The timers include a dividing circuit with an RC circuit. All power actuated apparatus are actuated by triac switches which are controlled by an opto driver. The bailer brake is pulse actuated for allowing the bailer to sink into crude oil without excess cable looseness.« less

Hidden attractors in dynamical models of phase-locked loop circuits: Limitations of simulation in MATLAB and SPICE

NASA Astrophysics Data System (ADS)

Kuznetsov, N. V.; Leonov, G. A.; Yuldashev, M. V.; Yuldashev, R. V.

2017-10-01

During recent years it has been shown that hidden oscillations, whose basin of attraction does not overlap with small neighborhoods of equilibria, may significantly complicate simulation of dynamical models, lead to unreliable results and wrong conclusions, and cause serious damage in drilling systems, aircrafts control systems, electromechanical systems, and other applications. This article provides a survey of various phase-locked loop based circuits (used in satellite navigation systems, optical, and digital communication), where such difficulties take place in MATLAB and SPICE. Considered examples can be used for testing other phase-locked loop based circuits and simulation tools, and motivate the development and application of rigorous analytical methods for the global analysis of phase-locked loop based circuits.

Multi-functional optical signal processing using optical spectrum control circuit

NASA Astrophysics Data System (ADS)

Hayashi, Shuhei; Ikeda, Tatsuhiko; Mizuno, Takayuki; Takahashi, Hiroshi; Tsuda, Hiroyuki

2015-02-01

Processing ultra-fast optical signals without optical/electronic conversion is in demand and time-to-space conversion has been proposed as an effective solution. We have designed and fabricated an arrayed-waveguide grating (AWG) based optical spectrum control circuit (OSCC) using silica planar lightwave circuit (PLC) technology. This device is composed of an AWG, tunable phase shifters and a mirror. The principle of signal processing is to spatially decompose the signal's frequency components by using the AWG. Then, the phase of each frequency component is controlled by the tunable phase shifters. Finally, the light is reflected back to the AWG by the mirror and synthesized. Amplitude of each frequency component can be controlled by distributing the power to high diffraction order light. The spectral controlling range of the OSCC is 100 GHz and its resolution is 1.67 GHz. This paper describes equipping the OSCC with optical coded division multiplex (OCDM) encoder/decoder functionality. The encoding principle is to apply certain phase patterns to the signal's frequency components and intentionally disperse the signal. The decoding principle is also to apply certain phase patterns to the frequency components at the receiving side. If the applied phase pattern compensates the intentional dispersion, the waveform is regenerated, but if the pattern is not appropriate, the waveform remains dispersed. We also propose an arbitrary filter function by exploiting the OSCC's amplitude and phase control attributes. For example, a filtered optical signal transmitted through multiple optical nodes that use the wavelength multiplexer/demultiplexer can be equalized.

Programmable Low-Voltage Circuit Breaker and Tester

NASA Technical Reports Server (NTRS)

Greenfield, Terry

2008-01-01

An instrumentation system that would comprise a remotely controllable and programmable low-voltage circuit breaker plus several electric-circuit-testing subsystems has been conceived, originally for use aboard a spacecraft during all phases of operation from pre-launch testing through launch, ascent, orbit, descent, and landing. The system could also be adapted to similar use aboard aircraft. In comparison with remotely controllable circuit breakers heretofore commercially available, this system would be smaller, less massive, and capable of performing more functions, as needed for aerospace applications.

Regulatory design governing progression of population growth phases in bacteria.

PubMed

Martínez-Antonio, Agustino; Lomnitz, Jason G; Sandoval, Santiago; Aldana, Maximino; Savageau, Michael A

2012-01-01

It has long been noted that batch cultures inoculated with resting bacteria exhibit a progression of growth phases traditionally labeled lag, exponential, pre-stationary and stationary. However, a detailed molecular description of the mechanisms controlling the transitions between these phases is lacking. A core circuit, formed by a subset of regulatory interactions involving five global transcription factors (FIS, HNS, IHF, RpoS and GadX), has been identified by correlating information from the well- established transcriptional regulatory network of Escherichia coli and genome-wide expression data from cultures in these different growth phases. We propose a functional role for this circuit in controlling progression through these phases. Two alternative hypotheses for controlling the transition between the growth phases are first, a continuous graded adjustment to changing environmental conditions, and second, a discontinuous hysteretic switch at critical thresholds between growth phases. We formulate a simple mathematical model of the core circuit, consisting of differential equations based on the power-law formalism, and show by mathematical and computer-assisted analysis that there are critical conditions among the parameters of the model that can lead to hysteretic switch behavior, which--if validated experimentally--would suggest that the transitions between different growth phases might be analogous to cellular differentiation. Based on these provocative results, we propose experiments to test the alternative hypotheses.

FREQUENCY STABILIZING SYSTEM

DOEpatents

Kerns, Q.A.; Anderson, O.A.

1960-05-01

An electronic control circuit is described in which a first signal frequency is held in synchronization with a second varying reference signal. The circuit receives the first and second signals as inputs and produces an output signal having an amplitude dependent upon rate of phase change between the two signals and a polarity dependent on direction of the phase change. The output may thus serve as a correction signal for maintaining the desired synchronization. The response of the system is not dependent on relative phase angle between the two compared signals. By having practically no capacitance in the circuit, there is minimum delay between occurrence of a phase shift and a response in the output signal and therefore very fast synchronization is effected.

Phase Control in Nonlinear Systems

NASA Astrophysics Data System (ADS)

Zambrano, Samuel; Seoane, Jesús M.; Mariño, Inés P.; Sanjuán, Miguel A. F.; Meucci, Riccardo

The following sections are included: * Introduction * Phase Control of Chaos * Description of the model * Numerical exploration of phase control of chaos * Experimental evidence of phase control of chaos * Phase Control of Intermittency in Dynamical Systems * Crisis-induced intermittency and its control * Experimental setup and implementation of the phase control scheme * Phase control of the laser in the pre-crisis regime * Phase control of the intermittency after the crisis * Phase control of the intermittency in the quadratic map * Phase Control of Escapes in Open Dynamical Systems * Control of open dynamical systems * Model description * Numerical simulations and heuristic arguments * Experimental implementation in an electronic circuit * Conclusions and Discussions * Acknowledgments * References

A design concept for an MMIC (Monolithic Microwave Integrated Circuit) microstrip phased array

NASA Technical Reports Server (NTRS)

Lee, Richard Q.; Smetana, Jerry; Acosta, Roberto

1987-01-01

A conceptual design for a microstrip phased array with monolithic microwave integrated circuit (MMIC) amplitude and phase controls is described. The MMIC devices used are 20 GHz variable power amplifiers and variable phase shifters recently developed by NASA contractors for applications in future Ka proposed design, which concept is for a general NxN element array of rectangular lattice geometry. Subarray excitation is incorporated in the MMIC phased array design to reduce the complexity of the beam forming network and the number of MMIC components required.

Circuit model of the ITER-like antenna for JET and simulation of its control algorithms

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

Durodié, Frédéric, E-mail: frederic.durodie@rma.ac.be; Křivská, Alena; Dumortier, Pierre

2015-12-10

The ITER-like Antenna (ILA) for JET [1] is a 2 toroidal by 2 poloidal array of Resonant Double Loops (RDL) featuring in-vessel matching capacitors feeding RF current straps in conjugate-T manner, a low impedance quarter-wave impedance transformer, a service stub allowing hydraulic actuator and water cooling services to reach the aforementioned capacitors and a 2nd stage phase-shifter-stub matching circuit allowing to correct/choose the conjugate-T working impedance. Toroidally adjacent RDLs are fed from a 3dB hybrid splitter. It has been operated at 33, 42 and 47MHz on plasma (2008-2009) while it presently estimated frequency range is from 29 to 49MHz. Atmore » the time of the design (2001-2004) as well as the experiments the circuit models of the ILA were quite basic. The ILA front face and strap array Topica model was relatively crude and failed to correctly represent the poloidal central septum, Faraday Screen attachment as well as the segmented antenna central septum limiter. The ILA matching capacitors, T-junction, Vacuum Transmission Line (VTL) and Service Stubs were represented by lumped circuit elements and simple transmission line models. The assessment of the ILA results carried out to decide on the repair of the ILA identified that achieving routine full array operation requires a better understanding of the RF circuit, a feedback control algorithm for the 2nd stage matching as well as tighter calibrations of RF measurements. The paper presents the progress in modelling of the ILA comprising a more detailed Topica model of the front face for various plasma Scrape Off Layer profiles, a comprehensive HFSS model of the matching capacitors including internal bellows and electrode cylinders, 3D-EM models of the VTL including vacuum ceramic window, Service stub, a transmission line model of the 2nd stage matching circuit and main transmission lines including the 3dB hybrid splitters. A time evolving simulation using the improved circuit model allowed to design and simulate the effectiveness of a feedback control algorithm for the 2nd stage matching and demonstrates the simultaneous matching and control of the 4 RDLs: 11 feedback loops control 21 actuators (8 capacitors, 4 phase shifters and 4 stubs for the 2nd stage matching, 4 main phase shifters controlling of the toroidal phasing and the electronically controlled phase between RF sources feeding top and bottom parts of the array and determines the poloidal phasing of the array which is solved explicitly at each time step) on (simulated) ELMy plasmas.« less

RF waveguide phase-directed power combiners

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

Nantista, Christopher D.; Dolgashev, Valery A.; Tantawi, Sami G.

2017-05-02

High power RF phase-directed power combiners include magic H hybrid and/or superhybrid circuits oriented in orthogonal H-planes and connected using E-plane bends and/or twists to produce compact 3D waveguide circuits, including 8.times.8 and 16.times.16 combiners. Using phase control at the input ports, RF power can be directed to a single output port, enabling fast switching between output ports for applications such as multi-angle radiation therapy.

ELECTROMAGNETIC AND ELECTROSTATIC GENERATORS: ANNOTATED BIBLIOGRAPHY.

DTIC Science & Technology

generator with split poles, ultrasonic-frequency generator, unipolar generator, single-phase micromotors , synchronous motor, asynchronous motor...asymmetrical rotor, magnetic circuit, dc micromotors , circuit for the automatic control of synchronized induction motors, induction torque micromotors , electric

Compact Feed Circuit with Quarter Wavelength Transmission Line Matrix Controlling Beams in Three Directions Including Boresight

NASA Astrophysics Data System (ADS)

Tsuji, Masatoshi

A compact feed circuit with a λ/4 transmission line matrix circuit for use in array antennas to control beams in three directions, including boresight, is presented. The feed circuit antenna is composed of five switches and λ/4 transmission lines, and the feeding matrix circuit yields phase differences of ±90° and 0°. The feed circuit can obtain a reliable output signal, as there is only a small degree of deviation of output signal with variations in the line width. The feed circuit is simulated, fabricated, and evaluated for ISM band, and the measured characteristics agree well with the results of the simulation. The size of feed circuit is 45 (H) × 48 (W) × 3 (T) mm.

A digital optical phase-locked loop for diode lasers based on field programmable gate array.

PubMed

Xu, Zhouxiang; Zhang, Xian; Huang, Kaikai; Lu, Xuanhui

2012-09-01

We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382∕MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad(2) and transition time of 100 μs under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.

A digital optical phase-locked loop for diode lasers based on field programmable gate array

NASA Astrophysics Data System (ADS)

Xu, Zhouxiang; Zhang, Xian; Huang, Kaikai; Lu, Xuanhui

2012-09-01

We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad2 and transition time of 100 μs under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.

Integrated optical transceiver with electronically controlled optical beamsteering

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

Davids, Paul; DeRose, Christopher; Tauke-Pedretti, Anna

A beam-steering optical transceiver is provided. The transceiver includes one or more modules, each comprising an antenna chip and a control chip bonded to the antenna chip. Each antenna chip has a feeder waveguide, a plurality of row waveguides that tap off from the feeder waveguide, and a plurality of metallic nanoantenna elements arranged in a two-dimensional array of rows and columns such that each row overlies one of the row waveguides. Each antenna chip also includes a plurality of independently addressable thermo-optical phase shifters, each configured to produce a thermo-optical phase shift in a respective row. Each antenna chipmore » also has, for each row, a row-wise heating circuit configured to produce a respective thermo-optic phase shift at each nanoantenna element along its row. The control chip includes controllable current sources for the independently addressable thermo-optical phase shifters and the row-wise heating circuits.« less

Design of a new low-phase-noise millimetre-wave quadrature voltage-controlled oscillator

NASA Astrophysics Data System (ADS)

Kashani, Zeinab; Nabavi, Abdolreza

2018-07-01

This paper presents a new circuit topology of millimetre-wave quadrature voltage-controlled oscillator (QVCO) using an improved Colpitts oscillator without tail bias. By employing an extra capacitance between the drain and source terminations of the transistors and optimising circuit values, a low-power and low-phase-noise (PN) oscillator is designed. For generating the output signals with 90° phase difference, a self-injection coupling network between two identical cores is used. The proposed QVCO dissipates no extra dc power for coupling, since there is no dc-path to ground for the coupled transistors and no extra noise is added to circuit. The best figure-of-merit is -188.5, the power consumption is 14.98-15.45 mW, in a standard 180-nm CMOS technology, for 58.2 GHz center frequency from 59.3 to 59.6 GHz. The PN is -104.86 dBc/Hz at 1-MHz offset.

Controller for a High-Power, Brushless dc Motor

NASA Technical Reports Server (NTRS)

Fleming, David J.; Makdad, Terence A.

1987-01-01

Driving and braking torques controllable. Control circuit operates 7-kW, 45-lb-ft (61-N-m), three-phase, brushless dc motor in both motor and generator modes. In motor modes, energy from power source is pulse-width modulated to motor through modified "H-bridge" circuit, in generator mode, energy from motor is pulse-width modulated into bank of load resistors to provide variable braking torques. Circuit provides high-resolution torque control in both directions over wide range of speeds and torques. Tested successfully at bus voltages up to 200 Vdc and currents up to 45 A.

Energy saving in ac generators

NASA Technical Reports Server (NTRS)

Nola, F. J.

1980-01-01

Circuit cuts no-load losses, without sacrificing full-load power. Phase-contro circuit includes gate-controlled semiconductor switch that cuts off applied voltage for most of ac cycle if generator idling. Switch "on" time increases when generator is in operation.

Compressed quantum computation using a remote five-qubit quantum computer

NASA Astrophysics Data System (ADS)

Hebenstreit, M.; Alsina, D.; Latorre, J. I.; Kraus, B.

2017-05-01

The notion of compressed quantum computation is employed to simulate the Ising interaction of a one-dimensional chain consisting of n qubits using the universal IBM cloud quantum computer running on log2(n ) qubits. The external field parameter that controls the quantum phase transition of this model translates into particular settings of the quantum gates that generate the circuit. We measure the magnetization, which displays the quantum phase transition, on a two-qubit system, which simulates a four-qubit Ising chain, and show its agreement with the theoretical prediction within a certain error. We also discuss the relevant point of how to assess errors when using a cloud quantum computer with a limited amount of runs. As a solution, we propose to use validating circuits, that is, to run independent controlled quantum circuits of similar complexity to the circuit of interest.

Optical modular arithmetic

NASA Astrophysics Data System (ADS)

Pavlichin, Dmitri S.; Mabuchi, Hideo

2014-06-01

Nanoscale integrated photonic devices and circuits offer a path to ultra-low power computation at the few-photon level. Here we propose an optical circuit that performs a ubiquitous operation: the controlled, random-access readout of a collection of stored memory phases or, equivalently, the computation of the inner product of a vector of phases with a binary selector" vector, where the arithmetic is done modulo 2pi and the result is encoded in the phase of a coherent field. This circuit, a collection of cascaded interferometers driven by a coherent input field, demonstrates the use of coherence as a computational resource, and of the use of recently-developed mathematical tools for modeling optical circuits with many coupled parts. The construction extends in a straightforward way to the computation of matrix-vector and matrix-matrix products, and, with the inclusion of an optical feedback loop, to the computation of a weighted" readout of stored memory phases. We note some applications of these circuits for error correction and for computing tasks requiring fast vector inner products, e.g. statistical classification and some machine learning algorithms.

[Study on a wireless energy transmission system for the noninvasive examination micro system inside alimentary tracts].

PubMed

He, Xiu; Yan, Guo-Zheng; Wang, Fu-Min

2008-01-01

A wireless energy transmission system for the MEMS system inside alimentary tracts is reported here in the paper. It consists of an automatic frequency tracking circuit of phase lock loop and phase shift PWM control circuit. Experimental results show that the energy transmission system is capable of automatic frequency-tracking and transmission power-adjusting and has stable received energy.

Frequency spectrum analyzer with phase-lock

DOEpatents

Boland, Thomas J.

1984-01-01

A frequency-spectrum analyzer with phase-lock for analyzing the frequency and amplitude of an input signal is comprised of a voltage controlled oscillator (VCO) which is driven by a ramp generator, and a phase error detector circuit. The phase error detector circuit measures the difference in phase between the VCO and the input signal, and drives the VCO locking it in phase momentarily with the input signal. The input signal and the output of the VCO are fed into a correlator which transfers the input signal to a frequency domain, while providing an accurate absolute amplitude measurement of each frequency component of the input signal.

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

Silva, E.R.C. da; Filho, B.J.C.

This paper presents a PWM current clamping circuit for improving a series resonant DC link converter. This circuit is capable of reducing current peaks to about 1.2--1.4 times the DC bias current. When desired, resonant transition creates notches in the dc link current, allowing the converter`s switches to synchronize with external PWM strategy. A regulated DC current source may be obtained--by using a conventional rectifier source--to feed a DC load or a current source inverter. Phase plane approach makes ease the understanding the operation, control and design procedure of the circuit. Another topology is derived and its features compared tomore » the first circuit. Simulation results for the simplified circuit and for a three-phase induction motor driven by such inverter will be presented. Moreover, the principle is corroborated by experimental results.« less

Fault diagnosis and fault-tolerant finite control set-model predictive control of a multiphase voltage-source inverter supplying BLDC motor.

PubMed

Salehifar, Mehdi; Moreno-Equilaz, Manuel

2016-01-01

Due to its fault tolerance, a multiphase brushless direct current (BLDC) motor can meet high reliability demand for application in electric vehicles. The voltage-source inverter (VSI) supplying the motor is subjected to open circuit faults. Therefore, it is necessary to design a fault-tolerant (FT) control algorithm with an embedded fault diagnosis (FD) block. In this paper, finite control set-model predictive control (FCS-MPC) is developed to implement the fault-tolerant control algorithm of a five-phase BLDC motor. The developed control method is fast, simple, and flexible. A FD method based on available information from the control block is proposed; this method is simple, robust to common transients in motor and able to localize multiple open circuit faults. The proposed FD and FT control algorithm are embedded in a five-phase BLDC motor drive. In order to validate the theory presented, simulation and experimental results are conducted on a five-phase two-level VSI supplying a five-phase BLDC motor. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Flutter Generator Control and Force Computer.

DTIC Science & Technology

1985-07-01

exciter module 2. Mechanical load 3. Rectifier and triac 4. Overall system 5. Velocity control 6. Microprocessor 7. Operation in 1 ’g’ environment 8...amplifier Output voltage from the rectifier/ triac circuit (figure 3) is a function of the conduction angle of each triac . In a 400 Hz 3-phase system...3IIGCICI FIRING CIRCUIT FIRING CIRCUIT TO MOTOR Figure 3. Rectifier and triac _____ -=low AEL-0242-TNI Figure 4 DEMAND(V V49 -9 APIFE M O T OR

Bidirectional amplifier

DOEpatents

Wright, James T.

1986-01-01

A bilateral circuit is operable for transmitting signals in two directions without generation of ringing due to feedback caused by the insertion of the circuit. The circuit may include gain for each of the signals to provide a bidirectional amplifier. The signals are passed through two separate paths, with a unidirectional amplifier in each path. A controlled sampling device is provided in each path for sampling the two signals. Any feedback loop between the two signals is disrupted by providing a phase displacement between the control signals for the two sampling devices.

Bidirectional amplifier

DOEpatents

Wright, J.T.

1984-02-02

A bilateral circuit is operable for transmitting signals in two directions without generation of ringing due to feedback caused by the insertion of the circuit. The circuit may include gain for each of the signals to provide a bidirectional amplifier. The signals are passed through two separate paths, with a unidirectional amplifier in each path. A controlled sampling device is provided in each path for sampling the two signals. Any feedback loop between the two signals is disrupted by providing a phase displacement between the control signals for the two sampling devices.

System and method for regulating resonant inverters

DOEpatents

Stevanovic, Ljubisa Dragoljub [Clifton Park, NY; Zane, Regan Andrew [Superior, CO

2007-08-28

A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonant inverter and a sensor for sensing one or more parameters of the resonant inverter. The one or more parameters are representative of a phase angle. The resonant inverter control system also includes a comparator for comparing the one or more parameters to a reference value and a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

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

Aeloiza, Eddy C.; Burgos, Rolando P.

A step-down AC/AC converter for use in an electric distribution system includes at least one chopper circuit for each one of a plurality of phases of the AC power, each chopper circuit including a four-quadrant switch coupled in series between primary and secondary sides of the chopper circuit and a current-bidirectional two-quadrant switch coupled between the secondary side of the chopper circuit and a common node. Each current-bidirectional two-quadrant switch is oriented in the same direction, with respect to the secondary side of the corresponding chopper circuit and the common node. The converter further includes a control circuit configured tomore » pulse-width-modulate control inputs of the switches, to convert a first multiphase AC voltage at the primary sides of the chopper circuits to a second multiphase AC voltage at the secondary sides of the chopper circuits, the second multiphase AC voltage being lower in voltage than the first multiphase AC voltage.« less

Attenuation of Activity in an Endogenous Analgesia Circuit by Ongoing Pain in the Rat

PubMed Central

Ferrari, Luiz F.; Gear, Robert W.; Levine, Jon D.

2010-01-01

Analgesic efficacy varies depending on the pain syndrome being treated. One reason for this may be a differential effect of individual pain syndromes on the function of endogenous pain control circuits at which these drugs act to produce analgesia. To test this hypothesis we examined the effects of diverse (i.e., ongoing inflammatory, neuropathic, or chronic widespread) pain syndromes on analgesia induced by activation of an opioid-mediated noxious stimulus-induced endogenous pain control circuit. This circuit was activated by subdermal capsaicin injection at a site remote from the site of nociceptive testing. Analgesia was not affected by carrageenan-induced inflammatory pain nor the early-phase of oxaliplatin neuropathy (a complication of cancer chemotherapy). However, the duration of analgesia was markedly shorter in the late-phase of oxaliplatin neuropathy and in alcoholic neuropathy. A model of fibromyalgia syndrome produced by chronic unpredictable stress and proinflammatory cytokines also shortened analgesia duration, but so did the same stress alone. Therefore, since chronic pain can activate neuroendocrine stress axes, we tested whether they are involved in the attenuation of analgesic duration induced by these pain syndromes. Rats in which the sympathoadrenal axis was ablated by adrenal medullectomy showed normal duration pain-induced analgesia in groups with either late-phase oxaliplatin neuropathy, alcoholic neuropathy, or exposure to sound stress. These results support the suggestion that pain syndromes can modulate activity in endogenous pain control circuits, and this effect is sympathoadrenal dependent. PMID:20943910

Continuous-variable geometric phase and its manipulation for quantum computation in a superconducting circuit.

PubMed

Song, Chao; Zheng, Shi-Biao; Zhang, Pengfei; Xu, Kai; Zhang, Libo; Guo, Qiujiang; Liu, Wuxin; Xu, Da; Deng, Hui; Huang, Keqiang; Zheng, Dongning; Zhu, Xiaobo; Wang, H

2017-10-20

Geometric phase, associated with holonomy transformation in quantum state space, is an important quantum-mechanical effect. Besides fundamental interest, this effect has practical applications, among which geometric quantum computation is a paradigm, where quantum logic operations are realized through geometric phase manipulation that has some intrinsic noise-resilient advantages and may enable simplified implementation of multi-qubit gates compared to the dynamical approach. Here we report observation of a continuous-variable geometric phase and demonstrate a quantum gate protocol based on this phase in a superconducting circuit, where five qubits are controllably coupled to a resonator. Our geometric approach allows for one-step implementation of n-qubit controlled-phase gates, which represents a remarkable advantage compared to gate decomposition methods, where the number of required steps dramatically increases with n. Following this approach, we realize these gates with n up to 4, verifying the high efficiency of this geometric manipulation for quantum computation.

Closed Loop solar array-ion thruster system with power control circuitry

NASA Technical Reports Server (NTRS)

Gruber, R. P. (Inventor)

1979-01-01

A power control circuit connected between a solar array and an ion thruster receives voltage and current signals from the solar array. The control circuit multiplies the voltage and current signals together to produce a power signal which is differentiated with respect to time. The differentiator output is detected by a zero crossing detector and, after suitable shaping, the detector output is phase compared with a clock in a phase demodulator. An integrator receives no output from the phase demodulator when the operating point is at the maximum power but is driven toward the maximum power point for non-optimum operation. A ramp generator provides minor variations in the beam current reference signal produced by the integrator in order to obtain the first derivative of power.

On Per-Phase Topology Control and Switching in Emerging Distribution Systems

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

Ding, Fei; Mousavi, Mirrasoul J.

This paper presents a new concept and approach for topology control and switching in distribution systems by extending the traditional circuit switching to laterals and single-phase loads. Voltage unbalance and other key performance indicators including voltage magnitudes, line loading, and energy losses are used to characterize and demonstrate the technical value of optimizing system topology on a per-phase basis in response to feeder conditions. The near-optimal per-phase topology control is defined as a series of hierarchical optimization problems. The proposed approach is respectively applied to IEEE 13-bus and 123-bus test systems for demonstration, which included the impact of integrating electricmore » vehicles (EVs) in the test circuit. It is concluded that the proposed approach can be effectively leveraged to improve voltage profiles with electric vehicles, the extent of which depends upon the performance of the base case without EVs.« less

Transient stability enhancement of electric power generating systems by 120-degree phase rotation

DOEpatents

Cresap, Richard L.; Taylor, Carson W.; Kreipe, Michael J.

1982-01-01

A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.

Single-stage three-phase boost power factor correction circuit for AC-DC converter

NASA Astrophysics Data System (ADS)

Azazi, Haitham Z.; Ahmed, Sayed M.; Lashine, Azza E.

2018-01-01

This article presents a single-stage three-phase power factor correction (PFC) circuit for AC-to-DC converter using a single-switch boost regulator, leading to improve the input power factor (PF), reducing the input current harmonics and decreasing the number of required active switches. A novel PFC control strategy which is characterised as a simple and low-cost control circuit was adopted, for achieving a good dynamic performance, unity input PF, and minimising the harmonic contents of the input current, at which it can be applied to low/medium power converters. A detailed analytical, simulation and experimental studies were therefore conducted. The effectiveness of the proposed controller algorithm is validated by the simulation results, which were carried out using MATLAB/SIMULINK environment. The proposed system is built and tested in the laboratory using DSP-DS1104 digital control board for an inductive load. The results revealed that the total harmonic distortion in the supply current was very low. Finally, a good agreement between simulation and experimental results was achieved.

Ultrafast quantum computation in ultrastrongly coupled circuit QED systems.

PubMed

Wang, Yimin; Guo, Chu; Zhang, Guo-Qiang; Wang, Gangcheng; Wu, Chunfeng

2017-03-10

The latest technological progress of achieving the ultrastrong-coupling regime in circuit quantum electrodynamics (QED) systems has greatly promoted the developments of quantum physics, where novel quantum optics phenomena and potential computational benefits have been predicted. Here, we propose a scheme to accelerate the nontrivial two-qubit phase gate in a circuit QED system, where superconducting flux qubits are ultrastrongly coupled to a transmission line resonator (TLR), and two more TLRs are coupled to the ultrastrongly-coupled system for assistant. The nontrivial unconventional geometric phase gate between the two flux qubits is achieved based on close-loop displacements of the three-mode intracavity fields. Moreover, as there are three resonators contributing to the phase accumulation, the requirement of the coupling strength to realize the two-qubit gate can be reduced. Further reduction in the coupling strength to achieve a specific controlled-phase gate can be realized by adding more auxiliary resonators to the ultrastrongly-coupled system through superconducting quantum interference devices. We also present a study of our scheme with realistic parameters considering imperfect controls and noisy environment. Our scheme possesses the merits of ultrafastness and noise-tolerance due to the advantages of geometric phases.

Ultrafast quantum computation in ultrastrongly coupled circuit QED systems

PubMed Central

Wang, Yimin; Guo, Chu; Zhang, Guo-Qiang; Wang, Gangcheng; Wu, Chunfeng

2017-01-01

The latest technological progress of achieving the ultrastrong-coupling regime in circuit quantum electrodynamics (QED) systems has greatly promoted the developments of quantum physics, where novel quantum optics phenomena and potential computational benefits have been predicted. Here, we propose a scheme to accelerate the nontrivial two-qubit phase gate in a circuit QED system, where superconducting flux qubits are ultrastrongly coupled to a transmission line resonator (TLR), and two more TLRs are coupled to the ultrastrongly-coupled system for assistant. The nontrivial unconventional geometric phase gate between the two flux qubits is achieved based on close-loop displacements of the three-mode intracavity fields. Moreover, as there are three resonators contributing to the phase accumulation, the requirement of the coupling strength to realize the two-qubit gate can be reduced. Further reduction in the coupling strength to achieve a specific controlled-phase gate can be realized by adding more auxiliary resonators to the ultrastrongly-coupled system through superconducting quantum interference devices. We also present a study of our scheme with realistic parameters considering imperfect controls and noisy environment. Our scheme possesses the merits of ultrafastness and noise-tolerance due to the advantages of geometric phases. PMID:28281654

A digital optical phase-locked loop for diode lasers based on field programmable gate array

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

Xu Zhouxiang; Zhang Xian; Huang Kaikai

2012-09-15

We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat notemore » line width below 1 Hz, residual mean-square phase error of 0.14 rad{sup 2} and transition time of 100 {mu}s under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.« less

30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-phase alternating current equipment; circuit breakers. 75.900 Section 75.900 Mineral Resources MINE... Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers. [Statutory Provisions] Low- and medium-voltage power circuits serving three-phase alternating current...

Apparatus for controlling the firing of rectifiers in polyphase rectifying circuits

DOEpatents

Yarema, R.J.

1979-09-18

A polyphase rectifier is controlled with precision by a circuit that filters and shifts a reference signal associated with each phase and that starts a ramp signal at a zero crossing of the shifted reference signal. The difference between the ramp signal and an external trigger signal is used to generate a pulse that switches power rectifiers into conduction. The circuit reduces effects of variations that introduce subharmonics into a rectified signal and it can be used for constant or time-varying external trigger signals.

Three phase AC motor controller

DOEpatents

Vuckovich, Michael; Wright, Maynard K.; Burkett, John P.

1984-03-20

A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

Controlling a Four-Quadrant Brushless Three-Phase dc Motor

NASA Technical Reports Server (NTRS)

Nola, F. J.

1986-01-01

Control circuit commutates windings of brushless, three-phase, permanent-magnet motor operating from power supply. With single analog command voltage, controller makes motor accelerate, drive steadily, or brake regeneratively, in clockwise or counterclockwise direction. Controller well suited for use with energy-storage flywheels, actuators for aircraft-control surfaces, cranes, industrial robots, and other electromechanical systems requiring bidirectional control or sudden stopping and reversal.

Low power digitally controlled oscillator designs with a novel 3-transistor XNOR gate

NASA Astrophysics Data System (ADS)

Kumar, Manoj; Arya, Sandeep K.; Pandey, Sujata

2012-03-01

Digital controlled oscillators (DCOs) are the core of all digital phase locked loop (ADPLL) circuits. Here, DCO structures with reduced hardware and power consumption having full digital control have been proposed. Three different DCO architectures have been proposed based on ring based topology. Three, four and five bit controlled DCO with NMOS, PMOS and NMOS & PMOS transistor switching networks are presented. A three-transistor XNOR gate has been used as the inverter which is used as the delay cell. Delay has been controlled digitally with a switch network of NMOS and PMOS transistors. The three bit DCO with one NMOS network shows frequency variations of 1.6141-1.8790 GHz with power consumption variations 251.9224-276.8591 μW. The four bit DCO with one NMOS network shows frequency variation of 1.6229-1.8868 GHz with varying power consumption of 251.9225-278.0740 μW. A six bit DCO with one NMOS switching network gave an output frequency of 1.7237-1.8962 GHz with power consumption of 251.928-278.998 μW. Output frequency and power consumption results for 4 & 6 bit DCO circuits with one PMOS and NMOS & PMOS switching network have also been presented. The phase noise parameter with an offset frequency of 1 MHz has also been reported for the proposed circuits. Comparisons with earlier reported circuits have been made and the present approach shows advantages over previous circuits.

Implementing N-quantum phase gate via circuit QED with qubit-qubit interaction

NASA Astrophysics Data System (ADS)

Said, T.; Chouikh, A.; Essammouni, K.; Bennai, M.

2016-02-01

We propose a method for realizing a quantum phase gate of one qubit simultaneously controlling N target qubits based on the qubit-qubit interaction. We show how to implement the proposed gate with one transmon qubit simultaneously controlling N transmon qubits in a circuit QED driven by a strong microwave field. In our scheme, the operation time of this phase gate is independent of the number N of qubits. On the other hand, this gate can be realized in a time of nanosecond-scale much smaller than the decoherence time and dephasing time both being the time of microsecond-scale. Numerical simulation of the occupation probabilities of the second excited lever shows that the scheme could be achieved efficiently within current technology.

A novel double-convection chaotic attractor, its adaptive control and circuit simulation

NASA Astrophysics Data System (ADS)

Mamat, M.; Vaidyanathan, S.; Sambas, A.; Mujiarto; Sanjaya, W. S. M.; Subiyanto

2018-03-01

A 3-D novel double-convection chaotic system with three nonlinearities is proposed in this research work. The dynamical properties of the new chaotic system are described in terms of phase portraits, Lyapunov exponents, Kaplan-Yorke dimension, dissipativity, stability analysis of equilibria, etc. Adaptive control and synchronization of the new chaotic system with unknown parameters are achieved via nonlinear controllers and the results are established using Lyapunov stability theory. Furthermore, an electronic circuit realization of the new 3-D novel chaotic system is presented in detail. Finally, the circuit experimental results of the 3-D novel chaotic attractor show agreement with the numerical simulations.

A 5GHz Band Low Noise and Wide Tuning Range Si-CMOS VCO with a Novel Varactors Pair Circuit

NASA Astrophysics Data System (ADS)

Ta, Tuan Thanh; Kameda, Suguru; Takagi, Tadashi; Tsubouchi, Kazuo

In this paper, a fully integrated 5GHz voltage controlled oscillator (VCO) is presented. The VCO is designed with 0.18µm silicon complementary metal oxide semiconductor (Si-CMOS) process. To achieve low phase noise, a novel varactors pair circuit is proposed to cancel effects of capacitance fluctuation that makes harmonic currents which increase phase noise of VCO. The VCO with the proposed varactor circuit has tuning range from 5.1GHz to 6.1GHz (relative value of 17.9%) and phase noise of lower than -110.8dBc/Hz at 1MHz offset over the full tuning range. Figure-of-merit-with-tuning-range (FOMT) of the proposed VCO is -182dBc/Hz.

1990 MTT-S International Microwave Symposium and Exhibition and Microwave and Millimeter-Wave Monolithic IC Symposium, Dallas, TX, May 7-10, 1990, Proceedings

NASA Astrophysics Data System (ADS)

McQuiddy, David N., Jr.; Sokolov, Vladimir

1990-12-01

The present conference discusses microwave filters, lightwave technology for microwave antennas, planar and quasi-planar guides, mixers and VCOs, cavity filters, discontinuity and coupling effects, control circuits, power dividers and phase shifters, microwave ICs, biological effects and medical applications, CAD and modeling for MMICs, directional couplers, MMIC design trends, microwave packaging and manufacturing, monolithic ICs, and solid-state devices and circuits. Also discussed are microwave and mm-wave superconducting technology, MICs for communication systems, the merging of optical and microwave technologies, microwave power transistors, ferrite devices, network measurements, advanced transmission-line structures, FET devices and circuits, field theory of IC discontinuities, active quasi-optical techniques, phased-array techniques and circuits, nonlinear CAD, sub-mm wave devices, and high power devices.

Learning the Art of Electronics

NASA Astrophysics Data System (ADS)

Hayes, Thomas C.; Horowitz, Paul

2016-03-01

1. DC circuits; 2. RC circuits; 3. Diode circuits; 4. Transistors I; 5. Transistors II; 6. Operational amplifiers I; 7. Operational amplifiers II: nice positive feedback; 8. Operational amplifiers III; 9. Operational amplifiers IV: nasty positive feedback; 10. Operational amplifiers V: PID motor control loop; 11. Voltage regulators; 12. MOSFET switches; 13. Group audio project; 14. Logic gates; 15. Logic compilers, sequential circuits, flip-flops; 16. Counters; 17. Memory: state machines; 18. Analog to digital: phase-locked loop; 19. Microcontrollers and microprocessors I: processor/controller; 20. I/O, first assembly language; 21. Bit operations; 22. Interrupt: ADC and DAC; 23. Moving pointers, serial buses; 24. Dallas Standalone Micro, SiLabs SPI RAM; 25. Toys in the attic; Appendices; Index.

Design and performance analysis of generalised integrator-based controller for grid connected PV system

NASA Astrophysics Data System (ADS)

Saxena, Hemant; Singh, Alka; Rai, J. N.

2018-07-01

This article discusses the design and control of a single-phase grid-connected photovoltaic (PV) system. A 5-kW PV system is designed and integrated at the DC link of an H-bridge voltage source converter (VSC). The control of the VSC and switching logic is modelled using a generalised integrator (GI). The use of GI or its variants such as second-order GI have recently evolved for synchronisation and are being used as phase locked loop (PLL) circuits for grid integration. Design of PLL circuits and the use of transformations such as Park's and Clarke's are much easier in three-phase systems. But obtaining in-phase and quadrature components becomes an important and challenging issue in single-phase systems. This article addresses this issue and discusses an altogether different application of GI for the design of compensator based on the extraction of in-phase and quadrature components. GI is frequently used as a PLL; however, in this article, it is not used for synchronisation purposes. A new controller has been designed for a single-phase grid-connected PV system working as a single-phase active compensator. Extensive simulation results are shown for the working of integrated PV system under different atmospheric and operating conditions during daytime as well as night conditions. Experimental results showing the proposed control approach are presented and discussed for the hardware set-up developed in the laboratory.

High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

DOEpatents

Murty, Balarama Vempaty

2000-01-01

A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

Design and experiment of vehicular charger AC/DC system based on predictive control algorithm

NASA Astrophysics Data System (ADS)

He, Guangbi; Quan, Shuhai; Lu, Yuzhang

2018-06-01

For the car charging stage rectifier uncontrollable system, this paper proposes a predictive control algorithm of DC/DC converter based on the prediction model, established by the state space average method and its prediction model, obtained by the optimal mathematical description of mathematical calculation, to analysis prediction algorithm by Simulink simulation. The design of the structure of the car charging, at the request of the rated output power and output voltage adjustable control circuit, the first stage is the three-phase uncontrolled rectifier DC voltage Ud through the filter capacitor, after by using double-phase interleaved buck-boost circuit with wide range output voltage required value, analyzing its working principle and the the parameters for the design and selection of components. The analysis of current ripple shows that the double staggered parallel connection has the advantages of reducing the output current ripple and reducing the loss. The simulation experiment of the whole charging circuit is carried out by software, and the result is in line with the design requirements of the system. Finally combining the soft with hardware circuit to achieve charging of the system according to the requirements, experimental platform proved the feasibility and effectiveness of the proposed predictive control algorithm based on the car charging of the system, which is consistent with the simulation results.

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.

Evaluation of high-voltage, high-power, solid-state remote power controllers for amps

NASA Technical Reports Server (NTRS)

Callis, Charles P.

1987-01-01

The Electrical Power Branch at Marshall Space Flight Center has a Power System Development Facility where various power circuit breadboards are tested and evaluated. This project relates to the evaluation of a particular remote power controller (RPC) energizing high power loads. The Facility equipment permits the thorough testing and evaluation of high-voltage, high-power solid-state remote power controllers. The purpose is to evaluate a Type E, 30 Ampere, 200 V dc remote power controller. Three phases of the RPC evaluation are presented. The RPC is evaluated within a low-voltage, low-power circuit to check its operational capability. The RPC is then evaluated while performing switch/circuit breaker functions within a 200 V dc, 30 Ampere power circuit. The final effort of the project relates to the recommended procedures for installing these RPC's into the existing Autonomously Managed Power System (AMPS) breadboard/test facility at MSFC.

Circuit design and simulation of a transmit beamforming ASIC for high-frequency ultrasonic imaging systems.

PubMed

Athanasopoulos, Georgios I; Carey, Stephen J; Hatfield, John V

2011-07-01

This paper describes the design of a programmable transmit beamformer application-specific integrated circuit (ASIC) with 8 channels for ultrasound imaging systems. The system uses a 20-MHz reference clock. A digital delay-locked loop (DLL) was designed with 50 variable delay elements, each of which provides a clock with different phase from a single reference. Two phase detectors compare the phase difference of the reference clock with the feedback clock, adjusting the delay of the delay elements to bring the feedback clock signal in phase with the reference clock signal. Two independent control voltages for the delay elements ensure that the mark space ratio of the pulses remain at 50%. By combining a 10- bit asynchronous counter with the delays from the DLL, each channel can be programmed to give a maximum time delay of 51 μs with 1 ns resolution. It can also give bursts of up to 64 pulses. Finally, for a single pulse, it can adjust the pulse width between 9 ns and 100 ns by controlling the current flowing through a capacitor in a one-shot circuit, for use with 40-MHz and 5-MHz transducers, respectively.

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.

Space shuttle main engine controller assembly, phase C-D. [with lagging system design and analysis

NASA Technical Reports Server (NTRS)

1973-01-01

System design and system analysis and simulation are slightly behind schedule, while design verification testing has improved. Input/output circuit design has improved, but digital computer unit (DCU) and mechanical design continue to lag. Part procurement was impacted by delays in printed circuit board, assembly drawing releases. These are the result of problems in generating suitable printed circuit artwork for the very complex and high density multilayer boards.

Common-signal-induced synchronization in photonic integrated circuits and its application to secure key distribution.

PubMed

Sasaki, Takuma; Kakesu, Izumi; Mitsui, Yusuke; Rontani, Damien; Uchida, Atsushi; Sunada, Satoshi; Yoshimura, Kazuyuki; Inubushi, Masanobu

2017-10-16

We experimentally achieve common-signal-induced synchronization in two photonic integrated circuits with short external cavities driven by a constant-amplitude random-phase light. The degree of synchronization can be controlled by changing the optical feedback phase of the two photonic integrated circuits. The change in the optical feedback phase leads to a significant redistribution of the spectral energy of optical and RF spectra, which is a unique characteristic of PICs with the short external cavity. The matching of the RF and optical spectra is necessary to achieve synchronization between the two PICs, and stable synchronization can be obtained over an hour in the presence of optical feedback. We succeed in generating information-theoretic secure keys and achieving the final key generation rate of 184 kb/s using the PICs.

A Close Loop Low-Power and High Speed 130 nm CMOS Sample and Hold Circuit Based on Switched Capacitor for ADC Module

NASA Astrophysics Data System (ADS)

Nasir, Z.; Ruslan, S. H.

2017-08-01

A sample and hold (S/H) block is typically used as an analogue to digital interface in the analogue to digital converter (ADC) system. Since ADC is widely used in processing signals, the power consumption of the ADC must be lowered to conserve energy. Therefore the S/H circuit must be of a low powered too. Sampling phase and hold phase are the two phases of the operation cycle of the S/H circuit. Switched capacitor (SC) techniques have been developed in order to allow the integration on a single silicon chip of both digital and analogue functions. By controlling switches around the SC, the SC circuit works by passing charge into and out of a capacitor. SC circuits are suitable for on chip implementations because they replace a resistor with switches and capacitors. In this research, a closed-loop sample and hold circuit based on SC is designed and simulated with Cadence EDA tools. The schematic, layout, and simulation of the circuit is done using generic Silterra 130 nm technology file. All the analysis is done using Virtuoso Analog Design Environment. Layout and schematic are drawn using Virtuoso Schematic Editor and Virtuoso Layout Editor, Calibre is used for post layout simulation. The closed loop S/H circuit based on SC is successfully designed and able to sample and hold the analogue input waveform. The power consumption of the circuit is 0.919 mW and the propagation delay is 64.96 ps.

Coherent optical monolithic phased-array antenna steering system

DOEpatents

Hietala, Vincent M.; Kravitz, Stanley H.; Vawter, Gregory A.

1994-01-01

An optical-based RF beam steering system for phased-array antennas comprising a photonic integrated circuit (PIC). The system is based on optical heterodyning employed to produce microwave phase shifting by a monolithic PIC constructed entirely of passive components. Microwave power and control signal distribution to the antenna is accomplished by optical fiber, permitting physical separation of the PIC and its control functions from the antenna. The system reduces size, weight, complexity, and cost of phased-array antenna systems.

Vortex spin-torque oscillator stabilized by phase locked loop using integrated circuits

NASA Astrophysics Data System (ADS)

Kreissig, Martin; Lebrun, R.; Protze, F.; Merazzo-Jaimes, K.; Hem, J.; Vila, L.; Ferreira, R.; Cyrille, M.-C.; Ellinger, F.; Cros, V.; Ebels, U.; Bortolotti, P.

2017-05-01

Spin-torque nano-oscillators (STO) are candidates for the next technological implementation of spintronic devices in commercial electronic systems. For use in microwave applications, improving the noise figures by efficient control of their phase dynamics is a mandatory requirement. In order to achieve this, we developed a compact phase locked loop (PLL) based on custom integrated circuits (ICs) and demonstrate that it represents an efficient way to reduce the phase noise level of a vortex based STO. The advantage of our approach to phase stabilize STOs is that our compact system is highly reconfigurable e.g. in terms of the frequency divider ratio N, RF gain and loop gain. This makes it robust against device to device variations and at the same time compatible with a large range of STOs. Moreover, by taking advantage of the natural highly non-isochronous nature of the STO, the STO frequency can be easily controlled by e.g. changing the divider ratio N.

Base drive and overlap protection circuit

DOEpatents

Gritter, David J.

1983-01-01

An inverter (34) which provides power to an A. C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A. C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A. C. machine is optimized. The control circuit includes a microcomputer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). A base drive and overlap protection circuit is included to insure that both transistors of a complimentary pair are not conducting at the same time. In its preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack (32) and a three-phase induction motor (18).

Nonequilibrium Phase Transitions. Appendix A-F

DTIC Science & Technology

1988-09-20

Module allows the separation between the control unit and the power circuits . Communications with the hostcomputer occurs via RS 232 serial port. The...hre] - D905-10123.1 ’- 43 Appendix E K- Contents: Page: Glossary of Terms 1. Principle of Construction of the DDC 4 2Thermal Circuit Of the DDC 6...Appendix E % 0 . r. fell. * re. .*......... .... 2. Thermal Circuit of the DDC: The thermal behaviour of the DDC can be represented by a lumped element

Annual Summary Report on Thermionic Cathode Project.

DTIC Science & Technology

1986-01-09

Voltage Operation The electron gun cathode is driven negative by a high voltageRadiation pulse modulator in the circuit of Figure 3-1. Typical current...tungsten filament. The bombardment heating system is stabilized by a feed- back control circuit . The power required to heat tne cathode is 315 W bom...project. The primary purpose of the first phase was to develop the bombardment heating circuit used to heat the LaB 6 cathode, and to test the beam

Universal discrete Fourier optics RF photonic integrated circuit architecture.

PubMed

Hall, Trevor J; Hasan, Mehedi

2016-04-04

This paper describes a coherent electro-optic circuit architecture that generates a frequency comb consisting of N spatially separated orders using a generalised Mach-Zenhder interferometer (MZI) with its N × 1 combiner replaced by an optical N × N Discrete Fourier Transform (DFT). Advantage may be taken of the tight optical path-length control, component and circuit symmetries and emerging trimming algorithms offered by photonic integration in any platform that offers linear electro-optic phase modulation such as LiNbO_3, silicon, III-V or hybrid technology. The circuit architecture subsumes all MZI-based RF photonic circuit architectures in the prior art given an appropriate choice of output port(s) and dimension N although the principal application envisaged is phase correlated subcarrier generation for all optical orthogonal frequency division multiplexing. A transfer matrix approach is used to model the operation of the architecture. The predictions of the model are validated by simulations performed using an industry standard software tool. Implementation is found to be practical.

A 24-GHz portable FMCW radar with continuous beam steering phased array (Conference Presentation)

NASA Astrophysics Data System (ADS)

Peng, Zhengyu; Li, Changzhi

2017-05-01

A portable 24-GHz frequency-modulated continuous-wave (FMCW) radar with continuous beam steering phased array is presented. This board-level integrated radar system consists of a phased array antenna, a radar transceiver and a baseband. The phased array used by the receiver is a 4-element linear array. The beam of the phased array can be continuously steered with a range of ±30° on the H-plane through an array of vector controllers. The vector controller is based on the concept of vector sum with binary-phase-shift attenuators. Each vector controller is capable of independently controlling the phase and the amplitude of each element of the linear array. The radar transceiver is based on the six-port technique. A free-running voltage controlled oscillator (VCO) is controlled by an analog "sawtooth" voltage generator to produce frequency-modulated chirp signal. This chirp signal is used as the transmitter signal, as well as the local oscillator (LO) signal to drive the six-port circuit. The transmitter antenna is a single patch antenna. In the baseband, the beat signal of the FMCW radar is detected by the six-port circuit and then processed by a laptop in real time. Experiments have been performed to reveal the capabilities of the proposed radar system for applications including indoor inverse synthetic aperture radar (ISAR) imaging, vital sign detection, and short-range navigation, etc. (This abstract is for the profiles session.)

Complex modulation using tandem polarization modulators

NASA Astrophysics Data System (ADS)

Hasan, Mehedi; Hall, Trevor

2017-11-01

A novel photonic technique for implementing frequency up-conversion or complex modulation is proposed. The proposed circuit consists of a sandwich of a quarter-wave plate between two polarization modulators, driven, respectively, by an in-phase and quadrature-phase signals. The operation of the circuit is modelled using a transmission matrix method. The theoretical prediction is then validated by simulation using an industry-standard software tool. The intrinsic conversion efficiency of the architecture is improved by 6 dB over a functionally equivalent design based on dual parallel Mach-Zehnder modulators. Non-ideal scenarios such as imperfect alignment of the optical components and power imbalances and phase errors in the electric drive signals are also analysed. As light travels, along one physical path, the proposed design can be implemented using discrete components with greater control of relative optical path length differences. The circuit can further be integrated in any material platform that offers electro-optic polarization modulators.

Temporal Interactions between Cortical Rhythms

PubMed Central

Roopun, Anita K.; Kramer, Mark A.; Carracedo, Lucy M.; Kaiser, Marcus; Davies, Ceri H.; Traub, Roger D.; Kopell, Nancy J.; Whittington, Miles A.

2008-01-01

Multiple local neuronal circuits support different, discrete frequencies of network rhythm in neocortex. Relationships between different frequencies correspond to mechanisms designed to minimise interference, couple activity via stable phase interactions, and control the amplitude of one frequency relative to the phase of another. These mechanisms are proposed to form a framework for spectral information processing. Individual local circuits can also transform their frequency through changes in intrinsic neuronal properties and interactions with other oscillating microcircuits. Here we discuss a frequency transformation in which activity in two co-active local circuits may combine sequentially to generate a third frequency whose period is the concatenation sum of the original two. With such an interaction, the intrinsic periodicity in each component local circuit is preserved – alternate, single periods of each original rhythm form one period of a new frequency – suggesting a robust mechanism for combining information processed on multiple concurrent spatiotemporal scales. PMID:19225587

30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

Code of Federal Regulations, 2011 CFR

2011-07-01

... portable or mobile three-phase alternating current equipment; circuit breakers. 77.900 Section 77.900... mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits supplying power to portable or mobile three-phase alternating current equipment shall be protected by...

Servo Platform Circuit Design of Pendulous Gyroscope Based on DSP

NASA Astrophysics Data System (ADS)

Tan, Lilong; Wang, Pengcheng; Zhong, Qiyuan; Zhang, Cui; Liu, Yunfei

2018-03-01

In order to solve the problem when a certain type of pendulous gyroscope in the initial installation deviation more than 40 degrees, that the servo platform can not be up to the speed of the gyroscope in the rough north seeking phase. This paper takes the digital signal processor TMS320F28027 as the core, uses incremental digital PID algorithm, carries out the circuit design of the servo platform. Firstly, the hardware circuit is divided into three parts: DSP minimum system, motor driving circuit and signal processing circuit, then the mathematical model of incremental digital PID algorithm is established, based on the model, writes the PID control program in CCS3.3, finally, the servo motor tracking control experiment is carried out, it shows that the design can significantly improve the tracking ability of the servo platform, and the design has good engineering practice.

Optoelectronic Infrastructure for Radio Frequency and Optical Phased Arrays

NASA Technical Reports Server (NTRS)

Cai, Jianhong

2015-01-01

Optoelectronic integrated circuits offer radiation-hardened solutions for satellite systems in addition to improved size, weight, power, and bandwidth characteristics. ODIS, Inc., has developed optoelectronic integrated circuit technology for sensing and data transfer in phased arrays. The technology applies integrated components (lasers, amplifiers, modulators, detectors, and optical waveguide switches) to a radio frequency (RF) array with true time delay for beamsteering. Optical beamsteering is achieved by controlling the current in a two-dimensional (2D) array. In this project, ODIS integrated key components to produce common RF-optical aperture operation.

Commutated automatic gain control system

NASA Technical Reports Server (NTRS)

Yost, S. R.

1982-01-01

A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

Cascaded Converters for Integration and Management of Grid Level Energy Storage Systems

NASA Astrophysics Data System (ADS)

Alaas, Zuhair

This research work proposes two cascaded multilevel inverter structures for BESS. The gating and switching control of switching devices in both inverter typologies are done by using a phase-shifted PWM scheme. The first proposed isolated multilevel inverter is made up of three-phase six-switch inverter blocks with a reduced number of power components compared with traditional isolated CHB. The suggested isolated converter has only one battery string for three-phase system that can be used for high voltage and high power applications such as grid connected BESS and alternative energy systems. The isolated inverter enables dq frame based simple control and eliminates the issues of single-phase pulsating power, which can cause detrimental impacts on certain dc sources. Simulation studies have been carried out to compare the proposed isolated multi-level inverter with an H-bridge cascaded transformer inverter. The simulation results verified the performance of the isolated inverter. The second proposed topology is a Hierarchal Cascaded Multilevel Converter (HCMC) with phase to phase SOC balancing capability which also for high voltage and high power battery energy storage systems. The HCMC has a hybrid structure of half-bridge converters and H-bridge inverters and the voltage can be hierarchically cascaded to reach the desired value at the half-bridge and the H-bridge levels. The uniform SOC battery management is achieved by controlling the half-bridge converters that are connected to individual battery modules/cells. Simulation studies and experimental results have been carried on a large scale battery system under different operating conditions to verify the effectiveness of the proposed inverters. Moreover, this dissertation presents a new three-phase SOC equalizing circuit, called six-switch energy-level balancing circuit (SSBC), which can be used to realize uniform SOC operation for full utilization of the battery capacity in proposed HCMC or any CMI inverter while keeping balanced three-phase operation. A sinusoidal PWM modulation technique is used to control power transferring between phases. Simulation results have been carried out to verify the performance of the proposed SSBC circuit of uniform three-phase SOC balancing.

Three-phase short circuit calculation method based on pre-computed surface for doubly fed induction generator

NASA Astrophysics Data System (ADS)

Ma, J.; Liu, Q.

2018-02-01

This paper presents an improved short circuit calculation method, based on pre-computed surface to determine the short circuit current of a distribution system with multiple doubly fed induction generators (DFIGs). The short circuit current, injected into power grid by DFIG, is determined by low voltage ride through (LVRT) control and protection under grid fault. However, the existing methods are difficult to calculate the short circuit current of DFIG in engineering practice due to its complexity. A short circuit calculation method, based on pre-computed surface, was proposed by developing the surface of short circuit current changing with the calculating impedance and the open circuit voltage. And the short circuit currents were derived by taking into account the rotor excitation and crowbar activation time. Finally, the pre-computed surfaces of short circuit current at different time were established, and the procedure of DFIG short circuit calculation considering its LVRT was designed. The correctness of proposed method was verified by simulation.

Method and apparatus for controlling electroslag remelting

DOEpatents

Maguire, Michael C.; Zanner, Frank J.; Damkroger, Brian K.; Miszkiel, Mark E.; Aronson, Eugene A.

1994-01-01

Method and apparatus for controlling electrode immersion depth in an electroslag remelting furnace. The phase difference of the alternating current circuit established in the furnace is calculated in real time and employed to more accurately control immersion depth than possible with voltage-swing systems.

System-Level Integrated Circuit (SLIC) Technology Development for Phased Array Antenna Applications

NASA Technical Reports Server (NTRS)

Windyka, John A.; Zablocki, Ed G.

1997-01-01

This report documents the efforts and progress in developing a 'system-level' integrated circuit, or SLIC, for application in advanced phased array antenna systems. The SLIC combines radio-frequency (RF) microelectronics, digital and analog support circuitry, and photonic interfaces into a single micro-hybrid assembly. Together, these technologies provide not only the amplitude and phase control necessary for electronic beam steering in the phased array, but also add thermally-compensated automatic gain control, health and status feedback, bias regulation, and reduced interconnect complexity. All circuitry is integrated into a compact, multilayer structure configured for use as a two-by-four element phased array module, operating at 20 Gigahertz, using a Microwave High-Density Interconnect (MHDI) process. The resultant hardware is constructed without conventional wirebonds, maintains tight inter-element spacing, and leads toward low-cost mass production. The measured performances and development issues associated with both the two-by-four element module and the constituent elements are presented. Additionally, a section of the report describes alternative architectures and applications supported by the SLIC electronics. Test results show excellent yield and performance of RF circuitry and full automatic gain control for multiple, independent channels. Digital control function, while suffering from lower manufacturing yield, also proved successful.

Synchronous Controlled Switching by VCB with Electromagnetic Operation Mechanism

NASA Astrophysics Data System (ADS)

Horinouchi, Katsuhiko; Tsukima, Mitsuru; Tohya, Nobumoto; Inoue, Ryuuichi; Sasao, Hiroyuki

Synchronously controlled switching to suppress transient overvoltage and overcurrent resulting from when the circuit breakers on medium voltage systems are closed is described. Firstly, by simulation it is found that if the closing time is synchronously controlled so that the contacts of the circuit breaker close completely at the instant when the voltage across contacts of the breaker at each of the three individual phases are zero, the resulting overvoltage and overcurrent is significantly suppressed when compared to conventional three phase simultaneous closing. Next, an algorithm for determining the closing timing based on a forecasted voltage zero waveform, obtained from voltage sampling data, is presented. Finally, a synchronous closing experiment of voltage 22kV utilizing a controller to implement the algorithm and a VCB with an electromagnetic operation mechanism is presented. The VCB was successfully closed at the zero point within a tolerance range of 200 microseconds.

Integrated coherent matter wave circuits

DOE PAGES

Ryu, C.; Boshier, M. G.

2015-09-21

An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through theirmore » electric polarizability. Moreover, the source of coherent matter waves is a Bose–Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry.« less

Utilizing zero-sequence switchings for reversible converters

DOEpatents

Hsu, John S.; Su, Gui-Jia; Adams, Donald J.; Nagashima, James M.; Stancu, Constantin; Carlson, Douglas S.; Smith, Gregory S.

2004-12-14

A method for providing additional dc inputs or outputs (49, 59) from a dc-to-ac inverter (10) for controlling motor loads (60) comprises deriving zero-sequence components (V.sub.ao, V.sub.bo, and V.sub.co) from the inverter (10) through additional circuit branches with power switching devices (23, 44, 46), transforming the voltage between a high voltage and a low voltage using a transformer or motor (42, 50), converting the low voltage between ac and dc using a rectifier (41, 51) or an H-bridge (61), and providing at least one low voltage dc input or output (49, 59). The transformation of the ac voltage may be either single phase or three phase. Where less than a 100% duty cycle is acceptable, a two-phase modulation of the switching signals controlling the inverter (10) reduces switching losses in the inverter (10). A plurality of circuits for carrying out the invention are also disclosed.

A low jitter PLL clock used for phase change memory

NASA Astrophysics Data System (ADS)

Xiao, Hong; Houpeng, Chen; Zhitang, Song; Daolin, Cai; Xi, Li

2013-02-01

A fully integrated low-jitter, precise frequency CMOS phase-locked loop (PLL) clock for the phase change memory (PCM) drive circuit is presented. The design consists of a dynamic dual-reset phase frequency detector (PFD) with high frequency acquisition, a novel low jitter charge pump, a CMOS ring oscillator based voltage-controlled oscillator (VCO), a 2nd order passive loop filter, and a digital frequency divider. The design is fabricated in 0.35 μm CMOS technology and consumes 20 mW from a supply voltage of 5 V. In terms of the PCM's program operation requirement, the output frequency range is from 1 to 140 MHz. For the 140 MHz output frequency, the circuit features a cycle-to-cycle jitter of 28 ps RMS and 250 ps peak-to-peak.

Digital-only PLL with adaptive search step

NASA Astrophysics Data System (ADS)

Lin, Ming-Lang; Huang, Shu-Chuan; Liu, Jie-Cherng

2014-06-01

In this paper, an all-digital phase-locked loop (PLL) with adaptively controlled up/down counter serves as the loop filter is presented, and it is implemented on a field-programmable gate array. The detailed circuit of the adaptive up/down counter implementing the adaptive search algorithm is also given, in which the search step for frequency acquisition is adaptively scaled down in half until it is reduced to zero. The phase jitter of the proposed PLL can be lowered, yet keeping with fast lock-in time. Thus, the dilemma between the low phase jitter and fast lock-in time of the traditional PLL can be resolved. Simulation results and circuit implementation show that the locked count, phase jitter and lock-in time of the proposed PLL are consistent with the theoretical predictions.

A Circuit to Demonstrate Phase Relationships in "RLC" Circuits

ERIC Educational Resources Information Center

Sokol, P. E.; Warren, G.; Zheng, B.; Smith, P.

2013-01-01

We have developed a circuit to demonstrate the phase relationships between resistive and reactive elements in series "RLC" circuits. We utilize a differential amplifier to allow the phases of the three elements and the current to be simultaneously displayed on an inexpensive four channel oscilloscope. We have included a novel circuit…

30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Low- and medium-voltage circuits serving... Medium-Voltage Alternating Current Circuits § 77.900 Low- and medium-voltage circuits serving portable or mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits...

30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage circuits serving... Medium-Voltage Alternating Current Circuits § 77.900 Low- and medium-voltage circuits serving portable or mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits...

30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Low- and medium-voltage circuits serving... Medium-Voltage Alternating Current Circuits § 77.900 Low- and medium-voltage circuits serving portable or mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage circuits...

The Study of Phase-shift Super-Frequency Induction Heating Power Supply

NASA Astrophysics Data System (ADS)

Qi, Hairun; Peng, Yonglong; Li, Yabin

This paper combines pulse-width phase-shift power modulation with fixed-angle phase-locked-control to adjust the inverter's output power, this method not only meets the work conditions of voltage inverter, but also realizes the large-scale of power modulation, and the main circuit is simple, the switching devices realize soft switching. This paper analyzes the relationship between the output power and phase-shift angle, the control strategy is simulated by Matlab/Simulink, and the results show that the method is feasible and meets the theoretical analysis

Decoding Grasping Movements from the Parieto-Frontal Reaching Circuit in the Nonhuman Primate.

PubMed

Nelissen, Koen; Fiave, Prosper Agbesi; Vanduffel, Wim

2018-04-01

Prehension movements typically include a reaching phase, guiding the hand toward the object, and a grip phase, shaping the hand around it. The dominant view posits that these components rely upon largely independent parieto-frontal circuits: a dorso-medial circuit involved in reaching and a dorso-lateral circuit involved in grasping. However, mounting evidence suggests a more complex arrangement, with dorso-medial areas contributing to both reaching and grasping. To investigate the role of the dorso-medial reaching circuit in grasping, we trained monkeys to reach-and-grasp different objects in the dark and determined if hand configurations could be decoded from functional magnetic resonance imaging (MRI) responses obtained from the reaching and grasping circuits. Indicative of their established role in grasping, object-specific grasp decoding was found in anterior intraparietal (AIP) area, inferior parietal lobule area PFG and ventral premotor region F5 of the lateral grasping circuit, and primary motor cortex. Importantly, the medial reaching circuit also conveyed robust grasp-specific information, as evidenced by significant decoding in parietal reach regions (particular V6A) and dorsal premotor region F2. These data support the proposed role of dorso-medial "reach" regions in controlling aspects of grasping and demonstrate the value of complementing univariate with more sensitive multivariate analyses of functional MRI (fMRI) data in uncovering information coding in the brain.

Multilevel photonic modules for millimeter-wave phased-array antennas

NASA Astrophysics Data System (ADS)

Paolella, Arthur C.; Bauerle, Athena; Joshi, Abhay M.; Wright, James G.; Coryell, Louis A.

2000-09-01

Millimeter wave phased array systems have antenna element sizes and spacings similar to MMIC chip dimensions by virtue of the operating wavelength. Designing modules in traditional planar packaing techniques are therefore difficult to implement. An advantageous way to maintain a small module footprint compatible with Ka-Band and high frequency systems is to take advantage of two leading edge technologies, opto- electronic integrated circuits (OEICs) and multilevel packaging technology. Under a Phase II SBIR these technologies are combined to form photonic modules for optically controlled millimeter wave phased array antennas. The proposed module, consisting of an OEIC integrated with a planar antenna array will operate on the 40GHz region. The OEIC consists of an InP based dual-depletion PIN photodetector and distributed amplifier. The multi-level module will be fabricated using an enhanced circuit processing thick film process. Since the modules are batch fabricated using an enhanced circuit processing thick film process. Since the modules are batch fabricated, using standard commercial processes, it has the potential to be low cost while maintaining high performance, impacting both military and commercial communications systems.

Automatic quadrature control and measuring system. [using optical coupling circuitry

NASA Technical Reports Server (NTRS)

Hamlet, J. F. (Inventor)

1974-01-01

A quadrature component cancellation and measuring system comprising a detection system for detecting the quadrature component from a primary signal, including reference circuitry to define the phase of the quadrature component for detection is described. A Raysistor optical coupling control device connects an output from the detection system to a circuit driven by a signal based upon the primary signal. Combining circuitry connects the primary signal and the circuit controlled by the Raysistor device to subtract quadrature components. A known current through the optically sensitive element produces a signal defining the magnitude of the quadrature component.

Frequency discriminator/phase detector

NASA Technical Reports Server (NTRS)

Crow, R. B.

1974-01-01

Circuit provides dual function of frequency discriminator/phase detector which reduces frequency acquisition time without adding to circuit complexity. Both frequency discriminators, in evaluated frequency discriminator/phase detector circuits, are effective two decades above and below center frequency.

Nonequilibrium Quantum Simulation in Circuit QED

NASA Astrophysics Data System (ADS)

Raftery, James John

Superconducting circuits have become a leading architecture for quantum computing and quantum simulation. In particular, the circuit QED framework leverages high coherence qubits and microwave resonators to construct systems realizing quantum optics models with exquisite precision. For example, the Jaynes-Cummings model has been the focus of significant theoretical interest as a means of generating photon-photon interactions. Lattices of such strongly correlated photons are an exciting new test bed for exploring non-equilibrium condensed matter physics such as dissipative phase transitions of light. This thesis covers a series of experiments which establish circuit QED as a powerful tool for exploring condensed matter physics with photons. The first experiment explores the use of ultra high speed arbitrary waveform generators for the direct digital synthesis of complex microwave waveforms. This new technique dramatically simplifies the classical control chain for quantum experiments and enables high bandwidth driving schemes expected to be essential for generating interesting steady-states and dynamical behavior. The last two experiments explore the rich physics of interacting photons, with an emphasis on small systems where a high degree of control is possible. The first experiment realizes a two-site system called the Jaynes-Cummings dimer, which undergoes a self-trapping transition where the strong photon-photon interactions block photon hopping between sites. The observation of this dynamical phase transition and the related dissipation-induced transition are key results of this thesis. The final experiment augments the Jaynes-Cummings dimer by redesigning the circuit to include in-situ control over photon hopping between sites using a tunable coupler. This enables the study of the dimer's localization transition in the steady-state regime.

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

Ryu, C.; Boshier, M. G.

An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through theirmore » electric polarizability. Moreover, the source of coherent matter waves is a Bose–Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry.« less

Controlled initialization of superconducting π-phaseshifters and possible applications

NASA Astrophysics Data System (ADS)

Mielke, Olaf; Ortlepp, Thomas; Kunert, Juergen; Meyer, Hans-Georg; Toepfer, Hannes

2010-05-01

The rapid single-flux quantum electronics (RSFQ) is a superconducting, naturally digital circuit family which is currently close to being commercially applied. RSFQ is outstanding because of its very low switching energy resulting in very low power consumption. This advantage causes, however, a significant influence of thermal noise. For industrial applications, a certain noise immunity is required which is still a challenge, especially for circuits of higher complexity. Integrating phase-shifting elements is a new concept for further improvements concerning stability against the influence of thermal noise. We have already shown that the implementation of phase-shifting elements significantly reduces the influence of thermal noise on circuit behavior by experimentally analyzing the bit-error rate (Mielke et al 2009 IEEE Trans. Appl. Supercond. 19 621-5). Concepts which are easily implementable in standard niobium technology are especially promising. The π-phaseshifter consists of a superconducting loop which is able to store a single flux quantum. The loop current related to the stored flux creates a well-defined phase shift. To achieve the correct functionality of complex circuits it is essential to store exactly one flux quantum in each π-phaseshifter during the cooling down of the chip. Thus, for studying the feasibility of this new approach, the initialization reliability of the π-phaseshifter needs to be verified. We present an experimental investigation of this reliability to obtain a general assessment for the application of the π-phaseshifter in niobium technology. Furthermore, we compare the configuration shielded by a solid ground plane with a configuration with a ground-plane hole below the π-phaseshifter. Justified by the experimental results we suggest programmable RSFQ circuits based on π-phaseshifters. The characteristics of these devices can be influenced by a controlled initialization of the π-phaseshifter. The fabrication was performed by FLUXONICS Foundry.

Motor control for a brushless DC motor

NASA Technical Reports Server (NTRS)

Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

1985-01-01

This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

Intelligent Gate Drive for Fast Switching and Crosstalk Suppression of SiC Devices

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

Zhang, Zheyu; Dix, Jeffery; Wang, Fei Fred

This study presents an intelligent gate drive for silicon carbide (SiC) devices to fully utilize their potential of high switching-speed capability in a phase-leg configuration. Based on the SiC device's intrinsic properties, a gate assist circuit consisting of two auxiliary transistors with two diodes is introduced to actively control gate voltages and gate loop impedances of both devices in a phase-leg configuration during different switching transients. Compared to conventional gate drives, the proposed circuit has the capability of accelerating the switching speed of the phase-leg power devices and suppressing the crosstalk to below device limits. Based on Wolfspeed 1200-V SiCmore » MOSFETs, the test results demonstrate the effectiveness of this intelligent gate drive under varying operating conditions. More importantly, the proposed intelligent gate assist circuitry is embedded into a gate drive integrated circuit, offering a simple, compact, and reliable solution for end-users to maximize benefits of SiC devices in actual power electronics applications.« less

Intelligent Gate Drive for Fast Switching and Crosstalk Suppression of SiC Devices

DOE PAGES

Zhang, Zheyu; Dix, Jeffery; Wang, Fei Fred; ...

2017-01-19

This study presents an intelligent gate drive for silicon carbide (SiC) devices to fully utilize their potential of high switching-speed capability in a phase-leg configuration. Based on the SiC device's intrinsic properties, a gate assist circuit consisting of two auxiliary transistors with two diodes is introduced to actively control gate voltages and gate loop impedances of both devices in a phase-leg configuration during different switching transients. Compared to conventional gate drives, the proposed circuit has the capability of accelerating the switching speed of the phase-leg power devices and suppressing the crosstalk to below device limits. Based on Wolfspeed 1200-V SiCmore » MOSFETs, the test results demonstrate the effectiveness of this intelligent gate drive under varying operating conditions. More importantly, the proposed intelligent gate assist circuitry is embedded into a gate drive integrated circuit, offering a simple, compact, and reliable solution for end-users to maximize benefits of SiC devices in actual power electronics applications.« less

Phased-array radar for airborne systems

NASA Astrophysics Data System (ADS)

Tahim, Raghbir S.; Foshee, James J.; Chang, Kai

2003-09-01

Phased array antenna systems, which support high pulse rates and high transmit power, are well suited for radar and large-scale surveillance. Sensors and communication systems can function as the eyes and ears for ballistic missile defense applications, providing early warning of attack, target detection and identification, target tracking, and countermeasure decision. In such applications, active array radar systems that contain solid-state transmitter sources and low-noise preamplifiers for transmission and reception are preferred over the conventional radar antennas, because the phased array radar offers the advantages of power management and efficiency, reliability, signal reception, beam steering target detection. The current phased array radar designs are very large, complex and expensive and less efficient because of high RF losses in the phase control circuits used for beam scan. Several thousands of phase shifters and drivers may be required for a single system thus making the system very complex and expensive. This paper describes the phased array radar system based on high power T/R modules, wide-band radiating planar antenna elements and very low loss wide-band phase control circuits (requiring reduced power levels) for beam scan. The phase shifter design is based on micro-strip feed lines perturbed by the proximity of voltage controlled piezoelectric transducer (PET). Measured results have shown an added insertion loss of less than 1 dB for a phase shift of 450 degrees from 2 to 20 GHz. The new wideband phased array radar design provides significant reduction in size cost and weight. Compared to the conventional phased array systems, the cost saving is more than 15 to 1.

Design of surface acoustic wave filters for the multiplex transmission system of multilevel inverter circuits

NASA Astrophysics Data System (ADS)

Kubo, Keita; Kanai, Nanae; Kobayashi, Fumiya; Goka, Shigeyoshi; Wada, Keiji; Kakio, Shoji

2017-07-01

We designed surface acoustic wave (SAW) filters for a multiplex transmission system of multilevel inverter circuits, and applied them to a single-phase three-level inverter. To reduce the transmission delay time of the SAW filters, a four-channel SAW filter array was fabricated and its characteristics were measured. The delay time of the SAW filters was <350 ns, and the delay time difference was reduced to ≤184 ns, less than half that previously reported. The SAW filters withstood up to 990 V, which is sufficient for the inverters used in most domestic appliances. A single-phase three-level inverter with the fabricated SAW filters worked with a total delay time shorter than our target delay time of 2.5 µs. The delay time difference of the proposed system was 0.26 µs, which is sufficient for preventing the inverter circuit from short-circuiting. The SAW filters controlled a multilevel inverter system with simple signal wiring and high dielectric withstanding voltages.

High accuracy digital aging monitor based on PLL-VCO circuit

NASA Astrophysics Data System (ADS)

Yuejun, Zhang; Zhidi, Jiang; Pengjun, Wang; Xuelong, Zhang

2015-01-01

As the manufacturing process is scaled down to the nanoscale, the aging phenomenon significantly affects the reliability and lifetime of integrated circuits. Consequently, the precise measurement of digital CMOS aging is a key aspect of nanoscale aging tolerant circuit design. This paper proposes a high accuracy digital aging monitor using phase-locked loop and voltage-controlled oscillator (PLL-VCO) circuit. The proposed monitor eliminates the circuit self-aging effect for the characteristic of PLL, whose frequency has no relationship with circuit aging phenomenon. The PLL-VCO monitor is implemented in TSMC low power 65 nm CMOS technology, and its area occupies 303.28 × 298.94 μm2. After accelerating aging tests, the experimental results show that PLL-VCO monitor improves accuracy about high temperature by 2.4% and high voltage by 18.7%.

WFL: Microwave Applications of Thin Ferroelectric Films

NASA Technical Reports Server (NTRS)

Romanofsky, Robert

2013-01-01

We have developed a family of tunable microwave circuits, operating from X- through Ka-band, based on laser ablated BaxSr1-xTiO films on lanthanum aluminate and magnesium oxide substrates. Circuits include voltage controlled oscillators, filters, phase shifters and antennas. A review of the basic theory of operation of these devices will be presented along with measured performance. Emphasis has been on low-loss phase shifters to enable a new phased array architecture. The critical role of phase shifter loss and transient response in reflectarray antennas will be discussed. The Ferroelectric Reflectarray Critical Components Space Experiment was launched on the penultimate Space Shuttle, STS-134, in May of 2011. It included a bank of ferroelectric phase shifters with two different stoichiometries as well as ancillary electronics. The experiment package and status will be reported. In addition, unusual results of a Van der Pauw measurement involving a ferroelectric film grown on buffered high resisitivity silicon will be discussed.

Triple voltage dc-to-dc converter and method

DOEpatents

Su, Gui-Jia

2008-08-05

A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

Pulse width modulation inverter with battery charger

DOEpatents

Slicker, James M.

1985-01-01

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

Pulse width modulation inverter with battery charger

NASA Technical Reports Server (NTRS)

Slicker, James M. (Inventor)

1985-01-01

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback DC-DC converter circuit for recharging the battery.

Nonequilibrium optical control of dynamical states in superconducting nanowire circuits.

PubMed

Madan, Ivan; Buh, Jože; Baranov, Vladimir V; Kabanov, Viktor V; Mrzel, Aleš; Mihailovic, Dragan

2018-03-01

Optical control of states exhibiting macroscopic phase coherence in condensed matter systems opens intriguing possibilities for materials and device engineering, including optically controlled qubits and photoinduced superconductivity. Metastable states, which in bulk materials are often associated with the formation of topological defects, are of more practical interest. Scaling to nanosize leads to reduced dimensionality, fundamentally changing the system's properties. In one-dimensional superconducting nanowires, vortices that are present in three-dimensional systems are replaced by fluctuating topological defects of the phase. These drastically change the dynamical behavior of the superconductor and introduce dynamical periodic long-range ordered states when the current is driven through the wire. We report the control and manipulation of transitions between different dynamically stable states in superconducting δ 3 -MoN nanowire circuits by ultrashort laser pulses. Not only can the transitions between different dynamically stable states be precisely controlled by light, but we also discovered new photoinduced hidden states that cannot be reached under near-equilibrium conditions, created while laser photoexcited quasi-particles are outside the equilibrium condition. The observed switching behavior can be understood in terms of dynamical stabilization of various spatiotemporal periodic trajectories of the order parameter in the superconductor nanowire, providing means for the optical control of the superconducting phase with subpicosecond control of timing.

Nonequilibrium optical control of dynamical states in superconducting nanowire circuits

PubMed Central

Madan, Ivan; Baranov, Vladimir V.

2018-01-01

Optical control of states exhibiting macroscopic phase coherence in condensed matter systems opens intriguing possibilities for materials and device engineering, including optically controlled qubits and photoinduced superconductivity. Metastable states, which in bulk materials are often associated with the formation of topological defects, are of more practical interest. Scaling to nanosize leads to reduced dimensionality, fundamentally changing the system’s properties. In one-dimensional superconducting nanowires, vortices that are present in three-dimensional systems are replaced by fluctuating topological defects of the phase. These drastically change the dynamical behavior of the superconductor and introduce dynamical periodic long-range ordered states when the current is driven through the wire. We report the control and manipulation of transitions between different dynamically stable states in superconducting δ3-MoN nanowire circuits by ultrashort laser pulses. Not only can the transitions between different dynamically stable states be precisely controlled by light, but we also discovered new photoinduced hidden states that cannot be reached under near-equilibrium conditions, created while laser photoexcited quasi-particles are outside the equilibrium condition. The observed switching behavior can be understood in terms of dynamical stabilization of various spatiotemporal periodic trajectories of the order parameter in the superconductor nanowire, providing means for the optical control of the superconducting phase with subpicosecond control of timing. PMID:29670935

Three-phase power factor controller with induced EMF sensing

NASA Technical Reports Server (NTRS)

Nola, F. J. (Inventor)

1984-01-01

A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.

Josephson junction microwave modulators for qubit control

NASA Astrophysics Data System (ADS)

Naaman, O.; Strong, J. A.; Ferguson, D. G.; Egan, J.; Bailey, N.; Hinkey, R. T.

2017-02-01

We demonstrate Josephson junction based double-balanced mixer and phase shifter circuits operating at 6-10 GHz and integrate these components to implement both a monolithic amplitude/phase vector modulator and an I/Q quadrature mixer. The devices are actuated by flux signals, dissipate no power on chip, exhibit input saturation powers in excess of 1 nW, and provide cryogenic microwave modulation solutions for integrated control of superconducting qubits.

Method and apparatus for pulse width modulation control of an AC induction motor

DOEpatents

Geppert, Steven; Slicker, James M.

1984-01-01

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

Method and apparatus for pulse width modulation control of an AC induction motor

NASA Technical Reports Server (NTRS)

Geppert, Steven (Inventor); Slicker, James M. (Inventor)

1984-01-01

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback DC-DC converter circuit for recharging the battery.

Phase-lock-loop application for fiber optic receiver

NASA Astrophysics Data System (ADS)

Ruggles, Stephen L.; Wills, Robert W.

1991-02-01

Phase-locked loop circuits are frequently employed in communication systems. In recent years, digital phase-locked loop circuits were utilized in optical communications systems. In an optical transceiver system, the digital phase-locked loop circuit is connected to the output of the receiver to extract a clock signal from the received coded data (NRZ, Bi-Phase, or Manchester). The clock signal is then used to reconstruct or recover the original data from the coded data. A theoretical approach to the design of a digital phase-locked loop circuit operation at 1 and 50 MHz is described. Hardware implementation of a breadboard design to function at 1 MHz and a printed-circuit board designed to function at 50 MHz were assembled using emitter coupled logic (ECL) to verify experimentally the theoretical design.

Phase-lock-loop application for fiber optic receiver

NASA Technical Reports Server (NTRS)

Ruggles, Stephen L.; Wills, Robert W.

1991-01-01

Phase-locked loop circuits are frequently employed in communication systems. In recent years, digital phase-locked loop circuits were utilized in optical communications systems. In an optical transceiver system, the digital phase-locked loop circuit is connected to the output of the receiver to extract a clock signal from the received coded data (NRZ, Bi-Phase, or Manchester). The clock signal is then used to reconstruct or recover the original data from the coded data. A theoretical approach to the design of a digital phase-locked loop circuit operation at 1 and 50 MHz is described. Hardware implementation of a breadboard design to function at 1 MHz and a printed-circuit board designed to function at 50 MHz were assembled using emitter coupled logic (ECL) to verify experimentally the theoretical design.

A hybrid analog-digital phase-locked loop for frequency mode non-contact scanning probe microscopy.

PubMed

Mehta, M M; Chandrasekhar, V

2014-01-01

Non-contact scanning probe microscopy (SPM) has developed into a powerful technique to image many different properties of samples. The conventional method involves monitoring the amplitude, phase, or frequency of a cantilever oscillating at or near its resonant frequency as it is scanned across the surface of a sample. For high Q factor cantilevers, monitoring the resonant frequency is the preferred method in order to obtain reasonable scan times. This can be done by using a phase-locked-loop (PLL). PLLs can be obtained as commercial integrated circuits, but these do not have the frequency resolution required for SPM. To increase the resolution, all-digital PLLs requiring sophisticated digital signal processors or field programmable gate arrays have also been implemented. We describe here a hybrid analog/digital PLL where most of the components are implemented using discrete analog integrated circuits, but the frequency resolution is provided by a direct digital synthesis chip controlled by a simple peripheral interface controller (PIC) microcontroller. The PLL has excellent frequency resolution and noise, and can be controlled and read by a computer via a universal serial bus connection.

A hybrid analog-digital phase-locked loop for frequency mode non-contact scanning probe microscopy

NASA Astrophysics Data System (ADS)

Mehta, M. M.; Chandrasekhar, V.

2014-01-01

Non-contact scanning probe microscopy (SPM) has developed into a powerful technique to image many different properties of samples. The conventional method involves monitoring the amplitude, phase, or frequency of a cantilever oscillating at or near its resonant frequency as it is scanned across the surface of a sample. For high Q factor cantilevers, monitoring the resonant frequency is the preferred method in order to obtain reasonable scan times. This can be done by using a phase-locked-loop (PLL). PLLs can be obtained as commercial integrated circuits, but these do not have the frequency resolution required for SPM. To increase the resolution, all-digital PLLs requiring sophisticated digital signal processors or field programmable gate arrays have also been implemented. We describe here a hybrid analog/digital PLL where most of the components are implemented using discrete analog integrated circuits, but the frequency resolution is provided by a direct digital synthesis chip controlled by a simple peripheral interface controller (PIC) microcontroller. The PLL has excellent frequency resolution and noise, and can be controlled and read by a computer via a universal serial bus connection.

Synchronous radio-frequency FM signal generator using direct digital synthesizers

NASA Astrophysics Data System (ADS)

Arablu, Masoud; Kafashi, Sajad; Smith, Stuart T.

2018-04-01

A novel Radio-Frequency Frequency-Modulated (RF-FM) signal generation method is introduced and a prototype circuit developed to evaluate its functionality and performance. The RF-FM signal generator uses a modulated, voltage-controlled time delay to correspondingly modulate the phase of a 10 MHz sinusoidal reference signal. This modulated reference signal is, in turn, used to clock a Direct Digital Synthesizer (DDS) circuit resulting in an FM signal at its output. The modulating signal that is input to the voltage-controlled time delay circuit is generated by another DDS that is synchronously clocked by the same 10 MHz sine wave signal before modulation. As a consequence, all of the digital components are timed from a single sine wave oscillator that forms the basis of all timing. The resultant output signal comprises a center, or carrier, frequency plus a series of phase-synchronized sidebands having exact integer harmonic frequency separation. In this study, carrier frequencies ranging from 10 MHz to 70 MHz are generated with modulation frequencies ranging from 10 kHz to 300 kHz. The captured spectra show that the FM signal characteristics, amplitude and phase, of the sidebands and the modulation depth are consistent with the Jacobi-Anger expansion for modulated harmonic signals.

Cheaper Synthesis Of Multipole-Brushless-dc-Motor Current

NASA Technical Reports Server (NTRS)

Alhorn, Dean C.; Howard, David E.

1994-01-01

Circuit converts output of single two-phase shaft-angle resolver to that of multi-speed three-phase shaft-angle resolver. Converter circuit applicable to generation of multispeed, multiphase shaft-angle-resolver signals from single two-phase shaft-angle resolver. Combination of converter circuit and single two-phase shaft-angle resolver offer advantages in cost, weight, size, and complexity. Design readily adaptable to two-phase motor.

Optically controlled phased array antenna concepts using GaAs monolithic microwave integrated circuits

NASA Technical Reports Server (NTRS)

Kunath, R. R.; Bhasin, K. B.

1986-01-01

The desire for rapid beam reconfigurability and steering has led to the exploration of new techniques. Optical techniques have been suggested as potential candidates for implementing these needs. Candidates generally fall into one of two areas: those using fiber optic Beam Forming Networks (BFNs) and those using optically processed BFNs. Both techniques utilize GaAs Monolithic Microwave Integrated Circuits (MMICs) in the BFN, but the role of the MMIC for providing phase and amplitude variations is largely eliminated by some new optical processing techniques. This paper discusses these two types of optical BFN designs and provides conceptual designs of both systems.

Static inverter with synchronous output waveform synthesized by time-optimal-response feedback

NASA Technical Reports Server (NTRS)

Kernick, A.; Stechschulte, D. L.; Shireman, D. W.

1976-01-01

Time-optimal-response 'bang-bang' or 'bang-hang' technique, using four feedback control loops, synthesizes static-inverter sinusoidal output waveform by self-oscillatory but yet synchronous pulse-frequency-modulation (SPFM). A single modular power stage per phase of ac output entails the minimum of circuit complexity while providing by feedback synthesis individual phase voltage regulation, phase position control and inherent compensation simultaneously for line and load disturbances. Clipped sinewave performance is described under off-limit load or input voltage conditions. Also, approaches to high power levels, 3-phase arraying and parallel modular connection are given.

BETA: Behavioral testability analyzer and its application to high-level test generation and synthesis for testability. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Chen, Chung-Hsing

1992-01-01

In this thesis, a behavioral-level testability analysis approach is presented. This approach is based on analyzing the circuit behavioral description (similar to a C program) to estimate its testability by identifying controllable and observable circuit nodes. This information can be used by a test generator to gain better access to internal circuit nodes and to reduce its search space. The results of the testability analyzer can also be used to select test points or partial scan flip-flops in the early design phase. Based on selection criteria, a novel Synthesis for Testability approach call Test Statement Insertion (TSI) is proposed, which modifies the circuit behavioral description directly. Test Statement Insertion can also be used to modify circuit structural description to improve its testability. As a result, Synthesis for Testability methodology can be combined with an existing behavioral synthesis tool to produce more testable circuits.

Combinational logic for generating gate drive signals for phase control rectifiers

NASA Technical Reports Server (NTRS)

Dolland, C. R.; Trimble, D. W. (Inventor)

1982-01-01

Control signals for phase-delay rectifiers, which require a variable firing angle that ranges from 0 deg to 180 deg, are derived from line-to-line 3-phase signals and both positive and negative firing angle control signals which are generated by comparing current command and actual current. Line-to-line phases are transformed into line-to-neutral phases and integrated to produce 90 deg phase delayed signals that are inverted to produce three cosine signals, such that for each its maximum occurs at the intersection of positive half cycles of the other two phases which are inputs to other inverters. At the same time, both positive and negative (inverted) phase sync signals are generated for each phase by comparing each with the next and producing a square wave when it is greater. Ramp, sync and firing angle controls signals are than used in combinational logic to generate the gate firing control signals SCR gate drives which fire SCR devices in a bridge circuit.

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 30-GHz monolithic receiver

NASA Technical Reports Server (NTRS)

Liu, Louis C. T.; Liu, Carol S.; Kessler, Joel R.; Wang, Shing-Kuo; Chang, Ching-Der

1986-01-01

Several monolithic integrated circuits have been developed to make a 30-GHz receiver. The receiver components include a low-noise amplifier (LNA), an IF amplifier, a mixer, and a phase shifter. The LNA has a 7-dB noise figure with over 17 dB of associated gain. The IF amplifier has a 13-dB gain with a 30-dB control range. The mixer has a conversion loss of 10.5 dB. The phase shifter has a 180-deg phase shift control and a minimum insertion loss of 1.6 dB.

Operation and Maintenance Manual, TECS 18.

DTIC Science & Technology

1978-11-01

width modulated variable output voltage and frequency using a three-phase transistor bridge circuit . Reduced power line electromagnetic interference...Description 3-1 Section II. Circuit Fundamentals 3-1 Section III. System Description 3-2 CHAPTER 4. Protection and Maintenance 4-1 Section I. Internal...Number I-la TECS 18 Electronic Module Location-Evaporator Side 1-3 1-lb TECS 18 Electronic Module Location-Condenser Side 1-4 1-2 Remote Control Panel 1-5

Improved photovoltaic performance from inorganic perovskite oxide thin films with mixed crystal phases

NASA Astrophysics Data System (ADS)

Chakrabartty, Joyprokash; Harnagea, Catalin; Celikin, Mert; Rosei, Federico; Nechache, Riad

2018-05-01

Inorganic ferroelectric perovskites are attracting attention for the realization of highly stable photovoltaic cells with large open-circuit voltages. However, the power conversion efficiencies of devices have been limited so far. Here, we report a power conversion efficiency of 4.20% under 1 sun illumination from Bi-Mn-O composite thin films with mixed BiMnO3 and BiMn2O5 crystal phases. We show that the photocurrent density and photovoltage mainly develop across grain boundaries and interfaces rather than within the grains. We also experimentally demonstrate that the open-circuit voltage and short-circuit photocurrent measured in the films are tunable by varying the electrical resistance of the device, which in turn is controlled by externally applying voltage pulses. The exploitation of multifunctional properties of composite oxides provides an alternative route towards achieving highly stable, high-efficiency photovoltaic solar energy conversion.

Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

NASA Astrophysics Data System (ADS)

Di Pendina, G.; Zianbetov, E.; Beigne, E.

2015-05-01

Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remaining in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28 nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160 mV up to 920 mV. The leakage current can be reduced to 154 pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes.

Multi-piecewise quadratic nonlinearity memristor and its 2N-scroll and 2N + 1-scroll chaotic attractors system.

PubMed

Wang, Chunhua; Liu, Xiaoming; Xia, Hu

2017-03-01

In this paper, two kinds of novel ideal active flux-controlled smooth multi-piecewise quadratic nonlinearity memristors with multi-piecewise continuous memductance function are presented. The pinched hysteresis loop characteristics of the two memristor models are verified by building a memristor emulator circuit. Using the two memristor models establish a new memristive multi-scroll Chua's circuit, which can generate 2N-scroll and 2N+1-scroll chaotic attractors without any other ordinary nonlinear function. Furthermore, coexisting multi-scroll chaotic attractors are found in the proposed memristive multi-scroll Chua's circuit. Phase portraits, Lyapunov exponents, bifurcation diagrams, and equilibrium point analysis have been used to research the basic dynamics of the memristive multi-scroll Chua's circuit. The consistency of circuit implementation and numerical simulation verifies the effectiveness of the system design.

Design of a signal conditioner for the Fermilab Magnet Test Facility

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

Giannelli, Pietro

2012-01-01

This thesis describes the design of a remotely-programmable signal conditioner for the harmonic measurement of accelerator magnets. A 10-channel signal conditioning circuit featuring bucking capabilities was designed from scratch and implemented to the level of the printed circuit board layout. Other system components were chosen from those available on the market. Software design was started with the definition of routine procedures. This thesis is part of an upgrade project for replacing obsolescent automated test equipment belonging to the Fermilab Magnet Test Facility. The design started with a given set of requirements. Using a top-down approach, all the circuits were designedmore » and their expected performances were theoretically predicted and simulated. A limited prototyping phase followed. The printed circuit boards were laid out and routed using a CAD software and focusing the design on maximum electromagnetic interference immunity. An embedded board was selected for controlling and interfacing the signal conditioning circuitry with the instrumentation network. Basic low level routines for hardware access were defined. This work covered the entire design process of the signal conditioner, resulting in a project ready for manufacturing. The expected performances are in line with the requirements and, in the cases where this was not possible, approval of trade-offs was sought and received from the end users. Part I deals with the global structure of the signal conditioner and the subdivision in functional macro-blocks. Part II treats the hardware design phase in detail, covering the analog and digital circuits, the printed circuit layouts, the embedded controller and the power supply selection. Part III deals with the basic hardware-related routines to be implemented in the final software.« less

Distinct neural circuits for control of movement vs. holding still

PubMed Central

2017-01-01

In generating a point-to-point movement, the brain does more than produce the transient commands needed to move the body part; it also produces the sustained commands that are needed to hold the body part at its destination. In the oculomotor system, these functions are mapped onto two distinct circuits: a premotor circuit that specializes in generating the transient activity that displaces the eyes and a “neural integrator” that transforms that transient input into sustained activity that holds the eyes. Different parts of the cerebellum adaptively control the motor commands during these two phases: the oculomotor vermis participates in fine tuning the transient neural signals that move the eyes, monitoring the activity of the premotor circuit via efference copy, whereas the flocculus participates in controlling the sustained neural signals that hold the eyes, monitoring the activity of the neural integrator. Here, I review the oculomotor literature and then ask whether this separation of control between moving and holding is a design principle that may be shared with other modalities of movement. To answer this question, I consider neurophysiological and psychophysical data in various species during control of head movements, arm movements, and locomotion, focusing on the brain stem, motor cortex, and hippocampus, respectively. The review of the data raises the possibility that across modalities of motor control, circuits that are responsible for producing commands that change the sensory state of a body part are distinct from those that produce commands that maintain that sensory state. PMID:28053244

A Single Chip Automotive Control LSI Using SOI Bipolar Complimentary MOS Double-Diffused MOS

NASA Astrophysics Data System (ADS)

Kawamoto, Kazunori; Mizuno, Shoji; Abe, Hirofumi; Higuchi, Yasushi; Ishihara, Hideaki; Fukumoto, Harutsugu; Watanabe, Takamoto; Fujino, Seiji; Shirakawa, Isao

2001-04-01

Using the example of an air bag controller, a single chip solution for automotive sub-control systems is investigated, by using a technological combination of improved circuits, bipolar complimentary metal oxide silicon double-diffused metal oxide silicon (BiCDMOS) and thick silicon on insulator (SOI). For circuits, an automotive specific reduced instruction set computer (RISC) center processing unit (CPU), and a novel, all integrated system clock generator, dividing digital phase-locked loop (DDPLL) are proposed. For the device technologies, the authors use SOI-BiCDMOS with trench dielectric-isolation (TD) which enables integration of various devices in an integrated circuit (IC) while avoiding parasitic miss operations by ideal isolation. The structures of the SOI layer and TD, are optimized for obtaining desired device characteristics and high electromagnetic interference (EMI) immunity. While performing all the air bag system functions over a wide range of supply voltage, and ambient temperature, the resulting single chip reduces the electronic parts to about a half of those in the conventional air bags. The combination of single chip oriented circuits and thick SOI-BiCDMOS technologies offered in this work is valuable for size reduction and improved reliability of automotive electronic control units (ECUs).

Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor

NASA Astrophysics Data System (ADS)

Afiqah Zainal, Nurul; Sooi Tat, Chan; Ajisman

2016-02-01

Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's ou tput is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor.

Controllable Bidirectional dc Power Sources For Large Loads

NASA Technical Reports Server (NTRS)

Tripp, John S.; Daniels, Taumi S.

1995-01-01

System redesigned for greater efficiency, durability, and controllability. Modern electronically controlled dc power sources proposed to supply currents to six electromagnets used to position aerodynamic test model in wind tunnel. Six-phase bridge rectifier supplies load with large current at voltage of commanded magnitude and polarity. Current-feedback circuit includes current-limiting feature giving some protection against overload.

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

A Phase-Locked Loop Epilepsy Network Emulator.

PubMed

Watson, P D; Horecka, K M; Cohen, N J; Ratnam, R

2016-10-15

Most seizure forecasting employs statistical learning techniques that lack a representation of the network interactions that give rise to seizures. We present an epilepsy network emulator (ENE) that uses a network of interconnected phase-locked loops (PLLs) to model synchronous, circuit-level oscillations between electrocorticography (ECoG) electrodes. Using ECoG data from a canine-epilepsy model (Davis et al. 2011) and a physiological entropy measure (approximate entropy or ApEn, Pincus 1995), we demonstrate the entropy of the emulator phases increases dramatically during ictal periods across all ECoG recording sites and across all animals in the sample. Further, this increase precedes the observable voltage spikes that characterize seizure activity in the ECoG data. These results suggest that the ENE is sensitive to phase-domain information in the neural circuits measured by ECoG and that an increase in the entropy of this measure coincides with increasing likelihood of seizure activity. Understanding this unpredictable phase-domain electrical activity present in ECoG recordings may provide a target for seizure detection and feedback control.

Method and apparatus for current-output peak detection

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

De Geronimo, Gianluigi

2017-01-24

A method and apparatus for a current-output peak detector. A current-output peak detector circuit is disclosed and works in two phases. The peak detector circuit includes switches to switch the peak detector circuit from the first phase to the second phase upon detection of the peak voltage of an input voltage signal. The peak detector generates a current output with a high degree of accuracy in the second phase.

Use of non-adiabatic geometric phase for quantum computing by NMR.

PubMed

Das, Ranabir; Kumar, S K Karthick; Kumar, Anil

2005-12-01

Geometric phases have stimulated researchers for its potential applications in many areas of science. One of them is fault-tolerant quantum computation. A preliminary requisite of quantum computation is the implementation of controlled dynamics of qubits. In controlled dynamics, one qubit undergoes coherent evolution and acquires appropriate phase, depending on the state of other qubits. If the evolution is geometric, then the phase acquired depend only on the geometry of the path executed, and is robust against certain types of error. This phenomenon leads to an inherently fault-tolerant quantum computation. Here we suggest a technique of using non-adiabatic geometric phase for quantum computation, using selective excitation. In a two-qubit system, we selectively evolve a suitable subsystem where the control qubit is in state |1, through a closed circuit. By this evolution, the target qubit gains a phase controlled by the state of the control qubit. Using the non-adiabatic geometric phase we demonstrate implementation of Deutsch-Jozsa algorithm and Grover's search algorithm in a two-qubit system.

Microwave Photonic Architecture for Direction Finding of LPI Emitters: Front End Analog Circuit Design and Component Characterization

DTIC Science & Technology

2016-09-01

design to control the phase shifters was complex, and the calibration process was time consuming. During the redesign process, we carried out...signals in time domain with a maximum sampling frequency of 20 Giga samples per second. In the previous tests of the design , the performance of...PHOTONIC ARCHITECTURE FOR DIRECTION FINDING OF LPI EMITTERS: FRONT-END ANALOG CIRCUIT DESIGN AND COMPONENT CHARACTERIZATION by Chew K. Tan

Phase Difference between Model Cortical Areas Determines Level of Information Transfer

PubMed Central

ter Wal, Marije; Tiesinga, Paul H.

2017-01-01

Communication between cortical sites is mediated by long-range synaptic connections. However, these connections are relatively static, while everyday cognitive tasks demand a fast and flexible routing of information in the brain. Synchronization of activity between distant cortical sites has been proposed as the mechanism underlying such a dynamic communication structure. Here, we study how oscillatory activity affects the excitability and input-output relation of local cortical circuits and how it alters the transmission of information between cortical circuits. To this end, we develop model circuits showing fast oscillations by the PING mechanism, of which the oscillatory characteristics can be altered. We identify conditions for synchronization between two brain circuits and show that the level of intercircuit coherence and the phase difference is set by the frequency difference between the intrinsic oscillations. We show that the susceptibility of the circuits to inputs, i.e., the degree of change in circuit output following input pulses, is not uniform throughout the oscillation period and that both firing rate, frequency and power are differentially modulated by inputs arriving at different phases. As a result, an appropriate phase difference between the circuits is critical for the susceptibility windows of the circuits in the network to align and for information to be efficiently transferred. We demonstrate that changes in synchrony and phase difference can be used to set up or abolish information transfer in a network of cortical circuits. PMID:28232796

Quartz/fused silica chip carriers

NASA Technical Reports Server (NTRS)

1992-01-01

The primary objective of this research and development effort was to develop monolithic microwave integrated circuit (MMIC) packaging which will operate efficiently at millimeter-wave frequencies. The packages incorporated fused silica as the substrate material which was selected due to its favorable electrical properties and potential performance improvement over more conventional materials for Ka-band operation. The first step towards meeting this objective is to develop a package that meets standard mechanical and thermal requirements using fused silica and to be compatible with semiconductor devices operating up to at least 44 GHz. The second step is to modify the package design and add multilayer and multicavity capacity to allow for application specific integrated circuits (ASIC's) to control multiple phase shifters. The final step is to adapt the package design to a phased array module with integral radiating elements. The first task was a continuation of the SBIR Phase 1 work. Phase 1 identified fused silica as a viable substrate material by demonstrating various plating, machining, and adhesion properties. In Phase 2 Task 1, a package was designed and fabricated to validate these findings. Task 2 was to take the next step in packaging and fabricate a multilayer, multichip module (MCM). This package is the predecessor to the phased array module and demonstrates the ability to via fill, circuit print, laminate, and to form vertical interconnects. The final task was to build a phased array module. The radiating elements were to be incorporated into the package instead of connecting to it with wire or ribbon bonds.

The role of Snell's law for a magnonic majority gate.

PubMed

Kanazawa, Naoki; Goto, Taichi; Sekiguchi, Koji; Granovsky, Alexander B; Ross, Caroline A; Takagi, Hiroyuki; Nakamura, Yuichi; Uchida, Hironaga; Inoue, Mitsuteru

2017-08-11

In the fifty years since the postulation of Moore's Law, the increasing energy consumption in silicon electronics has motivated research into emerging devices. An attractive research direction is processing information via the phase of spin waves within magnonic-logic circuits, which function without charge transport and the accompanying heat generation. The functional completeness of magnonic logic circuits based on the majority function was recently proved. However, the performance of such logic circuits was rather poor due to the difficulty of controlling spin waves in the input junction of the waveguides. Here, we show how Snell's law describes the propagation of spin waves in the junction of a Ψ-shaped magnonic majority gate composed of yttrium iron garnet with a partially metallized surface. Based on the analysis, we propose a magnonic counterpart of a core-cladding waveguide to control the wave propagation in the junction. This study has therefore experimentally demonstrated a fundamental building block of a magnonic logic circuit.

An X-Band SOS Resistive Gate-Insulator-Semiconductor /RIS/ switch

NASA Astrophysics Data System (ADS)

Kwok, S. P.

1980-02-01

The new X-Band Resistive Gate-Insulator-Semiconductor (RIS) switch has been fabricated on silicon-on-sapphire, and its equivalent circuit model characterized. An RIS SPST switch with 20-dB on/off isolation, 1.2-dB insertion loss, and power handling capacity in excess of 20-W peak has been achieved at X band. The device switching time is on the order of 600 ns, and it requires negligible control holding current in both on and off states. The device is compatible with monolithic integrated-circuit technology and thus is suitable for integration into low-cost monolithic phase shifters or other microwave integrated circuits.

Temporal integration and 1/f power scaling in a circuit model of cerebellar interneurons.

PubMed

Maex, Reinoud; Gutkin, Boris

2017-07-01

Inhibitory interneurons interconnected via electrical and chemical (GABA A receptor) synapses form extensive circuits in several brain regions. They are thought to be involved in timing and synchronization through fast feedforward control of principal neurons. Theoretical studies have shown, however, that whereas self-inhibition does indeed reduce response duration, lateral inhibition, in contrast, may generate slow response components through a process of gradual disinhibition. Here we simulated a circuit of interneurons (stellate and basket cells) of the molecular layer of the cerebellar cortex and observed circuit time constants that could rise, depending on parameter values, to >1 s. The integration time scaled both with the strength of inhibition, vanishing completely when inhibition was blocked, and with the average connection distance, which determined the balance between lateral and self-inhibition. Electrical synapses could further enhance the integration time by limiting heterogeneity among the interneurons and by introducing a slow capacitive current. The model can explain several observations, such as the slow time course of OFF-beam inhibition, the phase lag of interneurons during vestibular rotation, or the phase lead of Purkinje cells. Interestingly, the interneuron spike trains displayed power that scaled approximately as 1/ f at low frequencies. In conclusion, stellate and basket cells in cerebellar cortex, and interneuron circuits in general, may not only provide fast inhibition to principal cells but also act as temporal integrators that build a very short-term memory. NEW & NOTEWORTHY The most common function attributed to inhibitory interneurons is feedforward control of principal neurons. In many brain regions, however, the interneurons are densely interconnected via both chemical and electrical synapses but the function of this coupling is largely unknown. Based on large-scale simulations of an interneuron circuit of cerebellar cortex, we propose that this coupling enhances the integration time constant, and hence the memory trace, of the circuit. Copyright © 2017 the American Physiological Society.

Optically triggered high voltage switch network and method for switching a high voltage

DOEpatents

El-Sharkawi, Mohamed A.; Andexler, George; Silberkleit, Lee I.

1993-01-19

An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

Controllable 0–π Josephson junctions containing a ferromagnetic spin valve

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

Gingrich, E. C.; Niedzielski, Bethany M.; Glick, Joseph A.

Superconductivity and ferromagnetism are antagonistic forms of order, and rarely coexist. Many interesting new phenomena occur, however, in hybrid superconducting/ferromagnetic systems. For example, a Josephson junction containing a ferromagnetic material can exhibit an intrinsic phase shift of π in its ground state for certain thicknesses of the material. Such ‘π-junctions’ were first realized experimentally in 2001, and have been proposed as circuit elements for both high-speed classical superconducting computing and for quantum computing. Here we demonstrate experimentally that the phase state of a Josephson junction containing two ferromagnetic layers can be toggled between 0 and pi by changing the relativemore » orientation of the two magnetizations. These controllable 0–π junctions have immediate applications in cryogenic memory, where they serve as a necessary component to an ultralow power superconducting computer. Such a fully superconducting computer is estimated to be orders of magnitude more energy-efficient than current semiconductor-based supercomputers. Here, phase-controllable junctions also open up new possibilities for superconducting circuit elements such as superconducting ‘programmable logic’, where they could function in superconducting analogues to field-programmable gate arrays.« less

Controllable 0–π Josephson junctions containing a ferromagnetic spin valve

DOE PAGES

Gingrich, E. C.; Niedzielski, Bethany M.; Glick, Joseph A.; ...

2016-03-14

Superconductivity and ferromagnetism are antagonistic forms of order, and rarely coexist. Many interesting new phenomena occur, however, in hybrid superconducting/ferromagnetic systems. For example, a Josephson junction containing a ferromagnetic material can exhibit an intrinsic phase shift of π in its ground state for certain thicknesses of the material. Such ‘π-junctions’ were first realized experimentally in 2001, and have been proposed as circuit elements for both high-speed classical superconducting computing and for quantum computing. Here we demonstrate experimentally that the phase state of a Josephson junction containing two ferromagnetic layers can be toggled between 0 and pi by changing the relativemore » orientation of the two magnetizations. These controllable 0–π junctions have immediate applications in cryogenic memory, where they serve as a necessary component to an ultralow power superconducting computer. Such a fully superconducting computer is estimated to be orders of magnitude more energy-efficient than current semiconductor-based supercomputers. Here, phase-controllable junctions also open up new possibilities for superconducting circuit elements such as superconducting ‘programmable logic’, where they could function in superconducting analogues to field-programmable gate arrays.« less

New kind of injection-locked oscillator and its corresponding long-term stability control.

PubMed

Hong, Jun; Liu, An; Wang, Xiao-hu; Yao, Sheng-xing; Li, Zu-ling

2015-09-20

A new type of opto-electronic hybrid oscillator is proposed for the first time, to the best of our knowledge, and verified by experiments in this paper. Typical electronic oscillator-dielectric resonator oscillator as the first injection source is used to injection lock the first long-fiber loop-based opto-electronic oscillator (OEO); then its output is used to injection lock the second long-fiber opto-electronic oscillator. Using this method, low-phase noise output signal can be obtained. Experiments show that single side-band (SSB) phase noise of a 9.5 GHz oscillation signal at 10 kHz offset frequency decreases from -123 to -135  dBc/Hz after the first injection, then, through the second injection, the SSB phase noise drops down to -146  dBc/Hz. In order to solve the long-term stability problem of the above oscillator, a new stability-control circuit also is designed and verified by experiments. Experiments show that the Allan deviation decreases from 9.0×10(-11) to 2.2×10(-12) during 1 s after the long-term stability-control circuit being used.

Influence of the magnesium aspartate hydrochloride administration to the maternal circuit on the aspartate concentration of the fetal circuit under in vitro perfusion of human placenta.

PubMed

Malek, A; Leiser, R

2009-01-01

Magnesium aspartate hydrochloride (Magnesiocard, Mg-Asp-HCl) is proposed as a substitute of magnesium sulfate for the treatment of preeclampsia and premature labor. After an i.v. administration of a dose equivalent to that used in the treatment of preeclampsia to nonpregnant volunteers, a 10-fold increase of aspartic acid (Asp) over the physiological level was observed. Animal experiments have demonstrated that highly increased fetal levels of acidic amino acids such as Asp could be associated with neurotoxic damage in the fetal brain. The influence of such an elevation of Asp concentration in the maternal circuit on the fetal level, using the in vitro perfusion model of human placenta, was investigated. After a control phase (2h), a therapeutic dose of Mg combined with Asp (Magnesiocard, Mg-Asp-HCl) was applied to the maternal circuit approaching 10 times the physiological level of Asp. The administration was performed in two different phases simulating either a peak of maximum concentration (bolus application, 2h) or a steady state level (initially added, 4h). In four experiments, during experimental phases (6h) a slow increase in concentration in the fetal circuit was seen for Mg, AIB (alpha-aminoisobutyric acid, artificial amino acid) and creatinine confirming previous observations. In contrast, no net transfer of Asp across the placenta was seen. A continuous decrease in the concentration of Asp on both maternal and fetal side suggests active uptake and metabolization by the placenta. Viability control parameters remained stable indicating the absence of an effect on placental metabolism, permeability and morphology. Elevation of Asp concentration up to 10 times the physiological level by the administration of Mg-Asp-HCl to the maternal circuit under in vitro perfusion conditions of human placenta has no influence on the fetal level of Asp suggesting no transfer of Asp from the maternal to fetal compartment. Therefore, the administration of Mg-Asp-HCl to preeclamptic patients would be beneficial for the patients without any impact on placental or fetal physiology.

Postfabrication Phase Error Correction of Silicon Photonic Circuits by Single Femtosecond Laser Pulses

DOE PAGES

Bachman, Daniel; Chen, Zhijiang; Wang, Christopher; ...

2016-11-29

Phase errors caused by fabrication variations in silicon photonic integrated circuits are an important problem, which negatively impacts device yield and performance. This study reports our recent progress in the development of a method for permanent, postfabrication phase error correction of silicon photonic circuits based on femtosecond laser irradiation. Using beam shaping technique, we achieve a 14-fold enhancement in the phase tuning resolution of the method with a Gaussian-shaped beam compared to a top-hat beam. The large improvement in the tuning resolution makes the femtosecond laser method potentially useful for very fine phase trimming of silicon photonic circuits. Finally, wemore » also show that femtosecond laser pulses can directly modify silicon photonic devices through a SiO 2 cladding layer, making it the only permanent post-fabrication method that can tune silicon photonic circuits protected by an oxide cladding.« less

Device for limiting single phase ground fault of mining machines

NASA Astrophysics Data System (ADS)

Fediuk, R. S.; Stoyushko, N. Yu; Yevdokimova, Yu G.; Smoliakov, A. K.; Batarshin, V. O.; Timokhin, R. A.

2017-10-01

The paper shows the reasons and consequences of the single-phase ground fault. With all the variety of devices for limiting the current single-phase ground fault, it was found that the most effective are Peterson coils having different switching circuits. Measuring of the capacity of the network is of great importance in this case, a number of options capacitance measurement are presented. A closer look is taken at the device for limiting the current of single-phase short circuit, developed in the Far Eastern Federal University under the direction of Dr. G.E. Kuvshinov. The calculation of single-phase short-circuit currents in the electrical network, without compensation and with compensation of capacitive current is carried out. Simulation of a single-phase circuit in a network with the proposed device is conducted.

Variable current speed controller for eddy current motors

DOEpatents

Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

1982-03-12

A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

Phase 1 Feasibility Study: Seawater Hydraulic Transfer Pump

DTIC Science & Technology

1996-11-01

2442532 3408040 M/ DIRECT HYDRAULIC DRIVE FOR LARGE FLOTATION CELLS 2440714 3406737 A-5 M/ COMBINED ANTISKID AND TRACTION CONTROL ELECTRONIC BRAKE SYSTEM ...HYDRAULIC PRESSURE 2449168 3412870 M/ POWER STEERING PUMP WITH BALANCED PORTING 2446911 3411257 M/ HYDRAULIC BRAKE SYSTEM INCLUDING SLIP CONTROL ...2440401 3406424 M/ HYDRAULIC CIRCUIT FOR RUNNING A CRAWLER VEHICLE 2434313 3402015 M/ HYDRAULICALLY ACTUATED AIRCRAFT ENGINE CONTROL SYSTEM 2425918

Activity of the C. elegans egg-laying behavior circuit is controlled by competing activation and feedback inhibition

PubMed Central

Collins, Kevin M; Bode, Addys; Fernandez, Robert W; Tanis, Jessica E; Brewer, Jacob C; Creamer, Matthew S; Koelle, Michael R

2016-01-01

Like many behaviors, Caenorhabditis elegans egg laying alternates between inactive and active states. To understand how the underlying neural circuit turns the behavior on and off, we optically recorded circuit activity in behaving animals while manipulating circuit function using mutations, optogenetics, and drugs. In the active state, the circuit shows rhythmic activity phased with the body bends of locomotion. The serotonergic HSN command neurons initiate the active state, but accumulation of unlaid eggs also promotes the active state independent of the HSNs. The cholinergic VC motor neurons slow locomotion during egg-laying muscle contraction and egg release. The uv1 neuroendocrine cells mechanically sense passage of eggs through the vulva and release tyramine to inhibit egg laying, in part via the LGC-55 tyramine-gated Cl- channel on the HSNs. Our results identify discrete signals that entrain or detach the circuit from the locomotion central pattern generator to produce active and inactive states. DOI: http://dx.doi.org/10.7554/eLife.21126.001 PMID:27849154

Electronic circuits

NASA Technical Reports Server (NTRS)

1976-01-01

Twenty-nine circuits and circuit techniques developed for communications and instrumentation technology are described. Topics include pulse-code modulation, phase-locked loops, data coding, data recording, detection circuits, logic circuits, oscillators, and amplifiers.

Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

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

Di Pendina, G., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr; Zianbetov, E., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr; CNRS, SPINTEC, F-38000 Grenoble

2015-05-07

Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remainingmore » in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28 nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160 mV up to 920 mV. The leakage current can be reduced to 154 pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes.« less

Cryogenic Pound Circuits for Cryogenic Sapphire Oscillators

NASA Technical Reports Server (NTRS)

Dick, G. John; Wang, Rabi

2006-01-01

Two modern cryogenic variants of the Pound circuit have been devised to increase the frequency stability of microwave oscillators that include cryogenic sapphire-filled cavity resonators. The original Pound circuit is a microwave frequency discriminator that provides feedback to stabilize a voltage-controlled microwave oscillator with respect to an associated cavity resonator. In the present cryogenic Pound circuits, the active microwave devices are implemented by use of state-of-the-art commercially available tunnel diodes that exhibit low flicker noise (required for high frequency stability) and function well at low temperatures and at frequencies up to several tens of gigahertz. While tunnel diodes are inherently operable as amplitude detectors and amplitude modulators, they cannot, by themselves, induce significant phase modulation. Therefore, each of the present cryogenic Pound circuits includes passive circuitry that transforms the AM into the required PM. Each circuit also contains an AM detector that is used to sample the microwave signal at the input terminal of the high-Q resonator for the purpose of verifying the desired AM null at this point. Finally, each circuit contains a Pound signal detector that puts out a signal, at the modulation frequency, having an amplitude proportional to the frequency error in the input signal. High frequency stability is obtained by processing this output signal into feedback to a voltage-controlled oscillator to continuously correct the frequency error in the input signal.

PHASE DIFFERENTIAL INDICATING CIRCUIT

DOEpatents

Kirsten, F.A.

1962-01-01

An electronic circuit for totalizing the net phase difference between two alternating current signals is designed which responds to both increasing and decreasing phase changes. A phase comparator provldes an output pulse for each 360 deg of phase difference occurring, there being a negative pulse for phase shtft in one direction and a positive pulse for a phase shift in the opposite direction. A counting circuit utilizing glow discharge tubes receives the negative and positive pulses at a single input terminal and provides a running net total, pulses of one polarity dded and pulses of the opposite polarity being subtracted. The glow discharge tubes may be decaded to increase the total count capacity. (AEC)

Heart-Rate and Breath-Rate Monitor

NASA Technical Reports Server (NTRS)

Cooper, T. G.

1983-01-01

Circuit requiring only four integrated circuits (IC's) measures both heart rate and breath rate. Phase-locked loops lock on heart-rate and respiration-rate input signals. Each loop IC contains two phase comparators. Positive-edge-triggered circuit used in making monitors insensitive to dutycycle variations.

Development of a Converter-Based Transmission Line Emulator with Three-Phase Short-Circuit Fault Emulation Capability

DOE PAGES

Zhang, Shuoting; Liu, Bo; Zheng, Sheng; ...

2018-01-01

A transmission line emulator has been developed to flexibly represent interconnected ac lines under normal operating conditions in a voltage source converter (VSC)-based power system emulation platform. As the most serious short-circuit fault condition, the three-phase short-circuit fault emulation is essential for power system studies. Here, this paper proposes a model to realize a three-phase short-circuit fault emulation at different locations along a single transmission line or one of several parallel-connected transmission lines. At the same time, a combination method is proposed to eliminate the undesired transients caused by the current reference step changes while switching between the fault statemore » and the normal state. Experiment results verify the developed transmission line three-phase short-circuit fault emulation capability.« less

Development of a Converter-Based Transmission Line Emulator with Three-Phase Short-Circuit Fault Emulation Capability

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

Zhang, Shuoting; Liu, Bo; Zheng, Sheng

A transmission line emulator has been developed to flexibly represent interconnected ac lines under normal operating conditions in a voltage source converter (VSC)-based power system emulation platform. As the most serious short-circuit fault condition, the three-phase short-circuit fault emulation is essential for power system studies. Here, this paper proposes a model to realize a three-phase short-circuit fault emulation at different locations along a single transmission line or one of several parallel-connected transmission lines. At the same time, a combination method is proposed to eliminate the undesired transients caused by the current reference step changes while switching between the fault statemore » and the normal state. Experiment results verify the developed transmission line three-phase short-circuit fault emulation capability.« less

The NATO III 5 MHz Distribution System

NASA Technical Reports Server (NTRS)

Vulcan, A.; Bloch, M.

1981-01-01

A high performance 5 MHz distribution system is described which has extremely low phase noise and jitter characteristics and provides multiple buffered outputs. The system is completely redundant with automatic switchover and is self-testing. Since the 5 MHz reference signals distributed by the NATO III distribution system are used for up-conversion and multiplicative functions, a high degree of phase stability and isolation between outputs is necessary. Unique circuit design and packaging concepts insure that the isolation between outputs is sufficient to quarantee a phase perturbation of less than 0.0016 deg when other outputs are open circuited, short circuited or terminated in 50 ohms. Circuit design techniques include high isolation cascode amplifiers. Negative feedback stabilizes system gain and minimizes circuit phase noise contributions. Balanced lines, in lieu of single ended coaxial transmission media, minimize pickup.

A gallium-arsenide digital phase shifter for clock and control signal distribution in high-speed digital systems

NASA Technical Reports Server (NTRS)

Fouts, Douglas J.

1992-01-01

The design, implementation, testing, and applications of a gallium-arsenide digital phase shifter and fan-out buffer are described. The integrated circuit provides a method for adjusting the phase of high-speed clock and control signals in digital systems, without the need for pruning cables, multiplexing between cables of different lengths, delay lines, or similar techniques. The phase of signals distributed with the described chip can be dynamically adjusted in eight different steps of approximately 60 ps per step. The IC also serves as a fan-out buffer and provides 12 in-phase outputs. The chip is useful for distributing high-speed clock and control signals in synchronous digital systems, especially if components are distributed over a large physical area or if there is a large number of components.

Modeling and control of fuel cell based distributed generation systems

NASA Astrophysics Data System (ADS)

Jung, Jin Woo

This dissertation presents circuit models and control algorithms of fuel cell based distributed generation systems (DGS) for two DGS topologies. In the first topology, each DGS unit utilizes a battery in parallel to the fuel cell in a standalone AC power plant and a grid-interconnection. In the second topology, a Z-source converter, which employs both the L and C passive components and shoot-through zero vectors instead of the conventional DC/DC boost power converter in order to step up the DC-link voltage, is adopted for a standalone AC power supply. In Topology 1, two applications are studied: a standalone power generation (Single DGS Unit and Two DGS Units) and a grid-interconnection. First, dynamic model of the fuel cell is given based on electrochemical process. Second, two full-bridge DC to DC converters are adopted and their controllers are designed: an unidirectional full-bridge DC to DC boost converter for the fuel cell and a bidirectional full-bridge DC to DC buck/boost converter for the battery. Third, for a three-phase DC to AC inverter without or with a Delta/Y transformer, a discrete-time state space circuit model is given and two discrete-time feedback controllers are designed: voltage controller in the outer loop and current controller in the inner loop. And last, for load sharing of two DGS units and power flow control of two DGS units or the DGS connected to the grid, real and reactive power controllers are proposed. Particularly, for the grid-connected DGS application, a synchronization issue between an islanding mode and a paralleling mode to the grid is investigated, and two case studies are performed. To demonstrate the proposed circuit models and control strategies, simulation test-beds using Matlab/Simulink are constructed for each configuration of the fuel cell based DGS with a three-phase AC 120 V (L-N)/60 Hz/50 kVA and various simulation results are presented. In Topology 2, this dissertation presents system modeling, modified space vector PWM implementation (MSVPWM) and design of a closed-loop controller of the Z-source converter which utilizes L and C components and shoot-through zero vectors for the standalone AC power generation. The fuel cell system is modeled by an electrical R-C circuit in order to include slow dynamics of the fuel cells and a voltage-current characteristic of a cell is also considered. A discrete-time state space model is derived to implement digital control and a space vector pulse-width modulation (SVPWM) technique is modified to realize the shoot-through zero vectors that boost the DC-link voltage. Also, three discrete-time feedback controllers are designed: a discrete-time optimal voltage controller, a discrete-time sliding mode current controller, and a discrete-time PI DC-link voltage controller. Furthermore, an asymptotic observer is used to reduce the number of sensors and enhance the reliability of the system. To demonstrate the analyzed circuit model and proposed control strategy, various simulation results using Matlab/Simulink are presented under both light/heavy loads and linear/nonlinear loads for a three-phase AC 208 V (L-L)/60 Hz/10 kVA.

Single-Stage Step up/down Driver for Permanent-Magnet Synchronous Machines

NASA Astrophysics Data System (ADS)

Chen, T. R.; Juan, Y. L.; Huang, C. Y.; Kuo, C. T.

2017-11-01

The two-stage circuit composed of a step up/down dc converter and a three-phase voltage source inverter is usually adopted as the electric vehicle’s motor driver. The conventional topology is more complicated. Additional power loss resulted from twice power conversion would also cause lower efficiency. A single-stage step up/down Permanent-Magnet Synchronous Motor driver for Brushless DC (BLDC) Motor is proposed in this study. The number components and circuit complexity are reduced. The low frequency six-step square-wave control is used to reduce the switching losses. In the proposed topology, only one active switch is gated with a high frequency PWM signal for adjusting the rotation speed. The rotor position signals are fed back to calculate the motor speed for digital close-loop control in a MCU. A 600W prototype circuit is constructed to drive a BLDC motor with rated speed 3000 rpm, and can control the speed of six sections.

Experimental Demonstration of a Resonator-Induced Phase Gate in a Multiqubit Circuit-QED System.

PubMed

Paik, Hanhee; Mezzacapo, A; Sandberg, Martin; McClure, D T; Abdo, B; Córcoles, A D; Dial, O; Bogorin, D F; Plourde, B L T; Steffen, M; Cross, A W; Gambetta, J M; Chow, Jerry M

2016-12-16

The resonator-induced phase (RIP) gate is an all-microwave multiqubit entangling gate that allows a high degree of flexibility in qubit frequencies, making it attractive for quantum operations in large-scale architectures. We experimentally realize the RIP gate with four superconducting qubits in a three-dimensional circuit-QED architecture, demonstrating high-fidelity controlled-z (cz) gates between all possible pairs of qubits from two different 4-qubit devices in pair subspaces. These qubits are arranged within a wide range of frequency detunings, up to as large as 1.8 GHz. We further show a dynamical multiqubit refocusing scheme in order to isolate out 2-qubit interactions, and combine them to generate a 4-qubit Greenberger-Horne-Zeilinger state.

Experimental Demonstration of a Resonator-Induced Phase Gate in a Multiqubit Circuit-QED System

NASA Astrophysics Data System (ADS)

Paik, Hanhee; Mezzacapo, A.; Sandberg, Martin; McClure, D. T.; Abdo, B.; Córcoles, A. D.; Dial, O.; Bogorin, D. F.; Plourde, B. L. T.; Steffen, M.; Cross, A. W.; Gambetta, J. M.; Chow, Jerry M.

2016-12-01

The resonator-induced phase (RIP) gate is an all-microwave multiqubit entangling gate that allows a high degree of flexibility in qubit frequencies, making it attractive for quantum operations in large-scale architectures. We experimentally realize the RIP gate with four superconducting qubits in a three-dimensional circuit-QED architecture, demonstrating high-fidelity controlled-z (cz) gates between all possible pairs of qubits from two different 4-qubit devices in pair subspaces. These qubits are arranged within a wide range of frequency detunings, up to as large as 1.8 GHz. We further show a dynamical multiqubit refocusing scheme in order to isolate out 2-qubit interactions, and combine them to generate a 4-qubit Greenberger-Horne-Zeilinger state.

A new two-scroll chaotic attractor with three quadratic nonlinearities, its adaptive control and circuit design

NASA Astrophysics Data System (ADS)

Lien, C.-H.; Vaidyanathan, S.; Sambas, A.; Sukono; Mamat, M.; Sanjaya, W. S. M.; Subiyanto

2018-03-01

A 3-D new two-scroll chaotic attractor with three quadratic nonlinearities is investigated in this paper. First, the qualitative and dynamical properties of the new two-scroll chaotic system are described in terms of phase portraits, equilibrium points, Lyapunov exponents, Kaplan-Yorke dimension, dissipativity, etc. We show that the new two-scroll dissipative chaotic system has three unstable equilibrium points. As an engineering application, global chaos control of the new two-scroll chaotic system with unknown system parameters is designed via adaptive feedback control and Lyapunov stability theory. Furthermore, an electronic circuit realization of the new chaotic attractor is presented in detail to confirm the feasibility of the theoretical chaotic two-scroll attractor model.

A fast-locking PLL with all-digital locked-aid circuit

NASA Astrophysics Data System (ADS)

Kao, Shao-Ku; Hsieh, Fu-Jen

2013-02-01

In this article, a fast-locking phase-locked loop (PLL) with an all-digital locked-aid circuit is proposed and analysed. The proposed topology is based on two tuning loops: frequency and phase detections. A frequency detection loop is used to accelerate frequency locking time, and a phase detection loop is used to adjust fine phase errors between the reference and feedback clocks. The proposed PLL circuit is designed based on the 0.35 µm CMOS process with a 3.3 V supply voltage. Experimental results show that the locking time of the proposed PLL achieves a 87.5% reduction from that of a PLL without the locked-aid circuit.

30 CFR 75.800 - High-voltage circuits; circuit breakers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... shall be equipped with devices to provide protection against under-voltage grounded phase, short circuit... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. [Statutory Provisions] High-voltage circuits entering...

Engineering integrated photonics for heralded quantum gates

NASA Astrophysics Data System (ADS)

Meany, Thomas; Biggerstaff, Devon N.; Broome, Matthew A.; Fedrizzi, Alessandro; Delanty, Michael; Steel, M. J.; Gilchrist, Alexei; Marshall, Graham D.; White, Andrew G.; Withford, Michael J.

2016-06-01

Scaling up linear-optics quantum computing will require multi-photon gates which are compact, phase-stable, exhibit excellent quantum interference, and have success heralded by the detection of ancillary photons. We investigate the design, fabrication and characterisation of the optimal known gate scheme which meets these requirements: the Knill controlled-Z gate, implemented in integrated laser-written waveguide arrays. We show device performance to be less sensitive to phase variations in the circuit than to small deviations in the coupler reflectivity, which are expected given the tolerance values of the fabrication method. The mode fidelity is also shown to be less sensitive to reflectivity and phase errors than the process fidelity. Our best device achieves a fidelity of 0.931 ± 0.001 with the ideal 4 × 4 unitary circuit and a process fidelity of 0.680 ± 0.005 with the ideal computational-basis process.

Engineering integrated photonics for heralded quantum gates

PubMed Central

Meany, Thomas; Biggerstaff, Devon N.; Broome, Matthew A.; Fedrizzi, Alessandro; Delanty, Michael; Steel, M. J.; Gilchrist, Alexei; Marshall, Graham D.; White, Andrew G.; Withford, Michael J.

2016-01-01

Scaling up linear-optics quantum computing will require multi-photon gates which are compact, phase-stable, exhibit excellent quantum interference, and have success heralded by the detection of ancillary photons. We investigate the design, fabrication and characterisation of the optimal known gate scheme which meets these requirements: the Knill controlled-Z gate, implemented in integrated laser-written waveguide arrays. We show device performance to be less sensitive to phase variations in the circuit than to small deviations in the coupler reflectivity, which are expected given the tolerance values of the fabrication method. The mode fidelity is also shown to be less sensitive to reflectivity and phase errors than the process fidelity. Our best device achieves a fidelity of 0.931 ± 0.001 with the ideal 4 × 4 unitary circuit and a process fidelity of 0.680 ± 0.005 with the ideal computational-basis process. PMID:27282928

Engineering integrated photonics for heralded quantum gates.

PubMed

Meany, Thomas; Biggerstaff, Devon N; Broome, Matthew A; Fedrizzi, Alessandro; Delanty, Michael; Steel, M J; Gilchrist, Alexei; Marshall, Graham D; White, Andrew G; Withford, Michael J

2016-06-10

Scaling up linear-optics quantum computing will require multi-photon gates which are compact, phase-stable, exhibit excellent quantum interference, and have success heralded by the detection of ancillary photons. We investigate the design, fabrication and characterisation of the optimal known gate scheme which meets these requirements: the Knill controlled-Z gate, implemented in integrated laser-written waveguide arrays. We show device performance to be less sensitive to phase variations in the circuit than to small deviations in the coupler reflectivity, which are expected given the tolerance values of the fabrication method. The mode fidelity is also shown to be less sensitive to reflectivity and phase errors than the process fidelity. Our best device achieves a fidelity of 0.931 ± 0.001 with the ideal 4 × 4 unitary circuit and a process fidelity of 0.680 ± 0.005 with the ideal computational-basis process.

A model-based exploration of the role of pattern generating circuits during locomotor adaptation.

PubMed

Marjaninejad, Ali; Finley, James M

2016-08-01

In this study, we used a model-based approach to explore the potential contributions of central pattern generating circuits (CPGs) during adaptation to external perturbations during locomotion. We constructed a neuromechanical modeled of locomotion using a reduced-phase CPG controller and an inverted pendulum mechanical model. Two different forms of locomotor adaptation were examined in this study: split-belt treadmill adaptation and adaptation to a unilateral, elastic force field. For each simulation, we first examined the effects of phase resetting and varying the model's initial conditions on the resulting adaptation. After evaluating the effect of phase resetting on the adaptation of step length symmetry, we examined the extent to which the results from these simple models could explain previous experimental observations. We found that adaptation of step length symmetry during split-belt treadmill walking could be reproduced using our model, but this model failed to replicate patterns of adaptation observed in response to force field perturbations. Given that spinal animal models can adapt to both of these types of perturbations, our findings suggest that there may be distinct features of pattern generating circuits that mediate each form of adaptation.

Integrated mixed signal control IC for 500-kHz switching frequency buck regulator

NASA Astrophysics Data System (ADS)

Chen, Keng; Zhang, Hong

2015-12-01

The main purpose for this work is to study the challenges of designing a digital buck regulator using pipelined analog to digital converter (ADC). Although pipelined ADC can achieve high sampling speed, it will introduce additional phase lag to the buck circuit. Along with the latency brought by processing time of additional digital circuits, as well as the time delay associated with the switching frequency, the closed loop will be unstable; moreover, raw ADC outputs have low signal-to-noise ratio, which usually need back-end calibration. In order to compensate these phase lag and make control loop unconditional stable, as well as boost up signal-to-noise ratio of the ADC block with cost-efficient design, a finite impulse response filter followed by digital proportional-integral-derivative blocks were designed. All these digital function blocks were optimised with processing speed. In the system simulation, it can be found that this controller achieved output regulation within 10% of nominal 5 V output voltage under 1 A/µs load transient condition; moreover, with the soft-start method, there is no turn-on overshooting. The die size of this controller is controlled within 3 mm2 by using 180 nm CMOS technology.

Some Aspects of an Air-Core Single-Coil Magnetic Suspension System

NASA Technical Reports Server (NTRS)

Hamlet, Irvin L.; Kilgore, Robert A.

1966-01-01

This paper presents some of the technical aspects in the development at the Langley Research Center of an air-cove, dual-wound, single-coil, magnetic-suspension system with one-dimensional control. Overall electrical system design features and techniques are discussed in addition to the problems of control and stability. Special treatment is given to the operation of a dual-wound, high-current support coil which provides the bias fields and superimposed modulated field. Other designs features include a six-phase, solid-state power stage for modulation of the relatively large magnitude control current, and an associated six-phase trigger circuit.

Precision rectifier detectors for ac resistance bridge measurements with application to temperature control systems for irradiation creep experiments

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

Duncan, M. G.

The suitability of several temperature measurement schemes for an irradiation creep experiment is examined. It is found that the specimen resistance can be used to measure and control the sample temperature if compensated for resistance drift due to radiation and annealing effects. A modified Kelvin bridge is presented that allows compensation for resistance drift by periodically checking the sample resistance at a controlled ambient temperature. A new phase-insensitive method for detecting the bridge error signals is presented. The phase-insensitive detector is formed by averaging the magnitude of two bridge voltages. Although this method is substantially less sensitive to stray reactancesmore » in the bridge than conventional phase-sensitive detectors, it is sensitive to gain stability and linearity of the rectifier circuits. Accuracy limitations of rectifier circuits are examined both theoretically and experimentally in great detail. Both hand analyses and computer simulations of rectifier errors are presented. Finally, the design of a temperature control system based on sample resistance measurement is presented. The prototype is shown to control a 316 stainless steel sample to within a 0.15/sup 0/C short term (10 sec) and a 0.03/sup 0/C long term (10 min) standard deviation at temperatures between 150 and 700/sup 0/C. The phase-insensitive detector typically contributes less than 10 ppM peak resistance measurement error (0.04/sup 0/C at 700/sup 0/C for 316 stainless steel or 0.005/sup 0/C at 150/sup 0/C for zirconium).« less

30 CFR 75.825 - Power centers.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., and be designed and installed as follows: (1) Rated for the maximum phase-to-phase voltage of the circuit; (2) Rated for the full-load current of the circuit that is supplied power through the device. (3... current of the circuit or causes the current to be interrupted automatically before the disconnecting...

A 2-to-48-MHz Phase-Locked Loop

NASA Technical Reports Server (NTRS)

Koudelka, Robert D.

2004-01-01

A 2-to-48-MHz phase-locked loop (PLL), developed for the U.S. space program, meets or exceeds all space shuttle clock electrical interface requirements by taking as its reference a 2-to-48-MHz clock signal and outputting a phaselocked clock signal set at the same frequency as the reference clock with transistor- transistor logic (TTL) voltage levels. Because it is more adaptable than other PLLs, the new PLL can be used in industries that employ signaling devices and as a tool in future space missions. A conventional PLL consists of a phase/frequency detector, loop filter, and voltage-controlled oscillator in which each component exists individually and is integrated into a single device. PLL components phase-lock to a single frequency or to a narrow bandwidth of frequencies. It is this design, however, that prohibits them from maintaining phase lock to a dynamically changing reference clock when a large bandwidth is required a deficiency the new PLL overcomes. Since most PLL components require their voltage-controlled oscillators to operate at greater than 2-MHz frequencies, conventional PLLs often cannot achieve the low-frequency phase lock allowed by the new PLL. The 2-to-48-MHz PLL is built on a wire-wrap board with pins wired to three position jumpers; this makes changing configurations easy. It responds to variations in voltage-controlled oscillator (VCO) ranges, duty cycle, signal-to-noise ratio (SNR), amplitude, and jitter, exceeding design specifications. A consensus state machine, implemented in a VCO range detector which assures the PLL continues to operate in the correct range, is the primary control state machine for the 2-to-48-MHz PLL circuit. By using seven overlapping frequency ranges with hysteresis, the PLL output sets the resulting phase-locked clock signal at a frequency that agrees with the reference clock with TTL voltage levels. As a space-shuttle tool, the new PLL circuit takes the noisy, degraded reference clock signals as input and outputs phase-locked clock signals of the same frequency but with a corrected wave shape. Since its configuration circuit can be easily changed, the new PLL can do the following: readily respond to variations in VCO ranges, duty cycle, SNR, amplitude, and jitter; continuously operate in the correct VCO range because of its consensus state machine; and use its range detector implements to overlap seven frequency ranges with hysteresis, thus giving the current design a flexibility that exceeds anything available at the time of this development. These features will benefit any industry in which safe and timely clock signals are vital to operation.

A Phase-Locked Loop Epilepsy Network Emulator

PubMed Central

Watson, P.D.; Horecka, K. M.; Cohen, N.J.; Ratnam, R.

2015-01-01

Most seizure forecasting employs statistical learning techniques that lack a representation of the network interactions that give rise to seizures. We present an epilepsy network emulator (ENE) that uses a network of interconnected phase-locked loops (PLLs) to model synchronous, circuit-level oscillations between electrocorticography (ECoG) electrodes. Using ECoG data from a canine-epilepsy model (Davis et al. 2011) and a physiological entropy measure (approximate entropy or ApEn, Pincus 1995), we demonstrate the entropy of the emulator phases increases dramatically during ictal periods across all ECoG recording sites and across all animals in the sample. Further, this increase precedes the observable voltage spikes that characterize seizure activity in the ECoG data. These results suggest that the ENE is sensitive to phase-domain information in the neural circuits measured by ECoG and that an increase in the entropy of this measure coincides with increasing likelihood of seizure activity. Understanding this unpredictable phase-domain electrical activity present in ECoG recordings may provide a target for seizure detection and feedback control. PMID:26664133

Exploring the quantum critical behaviour in a driven Tavis–Cummings circuit

PubMed Central

Feng, M.; Zhong, Y.P.; Liu, T.; Yan, L.L.; Yang, W.L.; Twamley, J.; Wang, H.

2015-01-01

Quantum phase transitions play an important role in many-body systems and have been a research focus in conventional condensed-matter physics over the past few decades. Artificial atoms, such as superconducting qubits that can be individually manipulated, provide a new paradigm of realising and exploring quantum phase transitions by engineering an on-chip quantum simulator. Here we demonstrate experimentally the quantum critical behaviour in a highly controllable superconducting circuit, consisting of four qubits coupled to a common resonator mode. By off-resonantly driving the system to renormalize the critical spin-field coupling strength, we have observed a four-qubit nonequilibrium quantum phase transition in a dynamical manner; that is, we sweep the critical coupling strength over time and monitor the four-qubit scaled moments for a signature of a structural change of the system's eigenstates. Our observation of the nonequilibrium quantum phase transition, which is in good agreement with the driven Tavis–Cummings theory under decoherence, offers new experimental approaches towards exploring quantum phase transition-related science, such as scaling behaviours, parity breaking and long-range quantum correlations. PMID:25971985

PWM Inverter control and the application thereof within electric vehicles

DOEpatents

Geppert, Steven

1982-01-01

An inverter (34) which provides power to an A.C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A.C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A.C. machine is optimized. The control circuit includes a micro-computer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). In its preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack (32) and a three-phase induction motor (18).

Method for Fabricating and Packaging an M.Times.N Phased-Array Antenna

NASA Technical Reports Server (NTRS)

Xu, Xiaochuan (Inventor); Chen, Yihong (Inventor); Chen, Ray T. (Inventor); Subbaraman, Harish (Inventor)

2017-01-01

A method for fabricating an M.times.N, P-bit phased-array antenna on a flexible substrate is disclosed. The method comprising ink jet printing and hardening alignment marks, antenna elements, transmission lines, switches, an RF coupler, and multilayer interconnections onto the flexible substrate. The substrate of the M.times.N, P-bit phased-array antenna may comprise an integrated control circuit of printed electronic components such as, photovoltaic cells, batteries, resistors, capacitors, etc. Other embodiments are described and claimed.

Implementation of adiabatic geometric gates with superconducting phase qubits.

PubMed

Peng, Z H; Chu, H F; Wang, Z D; Zheng, D N

2009-01-28

We present an adiabatic geometric quantum computation strategy based on the non-degenerate energy eigenstates in (but not limited to) superconducting phase qubit systems. The fidelity of the designed quantum gate was evaluated in the presence of simulated thermal fluctuations in a superconducting phase qubits circuit and was found to be quite robust against random errors. In addition, it was elucidated that the Berry phase in the designed adiabatic evolution may be detected directly via the quantum state tomography developed for superconducting qubits. We also analyze the effects of control parameter fluctuations on the experimental detection of the Berry phase.

30 CFR 77.800 - High-voltage circuits; circuit breakers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... devices to provide protection against under voltage, grounded phase, short circuit and overcurrent. High... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High...

Neural Networks For Demodulation Of Phase-Modulated Signals

NASA Technical Reports Server (NTRS)

Altes, Richard A.

1995-01-01

Hopfield neural networks proposed for demodulating quadrature phase-shift-keyed (QPSK) signals carrying digital information. Networks solve nonlinear integral equations prior demodulation circuits cannot solve. Consists of set of N operational amplifiers connected in parallel, with weighted feedback from output terminal of each amplifier to input terminals of other amplifiers. Used to solve signal processing problems. Implemented as analog very-large-scale integrated circuit that achieves rapid convergence. Alternatively, implemented as digital simulation of such circuit. Also used to improve phase estimation performance over that of phase-locked loop.

Ultrasonic phased array controller for hyperthermia applications.

PubMed

Benkeser, P J; Pao, T L; Yoon, Y J

1991-01-01

Multiple and mechanically scanned ultrasound transducer systems have demonstrated the efficacy of using ultrasound to produce deep localized hyperthermia. The use of ultrasonic phased arrays has been proposed as an alternative to these systems. A phased array offers a more flexible approach to heating tumours in that the size, shape, and position of its focal region can be altered during the course of treatment in order to achieve the desired temperature distribution. This added flexibility comes at the cost of increased complexity of the hardware necessary to drive the transducer because each element requires its own amplifer with both phase and amplitude control. In order for phased arrays with large numbers of elements to be feasible for hyperthermia applications, the complexity of this circuitry must be minimized. This paper describes a circuit design which simplifies the electronics required to control a phased array transducer system for hyperthermia applications. The design is capable of controlling virtually any type of phased array transducer operating at frequencies less than 2 MHz. The system performance was verified through beam profile measurements using a 48-element tapered phased array transducer.

PULSE SYNTHESIZING GENERATOR

DOEpatents

Kerns, Q.A.

1963-08-01

>An electronlc circuit for synthesizing electrical current pulses having very fast rise times includes several sinewave generators tuned to progressively higher harmonic frequencies with signal amplitudes and phases selectable according to the Fourier series of the waveform that is to be synthesized. Phase control is provided by periodically triggering the generators at precisely controlled times. The outputs of the generators are combined in a coaxial transmission line. Any frequency-dependent delays that occur in the transmission line can be readily compensated for so that the desired signal wave shape is obtained at the output of the line. (AEC)

High stability buffered phase comparator

NASA Technical Reports Server (NTRS)

Adams, W. A.; Reinhardt, V. S. (Inventor)

1984-01-01

A low noise RF signal phase comparator comprised of two high stability driver buffer amplifiers driving a double balanced mixer which operate to generate a beat frequency between the two RF input signals coupled to the amplifiers from the RF sources is described. The beat frequency output from the mixer is applied to a low noise zero crossing detector which is the phase difference between the two RF inputs. Temperature stability is provided by mounting the amplifiers and mixer on a common circuit board with the active circuit elements located on one side of a circuit board and the passive circuit elements located on the opposite side. A common heat sink is located adjacent the circuit board. The active circuit elements are embedded into the bores of the heat sink which slows the effect of ambient temperature changes and reduces the temperature gradients between the active circuit elements, thus improving the cancellation of temperature effects. The two amplifiers include individual voltage regulators, which increases RF isolation.

A Role of Phase-Resetting in Coordinating Large Scale Neural Networks During Attention and Goal-Directed Behavior

PubMed Central

Voloh, Benjamin; Womelsdorf, Thilo

2016-01-01

Short periods of oscillatory activation are ubiquitous signatures of neural circuits. A broad range of studies documents not only their circuit origins, but also a fundamental role for oscillatory activity in coordinating information transfer during goal directed behavior. Recent studies suggest that resetting the phase of ongoing oscillatory activity to endogenous or exogenous cues facilitates coordinated information transfer within circuits and between distributed brain areas. Here, we review evidence that pinpoints phase resetting as a critical marker of dynamic state changes of functional networks. Phase resets: (1) set a “neural context” in terms of narrow band frequencies that uniquely characterizes the activated circuits; (2) impose coherent low frequency phases to which high frequency activations can synchronize, identifiable as cross-frequency correlations across large anatomical distances; (3) are critical for neural coding models that depend on phase, increasing the informational content of neural representations; and (4) likely originate from the dynamics of canonical E-I circuits that are anatomically ubiquitous. These multiple signatures of phase resets are directly linked to enhanced information transfer and behavioral success. We survey how phase resets re-organize oscillations in diverse task contexts, including sensory perception, attentional stimulus selection, cross-modal integration, Pavlovian conditioning, and spatial navigation. The evidence we consider suggests that phase-resets can drive changes in neural excitability, ensemble organization, functional networks, and ultimately, overt behavior. PMID:27013986

Monolithic microwave integrated circuits for sensors, radar, and communications systems; Proceedings of the Meeting, Orlando, FL, Apr. 2-4, 1991

NASA Technical Reports Server (NTRS)

Leonard, Regis F. (Editor); Bhasin, Kul B. (Editor)

1991-01-01

Consideration is given to MMICs for airborne phased arrays, monolithic GaAs integrated circuit millimeter wave imaging sensors, accurate design of multiport low-noise MMICs up to 20 GHz, an ultralinear low-noise amplifier technology for space communications, variable-gain MMIC module for space applications, a high-efficiency dual-band power amplifier for radar applications, a high-density circuit approach for low-cost MMIC circuits, coplanar SIMMWIC circuits, recent advances in monolithic phased arrays, and system-level integrated circuit development for phased-array antenna applications. Consideration is also given to performance enhancement in future communications satellites with MMIC technology insertion, application of Ka-band MMIC technology for an Orbiter/ACTS communications experiment, a space-based millimeter wave debris tracking radar, low-noise high-yield octave-band feedback amplifiers to 20 GHz, quasi-optical MESFET VCOs, and a high-dynamic-range mixer using novel balun structure.

Quantum phases in circuit QED with a superconducting qubit array

PubMed Central

Zhang, Yuanwei; Yu, Lixian; Liang, J. -Q; Chen, Gang; Jia, Suotang; Nori, Franco

2014-01-01

Circuit QED on a chip has become a powerful platform for simulating complex many-body physics. In this report, we realize a Dicke-Ising model with an antiferromagnetic nearest-neighbor spin-spin interaction in circuit QED with a superconducting qubit array. We show that this system exhibits a competition between the collective spin-photon interaction and the antiferromagnetic nearest-neighbor spin-spin interaction, and then predict four quantum phases, including: a paramagnetic normal phase, an antiferromagnetic normal phase, a paramagnetic superradiant phase, and an antiferromagnetic superradiant phase. The antiferromagnetic normal phase and the antiferromagnetic superradiant phase are new phases in many-body quantum optics. In the antiferromagnetic superradiant phase, both the antiferromagnetic and superradiant orders can coexist, and thus the system possesses symmetry. Moreover, we find an unconventional photon signature in this phase. In future experiments, these predicted quantum phases could be distinguished by detecting both the mean-photon number and the magnetization. PMID:24522250

Constant-current control method of multi-function electromagnetic transmitter.

PubMed

Xue, Kaichang; Zhou, Fengdao; Wang, Shuang; Lin, Jun

2015-02-01

Based on the requirements of controlled source audio-frequency magnetotelluric, DC resistivity, and induced polarization, a constant-current control method is proposed. Using the required current waveforms in prospecting as a standard, the causes of current waveform distortion and current waveform distortion's effects on prospecting are analyzed. A cascaded topology is adopted to achieve 40 kW constant-current transmitter. The responsive speed and precision are analyzed. According to the power circuit of the transmitting system, the circuit structure of the pulse width modulation (PWM) constant-current controller is designed. After establishing the power circuit model of the transmitting system and the PWM constant-current controller model, analyzing the influence of ripple current, and designing an open-loop transfer function according to the amplitude-frequency characteristic curves, the parameters of the PWM constant-current controller are determined. The open-loop transfer function indicates that the loop gain is no less than 28 dB below 160 Hz, which assures the responsive speed of the transmitting system; the phase margin is 45°, which assures the stabilization of the transmitting system. Experimental results verify that the proposed constant-current control method can keep the control error below 4% and can effectively suppress load change caused by the capacitance of earth load.

Constant-current control method of multi-function electromagnetic transmitter

NASA Astrophysics Data System (ADS)

Xue, Kaichang; Zhou, Fengdao; Wang, Shuang; Lin, Jun

2015-02-01

Based on the requirements of controlled source audio-frequency magnetotelluric, DC resistivity, and induced polarization, a constant-current control method is proposed. Using the required current waveforms in prospecting as a standard, the causes of current waveform distortion and current waveform distortion's effects on prospecting are analyzed. A cascaded topology is adopted to achieve 40 kW constant-current transmitter. The responsive speed and precision are analyzed. According to the power circuit of the transmitting system, the circuit structure of the pulse width modulation (PWM) constant-current controller is designed. After establishing the power circuit model of the transmitting system and the PWM constant-current controller model, analyzing the influence of ripple current, and designing an open-loop transfer function according to the amplitude-frequency characteristic curves, the parameters of the PWM constant-current controller are determined. The open-loop transfer function indicates that the loop gain is no less than 28 dB below 160 Hz, which assures the responsive speed of the transmitting system; the phase margin is 45°, which assures the stabilization of the transmitting system. Experimental results verify that the proposed constant-current control method can keep the control error below 4% and can effectively suppress load change caused by the capacitance of earth load.

A Low Power Low Phase Noise Oscillator for MICS Transceivers

PubMed Central

Li, Dawei; Liu, Dongsheng; Kang, Chaojian; Zou, Xuecheng

2017-01-01

A low-power, low-phase-noise quadrature oscillator for Medical Implantable Communications Service (MICS) transceivers is presented. The proposed quadrature oscillator generates 349~689 MHz I/Q (In-phase and Quadrature) signals covering the MICS band. The oscillator is based on a differential pair with positive feedback. Each delay cell consists of a few transistors enabling lower voltage operation. Since the oscillator is very sensitive to disturbances in the supply voltage and ground, a self-bias circuit for isolating the voltage disturbance is proposed to achieve bias voltages which can track the disturbances from the supply and ground. The oscillation frequency, which is controlled by the bias voltages, is less sensitive to the supply and ground noise, and a low phase noise is achieved. The chip is fabricated in the UMC (United Microelectronics Corporation) 0.18 μm CMOS (Complementary Metal Oxide Semiconductor) process; the core just occupies a 28.5 × 22 μm2 area. The measured phase noise is −108.45 dBc/Hz at a 1 MHz offset with a center frequency of 540 MHz. The gain of the oscillator is 0.309 MHz/mV with a control voltage from 0 V to 1.1 V. The circuit can work with a supply voltage as low as 1.2 V and the power consumption is only 0.46 mW at a 1.8 V supply voltage. PMID:28085107

A Low Power Low Phase Noise Oscillator for MICS Transceivers.

PubMed

Li, Dawei; Liu, Dongsheng; Kang, Chaojian; Zou, Xuecheng

2017-01-12

A low-power, low-phase-noise quadrature oscillator for Medical Implantable Communications Service (MICS) transceivers is presented. The proposed quadrature oscillator generates 349~689 MHz I/Q (In-phase and Quadrature) signals covering the MICS band. The oscillator is based on a differential pair with positive feedback. Each delay cell consists of a few transistors enabling lower voltage operation. Since the oscillator is very sensitive to disturbances in the supply voltage and ground, a self-bias circuit for isolating the voltage disturbance is proposed to achieve bias voltages which can track the disturbances from the supply and ground. The oscillation frequency, which is controlled by the bias voltages, is less sensitive to the supply and ground noise, and a low phase noise is achieved. The chip is fabricated in the UMC (United Microelectronics Corporation) 0.18 μm CMOS (Complementary Metal Oxide Semiconductor) process; the core just occupies a 28.5 × 22 μm² area. The measured phase noise is -108.45 dBc/Hz at a 1 MHz offset with a center frequency of 540 MHz. The gain of the oscillator is 0.309 MHz/mV with a control voltage from 0 V to 1.1 V. The circuit can work with a supply voltage as low as 1.2 V and the power consumption is only 0.46 mW at a 1.8 V supply voltage.

Performance of a 300 Mbps 1:16 serial/parallel optoelectronic receiver module

NASA Technical Reports Server (NTRS)

Richard, M. A.; Claspy, P. C.; Bhasin, K. B.; Bendett, M. B.

1990-01-01

Optical interconnects are being considered for the high speed distribution of multiplexed control signals in GaAs monolithic microwave integrated circuit (MMIC) based phased array antennas. The performance of a hybrid GaAs optoelectronic integrated circuit (OEIC) is described, as well as its design and fabrication. The OEIC converts a 16-bit serial optical input to a 16 parallel line electrical output using an on-board 1:16 demultiplexer and operates at data rates as high as 30b Mbps. The performance characteristics and potential applications of the device are presented.

Differential regulation of polarized synaptic vesicle trafficking and synapse stability in neural circuit rewiring in Caenorhabditis elegans

PubMed Central

Kurup, Naina; Kono, Karina

2017-01-01

Neural circuits are dynamic, with activity-dependent changes in synapse density and connectivity peaking during different phases of animal development. In C. elegans, young larvae form mature motor circuits through a dramatic switch in GABAergic neuron connectivity, by concomitant elimination of existing synapses and formation of new synapses that are maintained throughout adulthood. We have previously shown that an increase in microtubule dynamics during motor circuit rewiring facilitates new synapse formation. Here, we further investigate cellular control of circuit rewiring through the analysis of mutants obtained in a forward genetic screen. Using live imaging, we characterize novel mutations that alter cargo binding in the dynein motor complex and enhance anterograde synaptic vesicle movement during remodeling, providing in vivo evidence for the tug-of-war between kinesin and dynein in fast axonal transport. We also find that a casein kinase homolog, TTBK-3, inhibits stabilization of nascent synapses in their new locations, a previously unexplored facet of structural plasticity of synapses. Our study delineates temporally distinct signaling pathways that are required for effective neural circuit refinement. PMID:28636662

A design procedure for the phase-controlled parallel-loaded resonant inverter

NASA Technical Reports Server (NTRS)

King, Roger J.

1989-01-01

High-frequency-link power conversion and distribution based on a resonant inverter (RI) has been recently proposed. The design of several topologies is reviewed, and a simple approximate design procedure is developed for the phase-controlled parallel-loaded RI. This design procedure seeks to ensure the benefits of resonant conversion and is verified by data from a laboratory 2.5 kVA, 20-kHz converter. A simple phasor analysis is introduced as a useful approximation for design purposes. The load is considered to be a linear impedance (or an ac current sink). The design procedure is verified using a 2.5-kVA 20-kHz RI. Also obtained are predictable worst-case ratings for each component of the resonant tank circuit and the inverter switches. For a given load VA requirement, below-resonance operation is found to result in a significantly lower tank VA requirement. Under transient conditions such as load short-circuit, a reversal of the expected commutation sequence is possible.

Catheter associated urinary tract infection (CA-UTI) incidence in an Internal Medicine Ward of a Northern Italian Hospital.

PubMed

Izzo, Ilaria; Lania, Donatella; Bella, Daniele; Formaini Marioni, Cesare; Coccaglio, Romana; Colombini, Paolo

2015-09-01

Catheter-associated urinary tract infections (CA-UTI) are estimated to be the most frequent nosocomial infections (40%). A catheter is introduced to 10-25% of inpatients, and is often left on site for a long period of time. We carried out a prospective study on inpatients of our Internal Medicine ward to assess the incidence of CA-UTI under the implementation of corrective action. All inpatients who underwent introduction of a urinary catheter upon or after admission to our ward were included in the study. Patients with bacteriuria or positive urine culture before catheterization, others with less than 24 hours catheterism, or bearing a catheter on admission were all excluded from the study. CA-UTI diagnosis was assessed on the basis of CDC 2009 guidelines. The investigation was held between June 2010 and March 2013 in five steps or phases. In the first phase open circuit drainage catheterism was used, in the second phase close circuit drainage catheterism was introduced, while in the third phase disposable lubrification was added to closed circuit drainage catheterism. In the next step (phase 4) we introduced number of days of catheterism control and nurse training; in the last phase (5) emptying urine collection bags on a container was added. In phase 1 we estimated six UTIs out of 18 patients (incidence 33%), in phase 2 we had four infections out of 10 patients (40%). Given the results, we had to reflect on the quality of the procedures of catheter positioning and management . Where feasible, we improved technical practices and during follow-up there was evidence of CA-UTI in 10 patients over 25 (phase 3, 40%), and eight infections over 25 (phase 4, 32%). Once all these steps had been implemented, in phase 5 we determined a sharp reduction in CA-UTI (2 patients over 27, or 7.5%, p=0.025). This improvement was particularly evident in the rate of infection per days of catheter, which was reduced from 43.4/1000 to 13.6/1000. Although the statistical power of the present study has its limitations, we attained a significant reduction in catheter-associated UTIs through the implementation of close circuit catheterism and improvements in care practices.

Electromagnetic phenomena analysis in brushless DC motor with speed control using PWM method

NASA Astrophysics Data System (ADS)

Ciurys, Marek Pawel

2017-12-01

Field-circuit model of a brushless DC motor with speed control using PWM method was developed. Waveforms of electrical and mechanical quantities of the designed motor with a high pressure vane pump built in a rotor of the motor were computed. Analysis of electromagnetic phenomena in the system: single phase AC network - converter - BLDC motor was carried out.

All optical controlled photonic integrated circuits using azo dye functionized sol-gel material

NASA Astrophysics Data System (ADS)

Ke, Xianjun

The main focus of this dissertation is development and characterization of all-optical controllable azo dye functionized sol gel material, demonstrating a PIC fabrication technique on glass substrate using such material, and exploration and feasibility demonstration of three PIC functional devices namely optical variable attenuator, optical switches, and optical tunable filters using the material. The realization of all the devices in this dissertation are based on one material: dye functionalized sol-gel material. A photochromic sol-gel material functionalized with azo dye was synthesized and characterized. It possesses a photochromic characteristic under the control of green laser beam illumination. The material characteristics suggest the possibility of a new promising material platform candidate for the fabrication of alloptical controlled photonic integrated circuits. As the first potential application of the dye functionalized sol-gel material, an alloptical variable attenuator was designed and demonstrated. The optical variable attenuation is achieved in Mach-Zehnder interferometric configuration through all-optical modulation of sol-gel waveguide phase shifters. A 2 x 2 optical switch based on multimode interference (MMI) waveguide structure is proposed in the dissertation. The schematic configuration of the optical switch consists of a cascade of two identical MMIs with two all-optical controlled phase shifters realized by using the photochromic sol-gel material. The cross or bar switch state of the optical switch is determined by the phase difference between the two sol-gel waveguide phase shifters. An all-optical tunable filter is designed and its feasibility demonstrated by using the sol-gel photochromic material. Except for the phase change demonstrated on sol-gel waveguide phase shifters, dynamic gratings were observed on sol-gel film when exposed to two interference beams. This reveals the possibility of realizing Bragg grating-based tunable filters. The schematic configuration of proposed tunable filters consists of a single straight waveguide embedded with a sol-gel waveguide. The wavelength tuning of the tunable filters is accomplished by varying the grating period.

Quantum circuit dynamics via path integrals: Is there a classical action for discrete-time paths?

NASA Astrophysics Data System (ADS)

Penney, Mark D.; Enshan Koh, Dax; Spekkens, Robert W.

2017-07-01

It is straightforward to compute the transition amplitudes of a quantum circuit using the sum-over-paths methodology when the gates in the circuit are balanced, where a balanced gate is one for which all non-zero transition amplitudes are of equal magnitude. Here we consider the question of whether, for such circuits, the relative phases of different discrete-time paths through the configuration space can be defined in terms of a classical action, as they are for continuous-time paths. We show how to do so for certain kinds of quantum circuits, namely, Clifford circuits where the elementary systems are continuous-variable systems or discrete systems of odd-prime dimension. These types of circuit are distinguished by having phase-space representations that serve to define their classical counterparts. For discrete systems, the phase-space coordinates are also discrete variables. We show that for each gate in the generating set, one can associate a symplectomorphism on the phase-space and to each of these one can associate a generating function, defined on two copies of the configuration space. For discrete systems, the latter association is achieved using tools from algebraic geometry. Finally, we show that if the action functional for a discrete-time path through a sequence of gates is defined using the sum of the corresponding generating functions, then it yields the correct relative phases for the path-sum expression. These results are likely to be relevant for quantizing physical theories where time is fundamentally discrete, characterizing the classical limit of discrete-time quantum dynamics, and proving complexity results for quantum circuits.

Development of an X-Band 50 MW Multiple Beam Klystron

NASA Astrophysics Data System (ADS)

Song, Liqun; Ferguson, Patrick; Ives, R. Lawrence; Miram, George; Marsden, David; Mizuhara, Max

2003-12-01

Calabazas Creek Research, Inc. is developing an X-band 50 MW multiple beam klystron (MBK) on a DOE SBIR Phase II grant. The electrical design and preliminary mechanical design were completed on the Phase I. This MBK consists of eight discrete klystron circuits driven by eight electron beams located symmetrically on a circle with a radius of 6.3 cm. Each beam operates at 190 kV and 66 A. The eight beam electron gun is in development on a DOE SBIR Phase II grant. Each circuit consists of an input cavity, two gain cavities, three penultimate cavities, and a three cavity output circuit operating in the PI/2 mode. Ring resonators were initially proposed for the complete circuit; however, low beam — wave interaction resulted in the necessity to use discrete cavities for all eight circuits. The input cavities are coupled via hybrid waveguides to ensure constant drive power amplitude and phase. The output circuits can either be combined using compact waveguide twists driving a TE01 high power window or combined into a TM04 mode converter driving the same TE01 window. The gain and efficiency for a single circuit has been optimized using KLSC, a 2 1/2D large signal klystron code. Simulations for a single circuit predict an efficiency of 53% for a single output cavity and 55% for the three cavity output resonator. The total RF output power for this MBK is 55 MW. During the Phase II emphasis will be given to cost reduction techniques resulting in a robust — high efficient — long life high power amplifier.

Growth phase-dependent control of R27 conjugation is mediated by the interplay between the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA and the cAMP regulon.

PubMed

Gibert, Marta; Paytubi, Sonia; Beltrán, Sergi; Juárez, Antonio; Balsalobre, Carlos; Madrid, Cristina

2016-12-01

Plasmids of the incompatibility group HI1 (IncHI1) have been isolated from several Gram-negative pathogens and are associated with the spread of multidrug resistance. Their conjugation is tightly regulated and it is inhibited at temperatures higher than 30°C, indicating that conjugation occurs outside warm-blooded hosts. Using R27, the prototype of IncHI1 plasmids, we report that plasmid transfer efficiency in E. coli strongly depends on the physiological state of the donor cells. Conjugation frequency is high when cells are actively growing, dropping sharply when cells enter the stationary phase of growth. Accordingly, our transcriptomic assays show significant downregulation of numerous R27 genes during the stationary phase, including several tra (transfer) genes. Growth phase-dependent regulation of tra genes transcription is independent of H-NS, a silencer of horizontal gene transfer, and ppGpp and RpoS, regulators of the stationary phase, but highly dependent on the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA. The metabolic sensor cAMP, whose synthesis is chromosomally encoded, is also involved in the growth phase regulation of R27 conjugation by modulating htdA expression. Our data suggest that the involvement of regulators encoded by both chromosome and plasmid are required for efficient physiological control of IncHI1 plasmid conjugation. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Analytical design equations for self-tuned Class-E power amplifier.

PubMed

Hu, Zhe; Troyk, Philip

2011-01-01

For many emerging neural prosthesis designs that are powered by inductive coupling, their small physical size requires large current in the extracorporeal transmitter coil, and the Class-E power amplifier topology is often used for the transmitter design. Tuning of Class-E circuits for efficient operation is difficult and a self-tuned circuit can facilitate the tuning. The coil current is sensed and used to tune the switching of the transistor switch in the Class-E circuit in order to maintain its high-efficiency operation. Although mathematically complex, the analysis and design procedure for the self-tuned Class-E circuit can be simplified due to the current feedback control, which makes the phase angle between the switching pulse and the coil current predetermined. In this paper explicit analytical design equations are derived and a detailed design procedure is presented and compared with the conventional Class-E design approaches.

An Electromagnetically Actuated Vacuum Circuit Breaker Developed by Electromagnetic Analysis Coupled with Motion

NASA Astrophysics Data System (ADS)

Takeuchi, Toshie; Nakagawa, Takafumi; Tsukima, Mitsuru; Koyama, Kenichi; Tohya, Nobumoto; Yano, Tomotaka

A new electromagnetically actuated vacuum circuit breaker (VCB) has been designed and developed on the basis of the transient electromagnetic analysis coupled with motion. The VCB has three advanced bi-stable electromagnetic actuators, which control each phase independently. The VCB serves as a synchronous circuit breaker as well as a standard circuit breaker. In this work, the flux delay due to the eddy current is analytically formulated using the delay time constant of the actuator coil current, thereby leading to accurate driving behavior. With this analytical method, the electromagnetic mechanism for a 24kV rated VCB has been optimized; and as a result, the driving energy is reduced to one fifth of that of a conventional VCB employing spring mechanism, and the number of parts is significantly decreased. Therefore, the developed VCB becomes compact, highly reliable and highly durable.

Development of a digital solar simulator based on full-bridge converter

NASA Astrophysics Data System (ADS)

Liu, Chen; Feng, Jian; Liu, Zhilong; Tong, Weichao; Ji, Yibo

2014-02-01

With the development of solar photovoltaic, distribution schemes utilized in power grid had been commonly application, and photovoltaic (PV) inverter is an essential equipment in grid. In this paper, a digital solar simulator based on full-bridge structure is presented. The output characteristic curve of system is electrically similar to silicon solar cells, which can greatly simplify research methods of PV inverter, improve the efficiency of research and development. The proposed simulator consists on a main control board based on TM320F28335, phase-shifted zero-voltage-switching (ZVS) DC-DC full-bridge converter and voltage and current sampling circuit, that allows emulating the voltage-current curve with the open-circuit voltage (Voc) of 900V and the short-circuit current (Isc) of 18A .When the system connected to a PV inverter, the inverter can quickly track from the open-circuit to the maximum power point and keep stability.

Focal plane infrared readout circuit with automatic background suppression

NASA Technical Reports Server (NTRS)

Pain, Bedabrata (Inventor); Yang, Guang (Inventor); Sun, Chao (Inventor); Shaw, Timothy J. (Inventor); Wrigley, Chris J. (Inventor)

2002-01-01

A circuit for reading out a signal from an infrared detector includes a current-mode background-signal subtracting circuit having a current memory which can be enabled to sample and store a dark level signal from the infrared detector during a calibration phase. The signal stored by the current memory is subtracted from a signal received from the infrared detector during an imaging phase. The circuit also includes a buffered direct injection input circuit and a differential voltage readout section. By performing most of the background signal estimation and subtraction in a current mode, a low gain can be provided by the buffered direct injection input circuit to keep the gain of the background signal relatively small, while a higher gain is provided by the differential voltage readout circuit. An array of such readout circuits can be used in an imager having an array of infrared detectors. The readout circuits can provide a high effective handling capacity.

Pneumatic oscillator circuits for timing and control of integrated microfluidics.

PubMed

Duncan, Philip N; Nguyen, Transon V; Hui, Elliot E

2013-11-05

Frequency references are fundamental to most digital systems, providing the basis for process synchronization, timing of outputs, and waveform synthesis. Recently, there has been growing interest in digital logic systems that are constructed out of microfluidics rather than electronics, as a possible means toward fully integrated laboratory-on-a-chip systems that do not require any external control apparatus. However, the full realization of this goal has not been possible due to the lack of on-chip frequency references, thus requiring timing signals to be provided from off-chip. Although microfluidic oscillators have been demonstrated, there have been no reported efforts to characterize, model, or optimize timing accuracy, which is the fundamental metric of a clock. Here, we report pneumatic ring oscillator circuits built from microfluidic valves and channels. Further, we present a compressible-flow analysis that differs fundamentally from conventional circuit theory, and we show the utility of this physically based model for the optimization of oscillator stability. Finally, we leverage microfluidic clocks to demonstrate circuits for the generation of phase-shifted waveforms, self-driving peristaltic pumps, and frequency division. Thus, pneumatic oscillators can serve as on-chip frequency references for microfluidic digital logic circuits. On-chip clocks and pumps both constitute critical building blocks on the path toward achieving autonomous laboratory-on-a-chip devices.

Integrated Cryogenic Electronics Testbed (ICE-T) for Evaluation of Superconductor and Cryo-Semiconductor Integrated Circuits

NASA Astrophysics Data System (ADS)

Dotsenko, V. V.; Sahu, A.; Chonigman, B.; Tang, J.; Lehmann, A. E.; Gupta, V.; Talalevskii, A.; Ruotolo, S.; Sarwana, S.; Webber, R. J.; Gupta, D.

2017-02-01

Research and development of cryogenic application-specific integrated circuits (ASICs), such as high-frequency (tens of GHz) semiconductor and superconductor mixed-signal circuits and large-scale (>10,000 Josephson Junctions) superconductor digital circuits, have long been hindered by the absence of specialized cryogenic test apparatus. During their iterative development phase, most ASICs require many additional input-output lines for applying independent bias controls, injecting test signals, and monitoring outputs of different sub-circuits. We are developing a full suite of modular test apparatus based on cryocoolers that do not consume liquid helium, and support extensive electrical interfaces to standard and custom test equipment. Our design separates the cryogenics from electrical connections, allowing even inexperienced users to conduct testing by simply mounting their ASIC on a removable electrical insert. Thermal connections between the cold stages and the inserts are made with robust thermal links. ICE-T accommodates two independent electrical inserts at the same time. We have designed various inserts, such as universal ones with all 40 or 80 coaxial cables and those with customized wiring and temperature-controlled stages. ICE-T features fast thermal cycling for rapid testing, enables detailed testing over long periods (days to months, if necessary), and even supports automated testing of digital ICs with modular additions.

Multichannel, Active Low-Pass Filters

NASA Technical Reports Server (NTRS)

Lev, James J.

1989-01-01

Multichannel integrated circuits cascaded to obtain matched characteristics. Gain and phase characteristics of channels of multichannel, multistage, active, low-pass filter matched by making filter of cascaded multichannel integrated-circuit operational amplifiers. Concept takes advantage of inherent equality of electrical characteristics of nominally-identical circuit elements made on same integrated-circuit chip. Characteristics of channels vary identically with changes in temperature. If additional matched channels needed, chips containing more than two operational amplifiers apiece (e.g., commercial quad operational amplifliers) used. Concept applicable to variety of equipment requiring matched gain and phase in multiple channels - radar, test instruments, communication circuits, and equipment for electronic countermeasures.

Resonance Frequency Readout Circuit for a 900 MHz SAW Device

PubMed Central

Liu, Heng; Zhang, Chun; Weng, Zhaoyang; Guo, Yanshu; Wang, Zhihua

2017-01-01

A monolithic resonance frequency readout circuit with high resolution and short measurement time is presented for a 900 MHz RF surface acoustic wave (SAW) sensor. The readout circuit is composed of a fractional-N phase-locked loop (PLL) as the stimulus source to the SAW device and a phase-based resonance frequency detecting circuit using successive approximation (SAR). A new resonance frequency searching strategy has been proposed based on the fact that the SAW device phase-frequency response crosses zero monotonically around the resonance frequency. A dedicated instant phase difference detecting circuit is adopted to facilitate the fast SAR operation for resonance frequency searching. The readout circuit has been implemented in 180 nm CMOS technology with a core area of 3.24 mm2. In the experiment, it works with a 900 MHz SAW resonator with a quality factor of Q = 130. Experimental results show that the readout circuit consumes 7 mW power from 1.6 V supply. The frequency resolution is 733 Hz, and the relative accuracy is 0.82 ppm, and it takes 0.48 ms to complete one measurement. Compared to the previous results in the literature, this work has achieved the shortest measurement time with a trade-off between measurement accuracy and measurement time. PMID:28914799

Resonance Frequency Readout Circuit for a 900 MHz SAW Device.

PubMed

Liu, Heng; Zhang, Chun; Weng, Zhaoyang; Guo, Yanshu; Wang, Zhihua

2017-09-15

A monolithic resonance frequency readout circuit with high resolution and short measurement time is presented for a 900 MHz RF surface acoustic wave (SAW) sensor. The readout circuit is composed of a fractional-N phase-locked loop (PLL) as the stimulus source to the SAW device and a phase-based resonance frequency detecting circuit using successive approximation (SAR). A new resonance frequency searching strategy has been proposed based on the fact that the SAW device phase-frequency response crosses zero monotonically around the resonance frequency. A dedicated instant phase difference detecting circuit is adopted to facilitate the fast SAR operation for resonance frequency searching. The readout circuit has been implemented in 180 nm CMOS technology with a core area of 3.24 mm². In the experiment, it works with a 900 MHz SAW resonator with a quality factor of Q = 130. Experimental results show that the readout circuit consumes 7 mW power from 1.6 V supply. The frequency resolution is 733 Hz, and the relative accuracy is 0.82 ppm, and it takes 0.48 ms to complete one measurement. Compared to the previous results in the literature, this work has achieved the shortest measurement time with a trade-off between measurement accuracy and measurement time.

Design of a digital multiradian phase detector and its application in fusion plasma interferometry.

PubMed

Mlynek, A; Schramm, G; Eixenberger, H; Sips, G; McCormick, K; Zilker, M; Behler, K; Eheberg, J

2010-03-01

We discuss the circuit design of a digital multiradian phase detector that measures the phase difference between two 10 kHz square wave TTL signals and provides the result as a binary number. The phase resolution of the circuit is 1/64 period and its dynamic range is 256 periods. This circuit has been developed for fusion plasma interferometry with submillimeter waves on the ASDEX Upgrade tokamak. The results from interferometric density measurement are discussed and compared to those obtained with the previously used phase detectors, especially with respect to the occurrence of phase jumps. It is illustrated that the new phase measurement provides a powerful tool for automatic real-time validation of the measured density, which is important for feedback algorithms that are sensitive to spurious density signals.

An Improved Model Predictive Current Controller of Switched Reluctance Machines Using Time-Multiplexed Current Sensor

PubMed Central

Li, Bingchu; Ling, Xiao; Huang, Yixiang; Gong, Liang; Liu, Chengliang

2017-01-01

This paper presents a fixed-switching-frequency model predictive current controller using multiplexed current sensor for switched reluctance machine (SRM) drives. The converter was modified to distinguish currents from simultaneously excited phases during the sampling period. The only current sensor installed in the converter was time division multiplexing for phase current sampling. During the commutation stage, the control steps of adjacent phases were shifted so that sampling time was staggered. The maximum and minimum duty ratio of pulse width modulation (PWM) was limited to keep enough sampling time for analog-to-digital (A/D) conversion. Current sensor multiplexing was realized without complex adjustment of either driver circuit nor control algorithms, while it helps to reduce the cost and errors introduced in current sampling due to inconsistency between sensors. The proposed controller is validated by both simulation and experimental results with a 1.5 kW three-phase 12/8 SRM. Satisfied current sampling is received with little difference compared with independent phase current sensors for each phase. The proposed controller tracks the reference current profile as accurately as the model predictive current controller with independent phase current sensors, while having minor tracking errors compared with a hysteresis current controller. PMID:28513554

Design and Development of an Engineering Prototype Compact X-Ray Scanner (FMS 5000)

DTIC Science & Technology

1989-03-31

machined by "wire-EDM" (electro discharge machining ). Three different slice thicknesses can be selected from the scan menu. The set of slice thicknesses...circuit. This type of circuit is used whenever more than ten kilowatts of power are needed by a machine . For example, lathes and milling machines in a... machine shop usually use this type of input power. A three- phase circuit delivers power more efficiently than a single-phase circuit because three

Holonomic Quantum Control with Continuous Variable Systems.

PubMed

Albert, Victor V; Shu, Chi; Krastanov, Stefan; Shen, Chao; Liu, Ren-Bao; Yang, Zhen-Biao; Schoelkopf, Robert J; Mirrahimi, Mazyar; Devoret, Michel H; Jiang, Liang

2016-04-08

Universal computation of a quantum system consisting of superpositions of well-separated coherent states of multiple harmonic oscillators can be achieved by three families of adiabatic holonomic gates. The first gate consists of moving a coherent state around a closed path in phase space, resulting in a relative Berry phase between that state and the other states. The second gate consists of "colliding" two coherent states of the same oscillator, resulting in coherent population transfer between them. The third gate is an effective controlled-phase gate on coherent states of two different oscillators. Such gates should be realizable via reservoir engineering of systems that support tunable nonlinearities, such as trapped ions and circuit QED.

Distribution system model calibration with big data from AMI and PV inverters

DOE PAGES

Peppanen, Jouni; Reno, Matthew J.; Broderick, Robert J.; ...

2016-03-03

Efficient management and coordination of distributed energy resources with advanced automation schemes requires accurate distribution system modeling and monitoring. Big data from smart meters and photovoltaic (PV) micro-inverters can be leveraged to calibrate existing utility models. This paper presents computationally efficient distribution system parameter estimation algorithms to improve the accuracy of existing utility feeder radial secondary circuit model parameters. The method is demonstrated using a real utility feeder model with advanced metering infrastructure (AMI) and PV micro-inverters, along with alternative parameter estimation approaches that can be used to improve secondary circuit models when limited measurement data is available. Lastly, themore » parameter estimation accuracy is demonstrated for both a three-phase test circuit with typical secondary circuit topologies and single-phase secondary circuits in a real mixed-phase test system.« less

Distribution system model calibration with big data from AMI and PV inverters

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

Peppanen, Jouni; Reno, Matthew J.; Broderick, Robert J.

Efficient management and coordination of distributed energy resources with advanced automation schemes requires accurate distribution system modeling and monitoring. Big data from smart meters and photovoltaic (PV) micro-inverters can be leveraged to calibrate existing utility models. This paper presents computationally efficient distribution system parameter estimation algorithms to improve the accuracy of existing utility feeder radial secondary circuit model parameters. The method is demonstrated using a real utility feeder model with advanced metering infrastructure (AMI) and PV micro-inverters, along with alternative parameter estimation approaches that can be used to improve secondary circuit models when limited measurement data is available. Lastly, themore » parameter estimation accuracy is demonstrated for both a three-phase test circuit with typical secondary circuit topologies and single-phase secondary circuits in a real mixed-phase test system.« less

The relative phases of basal ganglia activities dynamically shape effective connectivity in Parkinson's disease.

PubMed

Cagnan, Hayriye; Duff, Eugene Paul; Brown, Peter

2015-06-01

Optimal phase alignment between oscillatory neural circuits is hypothesized to optimize information flow and enhance system performance. This theory is known as communication-through-coherence. The basal ganglia motor circuit exhibits exaggerated oscillatory and coherent activity patterns in Parkinson's disease. Such activity patterns are linked to compromised motor system performance as evinced by bradykinesia, rigidity and tremor, suggesting that network function might actually deteriorate once a certain level of net synchrony is exceeded in the motor circuit. Here, we characterize the processes underscoring excessive synchronization and its termination. To this end, we analysed local field potential recordings from the subthalamic nucleus and globus pallidus of five patients with Parkinson's disease (four male and one female, aged 37-64 years). We observed that certain phase alignments between subthalamic nucleus and globus pallidus amplified local neural synchrony in the beta frequency band while others either suppressed it or did not induce any significant change with respect to surrogates. The increase in local beta synchrony directly correlated with how long the two nuclei locked to beta-amplifying phase alignments. Crucially, administration of the dopamine prodrug, levodopa, reduced the frequency and duration of periods during which subthalamic and pallidal populations were phase-locked to beta-amplifying alignments. Conversely ON dopamine, the total duration over which subthalamic and pallidal populations were aligned to phases that left beta-amplitude unchanged with respect to surrogates increased. Thus dopaminergic input shifted circuit dynamics from persistent periods of locking to amplifying phase alignments, associated with compromised motoric function, to more dynamic phase alignment and improved motoric function. This effect of dopamine on local circuit resonance suggests means by which novel electrical interventions might prevent resonance-related pathological circuit interactions. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain.

JEN-1 Reactor Control System; SISTEMA DE CONTROL DEL REACTOR JEN-1

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

Cantillo, M.F.; Nuno, C.M.; Andreu, J.L.M.

1963-01-01

ABS>The JEN-1 3Mw power swimming pool reactor electrical control circuits are described. Start-up, power generation in the core, and shutdown are controlled by the reactor control system. This control system guarantees in each moment the safety conditions during reactor operation. Each circuit was represented by a scheme, complemented with a description of its function, components, and operation theory. Components described include: scram circuit; fission counter control circuit; servo control circuit; control circuit of safety sheets; control circuits of primary, secondary, and clean-up pump motors and tower fan motor; primary valve motor circuit; center cubicle alarm circuit; and process alarm circuit.more » (auth)« less

Generalized non-reciprocity in an optomechanical circuit via synthetic magnetism and reservoir engineering

NASA Astrophysics Data System (ADS)

Fang, Kejie; Luo, Jie; Metelmann, Anja; Matheny, Matthew H.; Marquardt, Florian; Clerk, Aashish A.; Painter, Oskar

2017-01-01

Synthetic magnetism has been used to control charge neutral excitations for applications ranging from classical beam steering to quantum simulation. In optomechanics, radiation-pressure-induced parametric coupling between optical (photon) and mechanical (phonon) excitations may be used to break time-reversal symmetry, providing the prerequisite for synthetic magnetism. Here we design and fabricate a silicon optomechanical circuit with both optical and mechanical connectivity between two optomechanical cavities. Driving the two cavities with phase-correlated laser light results in a synthetic magnetic flux, which, in combination with dissipative coupling to the mechanical bath, leads to non-reciprocal transport of photons with 35 dB of isolation. Additionally, optical pumping with blue-detuned light manifests as a particle non-conserving interaction between photons and phonons, resulting in directional optical amplification of 12 dB in the isolator through-direction. These results suggest the possibility of using optomechanical circuits to create a more general class of non-reciprocal optical devices, and further, to enable new topological phases for both light and sound on a microchip.

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

Bachman, Daniel; Chen, Zhijiang; Wang, Christopher

Phase errors caused by fabrication variations in silicon photonic integrated circuits are an important problem, which negatively impacts device yield and performance. This study reports our recent progress in the development of a method for permanent, postfabrication phase error correction of silicon photonic circuits based on femtosecond laser irradiation. Using beam shaping technique, we achieve a 14-fold enhancement in the phase tuning resolution of the method with a Gaussian-shaped beam compared to a top-hat beam. The large improvement in the tuning resolution makes the femtosecond laser method potentially useful for very fine phase trimming of silicon photonic circuits. Finally, wemore » also show that femtosecond laser pulses can directly modify silicon photonic devices through a SiO 2 cladding layer, making it the only permanent post-fabrication method that can tune silicon photonic circuits protected by an oxide cladding.« less

Cascade photonic integrated circuit architecture for electro-optic in-phase quadrature/single sideband modulation or frequency conversion.

PubMed

Hasan, Mehedi; Hall, Trevor

2015-11-01

A photonic integrated circuit architecture for implementing frequency upconversion is proposed. The circuit consists of a 1×2 splitter and 2×1 combiner interconnected by two stages of differentially driven phase modulators having 2×2 multimode interference coupler between the stages. A transfer matrix approach is used to model the operation of the architecture. The predictions of the model are validated by simulations performed using an industry standard software tool. The intrinsic conversion efficiency of the proposed design is improved by 6 dB over the alternative functionally equivalent circuit based on dual parallel Mach-Zehnder modulators known in the prior art. A two-tone analysis is presented to study the linearity of the proposed circuit, and a comparison is provided over the alternative. The proposed circuit is suitable for integration in any platform that offers linear electro-optic phase modulation such as LiNbO(3), silicon, III-V, or hybrid technology.

Dual-function photonic integrated circuit for frequency octo-tupling or single-side-band modulation.

PubMed

Hasan, Mehedi; Maldonado-Basilio, Ramón; Hall, Trevor J

2015-06-01

A dual-function photonic integrated circuit for microwave photonic applications is proposed. The circuit consists of four linear electro-optic phase modulators connected optically in parallel within a generalized Mach-Zehnder interferometer architecture. The photonic circuit is arranged to have two separate output ports. A first port provides frequency up-conversion of a microwave signal from the electrical to the optical domain; equivalently single-side-band modulation. A second port provides tunable millimeter wave carriers by frequency octo-tupling of an appropriate amplitude RF carrier. The circuit exploits the intrinsic relative phases between the ports of multi-mode interference couplers to provide substantially all the static optical phases needed. The operation of the proposed dual-function photonic integrated circuit is verified by computer simulations. The performance of the frequency octo-tupling and up-conversion functions is analyzed in terms of the electrical signal to harmonic distortion ratio and the optical single side band to unwanted harmonics ratio, respectively.

Initiative in Concurrent Engineering (DICE). Phase 1.

DTIC Science & Technology

1990-02-09

and power of commercial and military electronics systems. The continual evolution of HDE technology offers far greater flexibility in circuit design... powerful magnetic field of the permanent magnets in the sawyer motors. This makes it possible to have multiple robots in the workcell and to have them...Controller. The Adept IC was chosen because of its extensive processing power , integrated grayscale vision, standard 28 industrial I/O control

Active phase locking of thirty fiber channels using multilevel phase dithering method

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

Huang, Zhimeng; Luo, Yongquan, E-mail: yongquan-l@sina.com; Liu, Cangli

2016-03-15

An active phase locking of a large-scale fiber array with thirty channels has been demonstrated experimentally. In the experiment, the first group of thirty phase controllers is used to compensate the phase noises between the elements and the second group of thirty phase modulators is used to impose additional phase disturbances to mimic the phase noises in the high power fiber amplifiers. A multi-level phase dithering algorithm using dual-level rectangular-wave phase modulation and time division multiplexing can achieve the same phase control as single/multi-frequency dithering technique, but without coherent demodulation circuit. The phase locking efficiency of 30 fiber channels ismore » achieved about 98.68%, 97.82%, and 96.50% with no additional phase distortion, modulated phase distortion I (±1 rad), and phase distortion II (±2 rad), corresponding to the phase error of λ/54, λ/43, and λ/34 rms. The contrast of the coherent combined beam profile is about 89%. Experimental results reveal that the multi-level phase dithering technique has great potential in scaling to a large number of laser beams.« less

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

Shepard, Kenneth L.; Sturcken, Noah Andrew

Power controller includes an output terminal having an output voltage, at least one clock generator to generate a plurality of clock signals and a plurality of hardware phases. Each hardware phase is coupled to the at least one clock generator and the output terminal and includes a comparator. Each hardware phase is configured to receive a corresponding one of the plurality of clock signals and a reference voltage, combine the corresponding clock signal and the reference voltage to produce a reference input, generate a feedback voltage based on the output voltage, compare the reference input and the feedback voltage usingmore » the comparator and provide a comparator output to the output terminal, whereby the comparator output determines a duty cycle of the power controller. An integrated circuit including the power controller is also provided.« less

EV drivetrain inverter with V/HZ optimization

DOEpatents

Gritter, David J.; O'Neil, Walter K.

1986-01-01

An inverter (34) which provides power to an A.C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A.C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A.C. machine is optimized. The control circuit includes a micro-computer which calculates optimized machine control data signals from various parametric inputs and during steady state load conditions, seeks a best V/HZ ratio to minimize battery current drawn (system losses) from a D.C. power source (32). In the preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack and a three-phase induction motor (18).

Analog circuit for the measurement of phase difference between two noisy sine-wave signals

NASA Technical Reports Server (NTRS)

Shakkottai, P.; Kwack, E. Y.; Back, L. H.

1989-01-01

A simple circuit was designed to measure the phase difference between two noisy sine waves. It locks over a wide range of frequencies and produces an output proportional to the phase difference of rapidly varying signals. A square wave locked in frequency and phase to the first signal is produced by a phase-locked loop and is amplified by an operational amplifier.

Averaging of phase noise in PSK signals by an opto-electrical feed-forward circuit

NASA Astrophysics Data System (ADS)

Inoue, K.; Ohta, M.

2013-10-01

This paper proposes an opto-electrical feed-forward circuit that reduces phase noise in binary PSK signals by averaging the noise. Random and independent phase noise is averaged over several bit slots by externally modulating a phase-fluctuating PSK signal with feed-forward signal obtained from signal processing of the outputs of delay interferometers. The simulation results demonstrate a reduction in the phase noise.

Feedback Signal from Motoneurons Influences a Rhythmic Pattern Generator.

PubMed

Rotstein, Horacio G; Schneider, Elisa; Szczupak, Lidia

2017-09-20

Motoneurons are not mere output units of neuronal circuits that control motor behavior but participate in pattern generation. Research on the circuit that controls the crawling motor behavior in leeches indicated that motoneurons participate as modulators of this rhythmic motor pattern. Crawling results from successive bouts of elongation and contraction of the whole leech body. In the isolated segmental ganglia, dopamine can induce a rhythmic antiphasic activity of the motoneurons that control contraction (DE-3 motoneurons) and elongation (CV motoneurons). The study was performed in isolated ganglia where manipulation of the activity of specific motoneurons was performed in the course of fictive crawling ( crawling ). In this study, the membrane potential of CV was manipulated while crawling was monitored through the rhythmic activity of DE-3. Matching behavioral observations that show that elongation dominates the rhythmic pattern, the electrophysiological activity of CV motoneurons dominates the cycle. Brief excitation of CV motoneurons during crawling episodes resets the rhythmic activity of DE-3, indicating that CV feeds back to the rhythmic pattern generator. CV hyperpolarization accelerated the rhythm to an extent that depended on the magnitude of the cycle period, suggesting that CV exerted a positive feedback on the unit(s) of the pattern generator that controls the elongation phase. A simple computational model was implemented to test the consequences of such feedback. The simulations indicate that the duty cycle of CV depended on the strength of the positive feedback between CV and the pattern generator circuit. SIGNIFICANCE STATEMENT Rhythmic movements of animals are controlled by neuronal networks that have been conceived as hierarchical structures. At the basis of this hierarchy, we find the motoneurons, few neurons at the top control global aspects of the behavior (e.g., onset, duration); and within these two ends, specific neuronal circuits control the actual rhythmic pattern of movements. We have investigated whether motoneurons are limited to function as output units. Analysis of the network that controls crawling behavior in the leech has clearly indicated that motoneurons, in addition to controlling muscle activity, send signals to the pattern generator. Physiological and modeling studies on the role of specific motoneurons suggest that these feedback signals modulate the phase relationship of the rhythmic activity. Copyright © 2017 the authors 0270-6474/17/379149-11$15.00/0.

Computer simulations of stimulus dependent state switching in basic circuits of bursting neurons

NASA Astrophysics Data System (ADS)

Rabinovich, Mikhail; Huerta, Ramón; Bazhenov, Maxim; Kozlov, Alexander K.; Abarbanel, Henry D. I.

1998-11-01

We investigate the ability of oscillating neural circuits to switch between different states of oscillation in two basic neural circuits. We model two quite distinct small neural circuits. The first circuit is based on invertebrate central pattern generator (CPG) studies [A. I. Selverston and M. Moulins, The Crustacean Stomatogastric System (Springer-Verlag, Berlin, 1987)] and is composed of two neurons coupled via both gap junction and inhibitory synapses. The second consists of coupled pairs of interconnected thalamocortical relay and thalamic reticular neurons with both inhibitory and excitatory synaptic coupling. The latter is an elementary unit of the thalamic networks passing sensory information to the cerebral cortex [M. Steriade, D. A. McCormick, and T. J. Sejnowski, Science 262, 679 (1993)]. Both circuits have contradictory coupling between symmetric parts. The thalamocortical model has excitatory and inhibitory connections and the CPG has reciprocal inhibitory and electrical coupling. We describe the dynamics of the individual neurons in these circuits by conductance based ordinary differential equations of Hodgkin-Huxley type [J. Physiol. (London) 117, 500 (1952)]. Both model circuits exhibit bistability and hysteresis in a wide region of coupling strengths. The two main modes of behavior are in-phase and out-of-phase oscillations of the symmetric parts of the network. We investigate the response of these circuits, while they are operating in bistable regimes, to externally imposed excitatory spike trains with varying interspike timing and small amplitude pulses. These are meant to represent spike trains received by the basic circuits from sensory neurons. Circuits operating in a bistable region are sensitive to the frequency of these excitatory inputs. Frequency variations lead to changes from in-phase to out-of-phase coordination or vice versa. The signaling information contained in a spike train driving the network can place the circuit into one or another state depending on the interspike interval and this happens within a few spikes. These states are maintained by the basic circuit after the input signal is ended. When a new signal of the correct frequency enters the circuit, it can be switched to another state with the same ease.

A quantum diffractor for thermal flux

NASA Astrophysics Data System (ADS)

José Martínez-Pérez, Maria; Giazotto, Francesco

2014-04-01

Macroscopic phase coherence between weakly coupled superconductors leads to peculiar interference phenomena. Among these, magnetic flux-driven diffraction might be produced, in full analogy to light diffraction through a rectangular slit. This can be experimentally revealed by the electric current and, notably, also by the heat current transmitted through the circuit. The former was observed more than 50 years ago and represented the first experimental evidence of the phase-coherent nature of the Josephson effect, whereas the second one was still lacking. Here we demonstrate the existence of heat diffraction by measuring the modulation of the electronic temperature of a small metallic electrode nearby-contacted to a thermally biased short Josephson junction subjected to an in-plane magnetic field. The observed temperature dependence exhibits symmetry under magnetic flux reversal, and clear resemblance with a Fraunhofer-like modulation pattern. Our approach, joined to widespread methods for phase-biasing superconducting circuits, might represent an effective tool for controlling the thermal flux in nanoscale devices.

Compensated gain control circuit for buck regulator command charge circuit

DOEpatents

Barrett, David M.

1996-01-01

A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit.

Compensated gain control circuit for buck regulator command charge circuit

DOEpatents

Barrett, D.M.

1996-11-05

A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit. 5 figs.

Interrogator system for identifying electrical circuits

DOEpatents

Jatko, W.B.; McNeilly, D.R.

1988-04-12

A system for interrogating electrical leads to correctly ascertain the identity of equipment attached to remote ends of the leads is disclosed. The system includes a source of a carrier signal generated in a controller/receiver to be sent over the leads and an identifier unit at the equipment. The identifier is activated by command of the carrier and uses a portion of the carrier to produce a supply voltage. Each identifier is uniquely programmed for a specific piece of equipment, and causes the impedance of the circuit to be modified whereby the carrier signal is modulated according to that program. The modulation can be amplitude, frequency or phase modulation. A demodulator in the controller/receiver analyzes the modulated carrier signal, and if a verified signal is recognized displays and/or records the information. This information can be utilized in a computer system to prepare a wiring diagram of the electrical equipment attached to specific leads. Specific circuit values are given for amplitude modulation, and the system is particularly described for use with thermocouples. 6 figs.

Interrogator system for identifying electrical circuits

DOEpatents

Jatko, William B.; McNeilly, David R.

1988-01-01

A system for interrogating electrical leads to correctly ascertain the identity of equipment attached to remote ends of the leads. The system includes a source of a carrier signal generated in a controller/receiver to be sent over the leads and an identifier unit at the equipment. The identifier is activated by command of the carrier and uses a portion of the carrier to produce a supply voltage. Each identifier is uniquely programmed for a specific piece of equipment, and causes the impedance of the circuit to be modified whereby the carrier signal is modulated according to that program. The modulation can be amplitude, frequency or phase modulation. A demodulator in the controller/receiver analyzes the modulated carrier signal, and if a verified signal is recognized displays and/or records the information. This information can be utilized in a computer system to prepare a wiring diagram of the electrical equipment attached to specific leads. Specific circuit values are given for amplitude modulation, and the system is particularly described for use with thermocouples.

PHASE DETECTOR

DOEpatents

Kippenhan, D.O.

1959-09-01

A phase detector circuit is described for use at very high frequencies of the order of 50 megacycles. The detector circuit includes a pair of rectifiers inverted relative to each other. One voltage to be compared is applied to the two rectifiers in phase opposition and the other voltage to be compared is commonly applied to the two rectifiers. The two result:ng d-c voltages derived from the rectifiers are combined in phase opposition to produce a single d-c voltage having amplitude and polarity characteristics dependent upon the phase relation between the signals to be compared. Principal novelty resides in the employment of a half-wave transmission line to derive the phase opposing signals from the first voltage to be compared for application to the two rectifiers in place of the transformer commonly utilized for such purpose in phase detector circuits for operation at lower frequency.

Performance of a Ka-band transponder breadboard for deep-space applications

NASA Technical Reports Server (NTRS)

Mysoor, N. R.; Lane, J. P.; Kayalar, S.; Kermode, A. W.

1995-01-01

This article summarizes the design concepts applied in the development of and advanced Ka-band (34.4 GHz/32 GHz) transponder breadboard for the next generation of space communications systems applications. The selected architecture upgrades the X-band (7.2 GHz/8.4 GHz) deep-space transponder (DST) to provide Da-band up/Ka- and X-band down capability. The Ka-band transponder breadboard incorporates several state-of-the-art components, including sampling mixers, a Ka-band dielectric resonator oscillator, and microwave monolithic integrated circuits (MMICs). The MMICs that were tested in the breadboard include upconverters, downconverters, automatic gain control circuits, mixers, phase modulators, and amplifiers. The measured receiver dynamic range, tracking range, acquisition rate, static phase error, and phase jitter characteristics of the Ka-band breadboard interfaced to the advanced engineering model X-band DST are in good agreement with the expected performance. The results show a receiver tracking threshold of -149 dBm with a dynamic range of 80 dB and a downlink phase jitter of 7 deg rms. The analytical results of phase noise and Allan standard deviation are in good agreement with the experimental results.

High performance protection circuit for power electronics applications

NASA Astrophysics Data System (ADS)

Tudoran, Cristian D.; Dǎdârlat, Dorin N.; Toşa, Nicoleta; Mişan, Ioan

2015-12-01

In this paper we present a high performance protection circuit designed for the power electronics applications where the load currents can increase rapidly and exceed the maximum allowed values, like in the case of high frequency induction heating inverters or high frequency plasma generators. The protection circuit is based on a microcontroller and can be adapted for use on single-phase or three-phase power systems. Its versatility comes from the fact that the circuit can communicate with the protected system, having the role of a "sensor" or it can interrupt the power supply for protection, in this case functioning as an external, independent protection circuit.

Electronic Circuit Experiments and SPICE Simulation of Double Covering Bifurcation of 2-Torus Quasi-Periodic Flow in Phase-Locked Loop Circuit

NASA Astrophysics Data System (ADS)

Kamiyama, Kyohei; Endo, Tetsuro; Imai, Isao; Komuro, Motomasa

2016-06-01

Double covering (DC) bifurcation of a 2-torus quasi-periodic flow in a phase-locked loop circuit was experimentally investigated using an electronic circuit and via SPICE simulation; in the circuit, the input radio-frequency signal was frequency modulated by the sum of two asynchronous sinusoidal baseband signals. We observed both DC and period-doubling bifurcations of a discrete map on two Poincaré sections, which were realized by changing the sample timing from one baseband sinusoidal signal to the other. The results confirm the DC bifurcation of the original flow.

High Speed Solid State Circuit Breaker

NASA Technical Reports Server (NTRS)

Podlesak, Thomas F.

1993-01-01

The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

Intrinsic modulation of pulse-coupled integrate-and-fire neurons

NASA Astrophysics Data System (ADS)

Coombes, S.; Lord, G. J.

1997-11-01

Intrinsic neuromodulation is observed in sensory and neuromuscular circuits and in biological central pattern generators. We model a simple neuronal circuit with a system of two pulse-coupled integrate-and-fire neurons and explore the parameter regimes for periodic firing behavior. The inclusion of biologically realistic features shows that the speed and onset of neuronal response plays a crucial role in determining the firing phase for periodic rhythms. We explore the neurophysiological function of distributed delays arising from both the synaptic transmission process and dendritic structure as well as discrete delays associated with axonal communication delays. Bifurcation and stability diagrams are constructed with a mixture of simple analysis, numerical continuation and the Kuramoto phase-reduction technique. Moreover, we show that, for asynchronous behavior, the strength of electrical synapses can control the firing rate of the system.

Accuracy analysis of pointing control system of solar power station

NASA Technical Reports Server (NTRS)

Hung, J. C.; Peebles, P. Z., Jr.

1978-01-01

The first-phase effort concentrated on defining the minimum basic functions that the retrodirective array must perform, identifying circuits that are capable of satisfying the basic functions, and looking at some of the error sources in the system and how they affect accuracy. The initial effort also examined three methods for generating torques for mechanical antenna control, performed a rough analysis of the flexible body characteristics of the solar collector, and defined a control system configuration for mechanical pointing control of the array.

Small computer interface to a stepper motor

NASA Technical Reports Server (NTRS)

Berry, Fred A., Jr.

1986-01-01

A Commodore VIC-20 computer has been interfaced with a stepper motor to provide an inexpensive stepper motor controller. Only eight transistors and two integrated circuits compose the interface. The software controls the parallel interface of the computer and provides the four phase drive signals for the motor. Optical sensors control the zeroing of the 12-inch turntable positioned by the controller. The computer calculates the position information and movement of the table and may be programmed in BASIC to execute automatic sequences.

SNDR Limits of Oscillator-Based Sensor Readout Circuits.

PubMed

Cardes, Fernando; Quintero, Andres; Gutierrez, Eric; Buffa, Cesare; Wiesbauer, Andreas; Hernandez, Luis

2018-02-03

This paper analyzes the influence of phase noise and distortion on the performance of oscillator-based sensor data acquisition systems. Circuit noise inherent to the oscillator circuit manifests as phase noise and limits the SNR. Moreover, oscillator nonlinearity generates distortion for large input signals. Phase noise analysis of oscillators is well known in the literature, but the relationship between phase noise and the SNR of an oscillator-based sensor is not straightforward. This paper proposes a model to estimate the influence of phase noise in the performance of an oscillator-based system by reflecting the phase noise to the oscillator input. The proposed model is based on periodic steady-state analysis tools to predict the SNR of the oscillator. The accuracy of this model has been validated by both simulation and experiment in a 130 nm CMOS prototype. We also propose a method to estimate the SNDR and the dynamic range of an oscillator-based readout circuit that improves by more than one order of magnitude the simulation time compared to standard time domain simulations. This speed up enables the optimization and verification of this kind of systems with iterative algorithms.

A linearly controlled direct-current power source for high-current inductive loads in a magnetic suspension wind tunnel

NASA Technical Reports Server (NTRS)

Tripp, John S.; Daniels, Taumi S.

1990-01-01

The NASA Langley 6 inch magnetic suspension and balance system (MSBS) requires an independently controlled bidirectional DC power source for each of six positioning electromagnets. These electromagnets provide five-degree-of-freedom control over a suspended aerodynamic test model. Existing power equipment, which employs resistance coupled thyratron controlled rectifiers as well as AC to DC motor generator converters, is obsolete, inefficient, and unreliable. A replacement six phase bidirectional controlled bridge rectifier is proposed, which employs power MOSFET switches sequenced by hybrid analog/digital circuits. Full load efficiency is 80 percent compared to 25 percent for the resistance coupled thyratron system. Current feedback provides high control linearity, adjustable current limiting, and current overload protection. A quenching circuit suppresses inductive voltage impulses. It is shown that 20 kHz interference from positioning magnet power into MSBS electromagnetic model position sensors results predominantly from capacitively coupled electric fields. Hence, proper shielding and grounding techniques are necessary. Inductively coupled magnetic interference is negligible.

Design and development of a brushless, direct drive solar array reorientation system

NASA Technical Reports Server (NTRS)

Jessee, R. D.

1972-01-01

This report covers the design and development of the laboratory model, and is essentially a compilation of reports covering the system and its various parts. To enhance completeness, the final report of Phase 1 covering circuit development of the controller is also included. A controller was developed for a brushless, direct-drive, single axis solar array reorientation system for earth-pointed, passively-stabilized spacecraft. A control systems was designed and breadboard circuits were built and tested for performance. The controller is designed to take over automatic control of the array on command after the spacecraft is stabilized in orbit. The controller will orient the solar array to the sun vector and automatically track to maintain proper orientation. So long as the orbit is circular, orientation toward the sun is maintained even though the spacecraft goes into the shadow of the earth. Particular attention was given in the design to limit reaction between the array and the spacecraft.

A solid-state controllable power supply for a magnetic suspension wind tunnel

NASA Technical Reports Server (NTRS)

Daniels, Taumi S.; Tripp, John S.

1991-01-01

The NASA Langley 6-inch Magnetic Suspension and Balance System (6-in. MSBS) requires an independently controlled bidirectional dc power source for each of six positioning electromagnets. These electromagnets provide five-degree-of-freedom control over a suspended aerodynamic test model. Existing power equipment, which employs resistance-coupled thyratron-controlled rectifiers as well as ac to dc motor-generator converters, is obsolete, inefficient, and unreliable. A replacement six-phase bidirectional controlled bridge rectifier is proposed, which employs power MOSFET switches sequenced by hybrid analog/digital circuits. Full-load efficiency is 80 percent compared with 25 percent for the resistance-coupled thyratron system. Current feedback provides high control linearity, adjustable current limiting, and current overload protection. A quenching circuit suppresses inductive voltage impulses. It is shown that 20-kHz interference from positioning magnet power into MSBS electromagnetic model position sensors results predominantly from capacitively coupled electric fields. Hence, proper shielding and grounding techniques are necessary. Inductively coupled magnetic interference is negligible.

Adaptive control system for line-commutated inverters

NASA Technical Reports Server (NTRS)

Dolland, C. R.; Bailey, D. A. (Inventor)

1983-01-01

A control system for a permanent magnet motor driven by a multiphase line commutated inverter is provided with integration for integrating the back EMF of each phase of the motor. This is used in generating system control signals for an inverter gate logic using a sync and firing angle (alpha) control generator connected to the outputs of the integrators. A precision full wave rectifier provides a speed control feedback signal to a phase delay rectifier via a gain and loop compensation circuit and to the integrators for adaptive control of the attenuation of low frequencies by the integrators as a function of motor speed. As the motor speed increases, the attenuation of low frequency components by the integrators is increased to offset the gain of the integrators to spurious low frequencies.

Wide tracking range, auto ranging, low jitter phase lock loop for swept and fixed frequency systems

DOEpatents

Kerner, Thomas M.

2001-01-01

The present invention provides a wide tracking range phase locked loop (PLL) circuit that achieves minimal jitter in a recovered clock signal, regardless of the source of the jitter (i.e. whether it is in the source or the transmission media). The present invention PLL has automatic harmonic lockout detection circuitry via a novel lock and seek control logic in electrical communication with a programmable frequency discriminator and a code balance detector. (The frequency discriminator enables preset of a frequency window of upper and lower frequency limits to derive a programmable range within which signal acquisition is effected. The discriminator works in combination with the code balance detector circuit to minimize the sensitivity of the PLL circuit to random data in the data stream). In addition, the combination of a differential loop integrator with the lock and seek control logic obviates a code preamble and guarantees signal acquisition without harmonic lockup. An adaptive cable equalizer is desirably used in combination with the present invention PLL to recover encoded transmissions containing a clock and/or data. The equalizer automatically adapts to equalize short haul cable lengths of coaxial and twisted pair cables or wires and provides superior jitter performance itself. The combination of the equalizer with the present invention PLL is desirable in that such combination permits the use of short haul wires without significant jitter.

Robust mitotic entry is ensured by a latching switch.

PubMed

Tuck, Chloe; Zhang, Tongli; Potapova, Tamara; Malumbres, Marcos; Novák, Béla

2013-01-01

Cell cycle events are driven by Cyclin dependent kinases (CDKs) and by their counter-acting phosphatases. Activation of the Cdk1:Cyclin B complex during mitotic entry is controlled by the Wee1/Myt1 inhibitory kinases and by Cdc25 activatory phosphatase, which are themselves regulated by Cdk1:Cyclin B within two positive circuits. Impairing these two feedbacks with chemical inhibitors induces a transient entry into M phase referred to as mitotic collapse. The pathology of mitotic collapse reveals that the positive circuits play a significant role in maintaining the M phase state. To better understand the function of these feedback loops during G2/M transition, we propose a simple model for mitotic entry in mammalian cells including spatial control over Greatwall kinase phosphorylation. After parameter calibration, the model is able to recapture the complex and non-intuitive molecular dynamics reported by Potapova et al. (Potapova et al., 2011). Moreover, it predicts the temporal patterns of other mitotic regulators which have not yet been experimentally tested and suggests a general design principle of cell cycle control: latching switches buffer the cellular stresses which accompany cell cycle processes to ensure that the transitions are smooth and robust.

49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

Code of Federal Regulations, 2010 CFR

2010-10-01

... circuit controller operated by switch points or by switch locking mechanism. 236.303 Section 236.303... § 236.303 Control circuits for signals, selection through circuit controller operated by switch points or by switch locking mechanism. The control circuit for each aspect with indication more favorable...

49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

Code of Federal Regulations, 2012 CFR

2012-10-01

... circuit controller operated by switch points or by switch locking mechanism. 236.303 Section 236.303... § 236.303 Control circuits for signals, selection through circuit controller operated by switch points or by switch locking mechanism. The control circuit for each aspect with indication more favorable...

49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

Code of Federal Regulations, 2013 CFR

2013-10-01

... circuit controller operated by switch points or by switch locking mechanism. 236.303 Section 236.303... § 236.303 Control circuits for signals, selection through circuit controller operated by switch points or by switch locking mechanism. The control circuit for each aspect with indication more favorable...

49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

Code of Federal Regulations, 2014 CFR

2014-10-01

... circuit controller operated by switch points or by switch locking mechanism. 236.303 Section 236.303... § 236.303 Control circuits for signals, selection through circuit controller operated by switch points or by switch locking mechanism. The control circuit for each aspect with indication more favorable...

49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

Code of Federal Regulations, 2011 CFR

2011-10-01

... circuit controller operated by switch points or by switch locking mechanism. 236.303 Section 236.303... § 236.303 Control circuits for signals, selection through circuit controller operated by switch points or by switch locking mechanism. The control circuit for each aspect with indication more favorable...

Robust terahertz self-heterodyne system using a phase noise compensation technique.

PubMed

Song, Hajun; Song, Jong-In

2015-08-10

We propose and demonstrate a robust terahertz self-heterodyne system using a phase noise compensation technique. Conventional terahertz self-heterodyne systems suffer from degraded phase noise performance due to phase noise of the laser sources. The proposed phase noise compensation technique uses an additional photodiode and a simple electric circuit to produce phase noise identical to that observed in the terahertz signal produced by the self-heterodyne system. The phase noise is subsequently subtracted from the terahertz signal produced by the self-heterodyne system using a lock-in amplifier. While the terahertz self-heterodyne system using a phase noise compensation technique offers improved phase noise performance, it also provides a reduced phase drift against ambient temperature variations. The terahertz self-heterodyne system using a phase noise compensation technique shows a phase noise of 0.67 degree in terms of a standard deviation value even without using overall delay balance control. It also shows a phase drift of as small as approximately 10 degrees in an open-to-air measurement condition without any strict temperature control.

A novel architecture of recovered data comparison for high speed clock and data recovery

NASA Astrophysics Data System (ADS)

Gao, Susan; Li, Fei; Wang, Zhigong; Cui, Hongliang

2005-05-01

A clock and data recovery (CDR) circuit is one of the crucial blocks in high-speed serial link communication systems. The data received in these systems are asynchronous and noisy, requiring that a clock be extracted to allow synchronous operations. Furthermore, the data must be "retimed" so that the jitter accumulated during transmission is removed. This paper presents a novel architecture of CDR, which is very tolerant to long sequences of serial ones or zeros and also robust to occasional long absence of transitions. The design is based on the fact that a basic clock recovery having a clock recovery circuit (CRC) and a data decision circuit separately would generate a high jitter clock when the received non-return-to-zero (NRZ) data with long sequences of ones or zeros. To eliminate this drawback, the proposed architecture incorporates a data circuit decision circuit within the phase-locked loop (PLL) CRC. Other than this, a new phase detector (PD) is also proposed, which was easy to accomplish and robust at high speed. This PD is functional with a random input and automatically turns to disable during both the locked state and long absence of transitions. The voltage-controlled oscillator (VCO) is also designed delicately to suppress the jitter. Due to the high stability, the jitter is highly reduced when the loop is locked. The simulation results of such CDR working at 1.25Gb/s particularly for 1000BASE-X Gigabit Ethernet by using TSMC 0.25μm technology are presented to prove the feasibility of this architecture. One more CDR based on edge detection architecture is also built in the circuit for performance comparisons.

Three-phase multilevel solar inverter for motor drive system

NASA Astrophysics Data System (ADS)

Bhasagare, Mayuresh P.

This thesis deals with three phase inverters and the different control strategies that can be associated with an inverter being used together. The first part of this thesis discusses the present research in the fields of PV panels, motor drive systems and three phase inverters along with their control. This control includes various strategies like MPPT, Volts-Hertz and modulation index compensation. Incorporating these techniques together is the goal of this thesis. A new topology for operating an open end motor drive system has also been discusses, where a boost converter and a flyback converter have been used in cascade to run a three phase motor. The main advantage of this is increasing the number of levels and improving the quality of the output voltage, not to mention a few other benefits of having the proposed circuit. A new algorithm has also been designed for starting and stopping the motor, which controls the current drawn from the power source during starting.

Optical techniques to feed and control GaAs MMIC modules for phased array antenna applications

NASA Astrophysics Data System (ADS)

Bhasin, K. B.; Anzic, G.; Kunath, R. R.; Connolly, D. J.

A complex signal distribution system is required to feed and control GaAs monolithic microwave integrated circuits (MMICs) for phased array antenna applications above 20 GHz. Each MMIC module will require one or more RF lines, one or more bias voltage lines, and digital lines to provide a minimum of 10 bits of combined phase and gain control information. In a closely spaced array, the routing of these multiple lines presents difficult topology problems as well as a high probability of signal interference. To overcome GaAs MMIC phased array signal distribution problems optical fibers interconnected to monolithically integrated optical components with GaAs MMIC array elements are proposed as a solution. System architecture considerations using optical fibers are described. The analog and digital optical links to respectively feed and control MMIC elements are analyzed. It is concluded that a fiber optic network will reduce weight and complexity, and increase reliability and performance, but higher power will be required.

Optical techniques to feed and control GaAs MMIC modules for phased array antenna applications

NASA Technical Reports Server (NTRS)

Bhasin, K. B.; Anzic, G.; Kunath, R. R.; Connolly, D. J.

1986-01-01

A complex signal distribution system is required to feed and control GaAs monolithic microwave integrated circuits (MMICs) for phased array antenna applications above 20 GHz. Each MMIC module will require one or more RF lines, one or more bias voltage lines, and digital lines to provide a minimum of 10 bits of combined phase and gain control information. In a closely spaced array, the routing of these multiple lines presents difficult topology problems as well as a high probability of signal interference. To overcome GaAs MMIC phased array signal distribution problems optical fibers interconnected to monolithically integrated optical components with GaAs MMIC array elements are proposed as a solution. System architecture considerations using optical fibers are described. The analog and digital optical links to respectively feed and control MMIC elements are analyzed. It is concluded that a fiber optic network will reduce weight and complexity, and increase reliability and performance, but higher power will be required.

On precise phase difference measurement approach using border stability of detection resolution.

PubMed

Bai, Lina; Su, Xin; Zhou, Wei; Ou, Xiaojuan

2015-01-01

For the precise phase difference measurement, this paper develops an improved dual phase coincidence detection method. The measurement resolution of the digital phase coincidence detection circuits is always limited, for example, only at the nanosecond level. This paper reveals a new way to improve the phase difference measurement precision by using the border stability of the circuit detection fuzzy areas. When a common oscillator signal is used to detect the phase coincidence with the two comparison signals, there will be two detection fuzzy areas for the reason of finite detection resolution surrounding the strict phase coincidence. Border stability of fuzzy areas and the fluctuation difference of the two fuzzy areas can be even finer than the picoseconds level. It is shown that the system resolution obtained only depends on the stability of the circuit measurement resolution which is much better than the measurement device resolution itself.

Analysis of the phase control of the ITER ICRH antenna array. Influence on the load resilience and radiated power spectrum

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

Messiaen, A., E-mail: a.messiaen@fz-juelich.de; Ongena, J.; Vervier, M.

2015-12-10

The paper analyses how the phasing of the ITER ICRH 24 strap array evolves from the power sources up to the strap currents of the antenna. The study of the phasing control and coherence through the feeding circuits with prematching and automatic matching and decoupling network is made by modeling starting from the TOPICA matrix of the antenna array for a low coupling plasma profile and for current drive phasing (worst case for mutual coupling effects). The main results of the analysis are: (i) the strap current amplitude is well controlled by the antinode V{sub max} amplitude of the feedingmore » lines, (ii) the best toroidal phasing control is done by the adjustment of the mean phase of V{sub max} of each poloidal straps column, (iii) with well adjusted system the largest strap current phasing error is ±20°, (iv) the effect on load resilience remains well below the maximum affordable VSWR of the generators, (v) the effect on the radiated power spectrum versus k{sub //} computed by means of the coupling code ANTITER II remains small for the considered cases.« less

High performance protection circuit for power electronics applications

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

Tudoran, Cristian D., E-mail: cristian.tudoran@itim-cj.ro; Dădârlat, Dorin N.; Toşa, Nicoleta

2015-12-23

In this paper we present a high performance protection circuit designed for the power electronics applications where the load currents can increase rapidly and exceed the maximum allowed values, like in the case of high frequency induction heating inverters or high frequency plasma generators. The protection circuit is based on a microcontroller and can be adapted for use on single-phase or three-phase power systems. Its versatility comes from the fact that the circuit can communicate with the protected system, having the role of a “sensor” or it can interrupt the power supply for protection, in this case functioning as anmore » external, independent protection circuit.« less

Solid state light source driver establishing buck or boost operation

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

Palmer, Fred

A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boostmore » converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.« less

A photonic circuit for complementary frequency shifting, in-phase quadrature/single sideband modulation and frequency multiplication: analysis and integration feasibility

NASA Astrophysics Data System (ADS)

Hasan, Mehedi; Hu, Jianqi; Nikkhah, Hamdam; Hall, Trevor

2017-08-01

A novel photonic integrated circuit architecture for implementing orthogonal frequency division multiplexing by means of photonic generation of phase-correlated sub-carriers is proposed. The circuit can also be used for implementing complex modulation, frequency up-conversion of the electrical signal to the optical domain and frequency multiplication. The principles of operation of the circuit are expounded using transmission matrices and the predictions of the analysis are verified by computer simulation using an industry-standard software tool. Non-ideal scenarios that may affect the correct function of the circuit are taken into consideration and quantified. The discussion of integration feasibility is illustrated by a photonic integrated circuit that has been fabricated using 'library' components and which features most of the elements of the proposed circuit architecture. The circuit is found to be practical and may be fabricated in any material platform that offers a linear electro-optic modulator such as organic or ferroelectric thin films hybridized with silicon photonics.

A new mathematical model and control of a three-phase AC-DC voltage source converter

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

Blasko, V.; Kaura, V.

1997-01-01

A new mathematical model of the power circuit of a three-phase voltage source converter (VSC) was developed in the stationary and synchronous reference frames. The mathematical model was then used to analyze and synthesize the voltage and current control loops for the VSC. Analytical expressions were derived for calculating the gains and time constants of the current and voltage regulators. The mathematical model was used to control a 140-kW regenerative VSC. The synchronous reference frame model was used to define feedforward signals in the current regulators to eliminate the cross coupling between the d and q phases. It allowed themore » reduction of the current control loop to first-order plants and improved their tracking capability. The bandwidths of the current and voltage-control loops were found to be approximately 20 and 60 times (respectively) smaller than the sampling frequency. All control algorithms were implemented in a digital-signal processor. All results of the analysis were experimentally verified.« less

Design principles for elementary gene circuits: Elements, methods, and examples

NASA Astrophysics Data System (ADS)

Savageau, Michael A.

2001-03-01

The control of gene expression involves complex circuits that exhibit enormous variation in design. For years the most convenient explanation for these variations was historical accident. According to this view, evolution is a haphazard process in which many different designs are generated by chance; there are many ways to accomplish the same thing, and so no further meaning can be attached to such different but equivalent designs. In recent years a more satisfying explanation based on design principles has been found for at least certain aspects of gene circuitry. By design principle we mean a rule that characterizes some biological feature exhibited by a class of systems such that discovery of the rule allows one not only to understand known instances but also to predict new instances within the class. The central importance of gene regulation in modern molecular biology provides strong motivation to search for more of these underlying design principles. The search is in its infancy and there are undoubtedly many design principles that remain to be discovered. The focus of this three-part review will be the class of elementary gene circuits in bacteria. The first part reviews several elements of design that enter into the characterization of elementary gene circuits in prokaryotic organisms. Each of these elements exhibits a variety of realizations whose meaning is generally unclear. The second part reviews mathematical methods used to represent, analyze, and compare alternative designs. Emphasis is placed on particular methods that have been used successfully to identify design principles for elementary gene circuits. The third part reviews four design principles that make specific predictions regarding (1) two alternative modes of gene control, (2) three patterns of coupling gene expression in elementary circuits, (3) two types of switches in inducible gene circuits, and (4) the realizability of alternative gene circuits and their response to phased environmental cues. In each case, the predictions are supported by experimental evidence. These results are important for understanding the function, design, and evolution of elementary gene circuits.

A PWM transistor inverter for an ac electric vehicle drive

NASA Technical Reports Server (NTRS)

Slicker, J. M.

1981-01-01

A prototype system consisting of closely integrated motor, inverter, and transaxle has been built in order to demonstrate the feasibility of a three-phase ac transistorized inverter for electric vehicle applications. The microprocessor-controlled inverter employs monolithic power transistors to drive an oil-cooled, three-phase induction traction motor at a peak output power of 30 kW from a 144 V battery pack. Transistor safe switching requirements are discussed, and a circuit is presented for recovering trapped snubber inductor energy at transistor turn-off.

Trapping photons on the line: controllable dynamics of a quantum walk

NASA Astrophysics Data System (ADS)

Xue, Peng; Qin, Hao; Tang, Bao

2014-04-01

Optical interferometers comprising birefringent-crystal beam displacers, wave plates, and phase shifters serve as stable devices for simulating quantum information processes such as heralded coined quantum walks. Quantum walks are important for quantum algorithms, universal quantum computing circuits, quantum transport in complex systems, and demonstrating intriguing nonlinear dynamical quantum phenomena. We introduce fully controllable polarization-independent phase shifters in optical pathes in order to realize site-dependent phase defects. The effectiveness of our interferometer is demonstrated through realizing single-photon quantum-walk dynamics in one dimension. By applying site-dependent phase defects, the translational symmetry of an ideal standard quantum walk is broken resulting in localization effect in a quantum walk architecture. The walk is realized for different site-dependent phase defects and coin settings, indicating the strength of localization signature depends on the level of phase due to site-dependent phase defects and coin settings and opening the way for the implementation of a quantum-walk-based algorithm.

Miniature X-band GaAs MMIC analog and bi-phase modulators for spaceborne communications applications

NASA Technical Reports Server (NTRS)

Mysoor, Narayan R.; Ali, Fazal

1992-01-01

The design concepts, analyses, and the development of GaAs monolithic microwave integrated circuit (MMIC) linear-phase and digital modulators for the next generation of spaceborne communications systems are summarized. The design approach uses a very compact lumped-element, quadrature hybrid, and MESFET-varactors to provide low-loss and well-controlled phase performance for deep-space transponder (DST) applications. The measured results of the MESFET-diode show a capacitance range of 2:1 under reverse bias, and a Q of 38 at 10 GHz. Three cascaded sections of hybrid-coupled reflection phase shifters have been modeled and simulations performed to provide an X-band (8415 +/- 50 MHz) DST phase modulator with +/-2.5 radians of peak phase deviation.

Modeling and Analysis of Power Processing Systems (MAPPS), initial phase 2

NASA Technical Reports Server (NTRS)

Yu, Y.; Lee, F. C.; Wangenheim, H.; Warren, D.

1977-01-01

The overall objective of the program is to provide the engineering tools to reduce the analysis, design, and development effort, and thus the cost, in achieving the required performances for switching regulators and dc-dc converter systems. The program was both tutorial and application oriented. Various analytical methods were described in detail and supplemented with examples, and those with standardization appeals were reduced into computer-based subprograms. Major program efforts included those concerning small and large signal control-dependent performance analysis and simulation, control circuit design, power circuit design and optimization, system configuration study, and system performance simulation. Techniques including discrete time domain, conventional frequency domain, Lagrange multiplier, nonlinear programming, and control design synthesis were employed in these efforts. To enhance interactive conversation between the modeling and analysis subprograms and the user, a working prototype of the Data Management Program was also developed to facilitate expansion as future subprogram capabilities increase.

Superconducting Memristors

NASA Astrophysics Data System (ADS)

di Ventra, Massimiliano; Peotta, Sebastiano

2014-03-01

In his original work Josephson [Phys. Lett. 1, 251 (1962)] predicted that a phase-dependent conductance should be present in superconductor tunnel junctions. This effect attracted considerable attention in the past but is difficult to detect, mainly because it is hard to single it out from the background pair current. Here, we propose to isolate it by using a two-junction interferometer where the junctions have the same critical currents but different conductances. The pair current is completely suppressed when the magnetic flux in the loop is half of a flux quantum and the device is characterized by a pure phase-dependent conductance. According to the theory of nonlinear circuit elements this is in fact an ideal voltage-controlled memristor. Possible applications of this memristive device are memories and neuromorphic computing within the framework of ultrafast and low-energy superconducting digital circuits. This work has been supported by DOE under Grant No. DE-FG02-05ER46204.

Capacitive Trans-Impedance Amplifier Circuit with Charge Injection Compensation

NASA Technical Reports Server (NTRS)

Milkov, Mihail M. (Inventor); Gulbransen, David J. (Inventor)

2016-01-01

A capacitive trans-impedance amplifier circuit with charge injection compensation is provided. A feedback capacitor is connected between an inverting input port and an output port of an amplifier. A MOS reset switch has source and drain terminals connected between the inverting input and output ports of the amplifier, and a gate terminal controlled by a reset signal. The reset switch is open or inactive during an integration phase, and closed or active to electrically connect the inverting input port and output port of the amplifier during a reset phase. One or more compensation capacitors are provided that are not implemented as gate oxide or MOS capacitors. Each compensation capacitor has a first port connected to a compensation signal that is a static signal or a toggling compensation signal that toggles between two compensation voltage values, and a second port connected to the inverting input port of the amplifier.

Non-Intrusive Sensor for In-Situ Measurement of Recession Rate of Ablative and Eroding Materials

NASA Technical Reports Server (NTRS)

Papadopoulos, George (Inventor); Tiliakos, Nicholas (Inventor); Thomson, Clint (Inventor); Benel, Gabriel (Inventor)

2014-01-01

A non-intrusive sensor for in-situ measurement of recession rate of heat shield ablatives. An ultrasonic wave source is carried in the housing. A microphone is also carried in the housing, for collecting the reflected ultrasonic waves from an interface surface of the ablative material. A time phasing control circuit is also included for time-phasing the ultrasonic wave source so that the waves reflected from the interface surface of the ablative material focus on the microphone, to maximize the acoustic pressure detected by the microphone and to mitigate acoustic velocity variation effects through the material through a de-coupling process that involves a software algorithm. A software circuit for computing the location off of which the ultrasonic waves scattered to focus back at the microphone is also included, so that the recession rate of the heat shield ablative may be monitored in real-time through the scan-focus approach.

High Power Squeeze Type Phase Shifter at W-Band

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

Hill, Marc E

2000-09-28

We describe the design, fabrication and bench-study of a mm-wave phase-shifter employed as a high power recirculator for a traveling wave resonator circuit. The OFE copper phase shifter was prepared by electro-discharge machining. Measured phase-shifter characteristics are presented and compared with theory. The phase-shifter was employed in a traveling wave circuit at 91.4 GHz with circulating power of 0.2 MW and subjected to fields greater than 10 MV/m without evidence of breakdown.

Simulation of Flywheel Energy Storage System Controls

NASA Technical Reports Server (NTRS)

Truong, Long V.; Wolff, Frederick J.; Dravid, Narayan

2001-01-01

This paper presents the progress made in the controller design and operation of a flywheel energy storage system. The switching logic for the converter bridge circuit has been redefined to reduce line current harmonics, even at the highest operating speed of the permanent magnet motor-generator. An electromechanical machine model is utilized to simulate charge and discharge operation of the inertial energy in the flywheel. Controlling the magnitude of phase currents regulates the rate of charge and discharge. The resulting improvements are demonstrated by simulation.

Design and characterization of integrated components for SiN photonic quantum circuits.

PubMed

Poot, Menno; Schuck, Carsten; Ma, Xiao-Song; Guo, Xiang; Tang, Hong X

2016-04-04

The design, fabrication, and detailed calibration of essential building blocks towards fully integrated linear-optics quantum computation are discussed. Photonic devices are made from silicon nitride rib waveguides, where measurements on ring resonators show small propagation losses. Directional couplers are designed to be insensitive to fabrication variations. Their offset and coupling lengths are measured, as well as the phase difference between the transmitted and reflected light. With careful calibrations, the insertion loss of the directional couplers is found to be small. Finally, an integrated controlled-NOT circuit is characterized by measuring the transmission through different combinations of inputs and outputs. The gate fidelity for the CNOT operation with this circuit is estimated to be 99.81% after post selection. This high fidelity is due to our robust design, good fabrication reproducibility, and extensive characterizations.

Foundry fabricated photonic integrated circuit optical phase lock loop.

PubMed

Bałakier, Katarzyna; Fice, Martyn J; Ponnampalam, Lalitha; Graham, Chris S; Wonfor, Adrian; Seeds, Alwyn J; Renaud, Cyril C

2017-07-24

This paper describes the first foundry-based InP photonic integrated circuit (PIC) designed to work within a heterodyne optical phase locked loop (OPLL). The PIC and an external electronic circuit were used to phase-lock a single-line semiconductor laser diode to an incoming reference laser, with tuneable frequency offset from 4 GHz to 12 GHz. The PIC contains 33 active and passive components monolithically integrated on a single chip, fully demonstrating the capability of a generic foundry PIC fabrication model. The electronic part of the OPLL consists of commercially available RF components. This semi-packaged system stabilizes the phase and frequency of the integrated laser so that an absolute frequency, high-purity heterodyne signal can be generated when the OPLL is in operation, with phase noise lower than -100 dBc/Hz at 10 kHz offset from the carrier. This is the lowest phase noise level ever demonstrated by monolithically integrated OPLLs.

Mixed-Mode Operation of Hybrid Phase-Change Nanophotonic Circuits.

PubMed

Lu, Yegang; Stegmaier, Matthias; Nukala, Pavan; Giambra, Marco A; Ferrari, Simone; Busacca, Alessandro; Pernice, Wolfram H P; Agarwal, Ritesh

2017-01-11

Phase change materials (PCMs) are highly attractive for nonvolatile electrical and all-optical memory applications because of unique features such as ultrafast and reversible phase transitions, long-term endurance, and high scalability to nanoscale dimensions. Understanding their transient characteristics upon phase transition in both the electrical and the optical domains is essential for using PCMs in future multifunctional optoelectronic circuits. Here, we use a PCM nanowire embedded into a nanophotonic circuit to study switching dynamics in mixed-mode operation. Evanescent coupling between light traveling along waveguides and a phase-change nanowire enables reversible phase transition between amorphous and crystalline states. We perform time-resolved measurements of the transient change in both the optical transmission and resistance of the nanowire and show reversible switching operations in both the optical and the electrical domains. Our results pave the way toward on-chip multifunctional optoelectronic integrated devices, waveguide integrated memories, and hybrid processing applications.

SNDR Limits of Oscillator-Based Sensor Readout Circuits

PubMed Central

Buffa, Cesare; Wiesbauer, Andreas; Hernandez, Luis

2018-01-01

This paper analyzes the influence of phase noise and distortion on the performance of oscillator-based sensor data acquisition systems. Circuit noise inherent to the oscillator circuit manifests as phase noise and limits the SNR. Moreover, oscillator nonlinearity generates distortion for large input signals. Phase noise analysis of oscillators is well known in the literature, but the relationship between phase noise and the SNR of an oscillator-based sensor is not straightforward. This paper proposes a model to estimate the influence of phase noise in the performance of an oscillator-based system by reflecting the phase noise to the oscillator input. The proposed model is based on periodic steady-state analysis tools to predict the SNR of the oscillator. The accuracy of this model has been validated by both simulation and experiment in a 130 nm CMOS prototype. We also propose a method to estimate the SNDR and the dynamic range of an oscillator-based readout circuit that improves by more than one order of magnitude the simulation time compared to standard time domain simulations. This speed up enables the optimization and verification of this kind of systems with iterative algorithms. PMID:29401646

Two-dimensional lattice gauge theories with superconducting quantum circuits

PubMed Central

Marcos, D.; Widmer, P.; Rico, E.; Hafezi, M.; Rabl, P.; Wiese, U.-J.; Zoller, P.

2014-01-01

A quantum simulator of U(1) lattice gauge theories can be implemented with superconducting circuits. This allows the investigation of confined and deconfined phases in quantum link models, and of valence bond solid and spin liquid phases in quantum dimer models. Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well. Here we show how state-of-the-art superconducting technology allows us to simulate these phenomena in relatively small circuit lattices. By exploiting the strong non-linear couplings between quantized excitations emerging when superconducting qubits are coupled, we show how to engineer gauge invariant Hamiltonians, including ring-exchange and four-body Ising interactions. We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories. The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability. PMID:25512676

A clocking discipline for two-phase digital integrated circuits

NASA Astrophysics Data System (ADS)

Noice, D. C.

1983-09-01

Sooner or later a designer of digital circuits must face the problem of timing verification so he can avoid errors caused by clock skew, critical races, and hazards. Unlike previous verification methods, such as timing simulation and timing analysis, the approach presented here guarantees correct operation despite uncertainty about delays in the circuit. The result is a clocking discipline that deals with timing abstractions only. It is not based on delay calculations; it is only concerned with the correct, synchronous operation at some clock rate. Accordingly, it may be used earlier in the design cycle, which is particularly important to integrated circuit designs. The clocking discipline consists of a notation of clocking types, and composition rules for using the types. Together, the notation and rules define a formal theory of two phase clocking. The notation defines the names and exact characteristics for different signals that are used in a two phase digital system. The notation makes it possible to develop rules for propagating the clocking types through particular circuits.

An Agile Beam Transmit Array Using Coupled Oscillator Phase Control

NASA Technical Reports Server (NTRS)

Pogorzelski, Ronald S.; Scaramastra, Rocco P.; Huang, John; Beckon, Robert J.; Petree, Steve M.; Chavez, Cosme

1993-01-01

A few years ago York and colleagues suggested that injection locking of voltage controlled oscillators could be used to implement beam steering in a phased array [I]. The scheme makes use of the fact that when an oscillator is injection locked to an external signal, the phase difference between the output of the oscillator and the injection signal is governed by the difference between the injection frequency and the free running frequency of the oscillator (the frequency to which the oscillator is tuned). Thus, if voltage controlled oscillators (VCOs) are used, this phase difference is controlled by an applied voltage. Now, if a set of such oscillators are coupled to nearest neighbors, they can be made to mutually injection lock and oscillate as an ensemble. If they are all tuned to the same frequency, they will all oscillate in phase. Thus, if the outputs are connected to radiating elements forming a linear array, the antenna will radiate normal to the line of elements. Scanning is accomplished by antisymmetrically detuning the end oscillators in the array by application of a pair of appropriate voltages to their tuning ports. This results in a linear phase progression across the array which is just the phasing required to scan the beam. The scan angle is determined by the degree of detuning. We have constructed a seven element one dimensional agile beam array at S-band based on the above principle. Although, a few such arrays have been built in the past, this array possesses two unique features. First, the VCO MMICs have buffer amplifiers which isolate the output from the tuning circuit, and second, the oscillators are weakly coupled to each other at their resonant circuits rather than their outputs. This results in a convenient isolation between the oscillator array design and the radiating aperture design. An important parameter in the design is the so called coupling phase which determines the phase shift of the signals passing from one oscillator to its neighbors. Using this array, we have been able to verify the theoretical predictions concerning the effect of this phase on both the locking range and ensemble frequency of the array. However, the scan range achieved fell somewhat short of the theoretical value because of the amplitude variation of the oscillator outputs with tuning.

Josephson junction in the quantum mesoscopic electric circuits with charge discreteness

NASA Astrophysics Data System (ADS)

Pahlavani, H.

2018-04-01

A quantum mesoscopic electrical LC-circuit with charge discreteness including a Josephson junction is considered and a nonlinear Hamiltonian that describing the dynamic of such circuit is introduced. The quantum dynamical behavior (persistent current probability) is studied in the charge and phase regimes by numerical solution approaches. The time evolution of charge and current, number-difference and the bosonic phase and also the energy spectrum of a quantum mesoscopic electric LC-circuit with charge discreteness that coupled with a Josephson junction device are investigated. We show the role of the coupling energy and the electrostatic Coulomb energy of the Josephson junction in description of the quantum behavior and the spectral properties of a quantum mesoscopic electrical LC-circuits with charge discreteness.

A new chaotic attractor with two quadratic nonlinearities, its synchronization and circuit implementation

NASA Astrophysics Data System (ADS)

Vaidyanathan, S.; Sambas, A.; Sukono; Mamat, M.; Gundara, G.; Mada Sanjaya, W. S.; Subiyanto

2018-03-01

A 3-D new chaotic attractor with two quadratic nonlinearities is proposed in this paper. The dynamical properties of the new chaotic system are described in terms of phase portraits, equilibrium points, Lyapunov exponents, Kaplan-Yorke dimension, dissipativity, etc. We show that the new chaotic system has three unstable equilibrium points. The new chaotic attractor is dissipative in nature. As an engineering application, adaptive synchronization of identical new chaotic attractors is designed via nonlinear control and Lyapunov stability theory. Furthermore, an electronic circuit realization of the new chaotic attractor is presented in detail to confirm the feasibility of the theoretical chaotic attractor model.

30 CFR 77.900-2 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2011 CFR

2011-07-01

... protecting low- and medium-voltage circuits serving three-phase alternating current equipment and such record... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

30 CFR 75.900-3 - Testing, examination, and maintenance of circuit breakers; procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... current circuits serving three-phase alternating current equipment and their auxiliary devices shall be... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-3 Testing, examination, and...

30 CFR 77.900-1 - Testing, examination, and maintenance of circuit breakers; procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... protecting low- and medium-voltage circuits serving portable or mobile three-phase alternating current... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

30 CFR 77.900-2 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2010 CFR

2010-07-01

... protecting low- and medium-voltage circuits serving three-phase alternating current equipment and such record... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

30 CFR 77.900-1 - Testing, examination, and maintenance of circuit breakers; procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... protecting low- and medium-voltage circuits serving portable or mobile three-phase alternating current... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

30 CFR 75.900-3 - Testing, examination, and maintenance of circuit breakers; procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... current circuits serving three-phase alternating current equipment and their auxiliary devices shall be... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-3 Testing, examination, and...

Intralimb and Interlimb Cutaneous Reflexes during Locomotion in the Intact Cat.

PubMed

Hurteau, Marie-France; Thibaudier, Yann; Dambreville, Charline; Danner, Simon M; Rybak, Ilya A; Frigon, Alain

2018-04-25

When the foot contacts an obstacle during locomotion, cutaneous inputs activate spinal circuits to ensure dynamic balance and forward progression. In quadrupeds, this requires coordinated reflex responses between the four limbs. Here, we investigated the patterns and phasic modulation of cutaneous reflexes in forelimb and hindlimb muscles evoked by inputs from all four limbs. Five female cats were implanted to record muscle activity and to stimulate the superficial peroneal and superficial radial nerves during locomotion. Stimulating these nerves evoked short-, mid-, and longer-latency excitatory and/or inhibitory responses in all four limbs that were phase-dependent. The largest responses were generally observed during the peak activity of the muscle. Cutaneous reflexes during mid-swing were consistent with flexion of the homonymous limb and accompanied by modification of the stance phases of the other three limbs, by coactivating flexors and extensors and/or by delaying push-off. Cutaneous reflexes during mid-stance were consistent with stabilizing the homonymous limb by delaying and then facilitating its push-off and modifying the support phases of the homolateral and diagonal limbs, characterized by coactivating flexors and extensors, reinforcing extensor activity and/or delaying push-off. The shortest latencies of homolateral and diagonal responses were consistent with fast-conducting disynaptic or trisynaptic pathways. Descending homolateral and diagonal pathways from the forelimbs to the hindlimbs had a higher probability of eliciting responses compared with ascending pathways from the hindlimbs to the forelimbs. Thus, in quadrupeds, intralimb and interlimb reflexes activated by cutaneous inputs ensure dynamic coordination of the four limbs, producing a whole-body response. SIGNIFICANCE STATEMENT The skin contains receptors that, when activated, send inputs to spinal circuits, signaling a perturbation. Rapid responses, or reflexes, in muscles of the contacted limb and opposite homologous limb help maintain balance and forward progression. Here, we investigated reflexes during quadrupedal locomotion in the cat by electrically stimulating cutaneous nerves in each of the four limbs. Functionally, responses appear to modify the trajectory or stabilize the movement of the stimulated limb while modifying the support phase of the other limbs. Reflexes between limbs are mediated by fast-conducting pathways that involve excitatory and inhibitory circuits controlling each limb. The comparatively stronger descending pathways from cervical to lumbar circuits controlling the forelimbs and hindlimbs, respectively, could serve a protective function. Copyright © 2018 the authors 0270-6474/18/384104-19$15.00/0.

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.

Magnetically Controlled Variable Transformer

NASA Technical Reports Server (NTRS)

Kleiner, Charles T.

1994-01-01

Improved variable-transformer circuit, output voltage and current of which controlled by use of relatively small current supplied at relatively low power to control windings on its magnetic cores. Transformer circuits of this type called "magnetic amplifiers" because ratio between controlled output power and power driving control current of such circuit large. This ratio - power gain - can be as large as 100 in present circuit. Variable-transformer circuit offers advantages of efficiency, safety, and controllability over some prior variable-transformer circuits.

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

De Geronimo, Gianluigi

Embodiments of comparator circuits are disclosed. A comparator circuit may include a differential input circuit, an output circuit, a positive feedback circuit operably coupled between the differential input circuit and the output circuit, and a hysteresis control circuit operably coupled with the positive feedback circuit. The hysteresis control circuit includes a switching device and a transistor. The comparator circuit provides sub-hysteresis discrimination and high speed discrimination.

Single-phase frequency converter

NASA Astrophysics Data System (ADS)

Baciu, I.; Cunţan, C. D.

2017-01-01

The paper presents a continuous voltage inverter - AC (12V / 230V) made with IGBT and two-stage voltage transformer. The sequence control transistors is achieved using a ring counter whose clock signal is obtained with a monostable circuit LM 555. The frequency of the clock signal can be adjustment with a potentiometer that modifies the charging current of the capacitor which causes constant monostable circuit time. Command sequence consists of 8 intervals of which 6 are assigned to command four transistors and two for the period break at the beginning and end of the sequence control. To obtain an alternation consisting of two different voltage level, two transistors will be comanded, connected to different windings of the transformer and the one connected to the winding providing lower voltage must be comanded twice. The output of the numerator goes through an inverter type MOS and a current amplifier with bipolar transistor.To achieve galvanic separation, an optocoupler will be used for each IGBT transistor, while protection is achieved with resistance and diode circuit. At the end there is connected an LC filter for smoothing voltage variations.

Offset-free rail-to-rail derandomizing peak detect-and-hold circuit

DOEpatents

DeGeronimo, Gianluigi; O'Connor, Paul; Kandasamy, Anand

2003-01-01

A peak detect-and-hold circuit eliminates errors introduced by conventional amplifiers, such as common-mode rejection and input voltage offset. The circuit includes an amplifier, three switches, a transistor, and a capacitor. During a detect-and-hold phase, a hold voltage at a non-inverting in put terminal of the amplifier tracks an input voltage signal and when a peak is reached, the transistor is switched off, thereby storing a peak voltage in the capacitor. During a readout phase, the circuit functions as a unity gain buffer, in which the voltage stored in the capacitor is provided as an output voltage. The circuit is able to sense signals rail-to-rail and can readily be modified to sense positive, negative, or peak-to-peak voltages. Derandomization may be achieved by using a plurality of peak detect-and-hold circuits electrically connected in parallel.

Phase-locked-loop-based delay-line-free picosecond electro-optic sampling system

NASA Astrophysics Data System (ADS)

Lin, Gong-Ru; Chang, Yung-Cheng

2003-04-01

A delay-line-free, high-speed electro-optic sampling (EOS) system is proposed by employing a delay-time-controlled ultrafast laser diode as the optical probe. Versatile optoelectronic delay-time controllers (ODTCs) based on modified voltage-controlled phase-locked-loop phase-shifting technologies are designed for the laser. The integration of the ODTC circuit and the pulsed laser diode has replaced the traditional optomechanical delay-line module used in the conventional EOS system. This design essentially prevents sampling distortion from misalignment of the probe beam, and overcomes the difficulty in sampling free-running high-speed transients. The maximum tuning range, error, scanning speed, tuning responsivity, and resolution of the ODTC are 3.9π (700°), <5% deviation, 25-2405 ns/s, 0.557 ps/mV, and ˜1 ps, respectively. Free-running wave forms from the analog, digital, and pulsed microwave signals are sampled and compared with those measured by the commercial apparatus.

Low-power grating detection system chip for high-speed low-cost length and angle precision measurement

NASA Astrophysics Data System (ADS)

Hou, Ligang; Luo, Rengui; Wu, Wuchen

2006-11-01

This paper forwards a low power grating detection chip (EYAS) on length and angle precision measurement. Traditional grating detection method, such as resister chain divide or phase locked divide circuit are difficult to design and tune. The need of an additional CPU for control and display makes these methods' implementation more complex and costly. Traditional methods also suffer low sampling speed for the complex divide circuit scheme and CPU software compensation. EYAS is an application specific integrated circuit (ASIC). It integrates micro controller unit (MCU), power management unit (PMU), LCD controller, Keyboard interface, grating detection unit and other peripherals. Working at 10MHz, EYAS can afford 5MHz internal sampling rate and can handle 1.25MHz orthogonal signal from grating sensor. With a simple control interface by keyboard, sensor parameter, data processing and system working mode can be configured. Two LCD controllers can adapt to dot array LCD or segment bit LCD, which comprised output interface. PMU alters system between working and standby mode by clock gating technique to save power. EYAS in test mode (system action are more frequently than real world use) consumes 0.9mw, while 0.2mw in real world use. EYAS achieved the whole grating detection system function, high-speed orthogonal signal handling in a single chip with very low power consumption.

Module Twelve: Series AC Resistive-Reactive Circuits; Basic Electricity and Electronics Individualized Learning System.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

The module covers series circuits which contain both resistive and reactive components and methods of solving these circuits for current, voltage, impedance, and phase angle. The module is divided into six lessons: voltage and impedance in AC (alternating current) series circuits, vector computations, rectangular and polar notation, variational…

Ripple gate drive circuit for fast operation of series connected IGBTs

DOEpatents

Rockot, Joseph H.; Murray, Thomas W.; Bass, Kevin C.

2005-09-20

A ripple gate drive circuit includes a plurality of transistors having their power terminals connected in series across an electrical potential. A plurality of control circuits, each associated with one of the transistors, is provided. Each control circuit is responsive to a control signal and an optical signal received from at least one other control circuit for controlling the conduction of electrical current through the power terminals of the associated transistor. The control circuits are responsive to a first state of the control circuit for causing each transistor in series to turn on sequentially and responsive to a second state of the control signal for causing each transistor in series to turn off sequentially.

30 CFR 75.815 - Disconnect devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... phase-to-phase voltage of the circuit in which they are installed, and for the full-load current of the... explosion-proof enclosures, must be capable of interrupting the full-load current of the circuit or designed and installed to cause the current to be interrupted automatically prior to the opening of the...

30 CFR 75.815 - Disconnect devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... phase-to-phase voltage of the circuit in which they are installed, and for the full-load current of the... explosion-proof enclosures, must be capable of interrupting the full-load current of the circuit or designed and installed to cause the current to be interrupted automatically prior to the opening of the...

75 FR 41529 - Petitions for Modification

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-16

... number'' on the subject line, by any of the following methods: 1. Electronic Mail: Standards-Petitions... permissible pump trailing cables will not be smaller than 10 American Wire Gauge (AWG); (4) all circuit... will have an instantaneous trip unit calibrated to trip at 70 percent of phase-to-phase short-circuit...

75 FR 12793 - Petitions for Modification

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-17

... number'' on the subject line, by any of the following methods: 1. Electronic Mail: Standards-Petitions... cables will be no smaller than 10 American Wire Gauge (AWG); (4) all circuit breakers used to protect... unit calibrated to trip at 70% of phase to phase short circuit current. The trip setting of these...

Polarization entangled cluster state generation in a lithium niobate chip

NASA Astrophysics Data System (ADS)

Szep, Attila; Kim, Richard; Shin, Eunsung; Fanto, Michael L.; Osman, Joseph; Alsing, Paul M.

2016-10-01

We present a design of a quantum information processing C-phase (Controlled-phase) gate applicable for generating cluster states that has a form of integrated photonic circuits assembled with cascaded directional couplers on a Ti in-diffused Lithium Niobate (Ti-LN) platform where directional couplers as the integrated optical analogue of bulk beam splitters are used as fundamental building blocks. Based on experimentally optimized fabrication parameters of Ti-LN optical waveguides operating at an 810nm wavelength, an integrated Ti-LN quantum C-phase gate is designed and simulated. Our proposed C-phase gate consists of three tunable directional couplers cascaded together with having different weighted switching ratios for providing a tool of routing vertically- and horizontally-polarized photons independently. Its operation mechanism relies on selectively controlling the optical coupling of orthogonally polarized modes via the change in the index of refraction, and its operation is confirmed by the BPM simulation.

Programmable Oscillator

NASA Technical Reports Server (NTRS)

Quirk, Kevin J.; Patawaran, Ferze D.; Nguyen, Danh H.; Lee, Clement G.; Nguyen, Huy

2011-01-01

A programmable oscillator is a frequency synthesizer with an output phase that tracks an arbitrary function. An offset, phase-locked loop circuit is used in combination with an error control feedback loop to precisely control the output phase of the oscillator. To down-convert the received signal, several stages of mixing may be employed with the compensation for the time-base distortion of the carrier occurring at any one of those stages. In the Goldstone Solar System Radar (GSSR), the compensation occurs in the mixing from an intermediate frequency (IF), whose value is dependent on the station and band, to a common IF used in the final stage of down-conversion to baseband. The programmable oscillator (PO) is used in the final stage of down-conversion to generate the IF, along with a time-varying phase component that matches the time-base distortion of the carrier, thus removing it from the final down-converted signal.

49 CFR 236.5 - Design of control circuits on closed circuit principle.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Design of control circuits on closed circuit... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on...

49 CFR 236.5 - Design of control circuits on closed circuit principle.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Design of control circuits on closed circuit... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on...

49 CFR 236.5 - Design of control circuits on closed circuit principle.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Design of control circuits on closed circuit... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on...

49 CFR 236.5 - Design of control circuits on closed circuit principle.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on...

49 CFR 236.5 - Design of control circuits on closed circuit principle.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Design of control circuits on closed circuit... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on...

30 CFR 75.900-4 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2011 CFR

2011-07-01

... circuits serving three-phase alternating current equipment used in the mine. Such record shall be kept in a... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-4 Testing, examination, and...

30 CFR 75.900-4 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2010 CFR

2010-07-01

... circuits serving three-phase alternating current equipment used in the mine. Such record shall be kept in a... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-4 Testing, examination, and...

Photographic Video Disc Technology Assessment

DTIC Science & Technology

1976-09-27

by a universal type motor that is driven from the ac power lines using a triac . The triac is controlled by a phase locked loop control circuit that...Regardless of signal format, direct analogue or an A/D converted digital signal, it is recorded by modulated laser beam and can be read out by either...was made to record with frequency modulation (FM) because of its immunity to noise at low frequencies where much of the system noise is. The usual

Simulating quantum spin Hall effect in the topological Lieb lattice of a linear circuit network

NASA Astrophysics Data System (ADS)

Zhu, Weiwei; Hou, Shanshan; Long, Yang; Chen, Hong; Ren, Jie

2018-02-01

Inspired by the topological insulator circuit experimentally proposed by Jia Ningyuan et al. [Phys. Rev. X 5, 021031 (2015), 10.1103/PhysRevX.5.021031], we theoretically realize the topological Lieb lattice, a line-centered square lattice with rich topological properties, in a radio-frequency circuit. We design a specific capacitor-inductor connection to resemble the intrinsic spin-orbit coupling and construct the analog spin by mixing degrees of freedom of voltages. As such, we are able to simulate the quantum spin Hall effect in the topological Lieb lattice of linear circuits. We then investigate the spin-resolved topological edge mode and the topological phase transition of the band structure varied with capacitances. Finally, we discuss the extension of the π /2 phase change of hopping between sites to arbitrary phase values. Our results may find implications in engineering microwave topological metamaterials for signal transmission and energy harvesting.

No scanning depth imaging system based on TOF

NASA Astrophysics Data System (ADS)

Sun, Rongchun; Piao, Yan; Wang, Yu; Liu, Shuo

2016-03-01

To quickly obtain a 3D model of real world objects, multi-point ranging is very important. However, the traditional measuring method usually adopts the principle of point by point or line by line measurement, which is too slow and of poor efficiency. In the paper, a no scanning depth imaging system based on TOF (time of flight) was proposed. The system is composed of light source circuit, special infrared image sensor module, processor and controller of image data, data cache circuit, communication circuit, and so on. According to the working principle of the TOF measurement, image sequence was collected by the high-speed CMOS sensor, and the distance information was obtained by identifying phase difference, and the amplitude image was also calculated. Experiments were conducted and the experimental results show that the depth imaging system can achieve no scanning depth imaging function with good performance.

Universal null DTE (data terminal equipment)

DOEpatents

George, M.; Pierson, L.G.; Wilkins, M.E.

1987-11-09

A communication device in the form of data terminal equipment permits two data communication equipments, each having its own master clock and operating at substantially the same nominal clock rate, to communicate with each other in a multi-segment circuit configuration of a general communication network even when phase or frequency errors exist between the two clocks. Data transmitted between communication equipments of two segments of the communication network is buffered. A variable buffer fill circuit is provided to fill the buffer to a selectable extent prior to initiation of data output clocking. Selection switches are provided to select the degree of buffer preload. A dynamic buffer fill circuit may be incorporated for automatically selecting the buffer fill level as a function of the difference in clock frequencies of the two equipments. Controllable alarm circuitry is provided for selectively generating an underflow or an overflow alarm to one or both of the communicating equipments. 5 figs.

Universal null DTE

DOEpatents

George, Michael; Pierson, Lyndon G.; Wilkins, Mark E.

1989-01-01

A communication device in the form of data terminal equipment permits two data communication equipments, each having its own master clock and operating at substantially the same nominal clock rate, to communicate with each other in a multi-segment circuit configuration of a general communication network even when phase or frequency errors exist between the two clocks. Data transmitted between communication equipments of two segments of the communication network is buffered. A variable buffer fill circuit is provided to fill the buffer to a selectable extent prior to initiation of data output clocking. Selection switches are provided to select the degree of buffer preload. A dynamic buffer fill circuit may be incorporated for automatically selecting the buffer fill level as a function of the difference in clock frequencies of the two equipments. Controllable alarm circuitry is provided for selectively generating an underflow or an overflow alarm to one or both of the communicating equipments.

Self-consistent radiation-based simulation of electric arcs: II. Application to gas circuit breakers

NASA Astrophysics Data System (ADS)

Iordanidis, A. A.; Franck, C. M.

2008-07-01

An accurate and robust method for radiative heat transfer simulation for arc applications was presented in the previous paper (part I). In this paper a self-consistent mathematical model based on computational fluid dynamics and a rigorous radiative heat transfer model is described. The model is applied to simulate switching arcs in high voltage gas circuit breakers. The accuracy of the model is proven by comparison with experimental data for all arc modes. The ablation-controlled arc model is used to simulate high current PTFE arcs burning in cylindrical tubes. Model accuracy for the lower current arcs is evaluated using experimental data on the axially blown SF6 arc in steady state and arc resistance measurements close to current zero. The complete switching process with the arc going through all three phases is also simulated and compared with the experimental data from an industrial circuit breaker switching test.

A three-level advanced static VAr compensator

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

Ekanayake, J.B.; Jenkins, N.

1996-01-01

An Advanced Static VAr Compensator (ASVC) employing a three level inverter has been investigated for three phase applications. The paper describes the operating principles of the ASVC using an elementary single phase ASVC circuit. The construction of a hardware model of the three phase, three level ASVC is then presented. The performance of the ASVC is obtained from an experimental study carried out on this laboratory model. The use of the selective harmonic elimination modulation (SHEM) technique to minimize harmonics is explored. Experimental studies have been carried out to determine the speed of response of the scheme by controlling itmore » in a closed loop.« less

A self-resetting spiking phase-change neuron

NASA Astrophysics Data System (ADS)

Cobley, R. A.; Hayat, H.; Wright, C. D.

2018-05-01

Neuromorphic, or brain-inspired, computing applications of phase-change devices have to date concentrated primarily on the implementation of phase-change synapses. However, the so-called accumulation mode of operation inherent in phase-change materials and devices can also be used to mimic the integrative properties of a biological neuron. Here we demonstrate, using physical modelling of nanoscale devices and SPICE modelling of associated circuits, that a single phase-change memory cell integrated into a comparator type circuit can deliver a basic hardware mimic of an integrate-and-fire spiking neuron with self-resetting capabilities. Such phase-change neurons, in combination with phase-change synapses, can potentially open a new route for the realisation of all-phase-change neuromorphic computing.

A self-resetting spiking phase-change neuron.

PubMed

Cobley, R A; Hayat, H; Wright, C D

2018-05-11

Neuromorphic, or brain-inspired, computing applications of phase-change devices have to date concentrated primarily on the implementation of phase-change synapses. However, the so-called accumulation mode of operation inherent in phase-change materials and devices can also be used to mimic the integrative properties of a biological neuron. Here we demonstrate, using physical modelling of nanoscale devices and SPICE modelling of associated circuits, that a single phase-change memory cell integrated into a comparator type circuit can deliver a basic hardware mimic of an integrate-and-fire spiking neuron with self-resetting capabilities. Such phase-change neurons, in combination with phase-change synapses, can potentially open a new route for the realisation of all-phase-change neuromorphic computing.

Novel microwave photonic fractional Hilbert transformer using a ring resonator-based optical all-pass filter.

PubMed

Zhuang, Leimeng; Khan, Muhammad Rezaul; Beeker, Willem; Leinse, Arne; Heideman, René; Roeloffzen, Chris

2012-11-19

We propose and demonstrate a novel wideband microwave photonic fractional Hilbert transformer implemented using a ring resonator-based optical all-pass filter. The full programmability of the ring resonator allows variable and arbitrary fractional order of the Hilbert transformer. The performance analysis in both frequency and time domain validates that the proposed implementation provides a good approximation to an ideal fractional Hilbert transformer. This is also experimentally verified by an electrical S₂₁ response characterization performed on a waveguide realization of a ring resonator. The waveguide-based structure allows the proposed Hilbert transformer to be integrated together with other building blocks on a photonic integrated circuit to create various system-level functionalities for on-chip microwave photonic signal processors. As an example, a circuit consisting of a splitter and a ring resonator has been realized which can perform on-chip phase control of microwave signals generated by means of optical heterodyning, and simultaneous generation of in-phase and quadrature microwave signals for a wide frequency range. For these functionalities, this simple and on-chip solution is considered to be practical, particularly when operating together with a dual-frequency laser. To our best knowledge, this is the first-time on-chip demonstration where ring resonators are employed to perform phase control functionalities for optical generation of microwave signals by means of optical heterodyning.

Technology achievements and projections for communication satellites of the future

NASA Technical Reports Server (NTRS)

Bagwell, J. W.

1986-01-01

Multibeam systems of the future using monolithic microwave integrated circuits to provide phase control and power gain are contrasted with discrete microwave power amplifiers from 10 to 75 W and their associated waveguide feeds, phase shifters and power splitters. Challenging new enabling technology areas include advanced electrooptical control and signal feeds. Large scale MMIC's will be used incorporating on chip control interfaces, latching, and phase and amplitude control with power levels of a few watts each. Beam forming algorithms for 80 to 90 deg. wide angle scanning and precise beam forming under wide ranging environments will be required. Satelllite systems using these dynamically reconfigured multibeam antenna systems will demand greater degrees of beam interconnectivity. Multiband and multiservice users will be interconnected through the same space platform. Monolithic switching arrays operating over a wide range of RF and IF frequencies are contrasted with current IF switch technology implemented discretely. Size, weight, and performance improvements by an order of magnitude are projected.

Heralded quantum controlled-phase gates with dissipative dynamics in macroscopically distant resonators

NASA Astrophysics Data System (ADS)

Qin, Wei; Wang, Xin; Miranowicz, Adam; Zhong, Zhirong; Nori, Franco

2017-07-01

Heralded near-deterministic multiqubit controlled-phase gates with integrated error detection have recently been proposed by Borregaard et al. [Phys. Rev. Lett. 114, 110502 (2015), 10.1103/PhysRevLett.114.110502]. This protocol is based on a single four-level atom (a heralding quartit) and N three-level atoms (operational qutrits) coupled to a single-resonator mode acting as a cavity bus. Here we generalize this method for two distant resonators without the cavity bus between the heralding and operational atoms. Specifically, we analyze the two-qubit controlled-Z gate and its multiqubit-controlled generalization (i.e., a Toffoli-like gate) acting on the two-lowest levels of N qutrits inside one resonator, with their successful actions being heralded by an auxiliary microwave-driven quartit inside the other resonator. Moreover, we propose a circuit-quantum-electrodynamics realization of the protocol with flux and phase qudits in linearly coupled transmission-line resonators with dissipation. These methods offer a quadratic fidelity improvement compared to cavity-assisted deterministic gates.

Nonvolatile “AND,” “OR,” and “NOT” Boolean logic gates based on phase-change memory

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

Li, Y.; Zhong, Y. P.; Deng, Y. F.

2013-12-21

Electronic devices or circuits that can implement both logic and memory functions are regarded as the building blocks for future massive parallel computing beyond von Neumann architecture. Here we proposed phase-change memory (PCM)-based nonvolatile logic gates capable of AND, OR, and NOT Boolean logic operations verified in SPICE simulations and circuit experiments. The logic operations are parallel computing and results can be stored directly in the states of the logic gates, facilitating the combination of computing and memory in the same circuit. These results are encouraging for ultralow-power and high-speed nonvolatile logic circuit design based on novel memory devices.

Ferruleless coupled-cavity traveling-wave tube cold-test characteristics simulated with micro-SOS

NASA Technical Reports Server (NTRS)

Schroeder, Dana L.; Wilson, Jeffrey D.

1993-01-01

The three-dimensional, electromagnetic circuit analysis code, Micro-SOS, can be used to reduce expensive and time consuming experimental 'cold-testing' of traveling-wave tube (TWT) circuits. The frequency-phase dispersion and beam interaction impedance characteristics of a ferruleless coupled-cavity traveling-wave tube slow-wave circuit were simulated using the code. Computer results agree closely with experimental data. Variations in the cavity geometry dimensions of period length and gap-to-period ratio were modeled. These variations can be used in velocity taper designs to reduce the radiofrequency (RF) phase velocity in synchronism with the decelerating electron beam. Such circuit designs can result in enhanced TWT power and efficiency.

Equivalent circuit for VO{sub 2} phase change material film in reconfigurable frequency selective surfaces

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

Sanphuang, Varittha; Ghalichechian, Nima; Nahar, Niru K.

We developed equivalent circuits of phase change materials based on vanadium dioxide (VO{sub 2}) thin films. These circuits are used to model VO{sub 2} thin films for reconfigurable frequency selective surfaces (FSSs). This is important as it provides a way for designing complex structures. A reconfigurable FSS filter using VO{sub 2} ON/OFF switches is designed demonstrating −60 dB isolation between the states. This filter is used to provide the transmission and reflection responses of the FSS in the frequency range of 0.1–0.6 THz. The comparison between equivalent circuit and full-wave simulation shows excellent agreement.

Radiation-Hardened Electronics for Advanced Communications Systems

NASA Technical Reports Server (NTRS)

Whitaker, Sterling

2015-01-01

Novel approach enables high-speed special-purpose processors Advanced reconfigurable and reprogrammable communication systems will require sub-130-nanometer electronics. Legacy single event upset (SEU) radiation-tolerant circuits are ineffective at speeds greater than 125 megahertz. In Phase I of this project, ICs, LLC, demonstrated new base-level logic circuits that provide SEU immunity for sub-130-nanometer high-speed circuits. In Phase II, the company developed an innovative self-restoring logic (SRL) circuit and a system approach that provides high-speed, SEU-tolerant solutions that are effective for sub-130-nanometer electronics scalable to at least 22-nanometer processes. The SRL system can be used in the design of NASA's next-generation special-purpose processors, especially reconfigurable communication processors.

49 CFR 236.103 - Switch circuit controller or point detector.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Switch circuit controller or point detector. 236.103 Section 236.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... controller or point detector. Switch circuit controller, circuit controller, or point detector operated by...

49 CFR 236.103 - Switch circuit controller or point detector.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Switch circuit controller or point detector. 236.103 Section 236.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... controller or point detector. Switch circuit controller, circuit controller, or point detector operated by...

49 CFR 236.103 - Switch circuit controller or point detector.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Switch circuit controller or point detector. 236.103 Section 236.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... controller or point detector. Switch circuit controller, circuit controller, or point detector operated by...

49 CFR 236.103 - Switch circuit controller or point detector.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Switch circuit controller or point detector. 236.103 Section 236.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... controller or point detector. Switch circuit controller, circuit controller, or point detector operated by...

49 CFR 236.103 - Switch circuit controller or point detector.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Switch circuit controller or point detector. 236.103 Section 236.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... controller or point detector. Switch circuit controller, circuit controller, or point detector operated by...

Towards phase-coherent caloritronics in superconducting circuits

NASA Astrophysics Data System (ADS)

Fornieri, Antonio; Giazotto, Francesco

2017-10-01

The emerging field of phase-coherent caloritronics (from the Latin word calor, heat) is based on the possibility of controlling heat currents by using the phase difference of the superconducting order parameter. The goal is to design and implement thermal devices that can control energy transfer with a degree of accuracy approaching that reached for charge transport by contemporary electronic components. This can be done by making use of the macroscopic quantum coherence intrinsic to superconducting condensates, which manifests itself through the Josephson effect and the proximity effect. Here, we review recent experimental results obtained in the realization of heat interferometers and thermal rectifiers, and discuss a few proposals for exotic nonlinear phase-coherent caloritronic devices, such as thermal transistors, solid-state memories, phase-coherent heat splitters, microwave refrigerators, thermal engines and heat valves. Besides being attractive from the fundamental physics point of view, these systems are expected to have a vast impact on many cryogenic microcircuits requiring energy management, and possibly lay the first stone for the foundation of electronic thermal logic.

Towards phase-coherent caloritronics in superconducting circuits.

PubMed

Fornieri, Antonio; Giazotto, Francesco

2017-10-06

The emerging field of phase-coherent caloritronics (from the Latin word calor, heat) is based on the possibility of controlling heat currents by using the phase difference of the superconducting order parameter. The goal is to design and implement thermal devices that can control energy transfer with a degree of accuracy approaching that reached for charge transport by contemporary electronic components. This can be done by making use of the macroscopic quantum coherence intrinsic to superconducting condensates, which manifests itself through the Josephson effect and the proximity effect. Here, we review recent experimental results obtained in the realization of heat interferometers and thermal rectifiers, and discuss a few proposals for exotic nonlinear phase-coherent caloritronic devices, such as thermal transistors, solid-state memories, phase-coherent heat splitters, microwave refrigerators, thermal engines and heat valves. Besides being attractive from the fundamental physics point of view, these systems are expected to have a vast impact on many cryogenic microcircuits requiring energy management, and possibly lay the first stone for the foundation of electronic thermal logic.

Characteristic investigation and control of a modular multilevel converter-based HVDC system under single-line-to-ground fault conditions

DOE PAGES

Shi, Xiaojie; Wang, Zhiqiang; Liu, Bo; ...

2014-05-16

This paper presents the analysis and control of a multilevel modular converter (MMC)-based HVDC transmission system under three possible single-line-to-ground fault conditions, with special focus on the investigation of their different fault characteristics. Considering positive-, negative-, and zero-sequence components in both arm voltages and currents, the generalized instantaneous power of a phase unit is derived theoretically according to the equivalent circuit model of the MMC under unbalanced conditions. Based on this model, a novel double-line frequency dc-voltage ripple suppression control is proposed. This controller, together with the negative-and zero-sequence current control, could enhance the overall fault-tolerant capability of the HVDCmore » system without additional cost. To further improve the fault-tolerant capability, the operation performance of the HVDC system with and without single-phase switching is discussed and compared in detail. Lastly, simulation results from a three-phase MMC-HVDC system generated with MATLAB/Simulink are provided to support the theoretical analysis and proposed control schemes.« less

Effects of Random Circuit Fabrication Errors on Small Signal Gain and on Output Phase In a Traveling Wave Tube

NASA Astrophysics Data System (ADS)

Rittersdorf, I. M.; Antonsen, T. M., Jr.; Chernin, D.; Lau, Y. Y.

2011-10-01

Random fabrication errors may have detrimental effects on the performance of traveling-wave tubes (TWTs) of all types. A new scaling law for the modification in the average small signal gain and in the output phase is derived from the third order ordinary differential equation that governs the forward wave interaction in a TWT in the presence of random error that is distributed along the axis of the tube. Analytical results compare favorably with numerical results, in both gain and phase modifications as a result of random error in the phase velocity of the slow wave circuit. Results on the effect of the reverse-propagating circuit mode will be reported. This work supported by AFOSR, ONR, L-3 Communications Electron Devices, and Northrop Grumman Corporation.

Cooled, temperature controlled electrometer

DOEpatents

Morgan, John P.

1992-01-01

A cooled, temperature controlled electrometer for the measurement of small currents. The device employs a thermal transfer system to remove heat from the electrometer circuit and its environment and dissipate it to the external environment by means of a heat sink. The operation of the thermal transfer system is governed by a temperature regulation circuit which activates the thermal transfer system when the temperature of the electrometer circuit and its environment exceeds a level previously inputted to the external variable temperature control circuit. The variable temperature control circuit functions as subpart of the temperature control circuit. To provide temperature stability and uniformity, the electrometer circuit is enclosed by an insulated housing.

Cooled, temperature controlled electrometer

DOEpatents

Morgan, John P.

1992-08-04

A cooled, temperature controlled electrometer for the measurement of small currents. The device employs a thermal transfer system to remove heat from the electrometer circuit and its environment and dissipate it to the external environment by means of a heat sink. The operation of the thermal transfer system is governed by a temperature regulation circuit which activates the thermal transfer system when the temperature of the electrometer circuit and its environment exceeds a level previously inputted to the external variable temperature control circuit. The variable temperature control circuit functions as subpart of the temperature control circuit. To provide temperature stability and uniformity, the electrometer circuit is enclosed by an insulated housing.

49 CFR 234.203 - Control circuits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Control circuits. 234.203 Section 234.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect...

49 CFR 234.203 - Control circuits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Control circuits. 234.203 Section 234.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect...

Electronic firing systems and methods for firing a device

DOEpatents

Frickey, Steven J [Boise, ID; Svoboda, John M [Idaho Falls, ID

2012-04-24

An electronic firing system comprising a control system, a charging system, an electrical energy storage device, a shock tube firing circuit, a shock tube connector, a blasting cap firing circuit, and a blasting cap connector. The control system controls the charging system, which charges the electrical energy storage device. The control system also controls the shock tube firing circuit and the blasting cap firing circuit. When desired, the control system signals the shock tube firing circuit or blasting cap firing circuit to electrically connect the electrical energy storage device to the shock tube connector or the blasting cap connector respectively.

Experimental Chaos - Proceedings of the 3rd Conference

NASA Astrophysics Data System (ADS)

Harrison, Robert G.; Lu, Weiping; Ditto, William; Pecora, Lou; Spano, Mark; Vohra, Sandeep

1996-10-01

The Table of Contents for the full book PDF is as follows: * Preface * Spatiotemporal Chaos and Patterns * Scale Segregation via Formation of Domains in a Nonlinear Optical System * Laser Dynamics as Hydrodynamics * Spatiotemporal Dynamics of Human Epileptic Seizures * Experimental Transition to Chaos in a Quasi 1D Chain of Oscillators * Measuring Coupling in Spatiotemporal Dynamical Systems * Chaos in Vortex Breakdown * Dynamical Analysis * Radial Basis Function Modelling and Prediction of Time Series * Nonlinear Phenomena in Polyrhythmic Hand Movements * Using Models to Diagnose, Test and Control Chaotic Systems * New Real-Time Analysis of Time Series Data with Physical Wavelets * Control and Synchronization * Measuring and Controlling Chaotic Dynamics in a Slugging Fluidized Bed * Control of Chaos in a Laser with Feedback * Synchronization and Chaotic Diode Resonators * Control of Chaos by Continuous-time Feedback with Delay * A Framework for Communication using Chaos Sychronization * Control of Chaos in Switching Circuits * Astrophysics, Meteorology and Oceanography * Solar-Wind-Magnetospheric Dynamics via Satellite Data * Nonlinear Dynamics of the Solar Atmosphere * Fractal Dimension of Scalar and Vector Variables from Turbulence Measurements in the Atmospheric Surface Layer * Mechanics * Escape and Overturning: Subtle Transient Behavior in Nonlinear Mechanical Models * Organising Centres in the Dynamics of Parametrically Excited Double Pendulums * Intermittent Behaviour in a Heating System Driven by Phase Transitions * Hydrodynamics * Size Segregation in Couette Flow of Granular Material * Routes to Chaos in Rotational Taylor-Couette Flow * Experimental Study of the Laminar-Turbulent Transition in an Open Flow System * Chemistry * Order and Chaos in Excitable Media under External Forcing * A Chemical Wave Propagation with Accelerating Speed Accompanied by Hydrodynamic Flow * Optics * Instabilities in Semiconductor Lasers with Optical Injection * Spatio-Temporal Dynamics of a Bimode CO2 Laser with Saturable Absorber * Chaotic Homoclinic Phenomena in Opto-Thermal Devices * Observation and Characterisation of Low-Frequency Chaos in Semiconductor Lasers with External Feedback * Condensed Matter * The Application of Nonlinear Dynamics in the Study of Ferroelectric Materials * Cellular Convection in a Small Aspect Ratio Liquid Crystal Device * Driven Spin-Wave Dynamics in YIG Films * Quantum Chaology in Quartz * Small Signal Amplification Caused by Nonlinear Properties of Ferroelectrics * Composite Materials Evolved from Chaos * Electronics and Circuits * Controlling a Chaotic Array of Pulse-Coupled Fitzhugh-Nagumo Circuits * Experimental Observation of On-Off Intermittency * Phase Lock-In of Chaotic Relaxation Oscillators * Biology and Medicine * Singular Value Decomposition and Circuit Structure in Invertebrate Ganglia * Nonlinear Forecasting of Spike Trains from Neurons of a Mollusc * Ultradian Rhythm in the Sensitive Plants: Chaos or Coloured Noise? * Chaos and the Crayfish Sixth Ganglion * Hardware Coupled Nonlinear Oscillators as a Model of Retina

Spectrum Control through Discrete Frequency Diffraction in the Presence of Photonic Gauge Potentials

NASA Astrophysics Data System (ADS)

Qin, Chengzhi; Zhou, Feng; Peng, Yugui; Sounas, Dimitrios; Zhu, Xuefeng; Wang, Bing; Dong, Jianji; Zhang, Xinliang; Alù; , Andrea; Lu, Peixiang

2018-03-01

By using optical phase modulators in a fiber-optical circuit, we theoretically and experimentally demonstrate large control over the spectrum of an impinging signal, which may evolve analogously to discrete diffraction in spatial waveguide arrays. The modulation phase acts as a photonic gauge potential in the frequency dimension, realizing efficient control of the central frequency and bandwidth of frequency combs. We experimentally achieve a 50 GHz frequency shift and threefold bandwidth expansion of an impinging comb, as well as the frequency analogue of various refraction phenomena, including negative refraction and perfect focusing in the frequency domain, both for discrete and continuous incident spectra. Our study paves a promising way towards versatile frequency management for optical communications and signal processing using time modulation schemes.

Design structure for in-system redundant array repair in integrated circuits

DOEpatents

Bright, Arthur A.; Crumley, Paul G.; Dombrowa, Marc; Douskey, Steven M.; Haring, Rudolf A.; Oakland, Steven F.; Quellette, Michael R.; Strissel, Scott A.

2008-11-25

A design structure for repairing an integrated circuit during operation of the integrated circuit. The integrated circuit comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The design structure provides the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The design structure further passes the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

49 CFR 236.201 - Track-circuit control of signals.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.201 Track-circuit control of signals. The control circuits for home... 49 Transportation 4 2011-10-01 2011-10-01 false Track-circuit control of signals. 236.201 Section...

49 CFR 236.201 - Track-circuit control of signals.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.201 Track-circuit control of signals. The control circuits for home... 49 Transportation 4 2010-10-01 2010-10-01 false Track-circuit control of signals. 236.201 Section...

Integrated Inverter For Driving Multiple Electric Machines

DOEpatents

Su, Gui-Jia [Knoxville, TN; Hsu, John S [Oak Ridge, TN

2006-04-04

An electric machine drive (50) has a plurality of inverters (50a, 50b) for controlling respective electric machines (57, 62), which may include a three-phase main traction machine (57) and two-phase accessory machines (62) in a hybrid or electric vehicle. The drive (50) has a common control section (53, 54) for controlling the plurality of inverters (50a, 50b) with only one microelectronic processor (54) for controlling the plurality of inverters (50a, 50b), only one gate driver circuit (53) for controlling conduction of semiconductor switches (S1-S10) in the plurality of inverters (50a, 50b), and also includes a common dc bus (70), a common dc bus filtering capacitor (C1) and a common dc bus voltage sensor (67). The electric machines (57, 62) may be synchronous machines, induction machines, or PM machines and may be operated in a motoring mode or a generating mode.

Respiratory diagnostic possibilities during closed circuit anesthesia.

PubMed

Verkaaik, A P; Erdmann, W

1990-01-01

An automatic feed back controlled totally closed circuit system (Physioflex) has been developed for quantitative practice of inhalation anesthesia and ventilation. In the circuit system the gas is moved unidirectionally around by a blower at 70 l/min. In the system four membrane chambers are integrated for ventilation. Besides end-expiratory feed back control of inhalation anesthetics, and inspiratory closed loop control of oxygen, the system offers on-line registration of flow, volume and respiratory pressures as well as a capnogram and oxygen consumption. Alveolar ventilation and static compliance can easily be derived. On-line registration of oxygen consumption has proven to be of value for determination of any impairment of tissue oxygen supply when the oxygen delivery has dropped to critical values. Obstruction of the upper or lower airways are immediately detected and differentiated. Disregulations of metabolism, e.g. in malignant hyperthermia, are seen in a pre-crisis phase (increase of oxygen consumption and of CO2 production), and therapy can be started extremely early and before a disastrous condition has developed. Registration of compliance is only one of the continuously available parameters that guarantee a better and adequate control of lung function (e.g. atalectasis is early detected). The newly developed sophisticated anesthesia device enlarges tremendously the monitoring and respiratory diagnostic possibilities of artificial ventilation, gives new insights in the (patho)physiology and detects disturbances of respiratory parameters and metabolism in an early stage.

High-power converters for space applications

NASA Technical Reports Server (NTRS)

Park, J. N.; Cooper, Randy

1991-01-01

Phase 1 was a concept definition effort to extend space-type dc/dc converter technology to the megawatt level with a weight of less than 0.1 kg/kW (220 lb./MW). Two system designs were evaluated in Phase 1. Each design operates from a 5 kV stacked fuel cell source and provides a voltage step-up to 100 kV at 10 A for charging capacitors (100 pps at a duty cycle of 17 min on, 17 min off). Both designs use an MCT-based, full-bridge inverter, gaseous hydrogen cooling, and crowbar fault protection. The GE-CRD system uses an advanced high-voltage transformer/rectifier filter is series with a resonant tank circuit, driven by an inverter operating at 20 to 50 kHz. Output voltage is controlled through frequency and phase shift control. Fast transient response and stability is ensured via optimal control. Super-resonant operation employing MCTs provides the advantages of lossless snubbing, no turn-on switching loss, use of medium-speed diodes, and intrinsic current limiting under load-fault conditions. Estimated weight of the GE-CRD system is 88 kg (1.5 cu ft.). Efficiency of 94.4 percent and total system loss is 55.711 kW operating at 1 MW load power. The Maxwell system is based on a resonance transformer approach using a cascade of five LC resonant sections at 100 kHz. The 5 kV bus is converted to a square wave, stepped-up to a 100 kV sine wave by the LC sections, rectified, and filtered. Output voltage is controlled with a special series regulator circuit. Estimated weight of the Maxwell system is 83.8 kg (4.0 cu ft.). Efficiency is 87.2 percent and total system loss is 146.411 kW operating at 1 MW load power.

30 CFR 18.54 - High-voltage continuous mining machines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of high... removed. (c) Circuit-interrupting devices. Circuit-interrupting devices must be designed and installed to... ground. (e) Onboard ungrounded, three-phase power circuit. A continuous mining machine designed with an...

30 CFR 18.54 - High-voltage continuous mining machines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of high... removed. (c) Circuit-interrupting devices. Circuit-interrupting devices must be designed and installed to... ground. (e) Onboard ungrounded, three-phase power circuit. A continuous mining machine designed with an...

30 CFR 18.54 - High-voltage continuous mining machines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of high... removed. (c) Circuit-interrupting devices. Circuit-interrupting devices must be designed and installed to... ground. (e) Onboard ungrounded, three-phase power circuit. A continuous mining machine designed with an...

30 CFR 18.54 - High-voltage continuous mining machines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of high... removed. (c) Circuit-interrupting devices. Circuit-interrupting devices must be designed and installed to... ground. (e) Onboard ungrounded, three-phase power circuit. A continuous mining machine designed with an...

30 CFR 18.54 - High-voltage continuous mining machines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of high... removed. (c) Circuit-interrupting devices. Circuit-interrupting devices must be designed and installed to... ground. (e) Onboard ungrounded, three-phase power circuit. A continuous mining machine designed with an...

Slow-Wave Phase Shifters, Based on Thin Ferroelectric Films, for Reflectarray Antennas. Frequency-Agile Radio: Systems and Technlogies, WMG 139

NASA Technical Reports Server (NTRS)

Romanofsky, Robert R.

2006-01-01

We have developed relatively broadband K- and Ka-band phase shifters using synthetic (slow-wave) transmission lines employing coupled microstripline "varactors". The tunable coupled microstripline circuits are based on laser ablated BaSrTiO films on lanthanum aluminate substrates. A model and design criteria for these novel circuits will be presented, along with measured performance including anomalous phase delay characteristics. The critical role of phase shifter loss and transient response in reflectarray antennas will be emphasized.

Analysis and design of negative resistance oscillators using surface transverse wave-based single port resonators.

PubMed

Avramov, Ivan D

2003-03-01

This practically oriented paper presents the fundamentals for analysis, optimization, and design of negative resistance oscillators (NRO) stabilized with surface transverse wave (STW)-based single-port resonators (SPR). Data on a variety of high-Q, low-loss SPR devices in the 900- to 2000-MHz range, suitable for NRO applications, are presented, and a simple method for SPR parameter extraction through Pi-circuit measurements is outlined. Negative resistance analysis, based on S-parameter data of the active device, is performed on a tuned-base, grounded collector transistor NRO, known for its good stability and tuning at microwave frequencies. By adding a SPR in the emitter network, the static transducer capacitance is absorbed by the circuit and is used to generate negative resistance only over the narrow bandwidth of the acoustic device, eliminating the risk of spurious oscillations. The analysis allows exact prediction of the oscillation frequency, tuning range, loaded Q, and excess gain. Simulation and experimental data on a 915-MHz fixed-frequency NRO and a wide tuning range, voltage-controlled STW oscillator, built and tested experimentally, are presented. Practical design aspects including the choice of transistor, negative feedback circuits, load coupling, and operation at the highest phase slope for minimum phase noise are discussed.

Incorporating an Electrode Modification Layer with a Vertical Phase Separated Photoactive Layer for Efficient and Stable Inverted Nonfullerene Polymer Solar Cells.

PubMed

Shi, Zhenzhen; Liu, Hao; Wang, Yaping; Li, Jinyan; Bai, Yiming; Wang, Fuzhi; Bian, Xingming; Hayat, Tasawar; Alsaedi, Ahmed; Tan, Zhan'ao

2017-12-20

For bulk heterojunction polymer solar cells (PSCs), the donors and acceptors featuring specific phase separation and concentration distribution within the electron donor/acceptor blends crucially affect the exciton dissociation and charge transportation. Herein, efficient and stable nonfullerene inverted PSCs incorporating a phase separated photoactive layer and a titanium chelate electrode modification layer are demonstrated. Water contact angle (WCA), scanning kelvin probe microscopy (SKPM), and atomic force microscopy (AFM) techniques are implemented to characterize the morphology of photoactive layers. Compared with the control conventional device, the short-circuit current density (J sc ) is enhanced from 14.74 to 17.45 mAcm -2 . The power conversion efficiency (PCE) for the inverted PSCs with a titanium (diisopropoxide)-bis-(2,4-pentanedionate) (TIPD) layer increases from 9.67% to 11.69% benefiting from the declined exciton recombination and fairly enhanced charge transportation. Furthermore, the nonencapsulated inverted device with a TIPD layer demonstrates the best long-term stability, 85% of initial PCE remaining and an almost undecayed open-circuit voltage (V oc ) after 1440 h. Our results reveal that the titanium chelate is an excellent electrode modification layer to incorporate with a vertical phase separated photoactive layer for producing high-efficiency and high-stability inverted nonfullerene PSCs.

49 CFR 234.203 - Control circuits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Control circuits. 234.203 Section 234.203... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect the safe operation of a highway-rail grade crossing warning...

49 CFR 234.203 - Control circuits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Control circuits. 234.203 Section 234.203... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect the safe operation of a highway-rail grade crossing warning...

49 CFR 236.731 - Controller, circuit.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Controller, circuit. A device for opening and closing electric circuits. ...

Radiation Tolerant, Low Noise Phase Locked Loops in 65 nm CMOS Technology

NASA Astrophysics Data System (ADS)

Prinzie, Jeffrey; Christiansen, Jorgen; Moreira, Paulo; Steyaert, Michiel; Leroux, Paul

2018-04-01

This work presents an introduction to radiation hardened Phase Locked Loops (PLLs) for nuclear and high-energy physics application. An experimental circuit has been fabricated and irradiated with Xrays up to 600 Mrad. Heavy ions with an LET between 3.2 and 69.2 MeV.cm2/mg were used to verify the SEU cross section of the devices. A Two-photon Absorption (TPA) laser facility has been used to provide detailed results on the SEU sensitivity. The presented circuit employs TMR in the digital logic and an asynchronous phase-frequency detector (PFD) is presented. The PLL has a ringand LC-oscillator to be compared experimentally. The circuit has been fabricated in a 65 nm CMOS technology.

Flow-enhanced solution printing of all-polymer solar cells

DOE PAGES

Diao, Ying; Zhou, Yan; Kurosawa, Tadanori; ...

2015-08-12

Morphology control of solution coated solar cell materials presents a key challenge limiting their device performance and commercial viability. Here we present a new concept for controlling phase separation during solution printing using an all-polymer bulk heterojunction solar cell as a model system. The key aspect of our method lies in the design of fluid flow using a microstructured printing blade, on the basis of the hypothesis of flow-induced polymer crystallization. Our flow design resulted in a similar to 90% increase in the donor thin film crystallinity and reduced microphase separated donor and acceptor domain sizes. The improved morphology enhancedmore » all metrics of solar cell device performance across various printing conditions, specifically leading to higher short-circuit current, fill factor, open circuit voltage and significantly reduced device-to-device variation. However, we expect our design concept to have broad applications beyond all-polymer solar cells because of its simplicity and versatility.« less

Full control of far-field radiation via photonic integrated circuits decorated with plasmonic nanoantennas.

PubMed

Sun, Yi-Zhi; Feng, Li-Shuang; Bachelot, Renaud; Blaize, Sylvain; Ding, Wei

2017-07-24

We theoretically develop a hybrid architecture consisting of photonic integrated circuit and plasmonic nanoantennas to fully control optical far-field radiation with unprecedented flexibility. By exploiting asymmetric and lateral excitation from silicon waveguides, single gold nanorod and cascaded nanorod pair can function as component radiation pixels, featured by full 2π phase coverage and nanoscale footprint. These radiation pixels allow us to design scalable on-chip devices in a wavefront engineering fashion. We numerically demonstrate beam collimation with 30° out of the incident plane and nearly diffraction limited divergence angle. We also present high-numerical-aperture (NA) beam focusing with NA ≈0.65 and vector beam generation (the radially-polarized mode) with the mode similarity greater than 44%. This concept and approach constitutes a designable optical platform, which might be a future bridge between integrated photonics and metasurface functionalities.

Evaluation of an Affordable Wireless Node Sensor (Mote69) Designed for Internet of Thing (IoT) Device

NASA Astrophysics Data System (ADS)

Ruhiyat, Z. F.; Somantri, Y.; Wahyudin, D.; Hakim, D. L.

2018-02-01

This research aims to determine the student’s response to the implementation of Internet of Things (IoT) device based on RFM69, called Mote69, for practical work of Aircraft Electronic Circuits and Controllers. Participants in this study were students of a vocational high school of Aircraft Electronics which consisted of three groups. The first group is the students who have grades above the average class. The second group is the students who have grade the average class. The third group is the students who have grades below the average class. The research phase consisted of (1). Observation and Assessment of Empirical Issues; (2). Testing of Media Feasibility and Research Instruments; (3). Accumulate and Processing of Field Data; and (4). Results and Data Conclusions. The result of media feasibility showed that Mote69 is appropriate to be used in practical work of Aircraft Electronic Circuits and Controllers subject.

Flow-enhanced solution printing of all-polymer solar cells

PubMed Central

Diao, Ying; Zhou, Yan; Kurosawa, Tadanori; Shaw, Leo; Wang, Cheng; Park, Steve; Guo, Yikun; Reinspach, Julia A.; Gu, Kevin; Gu, Xiaodan; Tee, Benjamin C. K.; Pang, Changhyun; Yan, Hongping; Zhao, Dahui; Toney, Michael F.; Mannsfeld, Stefan C. B.; Bao, Zhenan

2015-01-01

Morphology control of solution coated solar cell materials presents a key challenge limiting their device performance and commercial viability. Here we present a new concept for controlling phase separation during solution printing using an all-polymer bulk heterojunction solar cell as a model system. The key aspect of our method lies in the design of fluid flow using a microstructured printing blade, on the basis of the hypothesis of flow-induced polymer crystallization. Our flow design resulted in a ∼90% increase in the donor thin film crystallinity and reduced microphase separated donor and acceptor domain sizes. The improved morphology enhanced all metrics of solar cell device performance across various printing conditions, specifically leading to higher short-circuit current, fill factor, open circuit voltage and significantly reduced device-to-device variation. We expect our design concept to have broad applications beyond all-polymer solar cells because of its simplicity and versatility. PMID:26264528

Ultrahigh-speed phaselocked-loop type clock recovery circuit using a travelling-wave laser diode amplifier as a 50 GHz phase detector

NASA Astrophysics Data System (ADS)

Kawanishi, S.; Takara, H.; Saruwatari, M.; Kitoh, T.

1993-09-01

Successful operation of a phase-locked loop is demonstrated using a traveling-wave laser-diode amplifier as a 50 GHz phase detector. Optical gain modulation in the laser diode amplifier and an all-optical clock multiplication technique using a silica-based guided-wave optical circuit are used to achieve the extremely high-speed operation. Also discussed is the possibility of more than 100 GHz operation.

Topological phase transition measured in a dissipative metamaterial

NASA Astrophysics Data System (ADS)

Rosenthal, Eric I.; Ehrlich, Nicole K.; Rudner, Mark S.; Higginbotham, Andrew P.; Lehnert, K. W.

2018-06-01

We construct a metamaterial from radio-frequency harmonic oscillators, and find two topologically distinct phases resulting from dissipation engineered into the system. These phases are distinguished by a quantized value of bulk energy transport. The impulse response of our circuit is measured and used to reconstruct the band structure and winding number of circuit eigenfunctions around a dark mode. Our results demonstrate that dissipative topological transport can occur in a wider class of physical systems than considered before.

Research of vibration control based on current mode piezoelectric shunt damping circuit

NASA Astrophysics Data System (ADS)

Liu, Weiwei; Mao, Qibo

2017-12-01

The piezoelectric shunt damping circuit using current mode approach is imposed to control the vibration of a cantilever beam. Firstly, the simulated inductance with large values are designed for the corresponding RL series shunt circuits. Moreover, with an example of cantilever beam, the second natural frequency of the beam is targeted to control for experiment. By adjusting the values of the equivalent inductance and equivalent resistance of the shunt circuit, the optimal damping of the shunt circuit is obtained. Meanwhile, the designed piezoelectric shunt damping circuit stability is experimental verified. Experimental results show that the proposed piezoelectric shunt damping circuit based on current mode circuit has good vibration control performance. However, the control performance will be reduced if equivalent inductance and equivalent resistance values deviate from optimal values.

Dual-circuit segmented rail phased induction motor

DOEpatents

Marder, Barry M.; Cowan, Jr., Maynard

2002-01-01

An improved linear motor utilizes two circuits, rather that one circuit and an opposed plate, to gain efficiency. The powered circuit is a flat conductive coil. The opposed segmented rail circuit is either a plurality of similar conductive coils that are shorted, or a plurality of ladders formed of opposed conductive bars connected by a plurality of spaced conductors. In each embodiment, the conductors are preferably cables formed from a plurality of intertwined insulated wires to carry current evenly.

Design of high precision temperature control system for TO packaged LD

NASA Astrophysics Data System (ADS)

Liang, Enji; Luo, Baoke; Zhuang, Bin; He, Zhengquan

2017-10-01

Temperature is an important factor affecting the performance of TO package LD. In order to ensure the safe and stable operation of LD, a temperature control circuit for LD based on PID technology is designed. The MAX1978 and an external PID circuit are used to form a control circuit that drives the thermoelectric cooler (TEC) to achieve control of temperature and the external load can be changed. The system circuit has low power consumption, high integration and high precision,and the circuit can achieve precise control of the LD temperature. Experiment results show that the circuit can achieve effective and stable control of the laser temperature.

100-GHz Phase Switch/Mixer Containing a Slot-Line Transition

NASA Technical Reports Server (NTRS)

Gaier, Todd; Wells, Mary; Dawson, Douglas

2009-01-01

A circuit that can function as a phase switch, frequency mixer, or frequency multiplier operates over a broad frequency range in the vicinity of 100 GHz. Among the most notable features of this circuit is a grounded uniplanar transition (in effect, a balun) between a slot line and one of two coplanar waveguides (CPWs). The design of this circuit is well suited to integration of the circuit into a microwave monolithic integrated circuit (MMIC) package. One CPW is located at the input end and one at the output end of the top side of a substrate on which the circuit is fabricated (see Figure 1). The input CPW feeds the input signal to antiparallel flip-chip Schottky diodes connected to the edges of the slot line. Phase switching is effected by the combination of (1) the abrupt transition from the input CPW to the slot line and (2) CPW ground tuning effected by switching of the bias on the diodes. Grounding of the slot metal to the bottom metal gives rise to a frequency cutoff in the slot. This cutoff is valuable for separating different frequency components when the circuit is used as a mixer or multiplier. Proceeding along the slot line toward the output end, one encounters the aforementioned transition, which couples the slot line to the output CPW. Impedance tuning of the transition is accomplished by use of a high-impedance section immediately before the transition.

30 CFR 75.824 - Electrical protection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... transformer and over-current relay in the neutral grounding resistor circuit. (vi) A single window-type current transformer that encircles all three-phase conductors must be used to activate the ground-fault... current transformer. (vii) A test circuit for the ground-fault device must be provided. The test circuit...

30 CFR 75.824 - Electrical protection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... transformer and over-current relay in the neutral grounding resistor circuit. (vi) A single window-type current transformer that encircles all three-phase conductors must be used to activate the ground-fault... current transformer. (vii) A test circuit for the ground-fault device must be provided. The test circuit...

30 CFR 75.824 - Electrical protection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... transformer and over-current relay in the neutral grounding resistor circuit. (vi) A single window-type current transformer that encircles all three-phase conductors must be used to activate the ground-fault... current transformer. (vii) A test circuit for the ground-fault device must be provided. The test circuit...

30 CFR 75.824 - Electrical protection.

Code of Federal Regulations, 2011 CFR

2011-07-01

... transformer and over-current relay in the neutral grounding resistor circuit. (vi) A single window-type current transformer that encircles all three-phase conductors must be used to activate the ground-fault... current transformer. (vii) A test circuit for the ground-fault device must be provided. The test circuit...

30 CFR 75.824 - Electrical protection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... transformer and over-current relay in the neutral grounding resistor circuit. (vi) A single window-type current transformer that encircles all three-phase conductors must be used to activate the ground-fault... current transformer. (vii) A test circuit for the ground-fault device must be provided. The test circuit...

49 CFR 236.205 - Signal control circuits; requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Signal control circuits; requirements. 236.205..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so...

49 CFR 236.205 - Signal control circuits; requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Signal control circuits; requirements. 236.205..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so...

49 CFR 236.205 - Signal control circuits; requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Signal control circuits; requirements. 236.205..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so...

49 CFR 236.205 - Signal control circuits; requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Signal control circuits; requirements. 236.205..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so...

49 CFR 236.205 - Signal control circuits; requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Signal control circuits; requirements. 236.205..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so...

Multi-format all-optical processing based on a large-scale, hybridly integrated photonic circuit.

PubMed

Bougioukos, M; Kouloumentas, Ch; Spyropoulou, M; Giannoulis, G; Kalavrouziotis, D; Maziotis, A; Bakopoulos, P; Harmon, R; Rogers, D; Harrison, J; Poustie, A; Maxwell, G; Avramopoulos, H

2011-06-06

We investigate through numerical studies and experiments the performance of a large scale, silica-on-silicon photonic integrated circuit for multi-format regeneration and wavelength-conversion. The circuit encompasses a monolithically integrated array of four SOAs inside two parallel Mach-Zehnder structures, four delay interferometers and a large number of silica waveguides and couplers. Exploiting phase-incoherent techniques, the circuit is capable of processing OOK signals at variable bit rates, DPSK signals at 22 or 44 Gb/s and DQPSK signals at 44 Gbaud. Simulation studies reveal the wavelength-conversion potential of the circuit with enhanced regenerative capabilities for OOK and DPSK modulation formats and acceptable quality degradation for DQPSK format. Regeneration of 22 Gb/s OOK signals with amplified spontaneous emission (ASE) noise and DPSK data signals degraded with amplitude, phase and ASE noise is experimentally validated demonstrating a power penalty improvement up to 1.5 dB.

Two-phase flow in the cooling circuit of a cryogenic rocket engine

NASA Astrophysics Data System (ADS)

Preclik, D.

1992-07-01

Transient two-phase flow was investigated for the hydrogen cooling circuit of the HM7 rocket engine. The nuclear reactor code ATHLET/THESEUS was adapted to cryogenics and applied to both principal and prototype experiments for validation and simulation purposes. The cooling circuit two-phase flow simulation focused on the hydrogen prechilling and pump transient phase prior to ignition. Both a single- and a multichannel model were designed and employed for a valve leakage flow, a nominal prechilling flow, and a prechilling with a subsequent pump-transient flow. The latter case was performed in order to evaluate the difference between a nominal and a delayed turbo-pump start-up. It was found that an extension of the nominal prechilling sequence in the order of 1 second is sufficient to finally provide for liquid injection conditions of hydrogen which, as commonly known, is undesirable for smooth ignition and engine starting transients.

A SERIES OF SUPPRESSIVE SIGNALS WITHIN THE DROSOPHILA CIRCADIAN NEURAL CIRCUIT GENERATES SEQUENTIAL DAILY OUTPUTS

PubMed Central

Liang, Xitong; Holy, Timothy E; Taghert, Paul H

2017-01-01

Summary We studied the Drosophila circadian neural circuit using whole brain imaging in vivo. Five major groups of pacemaker neurons display synchronized molecular clocks, yet each exhibits a distinct phase of daily Ca2+ activation. Light and neuropeptide PDF from morning cells (s-LNv) together delay the phase of the evening (LNd) group by ~12 h; PDF alone delays the phase of the DN3 group, by ~17 h. Neuropeptide sNPF, released from s-LNv and LNd pacemakers, produces latenight Ca2+ activation in the DN1 group. The circuit also features negative feedback by PDF to truncate the s-LNv Ca2+ wave and terminate PDF release. Both PDF and sNPF suppress basal Ca2+ levels in target pacemakers with long durations by cell autonomous actions. Thus, light and neuropeptides act dynamically at distinct hubs of the circuit to produce multiple suppressive events that create the proper tempo and sequence of circadian pacemaker neuronal activities. PMID:28552314

49 CFR 236.342 - Switch circuit controller.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Switch circuit controller. 236.342 Section 236.342... Instructions § 236.342 Switch circuit controller. Switch circuit controller connected at the point to switch... corresponding to switch point closure when switch point is open one-fourth inch or more. Inspection and Tests ...

49 CFR 236.342 - Switch circuit controller.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Switch circuit controller. 236.342 Section 236.342... Instructions § 236.342 Switch circuit controller. Switch circuit controller connected at the point to switch... corresponding to switch point closure when switch point is open one-fourth inch or more. Inspection and Tests ...

49 CFR 236.342 - Switch circuit controller.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Switch circuit controller. 236.342 Section 236.342... Instructions § 236.342 Switch circuit controller. Switch circuit controller connected at the point to switch... corresponding to switch point closure when switch point is open one-fourth inch or more. Inspection and Tests ...

49 CFR 236.342 - Switch circuit controller.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Switch circuit controller. 236.342 Section 236.342... Instructions § 236.342 Switch circuit controller. Switch circuit controller connected at the point to switch... corresponding to switch point closure when switch point is open one-fourth inch or more. Inspection and Tests ...

49 CFR 236.342 - Switch circuit controller.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Switch circuit controller. 236.342 Section 236.342... Instructions § 236.342 Switch circuit controller. Switch circuit controller connected at the point to switch... corresponding to switch point closure when switch point is open one-fourth inch or more. Inspection and Tests ...

49 CFR 236.721 - Circuit, control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ...

49 CFR 236.721 - Circuit, control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ...

49 CFR 236.721 - Circuit, control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ...

49 CFR 236.721 - Circuit, control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ...

Laser dynamics: The system dynamics and network theory of optoelectronic integrated circuit design

NASA Astrophysics Data System (ADS)

Tarng, Tom Shinming-T. K.

Laser dynamics is the system dynamics, communication and network theory for the design of opto-electronic integrated circuit (OEIC). Combining the optical network theory and optical communication theory, the system analysis and design for the OEIC fundamental building blocks is considered. These building blocks include the direct current modulation, inject light modulation, wideband filter, super-gain optical amplifier, E/O and O/O optical bistability and current-controlled optical oscillator. Based on the rate equations, the phase diagram and phase portrait analysis is applied to the theoretical studies and numerical simulation. The OEIC system design methodologies are developed for the OEIC design. Stimulating-field-dependent rate equations are used to model the line-width narrowing/broadening mechanism for the CW mode and frequency chirp of semiconductor lasers. The momentary spectra are carrier-density-dependent. Furthermore, the phase portrait analysis and the nonlinear refractive index is used to simulate the single mode frequency chirp. The average spectra of chaos, period doubling, period pulsing, multi-loops and analog modulation are generated and analyzed. The bifurcation-chirp design chart with modulation depth and modulation frequency as parameters is provided for design purpose.

Module Eleven: Capacitance; Basic Electricity and Electronics Individualized Learning System.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

In this module the student will learn about another circuit quantity, capacitance, and discover the effects of this component on circuit current, voltage, and power. The module is divided into seven lessons: the capacitor, theory of capacitance, total capacitance, RC (resistive-capacitive circuit) time constant, capacitive reactance, phase and…

A Novel Approach to Chemical Communications

DTIC Science & Technology

2010-06-17

of droplets in the microfludic circuit. Figure 4. Generation of droplets in the microfludic circuit. Figure 5. Space-time plots showing anti-phase... microfludic circuit. Final Report W911NF-07-1-0639 Page 11 Table 2. A sampling of microfluidics experiments Fluid1 for drop genera- tion Fluid2

Bridge Circuits: One Topic in the Modular Course in Electronics Instrumentation.

ERIC Educational Resources Information Center

Aldridge, Bill G.; Stringer, Gene A.

This learning module is intended to illustrate the functioning and uses of bridge circuits. The discussion and laboratory procedures suggested in the module presume familiarity with basic concepts of electronics such as voltage, current, resistance, capacitance, inductance, phase, and knowledge of such skills as breadboarding circuits from…

30 CFR 77.905 - Connection of single-phase loads.

Code of Federal Regulations, 2012 CFR

2012-07-01

... COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.905 Connection of single-phase loads. Single-phase loads shall be connected phase-to-phase in resistance grounded systems. ...

30 CFR 77.905 - Connection of single-phase loads.

Code of Federal Regulations, 2014 CFR

2014-07-01

... COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.905 Connection of single-phase loads. Single-phase loads shall be connected phase-to-phase in resistance grounded systems. ...

30 CFR 77.905 - Connection of single-phase loads.

Code of Federal Regulations, 2013 CFR

2013-07-01

... COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.905 Connection of single-phase loads. Single-phase loads shall be connected phase-to-phase in resistance grounded systems. ...

A wide-range 22-GHz LC-based CMOS voltage-controlled oscillator

NASA Astrophysics Data System (ADS)

Gharbieh, Karam; Ranneh, Mohammed; Abugharbieh, Khaldoon

2018-06-01

This work presents a novel voltage-controlled oscillator (VCO) design and simulations that combine a varactor bank with a transformer in the LC tank to achieve a high-frequency range. While the varactor bank is responsible for changing the capacitance in the LC tank, the transformer acts as a means to change the value of the inductance, hence allowing tune-ability in the two main components of the VCO. A control mechanism utilises a mixed-mode circuit consisting of comparators and a state machine. It allows efficient tuning of the VCO by controlling the capacitance and transformer in the LC tank. The VCO has a 10.75-22.43 GHz frequency range and the VCO gain, KVCO, is kept at a low value ranging from 98.6 to 175.7 MHz/V. The simulated phase noise is -111 dBc/Hz at 1 MHz offset from the 10.75 GHz oscillation frequency. The circuit is designed and simulated in 28 nm CMOS technology and uses a 1 V supply drawing a typical power of 14.74 mW.

High-Temperature-Superconductor Films In Microwave Circuits

NASA Technical Reports Server (NTRS)

Bhasin, K. B.; Warner, J. D.; Romanofsky, R. R.; Heinen, V. O.; Chorey, C. M.

1993-01-01

Report discusses recent developments in continuing research on fabrication and characterization of thin films of high-temperature superconducting material and incorporation of such films into microwave circuits. Research motivated by prospect of exploiting superconductivity to reduce electrical losses and thereby enhancing performance of such critical microwave components as ring resonators, filters, transmission lines, phase shifters, and feed lines in phased-array antennas.

Superconducting quantum circuits theory and application

NASA Astrophysics Data System (ADS)

Deng, Xiuhao

Superconducting quantum circuit models are widely used to understand superconducting devices. This thesis consists of four studies wherein the superconducting quantum circuit is used to illustrate challenges related to quantum information encoding and processing, quantum simulation, quantum signal detection and amplification. The existence of scalar Aharanov-Bohm phase has been a controversial topic for decades. Scalar AB phase, defined as time integral of electric potential, gives rises to an extra phase factor in wavefunction. We proposed a superconducting quantum Faraday cage to detect temporal interference effect as a consequence of scalar AB phase. Using the superconducting quantum circuit model, the physical system is solved and resulting AB effect is predicted. Further discussion in this chapter shows that treating the experimental apparatus quantum mechanically, spatial scalar AB effect, proposed by Aharanov-Bohm, can't be observed. Either a decoherent interference apparatus is used to observe spatial scalar AB effect, or a quantum Faraday cage is used to observe temporal scalar AB effect. The second study involves protecting a quantum system from losing coherence, which is crucial to any practical quantum computation scheme. We present a theory to encode any qubit, especially superconducting qubits, into a universal quantum degeneracy point (UQDP) where low frequency noise is suppressed significantly. Numerical simulations for superconducting charge qubit using experimental parameters show that its coherence time is prolong by two orders of magnitude using our universal degeneracy point approach. With this improvement, a set of universal quantum gates can be performed at high fidelity without losing too much quantum coherence. Starting in 2004, the use of circuit QED has enabled the manipulation of superconducting qubits with photons. We applied quantum optical approach to model coupled resonators and obtained a four-wave mixing toolbox to operate photons states. The model and toolbox are engineered with a superconducting quantum circuit where two superconducting resonators are coupled via the UQDP circuit. Using fourth order perturbation theory one can realize a complete set of quantum operations between these two photon modes. This helps open a new field to treat photon modes as qubits. Additional, a three-wave mixing scheme using phase qubits permits one to engineer the coupling Hamiltonian using a phase qubit as a tunable coupler. Along with Feynman's idea using quantum to simulate quantum, superconducting quantum simulators have been studied intensively recently. Taking the advantage of mesoscopic size of superconducting circuit and local tunability, we came out the idea to simulate quantum phase transition due to disorder. Our first paper was to propose a superconducting quantum simulator of Bose-Hubbard model to do site-wise manipulation and observe Mott-insulator to superfluid phase transition. The side-band cooling of an array of superconducting resonators is solved after the paper was published. In light of the developed technology in manipulating quantum information with superconducting circuit, one can couple other quantum oscillator system to superconducting resonators in order manipulation of its quantum states or parametric amplification of weak quantum signal. A theory that works for different coupling schemes has been studied in chapter 5. This will be a platform for further research.

Neuromorphic walking gait control.

PubMed

Still, Susanne; Hepp, Klaus; Douglas, Rodney J

2006-03-01

We present a neuromorphic pattern generator for controlling the walking gaits of four-legged robots which is inspired by central pattern generators found in the nervous system and which is implemented as a very large scale integrated (VLSI) chip. The chip contains oscillator circuits that mimic the output of motor neurons in a strongly simplified way. We show that four coupled oscillators can produce rhythmic patterns with phase relationships that are appropriate to generate all four-legged animal walking gaits. These phase relationships together with frequency and duty cycle of the oscillators determine the walking behavior of a robot driven by the chip, and they depend on a small set of stationary bias voltages. We give analytic expressions for these dependencies. This chip reduces the complex, dynamic inter-leg control problem associated with walking gait generation to the problem of setting a few stationary parameters. It provides a compact and low power solution for walking gait control in robots.

Solid state circuit controls direction, speed, and braking of dc motor

NASA Technical Reports Server (NTRS)

Hanna, M. F.

1966-01-01

Full-wave bridge rectifier circuit controls the direction, speed, and braking of a dc motor. Gating in the circuit of Silicon Controlled Rectifiers /SCRS/ controls output polarity and braking is provided by an SCR that is gated to short circuit the reverse voltage generated by reversal of motor rotation.

WIDE BAND REGENERATIVE FREQUENCY DIVIDER AND MULTIPLIER

DOEpatents

Laine, E.F.

1959-11-17

A regenerative frequency divider and multiplier having wide band input characteristics is presented. The circuit produces output oscillations having frequencies related by a fixed ratio to input oscillations over a wide band of frequencies. In accomplishing this end, the divider-multiplier includes a wide band input circuit coupled by mixer means to a wide band output circuit having a pass band related by a fixed ratio to that of the input circuit. A regenerative feedback circuit derives a fixed frequency ratio feedback signal from the output circuit and applies same to the mixer means in proper phase relation to sustain fixed frequency ratio oscillations in the output circuit.

A grid-connected single-phase photovoltaic micro inverter

NASA Astrophysics Data System (ADS)

Wen, X. Y.; Lin, P. J.; Chen, Z. C.; Wu, L. J.; Cheng, S. Y.

2017-11-01

In this paper, the topology of a single-phase grid-connected photovoltaic (PV) micro-inverter is proposed. The PV micro-inverter consists of DC-DC stage with high voltage gain boost and DC-AC conversion stage. In the first stage, we apply the active clamp circuit and two voltage multipliers to achieve soft switching technology and high voltage gain. In addition, the flower pollination algorithm (FPA) is employed for the maximum power point tracking (MPPT) in the PV module in this stage. The second stage cascades a H-bridge inverter and LCL filter. To feed high quality sinusoidal power into the grid, the software phase lock, outer voltage loop and inner current loop control method are adopted as the control strategy. The performance of the proposed topology is tested by Matlab/Simulink. A PV module with maximum power 300W and maximum power point voltage 40V is applied as the input source. The simulation results indicate that the proposed topology and the control strategy are feasible.

49 CFR 236.60 - Switch shunting circuit; use restricted.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and... circuit shall not be hereafter installed, except where tract or control circuit is opened by the circuit controller. [49 FR 3384, Jan. 26, 1984] Wires and Cables ...

49 CFR 236.60 - Switch shunting circuit; use restricted.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and... circuit shall not be hereafter installed, except where tract or control circuit is opened by the circuit controller. [49 FR 3384, Jan. 26, 1984] Wires and Cables ...

49 CFR 236.60 - Switch shunting circuit; use restricted.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and... circuit shall not be hereafter installed, except where tract or control circuit is opened by the circuit controller. [49 FR 3384, Jan. 26, 1984] Wires and Cables ...

49 CFR 236.60 - Switch shunting circuit; use restricted.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and... circuit shall not be hereafter installed, except where tract or control circuit is opened by the circuit controller. [49 FR 3384, Jan. 26, 1984] Wires and Cables ...

49 CFR 236.60 - Switch shunting circuit; use restricted.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and... circuit shall not be hereafter installed, except where tract or control circuit is opened by the circuit controller. [49 FR 3384, Jan. 26, 1984] Wires and Cables ...

49 CFR 236.732 - Controller, circuit; switch.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Controller, circuit; switch. 236.732 Section 236... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by a rod connected to a switch, derail or movable-point frog. ...

49 CFR 236.732 - Controller, circuit; switch.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Controller, circuit; switch. 236.732 Section 236... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by a rod connected to a switch, derail or movable-point frog. ...

49 CFR 236.732 - Controller, circuit; switch.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Controller, circuit; switch. 236.732 Section 236... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by a rod connected to a switch, derail or movable-point frog. ...

49 CFR 236.732 - Controller, circuit; switch.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Controller, circuit; switch. 236.732 Section 236... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by a rod connected to a switch, derail or movable-point frog. ...

49 CFR 236.732 - Controller, circuit; switch.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit; switch. 236.732 Section 236.732 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.732 Controller, circuit; switch. A device for opening and closing electric circuits, operated by a...

How to find the way out from four rooms? The learning of "chaining" associations may shed light on the neuropsychology of the deficit syndrome of schizophrenia.

PubMed

Polgár, Patricia; Farkas, Márta; Nagy, Orsolya; Kelemen, Oguz; Réthelyi, János; Bitter, István; Myers, Catherine E; Gluck, Mark A; Kéri, Szabolcs

2008-02-01

Recent meta-analytic evidence suggests that clinical neuropsychological methods are not likely to uncover circumscribed cognitive impairments in the deficit syndrome of schizophrenia. To overcome this issue, we adapted a cognitive neuroscience perspective and used a new "chaining" habit learning task. Participants were requested to navigate a cartoon character through a sequence of 4 rooms by learning to choose the open door from 3 colored doors in each room. The aim of the game was to learn the full sequence of rooms until the character reached the outside. In the training phase, each stimulus leading to reward (open door in each room) was trained via feedback until the complete sequence was learned. In the probe phase, the context of rewarded stimuli was manipulated: in a given room, in addition to the correct door of that room, there also appeared a door which was open in another room. Whereas the training phase is dominantly related to basal ganglia circuits, the context-dependent probe phase requires intact medial-temporal lobe functioning. Results revealed that deficit and non-deficit patients were similarly impaired on the probe phase compared with controls. However, the training phase was only compromised in deficit patients. More severe negative symptoms were associated with more errors on the training phase. Executive functions were unrelated to performance on the "chaining" task. These results indicate that the deficit syndrome is associated with prominently impaired stimulus-response reinforcement learning, which may indicate abnormal functioning of basal ganglia circuits.

Fully chip-embedded automation of a multi-step lab-on-a-chip process using a modularized timer circuit.

PubMed

Kang, Junsu; Lee, Donghyeon; Heo, Young Jin; Chung, Wan Kyun

2017-11-07

For highly-integrated microfluidic systems, an actuation system is necessary to control the flow; however, the bulk of actuation devices including pumps or valves has impeded the broad application of integrated microfluidic systems. Here, we suggest a microfluidic process control method based on built-in microfluidic circuits. The circuit is composed of a fluidic timer circuit and a pneumatic logic circuit. The fluidic timer circuit is a serial connection of modularized timer units, which sequentially pass high pressure to the pneumatic logic circuit. The pneumatic logic circuit is a NOR gate array designed to control the liquid-controlling process. By using the timer circuit as a built-in signal generator, multi-step processes could be done totally inside the microchip without any external controller. The timer circuit uses only two valves per unit, and the number of process steps can be extended without limitation by adding timer units. As a demonstration, an automation chip has been designed for a six-step droplet treatment, which entails 1) loading, 2) separation, 3) reagent injection, 4) incubation, 5) clearing and 6) unloading. Each process was successfully performed for a pre-defined step-time without any external control device.

Monolithic circuits for barium fluoride detectors used in nuclear physics experiments. CRADA final report

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

Varner, R.L.; Blankenship, J.L.; Beene, J.R.

1998-02-01

Custom monolithic electronic circuits have been developed recently for large detector applications in high energy physics where subsystems require tens of thousands of channels of signal processing and data acquisition. In the design and construction of these enormous detectors, it has been found that monolithic circuits offer significant advantages over discrete implementations through increased performance, flexible packaging, lower power and reduced cost per channel. Much of the integrated circuit design for the high energy physics community is directly applicable to intermediate energy heavy-ion and electron physics. This STTR project conducted in collaboration with researchers at the Holifield Radioactive Ion Beammore » Facility (HRIBF) at Oak Ridge National Laboratory, sought to develop a new integrated circuit chip set for barium fluoride (BaF{sub 2}) detector arrays based upon existing CMOS monolithic circuit designs created for the high energy physics experiments. The work under the STTR Phase 1 demonstrated through the design, simulation, and testing of several prototype chips the feasibility of using custom CMOS integrated circuits for processing signals from BaF{sub 2} detectors. Function blocks including charge-sensitive amplifiers, comparators, one shots, time-to-amplitude converters, analog memory circuits and buffer amplifiers were implemented during Phase 1 effort. Experimental results from bench testing and laboratory testing with sources were documented.« less

Neuroinspired control strategies with applications to flapping flight

NASA Astrophysics Data System (ADS)

Dorothy, Michael Ray

This dissertation is centered on a theoretical, simulation, and experimental study of control strategies which are inspired by biological systems. Biological systems, along with sufficiently complicated engineered systems, often have many interacting degrees of freedom and need to excite large-displacement oscillations in order to locomote. Combining these factors can make high-level control design difficult. This thesis revolves around three different levels of abstraction, providing tools for analysis and design. First, we consider central pattern generators (CPGs) to control flapping-flight dynamics. The key idea here is dimensional reduction - we want to convert complicated interactions of many degrees of freedom into a handful of parameters which have intuitive connections to the overall system behavior, leaving the control designer unconcerned with the details of particular motions. A rigorous mathematical and control theoretic framework to design complex three-dimensional wing motions is presented based on phase synchronization of nonlinear oscillators. In particular, we show that flapping-flying dynamics without a tail or traditional aerodynamic control surfaces can be effectively controlled by a reduced set of central pattern generator parameters that generate phase-synchronized or symmetry-breaking oscillatory motions of two main wings. Furthermore, by using a Hopf bifurcation, we show that tailless aircraft (inspired by bats) alternating between flapping and gliding can be effectively stabilized by smooth wing motions driven by the central pattern generator network. Results of numerical simulation with a full six-degree-of-freedom flight dynamic model validate the effectiveness of the proposed neurobiologically inspired control approach. Further, we present experimental micro aerial vehicle (MAV) research with low-frequency flapping and articulated wing gliding. The importance of phase difference control via an abstract mathematical model of central pattern generators is confirmed with a robotic bat on a 3-DOF pendulum platform. An aerodynamic model for the robotic bat based on the complex wing kinematics is presented. Closed loop experiments show that control dimension reduction is achievable - unstable longitudinal modes are stabilized and controlled using only two control parameters. A transition of flight modes, from flapping to gliding and vice-versa, is demonstrated within the CPG control scheme. The second major thrust is inspired by this idea that mode switching is useful. Many bats and birds adopt a mixed strategy of flapping and gliding to provide agility when necessary and to increase overall efficiency. This work explores dwell time constraints on switched systems with multiple, possibly disparate invariant limit sets. We show that, under suitable conditions, trajectories globally converge to a superset of the limit sets and then remain in a second, larger superset. We show the effectiveness of the dwell-time conditions by using examples of nonlinear switching limit cycles from our work on flapping flight. This level of abstraction has been found to be useful in many ways, but it also produces its own challenges. For example, we discuss death of oscillation which can occur for many limit-cycle controllers and the difficulty in incorporating fast, high-displacement reflex feedback. This leads us to our third major thrust - considering biologically realistic neuron circuits instead of a limit cycle abstraction. Biological neuron circuits are incredibly diverse in practice, giving us a convincing rationale that they can aid us in our quest for flexibility. Nevertheless, that flexibility provides its own challenges. It is not currently known how most biological neuron circuits work, and little work exists that connects the principles of a neuron circuit to the principles of control theory. We begin the process of trying to bridge this gap by considering the simplest of classical controllers, PD control. We propose a simple two-neuron, two-synapse circuit based on the concept that synapses provide attenuation and a delay. We present a simulation-based method of analysis, including a smoothing algorithm, a steady-state response curve, and a system identification procedure for capturing differentiation. There will never be One True Control Method that will solve all problems. Nature's solution to a diversity of systems and situations is equally diverse. This will inspire many strategies and require a multitude of analysis tools. This thesis is my contribution of a few.

Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

NASA Astrophysics Data System (ADS)

Heck, Martijn J. R.

2017-01-01

Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D) imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC) technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

Silicon Controlled Switch for Detection of Ionizing Radiation

DTIC Science & Technology

2015-12-01

sensitivity of previous NPS silicon controlled rectifier (SCR) based circuits. Additionally, the circuit in this thesis was able to detect AM-241 and...sensitivity of previous NPS silicon controlled rectifier (SCR) based circuits. Additionally, the circuit in this thesis was able to detect AM-241 and...Controlled Rectifier SCS Silicon-Controlled Switch SONAR SOund Navigation and Ranging VBIAS Applied Bias Voltage VH Holding Voltage VS Standalone SCS

30 CFR 77.902 - Low- and medium-voltage ground check monitor circuits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Low- and medium-voltage ground check monitor... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902 Low- and medium-voltage ground check monitor circuits. On and after September 30, 1971, three-phase low- and...

30 CFR 77.902 - Low- and medium-voltage ground check monitor circuits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Low- and medium-voltage ground check monitor... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902 Low- and medium-voltage ground check monitor circuits. On and after September 30, 1971, three-phase low- and...

30 CFR 77.902 - Low- and medium-voltage ground check monitor circuits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Low- and medium-voltage ground check monitor... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902 Low- and medium-voltage ground check monitor circuits. On and after September 30, 1971, three-phase low- and...

30 CFR 77.902 - Low- and medium-voltage ground check monitor circuits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage ground check monitor... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902 Low- and medium-voltage ground check monitor circuits. On and after September 30, 1971, three-phase low- and...

30 CFR 77.902 - Low- and medium-voltage ground check monitor circuits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Low- and medium-voltage ground check monitor... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902 Low- and medium-voltage ground check monitor circuits. On and after September 30, 1971, three-phase low- and...

Phase stable RF transport system

DOEpatents

Curtin, Michael T.; Natter, Eckard F.; Denney, Peter M.

1992-01-01

An RF transport system delivers a phase-stable RF signal to a load, such as an RF cavity of a charged particle accelerator. A circuit generates a calibration signal at an odd multiple frequency of the RF signal where the calibration signal is superimposed with the RF signal on a common cable that connects the RF signal with the load. Signal isolating diplexers are located at both the RF signal source end and load end of the common cable to enable the calibration to be inserted and extracted from the cable signals without any affect on the RF signal. Any phase shift in the calibration signal during traverse of the common cable is then functionally related to the phase shift in the RF signal. The calibration phase shift is used to control a phase shifter for the RF signal to maintain a stable RF signal at the load.

Redundant electronic circuit provides fail-safe control

NASA Technical Reports Server (NTRS)

Archer, J. W.

1970-01-01

Circuit using dual control amplifiers and dual position demand potentiometers powered from separate sources is used for reliable hydraulic valve controller that prevents closure of valve when control circuits fail, and maintains valve control to close tolerance for more common modes of controller failure.

Circuit For Control Of Electromechanical Prosthetic Hand

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

Circadian Regulation of Pineal Gland Rhythmicity

PubMed Central

Borjigin, Jimo; Zhang, L. Samantha; Calinescu, Anda-Alexandra

2011-01-01

The pineal gland is a neuroendocrine organ of the brain. Its main task is to synthesize and secrete melatonin, a nocturnal hormone with diverse physiological functions. This review will focus on the central and pineal mechanisms in generation of mammalian pineal rhythmicity including melatonin production. In particular, this review covers the following topics: (1) local control of serotonin and melatonin rhythms; (2) neurotransmitters involved in central control of melatonin; (3) plasticity of the neural circuit controlling melatonin production; (4) role of clock genes in melatonin formation; (5) phase control of pineal rhythmicity; (6) impact of light at night on pineal rhythms; and (7) physiological function of the pineal rhythmicity. PMID:21782887

Stripline feed for a microstrip array of patch elements with teardrop shaped probes

NASA Technical Reports Server (NTRS)

Huang, John (Inventor)

1990-01-01

A circularly polarized microstrip array antenna utilizing a honeycomb substrate made of dielectric material to support on one side the microstrip patch elements in an array, and on the other side a stripline circuit for feeding the patch elements in subarray groups of four with angular orientation and phase for producing circularly polarized radiation, preferably at a 0.degree., 90.degree., 180.degree. and 270.degree. relationship. The probe used for coupling each feed point in the stripline circuit to a microstrip patch element is teardrop shaped in order to introduce capacitance between the coupling probe and the metal sheet of the stripline circuit that serves as an antenna ground plane. The capacitance thus introduced tunes out inductance of the probe. The shape of the teardrop probe is not critical. The probe capacitance required is controlled by the maximum diameter for the teardrop shaped probe, which can be empirically determined for the operating frequency. An aluminum baffle around each subarray blocks out surface waves between subarrays.

Tribotronic Tuning Diode for Active Analog Signal Modulation.

PubMed

Zhou, Tao; Yang, Zhi Wei; Pang, Yaokun; Xu, Liang; Zhang, Chi; Wang, Zhong Lin

2017-01-24

Realizing active interaction with external environment/stimuli is a great challenge for current electronics. In this paper, a tribotronic tuning diode (TTD) is proposed by coupling a variable capacitance diode and a triboelectric nanogenerator in free-standing sliding mode. When the friction layer is sliding on the device surface for electrification, a reverse bias voltage is created and applied to the diode for tuning the junction capacitance. When the sliding distance increases from 0 to 25 mm, the capacitance of the TTD decreases from about 39 to 8 pF. The proposed TTD has been integrated into analog circuits and exhibited excellent performances in frequency modulation, phase shift, and filtering by sliding a finger. This work has demonstrated tunable diode and active analog signal modulation by tribotronics, which has great potential to replace ordinary variable capacitance diodes in various practical applications such as signal processing, electronic tuning circuits, precise tuning circuits, active sensor networks, electronic communications, remote controls, flexible electronics, etc.

A hypothalamic circuit for the circadian control of aggression.

PubMed

Todd, William D; Fenselau, Henning; Wang, Joshua L; Zhang, Rong; Machado, Natalia L; Venner, Anne; Broadhurst, Rebecca Y; Kaur, Satvinder; Lynagh, Timothy; Olson, David P; Lowell, Bradford B; Fuller, Patrick M; Saper, Clifford B

2018-05-01

'Sundowning' in dementia and Alzheimer's disease is characterized by early-evening agitation and aggression. While such periodicity suggests a circadian origin, whether the circadian clock directly regulates aggressive behavior is unknown. We demonstrate that a daily rhythm in aggression propensity in male mice is gated by GABAergic subparaventricular zone (SPZ GABA ) neurons, the major postsynaptic targets of the central circadian clock, the suprachiasmatic nucleus. Optogenetic mapping revealed that SPZ GABA neurons receive input from vasoactive intestinal polypeptide suprachiasmatic nucleus neurons and innervate neurons in the ventrolateral part of the ventromedial hypothalamus (VMH), which is known to regulate aggression. Additionally, VMH-projecting dorsal SPZ neurons are more active during early day than early night, and acute chemogenetic inhibition of SPZ GABA transmission phase-dependently increases aggression. Finally, SPZ GABA -recipient central VMH neurons directly innervate ventrolateral VMH neurons, and activation of this intra-VMH circuit drove attack behavior. Altogether, we reveal a functional polysynaptic circuit by which the suprachiasmatic nucleus clock regulates aggression.

Capability approval programme for Microwave Hybrid Integrated Circuits (MHICS)

NASA Astrophysics Data System (ADS)

1990-11-01

The general requirements for capability approval of a manufacturing line for Microwave Hybrid Integrated Circuits (MHICs) are defined. ESA approval mandate will be exercized upon conclusion of the evaluation phase and at the end of the program. Before the evaluation phase can commence, the manufacturer must define the capability approval domain by specifying the processes, materials and technology for which approval is sought.

Distortion of the convolution spectra of PSK signals in frequency multipliers

NASA Astrophysics Data System (ADS)

Viniarskii, V. F.; Marchenko, V. F.; Petrin, Iu. M.

1983-09-01

The influence of the input and output circuits of frequency multipliers on the convolution spectrum of binary and ternary PSK signals is examined. It is shown that transient processes caused by the phase switching of the input signal lead to the amplitude-phase modulation of the harmonic signal. Experimental results are presented on the balance circuits of MOS varactor doublers and triplers.

Controlling Arc Length in Plasma Welding

NASA Technical Reports Server (NTRS)

Iceland, W. F.

1986-01-01

Circuit maintains arc length on irregularly shaped workpieces. Length of plasma arc continuously adjusted by control circuit to maintain commanded value. After pilot arc is established, contactor closed and transfers arc to workpiece. Control circuit then half-wave rectifies ac arc voltage to produce dc control signal proportional to arc length. Circuit added to plasma arc welding machines with few wiring changes. Welds made with circuit cleaner and require less rework than welds made without it. Beads smooth and free of inclusions.

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

Propulsion controls

NASA Technical Reports Server (NTRS)

Harkney, R. D.

1980-01-01

Increased system requirements and functional integration with the aircraft have placed an increased demand on control system capability and reliability. To provide these at an affordable cost and weight and because of the rapid advances in electronic technology, hydromechanical systems are being phased out in favor of digital electronic systems. The transition is expected to be orderly from electronic trimming of hydromechanical controls to full authority digital electronic control. Future propulsion system controls will be highly reliable full authority digital electronic with selected component and circuit redundancy to provide the required safety and reliability. Redundancy may include a complete backup control of a different technology for single engine applications. The propulsion control will be required to communicate rapidly with the various flight and fire control avionics as part of an integrated control concept.

Defense Small Business Innovation Research Program (SBIR), Volume 4, Defense Agencies Abstracts of Phase 1 Awards 1991

DTIC Science & Technology

1991-01-01

EXPERIENCE IN DEVELOPING INTEGRATED OPTICAL DEVICES, NONLINEAR MAGNETIC-OPTIC MATERIALS, HIGH FREQUENCY MODULATORS, COMPUTER-AIDED MODELING AND SOPHISTICATED... HIGH -LEVEL PRESENTATION AND DISTRIBUTED CONTROL MODELS FOR INTEGRATING HETEROGENEOUS MECHANICAL ENGINEERING APPLICATIONS AND TOOLS. THE DESIGN IS FOCUSED...STATISTICALLY ACCURATE WORST CASE DEVICE MODELS FOR CIRCUIT SIMULATION. PRESENT METHODS OF WORST CASE DEVICE DESIGN ARE AD HOC AND DO NOT ALLOW THE

Near-term hybrid vehicle program, phase 1. Appendix C: Preliminary design data package

NASA Technical Reports Server (NTRS)

1979-01-01

The design methodology, the design decision rationale, the vehicle preliminary design summary, and the advanced technology developments are presented. The detailed vehicle design, the vehicle ride and handling and front structural crashworthiness analysis, the microcomputer control of the propulsion system, the design study of the battery switching circuit, the field chopper, and the battery charger, and the recent program refinements and computer results are presented.

An optimized low-power voltage controlled oscillator

NASA Astrophysics Data System (ADS)

Shah, Kriyang; Le, Hai Phuong; Singh, Jugdutt

2007-01-01

This paper presents an optimised low-power low-phase-noise Voltage Controlled Oscillator (VCO) for Bluetooth wireless applications. The system level design issues and tradeoffs related to Direct Conversion Receiver (DCR) and Low Intermediate Frequency (IF) architecture for Bluetooth are discussed. Subsequently, for a low IF architecture, the critical VCO performance parameters are derived from system specifications. The VCO presented in the paper is optimised by implementing a novel biasing circuit that employs two current mirrors, one at the top and the other one at the bottom of the cross-coupled complementary VCO, to give the exact replica of the current in both the arms of current mirror circuit. This approach, therefore, significantly reduces the system power consumption as well as improves the system performance. Results show that, the VCO consumes only 281μW of power at 2V supply. Its phase noise performance are -115dBc/Hz, -130dBc/Hz and -141dBc/Hz at the offset frequency of 1MHz, 3MHz and 5MHz respectively. Results indicate that 31% reduction in power consumption is achieved as compared to the traditional VCO design. These characteristics make the designed VCO a better candidate for Bluetooth wireless application where power consumption is the major issue.

Electronic control circuits: A compilation

NASA Technical Reports Server (NTRS)

1973-01-01

A compilation of technical R and D information on circuits and modular subassemblies is presented as a part of a technology utilization program. Fundamental design principles and applications are given. Electronic control circuits discussed include: anti-noise circuit; ground protection device for bioinstrumentation; temperature compensation for operational amplifiers; hybrid gatling capacitor; automatic signal range control; integrated clock-switching control; and precision voltage tolerance detector.

Measurement of phase difference for micromachined gyros driven by rotating aircraft.

PubMed

Zhang, Zengping; Zhang, Fuxue; Zhang, Wei

2013-08-21

This paper presents an approach for realizing a phase difference measurement of a new gyro. A silicon micromachined gyro was mounted on rotating aircraft for aircraft attitude control. Aircraft spin drives the silicon pendulum of a gyro rotating at a high speed so that it can sense the transverse angular velocity of the rotating aircraft based on the gyroscopic precession principle when the aircraft has transverse rotation. In applications of the rotating aircraft single channel control system, such as damping in the attitude stabilization loop, the gyro signal must be kept in sync with the control signal. Therefore, the phase difference between both signals needs to be measured accurately. Considering that phase difference is mainly produced by both the micromachined part and the signal conditioning circuit, a mathematical model has been established and analyzed to determine the gyro's phase frequency characteristics. On the basis of theoretical analysis, a dynamic simulation has been done for a case where the spin frequency is 15 Hz. Experimental results with the proposed measurement method applied to a silicon micromachined gyro driven by a rotating aircraft demonstrate that it is effective in practical applications. Measured curve and numerical analysis of phase frequency characteristic are in accordance, and the error between measurement and simulation is only 5.3%.

Q-band 4-state phase shifter in planar technology: Circuit design and performance analysis.

PubMed

Villa, E; Cagigas, J; Aja, B; de la Fuente, L; Artal, E

2016-09-01

A 30% bandwidth phase shifter with four phase states is designed to be integrated in a radio astronomy receiver. The circuit has two 90° out-of-phase microwave phase-shifting branches which are combined by Wilkinson power dividers. Each branch is composed of a 180° phase shifter and a band-pass filter. The 180° phase shifter is made of cascaded hybrid rings with microwave PIN diodes as switching devices. The 90° phase shift is achieved with the two band-pass filters. Experimental characterization has shown significant results, with average phase shift values of -90.7°, -181.7°, and 88.5° within the operation band, 35-47 GHz, and mean insertion loss of 7.4 dB. The performance of its integration in a polarimetric receiver for radio astronomy is analyzed, which validates the use of the presented phase shifter in such type of receiver.

Neural control of locomotion and training-induced plasticity after spinal and cerebral lesions.

PubMed

Knikou, Maria

2010-10-01

Standing and walking require a plethora of sensorimotor interactions that occur throughout the nervous system. Sensory afferent feedback plays a crucial role in the rhythmical muscle activation pattern, as it affects through spinal reflex circuits the spinal neuronal networks responsible for inducing and maintaining rhythmicity, drives short-term and long-term re-organization of the brain and spinal cord circuits, and contributes to recovery of walking after locomotor training. Therefore, spinal circuits integrating sensory signals are adjustable networks with learning capabilities. In this review, I will synthesize the mechanisms underlying phase-dependent modulation of spinal reflexes in healthy humans as well as those with spinal or cerebral lesions along with findings on afferent regulation of spinal reflexes and central pattern generator in reduced animal preparations. Recovery of walking after locomotor training has been documented in numerous studies but the re-organization of spinal interneuronal and cortical circuits need to be further explored at cellular and physiological levels. For maximizing sensorimotor recovery in people with spinal or cerebral lesions, a multidisciplinary approach (rehabilitation, pharmacology, and electrical stimulation) delivered during various sensorimotor constraints is needed. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2006-03-14

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2008-03-25

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Synthetic Plasma Liquid Based Electronic Circuits Realization-A Novel Concept.

PubMed

Pandya, Killol V; Kosta, ShivPrasad

2016-09-01

Biomedical research is contributing significant role in the field of biomedical engineering and applied science. It brings research and innovations to a different level. This study investigated artificial human blood -synthetic plasma liquid as conductive medium. Keeping in mind the conductivity of synthetic plasma, astable multivibrator as well as differential amplifier circuit were demonstrated. The circuits were given normal input voltages at regular temperature and ideal conditions. The result shows desired response which supports the novel concept. For both the circuits, phase shift of 180° achieved by analysing biological electronic circuits.

High-temperature brushless DC motor controller

DOEpatents

Cieslewski, Crzegorz; Lindblom, Scott C.; Maldonado, Frank J.; Eckert, Michael Nathan

2017-05-16

A motor control system for deployment in high temperature environments includes a controller; a first half-bridge circuit that includes a first high-side switching element and a first low-side switching element; a second half-bridge circuit that includes a second high-side switching element and a second low-side switching element; and a third half-bridge circuit that includes a third high-side switching element and a third; low-side switching element. The motor controller is arranged to apply a pulse width modulation (PWM) scheme to switch the first half-bridge circuit, second half-bridge circuit, and third half-bridge circuit to power a motor.

Packaging Of Control Circuits In A Robot Arm

NASA Technical Reports Server (NTRS)

Kast, William

1994-01-01

Packaging system houses and connects control circuitry mounted on circuit boards within shoulder, upper section, and lower section of seven-degree-of-freedom robot arm. Has modular design that incorporates surface-mount technology, multilayer circuit boards, large-scale integrated circuits, and multi-layer flat cables between sections for compactness. Three sections of robot arm contain circuit modules in form of stardardized circuit boards. Each module contains two printed-circuit cards, one of each face.

Integrated P-channel MOS gyrator

NASA Technical Reports Server (NTRS)

Hochmair, E. S. (Inventor)

1974-01-01

A gyrator circuit is described which is of the conventional configuration of two amplifiers in a circular loop, one producing zero phase shift and the other producing 180 phase reversal, in a circuit having medium Q composed of all field effect transistors of the same conductivity type. The current source to each gyrator amplifier comprises an amplifier which responds to changes in current, with the amplified signals feed back so as to limit current. The feedback amplifier has a large capacitor connected to bypass high frequency components, thereby stabilizing the output. The design makes possible fabrication of circuits with transistors of only one conductivity type, providing economies in manufacture and use.

GPS synchronized power system phase angle measurements

NASA Astrophysics Data System (ADS)

Wilson, Robert E.; Sterlina, Patrick S.

1994-09-01

This paper discusses the use of Global Positioning System (GPS) synchronized equipment for the measurement and analysis of key power system quantities. Two GPS synchronized phasor measurement units (PMU) were installed before testing. It was indicated that PMUs recorded the dynamic response of the power system phase angles when the northern California power grid was excited by the artificial short circuits. Power system planning engineers perform detailed computer generated simulations of the dynamic response of the power system to naturally occurring short circuits. The computer simulations use models of transmission lines, transformers, circuit breakers, and other high voltage components. This work will compare computer simulations of the same event with field measurement.

Secure TRNG with random phase stimulation

NASA Astrophysics Data System (ADS)

Wieczorek, Piotr Z.

2017-08-01

In this paper a novel TRNG concept is proposed which is a vital part of cryptographic systems. The proposed TRNG involves phase variability of a pair of ring oscillators (ROs) to force the multiple metastable events in a flip-flop (FF). In the solution, the ROs are periodically activated to ensure the violation of the FF timing and resultant state randomness, while the TRNG circuit adapts the structure of ROs to obtain the maximum entropy and circuit security. The TRNG can be implemented in inexpensive re-programmable devices (CPLDs or FPGAs) without the use of Digital Clock Managers (DCMs). Preliminary test results proved the circuit's immunity to the intentional frequency injection attacks.

High power ferrite microwave switch

NASA Technical Reports Server (NTRS)

Bardash, I.; Roschak, N. K.

1975-01-01

A high power ferrite microwave switch was developed along with associated electronic driver circuits for operation in a spaceborne high power microwave transmitter in geostationary orbit. Three units were built and tested in a space environment to demonstrate conformance to the required performance characteristics. Each unit consisted of an input magic-tee hybrid, two non-reciprocal latching ferrite phase shifters, an out short-slot 3 db quadrature coupler, a dual driver electronic circuit, and input logic interface circuitry. The basic mode of operation of the high power ferrite microwave switch is identical to that of a four-port, differential phase shift, switchable circulator. By appropriately designing the phase shifters and electronic driver circuits to operate in the flux-transfer magnetization mode, power and temperature insensitive operation was achieved. A list of the realized characteristics of the developed units is given.

The objective structured clinical examination revisited for postgraduate trainees in general practice.

PubMed

Schoenmakers, Birgitte; Wens, Johan

2014-03-04

To investigate if the psychometric qualities of an OSCE consisting of more complex simulated patient encounters remain valid and reliable in the assessment of postgraduate trainees in general practice. In this intervention study without control group, the traditional OSCE was formally replaced by the new, complex version. The study population was composed by all postgraduate trainees (second and third phase) in general practice during the ongoing academic year. Data were handled and collected as part of the formal assessment program. Univariate analyses, the variance of scores and multivariate analyses were performed to assess the test qualities. A total of 340 students participated. Average final scores were slightly higher for third-phase students (t-test, p =0.05). Overall test scores were equally distributed on station level, circuit level and phase level. A multiple regression analysis revealed that test scores were dependent on the stations and circuits, but not on the master phase. In a changing learning environment, assessment and evaluation strategies require reorientation. The reliability and validity of the OSCE remain subject to discussion. In particular, when it comes to content and design, the traditional OSCE might underestimate the performance level of postgraduate trainees in general practice. A reshaping of this OSCE to a more sophisticated design with more complex patient encounters appears to restore the validity of the test results.

Gas-liquid two-phase flow behaviors and performance characteristics of proton exchange membrane fuel cells in a short-term microgravity environment

NASA Astrophysics Data System (ADS)

Guo, Hang; Liu, Xuan; Zhao, Jian Fu; Ye, Fang; Ma, Chong Fang

2017-06-01

In this work, proton exchange membrane fuel cells (PEMFCs) with transparent windows are designed to study the gas-liquid two-phase flow behaviors inside flow channels and the performance of a PEMFC with vertical channels and a PEMFC with horizontal channels in a normal gravity environment and a 3.6 s short-term microgravity environment. Experiments are conducted under high external circuit load and low external circuit load at low temperature where is 35 °C. The results of the present experimental work demonstrate that the performance and the gas-liquid two-phase flow behaviors of the PEMFC with vertical channels exhibits obvious changes when the PEMFCs enter the 3.6 s short-term microgravity environment from the normal gravity environment. Meanwhile, the performance of the PEMFC with vertical channels increases after the PEMFC enters the 3.6 s short-term microgravity environment under high external circuit load, while under low external circuit load, the PEMFC with horizontal channels exhibits better performance in both the normal gravity environment and the 3.6 s short-term microgravity environment.

Graphene Ambipolar Nanoelectronics for High Noise Rejection Amplification.

PubMed

Liu, Che-Hung; Chen, Qi; Liu, Chang-Hua; Zhong, Zhaohui

2016-02-10

In a modern wireless communication system, signal amplification is critical for overcoming losses during multiple data transformations/processes and long-distance transmission. Common mode and differential mode are two fundamental amplification mechanisms, and they utilize totally different circuit configurations. In this paper, we report a new type of dual-gate graphene ambipolar device with capability of operating under both common and differential modes to realize signal amplification. The signal goes through two stages of modulation where the phase of signal can be individually modulated to be either in-phase or out-of-phase at two stages by exploiting the ambipolarity of graphene. As a result, both common and differential mode amplifications can be achieved within one single device, which is not possible in the conventional circuit configuration. In addition, a common-mode rejection ratio as high as 80 dB can be achieved, making it possible for low noise circuit application. These results open up new directions of graphene-based ambipolar electronics that greatly simplify the RF circuit complexity and the design of multifunction device operation.

Theoretical analysis and modeling of a photonic integrated circuit for frequency 8-tupled and 24-tupled millimeter wave signal generation.

PubMed

Hasan, Mehedi; Guemri, Rabiaa; Maldonado-Basilio, Ramón; Lucarz, Frédéric; de Bougrenet de la Tocnaye, Jean-Louis; Hall, Trevor

2014-12-15

A photonic circuit design for implementing frequency 8-tupling and 24-tupling is proposed. The front- and back-end of the circuit comprises 4×4 MMI couplers enclosing an array of four pairs of phase modulators and 2×2 MMI couplers. The proposed design for frequency multiplication requires no optical or electrical filters, the operation is not limited to carefully adjusted modulation indexes, and the drift originated from static DC bias is mitigated by making use of the intrinsic phase relations of multi-mode interference couplers. A transfer matrix approach is used to represent the main building blocks of the design and hence to describe the operation of the frequency 8-tupling and 24-tupling. The concept is theoretically developed and demonstrated by simulations. Ideal and imperfect power imbalances in the multi-mode interference couplers, as well as ideal and imperfect phases of the electric drives to the phase modulators, are analyzed.

Full wave modulator-demodulator amplifier apparatus. [for generating rectified output signal

NASA Technical Reports Server (NTRS)

Black, J. M. (Inventor)

1974-01-01

A full-wave modulator-demodulator apparatus is described including an operational amplifier having a first input terminal coupled to a circuit input terminal, and a second input terminal alternately coupled to the circuit input terminal. A circuit is ground by a switching circuit responsive to a phase reference signal and the operational amplifier is alternately switched between a non-inverting mode and an inverting mode. The switching circuit includes three field-effect transistors operatively associated to provide the desired switching function in response to an alternating reference signal of the same frequency as an AC input signal applied to the circuit input terminal.

Low phase noise oscillator using two parallel connected amplifiers

NASA Technical Reports Server (NTRS)

Kleinberg, Leonard L.

1987-01-01

A high frequency oscillator is provided by connecting two amplifier circuits in parallel where each amplifier circuit provides the other amplifier circuit with the conditions necessary for oscillation. The inherent noise present in both amplifier circuits causes the quiescent current, and in turn, the generated frequency, to change. The changes in quiescent current cause the transconductance and the load impedance of each amplifier circuit to vary, and this in turn results in opposing changes in the input susceptance of each amplifier circuit. Because the changes in input susceptance oppose each other, the changes in quiescent current also oppose each other. The net result is that frequency stability is enhanced.

Processing circuit with asymmetry corrector and convolutional encoder for digital data

NASA Technical Reports Server (NTRS)

Pfiffner, Harold J. (Inventor)

1987-01-01

A processing circuit is provided for correcting for input parameter variations, such as data and clock signal symmetry, phase offset and jitter, noise and signal amplitude, in incoming data signals. An asymmetry corrector circuit performs the correcting function and furnishes the corrected data signals to a convolutional encoder circuit. The corrector circuit further forms a regenerated clock signal from clock pulses in the incoming data signals and another clock signal at a multiple of the incoming clock signal. These clock signals are furnished to the encoder circuit so that encoded data may be furnished to a modulator at a high data rate for transmission.

Circuit engineering principles for construction of bipolar large-scale integrated circuit storage devices and very large-scale main memory

NASA Astrophysics Data System (ADS)

Neklyudov, A. A.; Savenkov, V. N.; Sergeyez, A. G.

1984-06-01

Memories are improved by increasing speed or the memory volume on a single chip. The most effective means for increasing speeds in bipolar memories are current control circuits with the lowest extraction times for a specific power consumption (1/4 pJ/bit). The control current circuitry involves multistage current switches and circuits accelerating transient processes in storage elements and links. Circuit principles for the design of bipolar memories with maximum speeds for an assigned minimum of circuit topology are analyzed. Two main classes of storage with current control are considered: the ECL type and super-integrated injection type storage with data capacities of N = 1/4 and N 4/16, respectively. The circuits reduce logic voltage differentials and the volumes of lexical and discharge buses and control circuit buses. The limiting speed is determined by the antiinterference requirements of the memory in storage and extraction modes.

Control system for a wound-rotor motor

DOEpatents

Ellis, James N.

1983-01-01

A load switching circuit for switching two or more transformer taps under load carrying conditions includes first and second parallel connected bridge rectifier circuits which control the selective connection of a direct current load to taps of a transformer. The first bridge circuit is normally conducting so that the load is connected to a first tap through the first bridge circuit. To transfer the load to the second tap, a switch is operable to connect the second bridge circuit to a second tap, and when the second bridge circuit begins to conduct, the first bridge circuit ceases conduction because the potential at the second tap is higher than the potential at the first tap, and the load is thus connected to the second tap through the second bridge circuit. The load switching circuit is applicable in a motor speed controller for a wound-rotor motor for effecting tap switching as a function of motor speed while providing a stepless motor speed control characteristic.