Science.gov

Sample records for high voltage operations

  1. Upgrade of the TITAN EBIT High Voltage Operation

    NASA Astrophysics Data System (ADS)

    Foster, Matt; Titan Collaboration

    2016-09-01

    TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) is a setup dedicated to highly precise mass measurements of short-lived isotopes down to 10ms. TITAN's Electron Beam Ion Trap (EBIT) is a charge breeder integrated into the setup to perform in-trap decay spectroscopy of highly charged ions and increase the precision of mass measurements. In its previous configuration TITAN's EBIT could not fulfil its maximum design specification due to high voltage safety restrictions, limiting its obtainable charge states. A recently completed upgrade of the high voltage operation that will allow the EBIT to fulfil its design specification and achieve higher charge states for heavier species is undergoing preliminary tests with stable beam. Simulations were performed to optimise the injection and extraction efficiency at high voltage and initial tests have involved using a Ge detector to identify x-rays produced by charge breeding stable ions. Future work comprises exploring electron capture rates of Ne-, He- and H-like charge states of 64Cu and higher masses, which were not previously accessible. The function of the EBIT within the TITAN setup, the work carried out on the upgrade thus far and its scope for future work will be presented.

  2. Impact of Solar Array Designs on High Voltage Operations

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.; Ferguson, Dale; Piszczor, Mike; ONeill, Mark

    2006-01-01

    As power levels of advanced spacecraft climb above 25 kW, higher solar array operating voltages become attractive. Even in today s satellites, operating spacecraft buses at 100 V and above has led to arcing in GEO communications satellites, so the issue of spacecraft charging and solar array arcing remains a design problem. In addition, micrometeoroid impacts on all of these arrays can also lead to arcing if the spacecraft is at an elevated potential. For example, tests on space station hardware disclosed arcing at 75V on anodized A1 structures that were struck with hypervelocity particles in Low Earth Orbit (LEO) plasmas. Thus an understanding of these effects is necessary to design reliable high voltage solar arrays of the future, especially in light of the Vision for Space Exploration of NASA. In the future, large GEO communication satellites, lunar bases, solar electric propulsion missions, high power communication systems around Mars can lead to power levels well above 100 kW. As noted above, it will be essential to increase operating voltages of the solar arrays well above 80 V to keep the mass of cabling needed to carry the high currents to an acceptable level. Thus, the purpose of this paper is to discuss various solar array approaches, to discuss the results of testing them at high voltages, in the presence of simulated space plasma and under hypervelocity impact. Three different types of arrays will be considered. One will be a planar array using thin film cells, the second will use planar single or multijunction cells and the last will use the Stretched Lens Array (SLA - 8-fold concentration). Each of these has different approaches for protection from the space environment. The thin film cell based arrays have minimal covering due to their inherent radiation tolerance, conventional GaAs and multijunction cells have the traditional cerium-doped microsheet glasses (of appropriate thickness) that are usually attached with Dow Corning DC 93-500 silicone

  3. A magnesium–sodium hybrid battery with high operating voltage

    DOE PAGES

    Dong, Hui; Li, Yifei; Liang, Yanliang; ...

    2016-06-10

    Here, we report a high performance magnesium-sodium hybrid battery utilizing a magnesium-sodium dual-salt electrolyte, a magnesium anode, and a Berlin green cathode. The cell delivers an average discharge voltage of 2.2 V and a reversible capacity of 143 mA h g–1. We also demonstrate the cell with an energy density of 135 W h kg–1 and a high power density of up to 1.67 kW kg–1.

  4. A magnesium–sodium hybrid battery with high operating voltage

    SciTech Connect

    Dong, Hui; Li, Yifei; Liang, Yanliang; Li, Guosheng; Sun, Cheng -Jun; Ren, Yang; Lu, Yuhao; Yao, Yan

    2016-06-10

    Here, we report a high performance magnesium-sodium hybrid battery utilizing a magnesium-sodium dual-salt electrolyte, a magnesium anode, and a Berlin green cathode. The cell delivers an average discharge voltage of 2.2 V and a reversible capacity of 143 mA h g–1. We also demonstrate the cell with an energy density of 135 W h kg–1 and a high power density of up to 1.67 kW kg–1.

  5. A magnesium–sodium hybrid battery with high operating voltage

    SciTech Connect

    Dong, Hui; Li, Yifei; Liang, Yanliang; Li, Guosheng; Sun, Cheng-Jun; Ren, Yang; Lu, Yuhao; Yao, Yan

    2016-06-10

    We report a high performance magnesium-sodium hybrid battery utilizing a magnesium-sodium dual-salt electrolyte, a magnesium anode, and a Berlin green cathode. The cell delivers an average discharge voltage of 2.2 V and a reversible capacity of 143 mAh g-1. We also demonstrate the cell with an energy density of 135 Wh kg-1 and a high power density of up to 1.67 kW kg-1.

  6. High Voltage SPT Performance

    NASA Technical Reports Server (NTRS)

    Manzella, David; Jacobson, David; Jankovsky, Robert

    2001-01-01

    A 2.3 kW stationary plasma thruster designed to operate at high voltage was tested at discharge voltages between 300 and 1250 V. Discharge specific impulses between 1600 and 3700 sec were demonstrated with thrust between 40 and 145 mN. Test data indicated that discharge voltage can be optimized for maximum discharge efficiency. The optimum discharge voltage was between 500 and 700 V for the various anode mass flow rates considered. The effect of operating voltage on optimal magnet field strength was investigated. The effect of cathode flow rate on thruster efficiency was considered for an 800 V discharge.

  7. Description and operating instructions: TEMPO high-voltage microwave driver, Walter Reed Army Institute of Research

    SciTech Connect

    Rohwein, G.J.

    1988-06-01

    This manual describes the TEMPO high-voltage (HV) microwave driver and provides operating procedures and general maintenance requirements. It is intended as a guide for experienced personnel familiar with operating HV pulsed power equipment and not as a detailed instruction for inexperienced operators. For safety reasons, inexperienced personnel should never attempt to charge and fire HV pulsed power equipment. Serious personnel injury and damage to the machine can result from improper operation. 13 figs., 1 tab.

  8. The design, construction, and operation of long-distance high-voltage electricity transmission technologies.

    SciTech Connect

    Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

    2008-03-03

    This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these

  9. High-Voltage Pulse Voltage Generator,

    DTIC Science & Technology

    1979-12-21

    the invention: I. I. Kalyatskiy, V. I. Kurets, and V. I. Safronov Well-known are pulse voltage generators which employ the Arkad’yev- Marx principle of...P2, and hereafter the device operates like an ordinary GIN [pulse volt- age generator] according to the Arkad’yev- Marx principle. The Object of the...Invention The high-voltage pulse voltage generator, assembled according to the Arkad’yev- Marx arrangement, each stage of which incorporates reactive

  10. Observations of Transient ISS Floating Potential Variations During High Voltage Solar Array Operations

    NASA Technical Reports Server (NTRS)

    Willis, Emily M.; Minow, Joseph I.; Parker, Linda N.; Pour, Maria Z. A.; Swenson, Charles; Nishikawa, Ken-ichi; Krause, Linda Habash

    2016-01-01

    The International Space Station (ISS) continues to be a world-class space research laboratory after over 15 years of operations, and it has proven to be a fantastic resource for observing spacecraft floating potential variations related to high voltage solar array operations in Low Earth Orbit (LEO). Measurements of the ionospheric electron density and temperature along the ISS orbit and variations in the ISS floating potential are obtained from the Floating Potential Measurement Unit (FPMU). In particular, rapid variations in ISS floating potential during solar array operations on time scales of tens of milliseconds can be recorded due to the 128 Hz sample rate of the Floating Potential Probe (FPP) pro- viding interesting insight into high voltage solar array interaction with the space plasma environment. Comparing the FPMU data with the ISS operations timeline and solar array data provides a means for correlating some of the more complex and interesting transient floating potential variations with mission operations. These complex variations are not reproduced by current models and require further study to understand the underlying physical processes. In this paper we present some of the floating potential transients observed over the past few years along with the relevant space environment parameters and solar array operations data.

  11. Spacecraft Charging Current Balance Model Applied to High Voltage Solar Array Operations

    NASA Technical Reports Server (NTRS)

    Willis, Emily M.; Pour, Maria Z. A.

    2016-01-01

    Spacecraft charging induced by high voltage solar arrays can result in power losses and degradation of spacecraft surfaces. In some cases, it can even present safety issues for astronauts performing extravehicular activities. An understanding of the dominant processes contributing to spacecraft charging induced by solar arrays is important to current space missions, such as the International Space Station, and to any future space missions that may employ high voltage solar arrays. A common method of analyzing the factors contributing to spacecraft charging is the current balance model. Current balance models are based on the simple idea that the spacecraft will float to a potential such that the current collecting to the surfaces equals the current lost from the surfaces. However, when solar arrays are involved, these currents are dependent on so many factors that the equation becomes quite complicated. In order for a current balance model to be applied to solar array operations, it must incorporate the time dependent nature of the charging of dielectric surfaces in the vicinity of conductors1-3. This poster will present the factors which must be considered when developing a current balance model for high voltage solar array operations and will compare results of a current balance model with data from the Floating Potential Measurement Unit4 on board the International Space Station.

  12. High-density magnetoresistive random access memory operating at ultralow voltage at room temperature

    PubMed Central

    Hu, Jia-Mian; Li, Zheng; Chen, Long-Qing; Nan, Ce-Wen

    2011-01-01

    The main bottlenecks limiting the practical applications of current magnetoresistive random access memory (MRAM) technology are its low storage density and high writing energy consumption. Although a number of proposals have been reported for voltage-controlled memory device in recent years, none of them simultaneously satisfy the important device attributes: high storage capacity, low power consumption and room temperature operation. Here we present, using phase-field simulations, a simple and new pathway towards high-performance MRAMs that display significant improvements over existing MRAM technologies or proposed concepts. The proposed nanoscale MRAM device simultaneously exhibits ultrahigh storage capacity of up to 88 Gb inch−2, ultralow power dissipation as low as 0.16 fJ per bit and room temperature high-speed operation below 10 ns. PMID:22109527

  13. Repeated Strike Process During Disconnector Operation in Ultra-High Voltage Gas-Insulated Switchgear

    NASA Astrophysics Data System (ADS)

    Guan, Yonggang; Cai, Yuanji; Chen, Weijiang; Liu, Weidong; Li, Zhibing; Yue, Gongchang; Zhang, Junmin

    2016-03-01

    Very fast transient over-voltage (VFTO), induced by disconnector operations in gas-insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the experimental results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO. supported in part by National Natural Science Foundation of China (No. 51277106) and in part by the National Basic Research Program of China (973 Program) (No. 2011CB209405)

  14. High Voltage Pulsed Operation of Intense Neutron Source-Electron (INS-e) Device

    NASA Astrophysics Data System (ADS)

    Park, J.; Nebel, R. A.; Stange, S. M.; Taccetti, J. M.; Krupakar Murali, S.

    2003-10-01

    Theoretical works on Periodically Oscillating Plasma Sphere or POPS have suggested that a spherical ion cloud in a uniform electron background may undergo a self-similar collapse that can result in the periodic and simultaneous attainment of ultra-high densities and temperatures. Several promising results, such as the formation of stable deep potential wells with a nearly uniform radial electron density profile, have been obtained in INS-e. However, there are a number of experimental obstacles in order to test the efficacy of POPS. Presently, background ionization and resulting charge neutralization make it difficult to maintain a potential well if the gas pressure is raised above 3x10-6 torr. The space-charge effect in the electron emitters limits the amount of electron injection and precludes a deep potential well of more than 200 V. To mitigate these problems, we are in the process of upgrading the INS-e device to employ pulsed (0.1 - 10 ms), high voltage ( 2kV), and high current ( a few amperes) operations. An overview of this upgrade and initial results form high voltage pulsed operations will be presented.

  15. Low voltage to high voltage level shifter and related methods

    NASA Technical Reports Server (NTRS)

    Mentze, Erik J. (Inventor); Hess, Herbert L. (Inventor); Buck, Kevin M. (Inventor); Cox, David F. (Inventor)

    2006-01-01

    A shifter circuit comprises a high and low voltage buffer stages and an output buffer stage. The high voltage buffer stage comprises multiple transistors arranged in a transistor stack having a plurality of intermediate nodes connecting individual transistors along the stack. The transistor stack is connected between a voltage level being shifted to and an input voltage. An inverter of this stage comprises multiple inputs and an output. Inverter inputs are connected to a respective intermediate node of the transistor stack. The low voltage buffer stage has an input connected to the input voltage and an output, and is operably connected to the high voltage buffer stage. The low voltage buffer stage is connected between a voltage level being shifted away from and a lower voltage. The output buffer stage is driven by the outputs of the high voltage buffer stage inverter and the low voltage buffer stage.

  16. High Voltage Insulation Technology

    NASA Astrophysics Data System (ADS)

    Scherb, V.; Rogalla, K.; Gollor, M.

    2008-09-01

    In preparation of new Electronic Power Conditioners (EPC's) for Travelling Wave Tub Amplifiers (TWTA's) on telecom satellites a study for the development of new high voltage insulation technology is performed. The initiative is mandatory to allow compact designs and to enable higher operating voltages. In a first task a market analysis was performed, comparing different materials with respect to their properties and processes. A hierarchy of selection criteria was established and finally five material candidates (4 Epoxy resins and 1 Polyurethane resin) were selected to be further investigated in the test program. Samples for the test program were designed to represent core elements of an EPC, the high voltage transformer and Printed Circuit Boards of the high voltage section. All five materials were assessed in the practical work flow of the potting process and electrical, mechanical, thermal and lifetime testing was performed. Although the lifetime tests results were overlayed by a larges scatter, finally two candidates have been identified for use in a subsequent qualification program. This activity forms part of element 5 of the ESA ARTES Programme.

  17. High Voltage Seismic Generator

    NASA Astrophysics Data System (ADS)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  18. High voltage, high power operation of the plasma erosion opening switch

    SciTech Connect

    Neri, J.M.; Boller, J.R.; Ottinger, P.F.; Weber, B.V.; Young, F.C.

    1987-04-07

    A Plasma Erosion Opening Switch (PEOS) is used as the opening switch for a vacuum inductive storage system driven by a 1.8-MV, 1.6-TW pulsed power generator. A 135-nH vacuum inductor is current charged to approx.750 kA in 50 ns through the closed PEOS which then opens in <10 ns into an inverse ion diode load. Electrical diagnostics and nuclear activations from ions accelerated in the diode yield a peak load voltage (4.25 MV) and peak load power (2.8 TW) that are 2.4 and 1.8 times greater than ideal matched load values for the same generator pulse.

  19. High-mobility low-temperature ZnO transistors with low-voltage operation

    NASA Astrophysics Data System (ADS)

    Bong, Hyojin; Lee, Wi Hyoung; Lee, Dong Yun; Kim, Beom Joon; Cho, Jeong Ho; Cho, Kilwon

    2010-05-01

    Low voltage high mobility n-type thin film transistors (TFTs) based on sol-gel processed zinc oxide (ZnO) were fabricated using a high capacitance ion gel gate dielectric. The ion gel gated solution-processed ZnO TFTs were found to exhibit excellent electrical properties. TFT carrier mobilities were 13 cm2/V s, ON/OFF current ratios were 105, regardless of the sintering temperature used for the preparation of the ZnO thin films. Ion gel gated ZnO TFTs are successfully demonstrated on plastic substrates for the large area flexible electronics.

  20. Design and Construction of Low Cost High Voltage dc Power Supply for Constant Power Operation

    NASA Astrophysics Data System (ADS)

    Kumar, N. S.; Jayasankar, V.

    2013-06-01

    Pulsed load applications like laser based systems need high voltage dc power supplies with better regulation characteristics. This paper presents the design, construction and testing of dc power supply with 1 kV output at 300 W power level. The designed converter has half bridge switched mode power supply (SMPS) configuration with 20 kHz switching. The paper covers the design of half bridge inverter, closed loop control, High frequency transformer and other related electronics. The designed power supply incorporates a low cost OPAMP based feedback controller which is designed using small signal modelling of the converter. The designed converter was constructed and found to work satisfactorily as per the specifications.

  1. Wide Operating Temperature Range Electrolytes for High Voltage and High Specific Energy Li-Ion Cells

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Hwang, C.; Krause, F. C.; Soler, J.; West, W. C.; Ratnakumar, B. V.; Amine, K.

    2012-01-01

    A number of electrolyte formulations that have been designed to operate over a wide temperature range have been investigated in conjunction with layered-layered metal oxide cathode materials developed at Argonne. In this study, we have evaluated a number of electrolytes in Li-ion cells consisting of Conoco Phillips A12 graphite anodes and Toda HE5050 Li(1.2)Ni(0.15)Co(0.10)Mn(0.55)O2 cathodes. The electrolytes studied consisted of LiPF6 in carbonate-based electrolytes that contain ester co-solvents with various solid electrolyte interphase (SEI) promoting additives, many of which have been demonstrated to perform well in 4V systems. More specifically, we have investigated the performance of a number of methyl butyrate (MB) containing electrolytes (i.e., LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + MB (20:20:60 v/v %) that contain various additives, including vinylene carbonate, lithium oxalate, and lithium bis(oxalato)borate (LiBOB). When these systems were evaluated at various rates at low temperatures, the methyl butyrate-based electrolytes resulted in improved rate capability compared to cells with all carbonate-based formulations. It was also ascertained that the slow cathode kinetics govern the generally poor rate capability at low temperature in contrast to traditionally used LiNi(0.80)Co(0.15)Al(0.05)O2-based systems, rather than being influenced strongly by the electrolyte type.

  2. High-efficient and brightness white organic light-emitting diodes operated at low bias voltage

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Yu, Junsheng; Yuan, Kai; Jian, Yadong

    2010-10-01

    White organic light-emitting diodes (OLEDs) used for display application and lighting need to possess high efficiency, high brightness, and low driving voltage. In this work, white OLEDs consisted of ambipolar 9,10-bis 2-naphthyl anthracene (ADN) as a host of blue light-emitting layer (EML) doped with tetrabutyleperlene (TBPe) and a thin codoped layer consisted of N, N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB) as a host of yellow light-emitting layer doped with 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB) were investigated. With appropriate tuning in the film thickness, position, and dopant concentration of the co-doped layer, a white OLED with a luminance yield of 10.02 cd/A with the CIE coordinates of (0.29, 0.33) has been achieved at a bias voltage of 9 V and a luminance level of over 10,000 cd/m2. By introducing the PIN structure with both HIL and bis(10- hydroxybenzo-quinolinato)-beryllium (BeBq2) ETL, the power efficiency of white OLED was improved.

  3. High-voltage distributors

    NASA Technical Reports Server (NTRS)

    Mcchesney, J. F., Jr.

    1974-01-01

    Two distributors reduce high-voltage breakdowns and corona discharges. Both distributors are constructed to prevent air traps and facilitate servicing without soldering. Occurrence of coronas is also minimized due to smooth surfaces of device.

  4. High voltage power supply

    NASA Technical Reports Server (NTRS)

    Ruitberg, A. P.; Young, K. M. (Inventor)

    1985-01-01

    A high voltage power supply is formed by three discrete circuits energized by a battery to provide a plurality of concurrent output signals floating at a high output voltage on the order of several tens of kilovolts. In the first two circuits, the regulator stages are pulse width modulated and include adjustable ressistances for varying the duty cycles of pulse trains provided to corresponding oscillator stages while the third regulator stage includes an adjustable resistance for varying the amplitude of a steady signal provided to a third oscillator stage. In the first circuit, the oscillator, formed by a constant current drive network and a tuned resonant network included a step up transformer, is coupled to a second step up transformer which, in turn, supplies an amplified sinusoidal signal to a parallel pair of complementary poled rectifying, voltage multiplier stages to generate the high output voltage.

  5. High voltage coaxial switch

    DOEpatents

    Rink, John P.

    1983-07-19

    A coaxial high voltage, high current switch having a solid cylindrical cold cathode coaxially surrounded by a thin hollow cylindrical inner electrode and a larger hollow cylindrical outer electrode. A high voltage trigger between the cathode and the inner electrode causes electrons to be emitted from the cathode and flow to the inner electrode preferably through a vacuum. Some of the electrons penetrate the inner electrode and cause a volumetric discharge in the gas (which may be merely air) between the inner and outer electrodes. The discharge provides a low impedance path between a high voltage charge placed on the outer electrode and a load (which may be a high power laser) coupled to the inner electrode. For high repetition rate the gas between the inner and outer electrodes may be continuously exchanged or refreshed under pressure.

  6. High voltage coaxial switch

    DOEpatents

    Rink, J.P.

    1983-07-19

    A coaxial high voltage, high current switch having a solid cylindrical cold cathode coaxially surrounded by a thin hollow cylindrical inner electrode and a larger hollow cylindrical outer electrode. A high voltage trigger between the cathode and the inner electrode causes electrons to be emitted from the cathode and flow to the inner electrode preferably through a vacuum. Some of the electrons penetrate the inner electrode and cause a volumetric discharge in the gas (which may be merely air) between the inner and outer electrodes. The discharge provides a low impedance path between a high voltage charge placed on the outer electrode and a load (which may be a high power laser) coupled to the inner electrode. For high repetition rate the gas between the inner and outer electrodes may be continuously exchanged or refreshed under pressure. 3 figs.

  7. High voltage pulse generator

    DOEpatents

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  8. High voltage battery cell scanner development

    NASA Technical Reports Server (NTRS)

    Lepisto, J. W.; Decker, D. K.; Graves, J.

    1983-01-01

    Battery cell voltage scanners have been previously used in low voltage spacecraft applications. In connection with future missions involving an employment of high-power high voltage power subsystems and/or autonomous power subsystem management for unattended operation, it will be necessary to utilize battery cell voltage scanners to provide battery cell voltage information for early detection of impending battery cell degradation/failures. In preparation for such missions, a novel battery cell voltage scanner design has been developed. The novel design makes use of low voltage circuit modules which can be applied to high voltage batteries in a building block fashion. A description is presented of the design concept and test results of the high voltage battery cell scanner, and its operation with an autonomously managed power subsystem is discussed.

  9. Determination of threshold and maximum operating electric stresses for selected high voltage insulation. Task 3: Investigation of high voltage capacitor insulation

    NASA Astrophysics Data System (ADS)

    Sosnowski, M.; Eager, G. S., Jr.

    1984-03-01

    The threshold voltage of capacitor insulation was investigated. The experimental work was performed on samples prepared from commercial polypropylene insulated, liquid-filled capacitors. The samples were vacuum-impregnated with the original capacitor insulating liquid obtained from the manufacturer. A limited number of full-size capacitor elements also were tested. Impulse voltage breakdown tests with dc voltage prestressing were performed at room temperature and 75 C. From the results of these tests, the threshold voltage of the samples of the capacitor insulation was determined at both temperatures and that of the whole capacitor elements at room temperature. The threshold voltage of the capacitor insulation was found to be approximately equal to the impulse breakdown voltage. No difference was found between the threshold voltage at room temperature and at 75 C. The threshold voltage of the whole capacitor elements at room temperature was found to be equal to approximately 80% of the threshold voltage of the capacitor insulation samples.

  10. High voltage variable diameter insulator

    DOEpatents

    Vanacek, D.L.; Pike, C.D.

    1982-07-13

    A high voltage feedthrough assembly having a tubular insulator extending between the ground plane ring and the high voltage ring. The insulator is made of Pyrex and decreases in diameter from the ground plane ring to the high voltage ring, producing equipotential lines almost perpendicular to the wall of the insulator to optimize the voltage-holding capability of the feedthrough assembly.

  11. Determination of threshold and maximum operating electric stresses for selected high voltage insulations. Task III. Investigation of high voltage capacitor insulation. Progress report No. 4

    SciTech Connect

    Sosnowski, M.; Eager, G.S. Jr.

    1984-03-01

    This report covers the investigation of threshold voltage of capacitor insulation. The experimental work was performed on samples prepared from commercial polypropylene insulated, liquid-filled capacitors. The samples were vacuum-impregnated with the original capacitor insulating liquid obtained from the manufacturer. A limited number of full-size capacitor elements also were tested. Impulse voltage breakdown tests with dc voltage prestressing were performed at room temperature and 75/sup 0/C. From the results of these tests, the threshold voltage of the samples of the capacitor insulation was determined at both temperatures and that of the whole capacitor elements at room temperature. The threshold voltage of the capacitor insulation was found to be approximately equal to the impulse breakdown voltage. No difference was found between the threshold voltage at room temperature and at 75/sup 0/C. The threshold voltage of the whole capacitor elements at room temperature was found to be equal to approximately 80% of the threshold voltage of the capacitor insulation samples.

  12. Compact high-voltage structures

    SciTech Connect

    Wilson, M. J.; Goerz, D.A.

    1997-06-09

    A basic understanding of the critical issues limiting the compactness of high-voltage systems is required for the next generation of impulse generators. In the process of optimizing the design of a highly reliable solid-dielectric over-voltage switch, an understanding of the limiting factors found are shown. Results of a l3O kV operating switch, having a modest field enhancement of 16% above the average field stress in the switching region, are reported. The resulting high reliability is obtained by reducing the standard deviation of the switch to 6.8%. The total height of the switch is 1 mm. The resulting operating parameters are obtained by controlling field distribution across the entire switch package and field shaping the desired point of switch closure. The disclosed field management technique provides an approach to improve other highly stressed components and structures.

  13. Insulators for high voltages

    SciTech Connect

    Looms, J.S.T.

    1987-01-01

    This book describes electrical insulators for high voltage applications. Topics considered include the insulating materials, the manufacture of wet process porcelain, the manufacture of tempered glass, the glass-fibre core, the polymeric housing, the common problem - terminating an insulator, mechanical constraints, the physics of pollution flashover, the physics of contamination, testing of insulators, conclusions from testing, remedies for flashover, insulators for special cases, interference and noise, and the insulator of the future.

  14. High voltage generator

    DOEpatents

    Schwemin, A. J.

    1959-03-17

    A generator for producing relatively large currents at high voltages is described. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The above-noted circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.

  15. High voltage pulse conditioning

    DOEpatents

    Springfield, Ray M.; Wheat, Jr., Robert M.

    1990-01-01

    Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

  16. HIGH VOLTAGE GENERATOR

    DOEpatents

    Schwemin, A.J.

    1959-03-17

    A generator is presented for producing relatively large currents at high voltages. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.

  17. HIGH VOLTAGE ION SOURCE

    DOEpatents

    Luce, J.S.

    1960-04-19

    A device is described for providing a source of molecular ions having a large output current and with an accelerated energy of the order of 600 kv. Ions are produced in an ion source which is provided with a water-cooled source grid of metal to effect maximum recombination of atomic ions to molecular ions. A very high accelerating voltage is applied to withdraw and accelerate the molecular ions from the source, and means are provided for dumping the excess electrons at the lowest possible potentials. An accelerating grid is placed adjacent to the source grid and a slotted, grounded accelerating electrode is placed adjacent to the accelerating grid. A potential of about 35 kv is maintained between the source grid and accelerating grid, and a potential of about 600 kv is maintained between the accelerating grid and accelerating electrode. In order to keep at a minimum the large number of oscillating electrons which are created when such high voltages are employed in the vicinity of a strong magnetic field, a plurality of high voltage cascaded shields are employed with a conventional electron dumping system being employed between each shield so as to dump the electrons at the lowest possible potential rather than at 600 kv.

  18. High voltage DC power supply

    DOEpatents

    Droege, T.F.

    1989-12-19

    A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively. 7 figs.

  19. High voltage DC power supply

    DOEpatents

    Droege, Thomas F.

    1989-01-01

    A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively.

  20. High Voltage TAL Erosion Characterization

    NASA Technical Reports Server (NTRS)

    Jacobson, David T.

    2003-01-01

    Extended operation of a D-80 anode layer thruster at high voltage was investigated. The thruster was operated for 1200 hours at 700 Volts and 4 Amperes. Laser profilometry was employed to quantify the erosion of the thruster's graphite guard rings and electrodes at 0, 300, 600, 900, and 1200 hours. Thruster performance and electrical characteristics were monitored over the duration of the investigation. The guard rings exhibited asymmetric erosion that was greatest in the region of the cathode. Erosion of the guard rings exposed the magnet poles between 600 to 900 hours of operation.

  1. Diode-less operation of a resonantly charged repetitive high voltage pulser circuit

    NASA Astrophysics Data System (ADS)

    Biswas, Dhruba J.; Nilaya, J. Padma

    2001-05-01

    We report here that the unique geometry of the rotating dielectric spark gap allows the diode-less operation of a command resonant charging pulser network. An average power of about 3.5 kW with a peak value of 75 MW was switched at a repetition rate of 600 Hz into a dummy load resembling a typical TEA CO2 laser.

  2. APPARATUS FOR REGULATING HIGH VOLTAGE

    DOEpatents

    Morrison, K.G.

    1951-03-20

    This patent describes a high-voltage regulator of the r-f type wherein the modulation of the r-f voltage is accomplished at a high level, resulting in good stabilization over a large range of load conditions.

  3. Powerful electrostatic FEL: Regime of operation, recovery of the spent electron beam and high voltage generator

    SciTech Connect

    Boscolo, I.; Gong, J.

    1995-02-01

    FEL, driven by a Cockcroft-Walton electrostatic accelerator with the recovery of the spent electron beam, is proposed as powerful radiation source for plasma heating. The low gain and high gain regimes are compared in view of the recovery problem and the high gain regime is shown to be much more favourable. A new design of the onion Cockcroft-Walton is presented.

  4. High voltage variable diameter insulator

    DOEpatents

    Vanecek, David L.; Pike, Chester D.

    1984-01-01

    A high voltage feedthrough assembly (10) having a tubular insulator (15) extending between the ground plane ring (16) and the high voltage ring (30). The insulator (15) is made of Pyrex and decreases in diameter from the ground plane ring (16) to the high voltage ring (30), producing equipotential lines almost perpendicular to the wall (27) of the insulator (15) to optimize the voltage-holding capability of the feedthrough assembly (10).

  5. High voltage isolation transformer

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Ruitberg, A. P. (Inventor)

    1985-01-01

    A high voltage isolation transformer is provided with primary and secondary coils separated by discrete electrostatic shields from the surfaces of insulating spools on which the coils are wound. The electrostatic shields are formed by coatings of a compound with a low electrical conductivity which completely encase the coils and adhere to the surfaces of the insulating spools adjacent to the coils. Coatings of the compound also line axial bores of the spools, thereby forming electrostatic shields separating the spools from legs of a ferromagnetic core extending through the bores. The transformer is able to isolate a high constant potential applied to one of its coils, without the occurrence of sparking or corona, by coupling the coatings, lining the axial bores to the ferromagnetic core and by coupling one terminal of each coil to the respective coating encasing the coil.

  6. High voltage feedthrough bushing

    DOEpatents

    Brucker, John P.

    1993-01-01

    A feedthrough bushing for a high voltage diode provides for using compression sealing for all sealing surfaces. A diode assembly includes a central conductor extending through the bushing and a grading ring assembly circumferentially surrounding and coaxial with the central conductor. A flexible conductive plate extends between and compressively seals against the central conductor and the grading ring assembly, wherein the flexibility of the plate allows inner and outer portions of the plate to axially translate for compression sealing against the central conductor and the grading ring assembly, respectively. The inner portion of the plate is bolted to the central conductor for affecting sealing. A compression beam is also bolted to the central conductor and engages the outer portion of the plate to urge the outer portion toward the grading ring assembly to obtain compression sealing therebetween.

  7. Low-voltage high-performance silicon photonic devices and photonic integrated circuits operating up to 30 Gb/s.

    PubMed

    Kim, Gyungock; Park, Jeong Woo; Kim, In Gyoo; Kim, Sanghoon; Kim, Sanggi; Lee, Jong Moo; Park, Gun Sik; Joo, Jiho; Jang, Ki-Seok; Oh, Jin Hyuk; Kim, Sun Ae; Kim, Jong Hoon; Lee, Jun Young; Park, Jong Moon; Kim, Do-Won; Jeong, Deog-Kyoon; Hwang, Moon-Sang; Kim, Jeong-Kyoum; Park, Kyu-Sang; Chi, Han-Kyu; Kim, Hyun-Chang; Kim, Dong-Wook; Cho, Mu Hee

    2011-12-19

    We present high performance silicon photonic circuits (PICs) defined for off-chip or on-chip photonic interconnects, where PN depletion Mach-Zehnder modulators and evanescent-coupled waveguide Ge-on-Si photodetectors were monolithically integrated on an SOI wafer with CMOS-compatible process. The fabricated silicon PIC(off-chip) for off-chip optical interconnects showed operation up to 30 Gb/s. Under differential drive of low-voltage 1.2 V(pp), the integrated 1 mm-phase-shifter modulator in the PIC(off-chip) demonstrated an extinction ratio (ER) of 10.5dB for 12.5 Gb/s, an ER of 9.1dB for 20 Gb/s, and an ER of 7.2 dB for 30 Gb/s operation, without adoption of travelling-wave electrodes. The device showed the modulation efficiency of V(π)L(π) ~1.59 Vcm, and the phase-shifter loss of 3.2 dB/mm for maximum optical transmission. The Ge photodetector, which allows simpler integration process based on reduced pressure chemical vapor deposition exhibited operation over 30 Gb/s with a low dark current of 700 nA at -1V. The fabricated silicon PIC(intra-chip) for on-chip (intra-chip) photonic interconnects, where the monolithically integrated modulator and Ge photodetector were connected by a silicon waveguide on the same chip, showed on-chip data transmissions up to 20 Gb/s, indicating potential application in future silicon on-chip optical network. We also report the performance of the hybrid silicon electronic-photonic IC (EPIC), where a PIC(intra-chip) chip and 0.13μm CMOS interface IC chips were hybrid-integrated.

  8. High Voltage Distribution

    NASA Astrophysics Data System (ADS)

    Norbeck, Edwin; Miller, Michael; Onel, Yasar

    2010-11-01

    For detector arrays that require 5 to 10 kV at a few microamps each for hundreds of detectors, using hundreds of HV power supplies is unreasonable. Bundles of hundreds of HV cables take up space that should be filled with detectors. A typical HV module can supply 1 ma, enough current for hundreds of detectors. It is better to use a single HV module and distribute the current as needed. We show a circuit that, for each detector, measures the current, cuts off the voltage if the current exceeds a set maximum, and allows the HV to be turned on or off from a control computer. The entire array requires a single HV cable and 2 or 3 control lines. This design provides the same voltage to all of the detectors, the voltage set by the single HV module. Some additional circuitry would allow a computer controlled voltage drop between the HV and each individual detector.

  9. Fabrication and operation of a two-dimensional ion-trap lattice on a high-voltage microchip.

    PubMed

    Sterling, R C; Rattanasonti, H; Weidt, S; Lake, K; Srinivasan, P; Webster, S C; Kraft, M; Hensinger, W K

    2014-04-04

    Microfabricated ion traps are a major advancement towards scalable quantum computing with trapped ions. The development of more versatile ion-trap designs, in which tailored arrays of ions are positioned in two dimensions above a microfabricated surface, will lead to applications in fields as varied as quantum simulation, metrology and atom-ion interactions. Current surface ion traps often have low trap depths and high heating rates, because of the size of the voltages that can be applied to them, limiting the fidelity of quantum gates. Here we report on a fabrication process that allows for the application of very high voltages to microfabricated devices in general and use this advance to fabricate a two-dimensional ion-trap lattice on a microchip. Our microfabricated architecture allows for reliable trapping of two-dimensional ion lattices, long ion lifetimes, rudimentary shuttling between lattice sites and the ability to deterministically introduce defects into the ion lattice.

  10. Operation of High-Voltage Transverse Shock Wave Ferromagnetic Generator in the Open Circuit and Charging Modes

    DTIC Science & Technology

    2005-06-01

    FMGs are based on the transverse (when the shock wave propagates across the magnetization vector M) shock demagnetization of Nd2Fe14B hard...generators based on the transverse (when the shock wave propagates across the magnetization vector M) shock wave demagnetization of Nd2Fe14B hard...and photo of a high-voltage transverse FMG are shown in Fig. 1. It contains a hollow hard ferromagnetic cylindrical Nd2Fe14B energy-carrying

  11. Comparative High Voltage Impulse Measurement

    PubMed Central

    FitzPatrick, Gerald J.; Kelley, Edward F.

    1996-01-01

    A facility has been developed for the determination of the ratio of pulse high voltage dividers over the range from 10 kV to 300 kV using comparative techniques with Kerr electro-optic voltage measurement systems and reference resistive voltage dividers. Pulse voltage ratios of test dividers can be determined with relative expanded uncertainties of 0.4 % (coverage factor k = 2 and thus a two standard deviation estimate) or less using the complementary resistive divider/Kerr cell reference systems. This paper describes the facility and specialized procedures used at NIST for the determination of test voltage divider ratios through comparative techniques. The error sources and special considerations in the construction and use of reference voltage dividers to minimize errors are discussed, and estimates of the measurement uncertainties are presented. PMID:27805083

  12. Calibration of Voltage Transformers and High- Voltage Capacitors at NIST

    PubMed Central

    Anderson, William E.

    1989-01-01

    The National Institute of Standards and Technology (NIST) calibration service for voltage transformers and high-voltage capacitors is described. The service for voltage transformers provides measurements of ratio correction factors and phase angles at primary voltages up to 170 kV and secondary voltages as low as 10 V at 60 Hz. Calibrations at frequencies from 50–400 Hz are available over a more limited voltage range. The service for high-voltage capacitors provides measurements of capacitance and dissipation factor at applied voltages ranging from 100 V to 170 kV at 60 Hz depending on the nominal capacitance. Calibrations over a reduced voltage range at other frequencies are also available. As in the case with voltage transformers, these voltage constraints are determined by the facilities at NIST. PMID:28053409

  13. Extended-gate-type IGZO electric-double-layer TFT immunosensor with high sensitivity and low operation voltage

    NASA Astrophysics Data System (ADS)

    Liang, Lingyan; Zhang, Shengnan; Wu, Weihua; Zhu, Liqiang; Xiao, Hui; Liu, Yanghui; Zhang, Hongliang; Javaid, Kashif; Cao, Hongtao

    2016-10-01

    An immunosensor is proposed based on the indium-gallium-zinc-oxide (IGZO) electric-double-layer thin-film transistor (EDL TFT) with a separating extended gate. The IGZO EDL TFT has a field-effect mobility of 24.5 cm2 V-1 s-1 and an operation voltage less than 1.5 V. The sensors exhibit the linear current response to label-free target immune molecule in the concentrations ranging from 1.6 to 368 × 10-15 g/ml with a detection limit of 1.6 × 10-15 g/ml (0.01 fM) under an ultralow operation voltage of 0.5 V. The IGZO TFT component demonstrates a consecutive assay stability and recyclability due to the unique structure with the separating extended gate. With the excellent electrical properties and the potential for plug-in-card-type multifunctional sensing, extended-gate-type IGZO EDL TFTs can be promising candidates for the development of a label-free biosensor for public health applications.

  14. Thyratron Marx High Voltage Generator.

    DTIC Science & Technology

    This invention relates to a high voltage pulse generator of the Marx type, in which capacitors are charged in parallel and discharged in series...Amongst the many techniques for producing high voltage pulses, the Marx generator is probably the best known and most widely used. For the combination of...short risetime and low output impendance (i.e. high power), large energy, high efficiency and waveform flexibility -- the Marx principle is peerless

  15. High voltage solar array experiments

    NASA Technical Reports Server (NTRS)

    Kennerud, K. L.

    1974-01-01

    The interaction between the components of a high voltage solar array and a simulated space plasma is studied to obtain data for the design of a high voltage solar array capable of 15kW at 2 to 16kV. Testing was conducted in a vacuum chamber 1.5-m long by 1.5-m diameter having a plasma source which simulated the plasma conditions existing in earth orbit between 400 nautical miles and synchronous altitude. Test samples included solar array segments pinholes in insulation covering high voltage electrodes, and plain dielectric samples. Quantitative data are presented in the areas of plasma power losses, plasma and high voltage induced damage, and dielectric properties. Limitations of the investigation are described.

  16. High voltage power transistor development

    NASA Technical Reports Server (NTRS)

    Hower, P. L.

    1981-01-01

    Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

  17. High-voltage-compatible, fully depleted CCDs

    SciTech Connect

    Holland, Stephen E.; Bebek, Chris J.; Dawson, Kyle S.; Emes, JohnE.; Fabricius, Max H.; Fairfield, Jessaym A.; Groom, Don E.; Karcher, A.; Kolbe, William F.; Palaio, Nick P.; Roe, Natalie A.; Wang, Guobin

    2006-05-15

    We describe charge-coupled device (CCD) developmentactivities at the Lawrence Berkeley National Laboratory (LBNL).Back-illuminated CCDs fabricated on 200-300 mu m thick, fully depleted,high-resistivity silicon substrates are produced in partnership with acommercial CCD foundry.The CCDs are fully depleted by the application ofa substrate bias voltage. Spatial resolution considerations requireoperation of thick, fully depleted CCDs at high substrate bias voltages.We have developed CCDs that are compatible with substrate bias voltagesof at least 200V. This improves spatial resolution for a given thickness,and allows for full depletion of thicker CCDs than previously considered.We have demonstrated full depletion of 650-675 mu m thick CCDs, withpotential applications in direct x-ray detection. In this work we discussthe issues related to high-voltage operation of fully depleted CCDs, aswell as experimental results on high-voltage-compatible CCDs.

  18. Achieving high mobility, low-voltage operating organic field-effect transistor nonvolatile memory by an ultraviolet-ozone treating ferroelectric terpolymer

    NASA Astrophysics Data System (ADS)

    Xiang, Lanyi; Wang, Wei; Xie, Wenfa

    2016-11-01

    Poly(vinylidene fluoride–trifluoroethylene) has been widely used as a dielectric of the ferroelectric organic field-effect transistor (FE-OFET) nonvolatile memory (NVM). Some critical issues, including low mobility and high operation voltage, existed in these FE-OFET NVMs, should be resolved before considering to their commercial application. In this paper, we demonstrated low-voltage operating FE-OFET NVMs based on a ferroelectric terpolymer poly(vinylidene-fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] owed to its low coercive field. By applying an ultraviolet-ozone (UVO) treatment to modify the surface of P(VDF-TrFE-CTFE) films, the growth model of the pentacene film was changed, which improved the pentacene grain size and the interface morphology of the pentacene/P(VDF-TrFE-CTFE). Thus, the mobility of the FE-OFET was significantly improved. As a result, a high performance FE-OFET NVM, with a high mobility of 0.8 cm2 V‑1 s‑1, large memory window of 15.4~19.2, good memory on/off ratio of 103, the reliable memory endurance over 100 cycles and stable memory retention ability, was achieved at a low operation voltage of ±15 V.

  19. Achieving high mobility, low-voltage operating organic field-effect transistor nonvolatile memory by an ultraviolet-ozone treating ferroelectric terpolymer

    PubMed Central

    Xiang, Lanyi; Wang, Wei; Xie, Wenfa

    2016-01-01

    Poly(vinylidene fluoride–trifluoroethylene) has been widely used as a dielectric of the ferroelectric organic field-effect transistor (FE-OFET) nonvolatile memory (NVM). Some critical issues, including low mobility and high operation voltage, existed in these FE-OFET NVMs, should be resolved before considering to their commercial application. In this paper, we demonstrated low-voltage operating FE-OFET NVMs based on a ferroelectric terpolymer poly(vinylidene-fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] owed to its low coercive field. By applying an ultraviolet-ozone (UVO) treatment to modify the surface of P(VDF-TrFE-CTFE) films, the growth model of the pentacene film was changed, which improved the pentacene grain size and the interface morphology of the pentacene/P(VDF-TrFE-CTFE). Thus, the mobility of the FE-OFET was significantly improved. As a result, a high performance FE-OFET NVM, with a high mobility of 0.8 cm2 V−1 s−1, large memory window of 15.4~19.2, good memory on/off ratio of 103, the reliable memory endurance over 100 cycles and stable memory retention ability, was achieved at a low operation voltage of ±15 V. PMID:27824101

  20. Simulation of Thick Gated Silicon Drift X-ray Detector Operated by a Single High-Voltage Source

    NASA Astrophysics Data System (ADS)

    Matsuura, Hideharu

    2013-02-01

    High-resolution X-ray detectors can be used to detect traces of hazardous or radioactive elements in food, soil, and the human body by measuring the energies and counts of emitted X-ray fluorescence photons. We have simulated the electric potential distributions in gated silicon drift detectors (GSDDs) with an active area of 18 mm2 and a Si thickness between 0.625 and 1.5 mm. A GSDD gate pattern was designed for each Si thickness and for various oxide charge densities in the SiO2 passivating layer near the SiO2/Si interface. The simulated GSDDs required approximately half the reverse bias voltage required by Si pin detectors. Our detector design could improve the absorption of Cd or Cs X-ray fluorescence photons and would reduce the cost of X-ray detection systems.

  1. Improved Programmable High-Voltage Power Supply

    NASA Technical Reports Server (NTRS)

    Castell, Karen; Rutberg, Arthur

    1994-01-01

    Improved dc-to-dc converter functions as programmable high-voltage power supply with low-power-dissipation voltage regulator on high-voltage side. Design of power supply overcomes deficiencies of older designs. Voltage regulation with low power dissipation provided on high-voltage side.

  2. High voltage thermal cells

    NASA Astrophysics Data System (ADS)

    Ryan, David M.

    An experiment aimed at a search for new, high-energy cathodes for thermal cells is described. The experiment has begun to reduce the solubility, volatility, and mobility of the cathode materials by preparing and testing massive, relatively immobile cathode molecules. A good candidate for this is the vanadium series, which forms rings, chains, clusters and Keggin compounds. The first three compounds of this genre have been prepared: K3V5O14, Na6V10O28, and K7(Ni4+V13O30). Only the first of these compounds has been tested as a cathode material. The K3V5O14 demonstrated better performance than V2O5, but it is not as good as the FeS2 cells used for benchmarks.

  3. High voltage testing for the Majorana Demonstrator

    SciTech Connect

    Abgrall, N.; Arnquist, Isaac J.; Avignone, F. T.; Barabash, A.; Bertrand, F.; Bradley, A. W.; Brudanin, V.; Busch, Matthew; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, C. D.; Chu, Pamela M.; Cuesta, C.; Detwiler, Jason A.; Doe, P. J.; Dunagan, C.; Efremenko, Yuri; Ejiri, H.; Elliott, S. R.; Fu, Z.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I.; Guiseppe, V. E.; Henning, R.; Hoppe, Eric W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K.; Kidd, M. F.; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Li, Alexander D.; MacMullin, J.; Martin, R. D.; Massarcyk, R.; Meijer, S. J.; Mertens, S.; Orrell, John L.; O'Shaughnessy, C.; Poon, Alan W.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero Romo, M.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, Anne-Marie E.; Tedeschi, D.; Thompson, Andrew; Ton, K. T.; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, Chang-Hong; Yumatov, V.

    2016-07-01

    The Majorana Collaboration is constructing theMajorana Demonstrator, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of theMajorana Demonstrator. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of the high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the Majorana Demonstrator was characterized and the micro-discharge effects during theMajorana Demonstrator commissioning phase were studied. A stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.

  4. High voltage testing for the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Dunagan, C.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Fu, Z.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Li, A.; MacMullin, J.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Thompson, A.; Ton, K. T.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.

    2016-07-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of the MAJORANA DEMONSTRATOR. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of the high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the MAJORANA DEMONSTRATOR was characterized and the micro-discharge effects during the MAJORANA DEMONSTRATOR commissioning phase were studied. A stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.

  5. High voltage testing for the Majorana Demonstrator

    SciTech Connect

    Abgrall, N.; Arnquist, I. J.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y. -D.; Christofferson, C. D.; Chu, P. -H.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Dunagan, C.; Efremenko, Yu.; Ejiri, H.; Elliot, S. R.; Fu, Z.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Li, A.; MacMullin, J.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Thompson, A.; Ton, K. T.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C. -H.; Yumatov, V.

    2016-04-04

    The Majorana Collaboration is constructing the Majorana Demonstrator, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of the Majorana Demonstrator. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of the high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the Majorana Demonstrator was characterized and the micro-discharge effects during the Majorana Demonstrator commissioning phase were studied. Furthermore, a stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.

  6. High voltage testing for the Majorana Demonstrator

    DOE PAGES

    Abgrall, N.; Arnquist, I. J.; Avignone, III, F. T.; ...

    2016-04-04

    The Majorana Collaboration is constructing the Majorana Demonstrator, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of the Majorana Demonstrator. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of themore » high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the Majorana Demonstrator was characterized and the micro-discharge effects during the Majorana Demonstrator commissioning phase were studied. Furthermore, a stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.« less

  7. Determination of threshold and maximum operating electric stresses for selected high voltage insulations: Investigation of aged polymeric dielectric cable. Final report

    SciTech Connect

    Eager, G.S. Jr.; Seman, G.W.; Fryszczyn, B.

    1995-11-01

    Based on the successful completion of the extensive research project DOE/ET/29303-1 February 1982 to develop a new method for the determination of threshold voltage in XLPE and EPR insulated cables, tests were initiated to establish the maximum safe operating voltage stresses of crosslinked polyethylene insulated cables that become wet when they operate in a moist environment. The present report covers the measurement of the threshold voltage, the a.c. breakdown voltage and the impulse breakdown voltage of XLPE cable after undergoing accelerated laboratory aging in water. Model and 15 kV XLPE cables were manufactured in commercial equipment using state-of-the-art semiconducting shields and XLPE insulation. The threshold voltage, a.c. voltage breakdown and impulse voltage breakdown of the model cables were determined before aging, after aging one week and after aging 26 weeks. The model cable, following 26 weeks aging, was dried by passing dry gas through the conductor interstices which removed moisture from the cable. The threshold voltage, the a.c. voltage breakdown and the impulse voltage breakdown of the XLPE model cable after drying was measured.

  8. Low voltage operation of plasma focus.

    PubMed

    Shukla, Rohit; Sharma, S K; Banerjee, P; Das, R; Deb, P; Prabahar, T; Das, B K; Adhikary, B; Shyam, A

    2010-08-01

    Plasma foci of compact sizes and operating with low energies (from tens of joules to few hundred joules) have found application in recent years and have attracted plasma-physics scientists and engineers for research in this direction. We are presenting a low energy and miniature plasma focus which operates from a capacitor bank of 8.4 muF capacity, charged at 4.2-4.3 kV and delivering approximately 52 kA peak current at approximately 60 nH calculated circuit inductance. The total circuit inductance includes the plasma focus inductance. The reported plasma focus operates at the lowest voltage among all reported plasma foci so far. Moreover the cost of capacitor bank used for plasma focus is nearly 20 U.S. dollars making it very cheap. At low voltage operation of plasma focus, the initial breakdown mechanism becomes important for operation of plasma focus. The quartz glass tube is used as insulator and breakdown initiation is done on its surface. The total energy of the plasma focus is approximately 75 J. The plasma focus system is made compact and the switching of capacitor bank energy is done by manual operating switch. The focus is operated with hydrogen and deuterium filled at 1-2 mbar.

  9. Lithium intercalation and structural changes at the LiCoO2 surface under high voltage battery operation

    NASA Astrophysics Data System (ADS)

    Taminato, Sou; Hirayama, Masaaki; Suzuki, Kota; Tamura, Kazuhisa; Minato, Taketoshi; Arai, Hajime; Uchimoto, Yoshiharu; Ogumi, Zempachi; Kanno, Ryoji

    2016-03-01

    An epitaxial-film model electrode of LiCoO2(104) was fabricated on SrRuO3(100)/Nb:SrTiO3(100) using pulsed laser deposition. The 50 nm thick LiCoO2(104) film exhibited lithium (de-)intercalation activity with a first discharge capacity of 119 mAh g-1 between 3.0 and 4.4 V, followed by a gradual capacity fading with subsequent charge-discharge cycles. In contrast, a 3.2 nm thick Li3PO4-coated film exhibited a higher intercalation capacity of 148 mAh g-1 with superior cycle retention than the uncoated film. In situ surface X-ray diffraction measurements revealed a small lattice change at the coated surface during the (de-)intercalation processes compared to the uncoated surface. The surface modification of LiCoO2 by the Li3PO4 coating could lead to improvement of the structural stability at the surface region during lithium (de-)intercalation at high voltage.

  10. High Voltage Space Solar Arrays

    NASA Technical Reports Server (NTRS)

    Ferguson, D. C.; Hillard, G. B.; Vayner, B. V.; Galofaro, J. T.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Recent tests performed at the NASA Glenn Research Center and elsewhere have shown promise in the design and construction of high voltage (300-1000 V) solar arrays for space applications. Preliminary results and implications for solar array design will be discussed, with application to direct-drive electric propulsion and space solar power.

  11. LHCb calorimeters high voltage system

    NASA Astrophysics Data System (ADS)

    Gilitsky, Yu.; Golutvin, A.; Konoplyannikov, A.; Lefrancois, J.; Perret, P.; Schopper, A.; Soldatov, M.; Yakimchuk, V.

    2007-02-01

    The calorimeter system in LHCb aims to identify electrons, photons and hadrons. All calorimeters are equipped with Hamamatsu photo tubes as devices for light to signal conversion. Eight thousand R7899-20 tubes are used for electromagnetic and hadronic calorimeters and two hundred 64 channels multi-anode R7600-00-M64 for Scintillator-Pad/Preshower detectors. The calorimeter high voltage (HV) system is based on a Cockroft Walton (CW) voltage converter and a control board connected to the Experiment Control System (ECS) by serial bus. The base of each photomultiplier tube (PMT) is built with a high voltage converter and constructed on an individual printed circuit board, using compact surface mount components. The base is attached directly to the PMT. There are no HV cables in the system. A Field Programmable Gate Array (FPGA) is used on the control board as an interface between the ECS and the 200 control channels. The FPGA includes also additional functionalities allowing automated monitoring and ramp up of the high voltage values. This paper describes the HV system architecture, some technical details of the electronics implementation and summarizes the system performance. This safe and low power consumption HV electronic system for the photomultiplier tubes can be used for various biomedical apparatus too.

  12. High-Voltage Droplet Dispenser

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.

    2003-01-01

    An apparatus that is extremely effective in dispensing a wide range of droplets has been developed. This droplet dispenser is unique in that it utilizes a droplet bias voltage, as well as an ionization pulse, to release a droplet. Apparatuses that deploy individual droplets have been used in many applications, including, notably, study of combustion of liquid fuels. Experiments on isolated droplets are useful in that they enable the study of droplet phenomena under well-controlled and simplified conditions. In this apparatus, a syringe dispenses a known value of liquid, which emerges from, and hangs onto, the outer end of a flat-tipped, stainless steel needle. Somewhat below the needle tip and droplet is a ring electrode. A bias high voltage, followed by a high-voltage pulse, is applied so as to attract the droplet sufficiently to pull it off the needle. The voltages are such that the droplet and needle are negatively charged and the ring electrode is positively charged.

  13. Investigation of the Effects of Cathode Flow Fraction and Position on the Performance and Operation of the High Voltage Hall Accelerator

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In- Space Propulsion Technology office is sponsoring NASA Glenn Research Center (GRC) to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. Tests were performed within NASA GRC Vacuum Facility 5 at background pressure levels that were six times lower than what has previously been attained in other vacuum facilities. A study was conducted to assess the impact of varying the cathode-to-anode flow fraction and cathode position on the performance and operational characteristics of the High Voltage Hall Accelerator (HiVHAc) thruster. In addition, the impact of injecting additional xenon propellant in the vicinity of the cathode was also assessed. Cathode-to-anode flow fraction sensitivity tests were performed for power levels between 1.0 and 3.9 kW. It was found that varying the cathode flow fraction from 5 to approximately 10% of the anode flow resulted in the cathode-to-ground voltage becoming more positive. For an operating condition of 3.8 kW and 500 V, varying the cathode position from a distance of closest approach to 600 mm away did not result in any substantial variation in thrust but resulted in the cathode-to-ground changing from -17 to -4 V. The change in the cathode-to-ground voltage along with visual observations indicated a change in how the cathode plume was coupling to the thruster discharge. Finally, the injection of secondary xenon flow in the vicinity of the cathode had an impact similar to increasing the cathode-to-anode flow fraction, where the cathode-to-ground voltage became more positive and discharge current and thrust increased slightly. Future tests of the HiVHAc thruster are planned with a centrally mounted cathode in order to further assess the impact of cathode position on thruster performance.

  14. High voltage photovoltaic power converter

    DOEpatents

    Haigh, Ronald E.; Wojtczuk, Steve; Jacobson, Gerard F.; Hagans, Karla G.

    2001-01-01

    An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

  15. TRANSISTOR HIGH VOLTAGE POWER SUPPLY

    DOEpatents

    Driver, G.E.

    1958-07-15

    High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

  16. PLATEAUING COSMIC RAY DETECTORS TO ACHIEVE OPTIMUM OPERATING VOLTAGE

    SciTech Connect

    Knoff, E.N.; Peterson, R.S.

    2008-01-01

    Through QuarkNet, students across the country have access to cosmic ray detectors in their high school classrooms. These detectors operate using a scintillator material and a photomultiplier tube (PMT). A data acquisition (DAQ) board counts cosmic ray hits from the counters. Through an online e-Lab, students can analyze and share their data. In order to collect viable data, the PMTs should operate at their plateau voltages. In these plateau ranges, the number of counts per minute remains relatively constant with small changes in PMT voltage. We sought to plateau the counters in the test array and to clarify the plateauing procedure itself. In order to most effectively plateau the counters, the counters should be stacked and programmed to record the number of coincident hits as well as their singles rates. We also changed the threshold value that a signal must exceed in order to record a hit and replateaued the counters. For counter 1, counter 2, and counter 3, we found plateau voltages around 1V. The singles rate plateau was very small, while the coincidence plateau was very long. The plateau voltages corresponded to a singles rate of 700–850 counts per minute. We found very little effect of changing the threshold voltages. Our chosen plateau voltages produced good performance studies on the e-Lab. Keeping in mind the nature of the experiments conducted by the high school students, we recommend a streamlined plateauing process. Because changing the threshold did not drastically affect the plateau voltage or the performance study, students should choose a threshold value, construct plateau graphs, and analyze their data using a performance study. Even if the counters operate slightly off their plateau voltage, they should deliver good performance studies and return reliable results.

  17. 29. Detail view north showing amperage and voltage meters, operator's ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Detail view north showing amperage and voltage meters, operator's room, west operator's house. - Yellow Mill Bridge, Spanning Yellow Mill Channel at Stratford Avenue, Bridgeport, Fairfield County, CT

  18. High voltage RF feedthrough bushing

    DOEpatents

    Grotz, Glenn F.

    1984-01-01

    Described is a multi-element, high voltage radio frequency bushing for trmitting RF energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

  19. Conceptual definition of a high voltage power supply test facility

    NASA Technical Reports Server (NTRS)

    Biess, John J.; Chu, Teh-Ming; Stevens, N. John

    1989-01-01

    NASA Lewis Research Center is presently developing a 60 GHz traveling wave tube for satellite cross-link communications. The operating voltage for this new tube is - 20 kV. There is concern about the high voltage insulation system and NASA is planning a space station high voltage experiment that will demonstrate both the 60 GHz communications and high voltage electronics technology. The experiment interfaces, requirements, conceptual design, technology issues and safety issues are determined. A block diagram of the high voltage power supply test facility was generated. It includes the high voltage power supply, the 60 GHz traveling wave tube, the communications package, the antenna package, a high voltage diagnostics package and a command and data processor system. The interfaces with the space station and the attached payload accommodations equipment were determined. A brief description of the different subsystems and a discussion of the technology development needs are presented.

  20. High voltage source control on FODS

    NASA Astrophysics Data System (ADS)

    Patalakha, D. I.; Kalinin, A. Yu; Kulagin, N. V.

    2017-01-01

    The implementation of the high voltage power supply control system (HVPSCS) for experimental setup FODS (FOcusing Doublearmed Spectrometer) at accelerator U-70 of the Federal State Budgetary Institution State Research Center Of Russia Institute for High Energy Physics of the National Research Centre “Kurchatov Institute” (hereinafter referred to as IHEP) or for the test bench of the detector components is considered. The required set of hardware is defined and the appropriate software to operate HVPSCS is written in C/C++ codes. The date acquisition (DAQ) system [1] makes automatic control on HVPSCS for data taking run. It allows to get the dependence of appropriate detector parameters on the high voltage supply values and choose its optimal values for FODS detectors. The test run results of HVPSCS are presented.

  1. High voltage feed through bushing

    DOEpatents

    Brucker, J.P.

    1993-04-06

    A feed through bushing for a high voltage diode provides for using compression sealing for all sealing surfaces. A diode assembly includes a central conductor extending through the bushing and a grading ring assembly circumferentially surrounding and coaxial with the central conductor. A flexible conductive plate extends between and compressively seals against the central conductor and the grading ring assembly, wherein the flexibility of the plate allows inner and outer portions of the plate to axially translate for compression sealing against the central conductor and the grading ring assembly, respectively. The inner portion of the plate is bolted to the central conductor for affecting sealing. A compression beam is also bolted to the central conductor and engages the outer portion of the plate to urge the outer portion toward the grading ring assembly to obtain compression sealing therebetween.

  2. High voltage load resistor array

    DOEpatents

    Lehmann, Monty Ray

    2005-01-18

    A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

  3. High voltage solar cell power generating system

    NASA Technical Reports Server (NTRS)

    Levy, E., Jr.; Opjorden, R. W.; Hoffman, A. C.

    1974-01-01

    A laboratory solar power system regulated by on-panel switches has been delivered for operating high power (3 kW), high voltage (15,000 volt) loads (communication tubes, ion thrusters). The modular system consists of 26 solar arrays, each with an integral light source and cooling system. A typical array contains 2,560 series-connected cells. Each light source consists of twenty 500-watt tungsten iodide lamps providing plus or minus 5 percent uniformity at one solar constant. An array temperature of less than 40 C is achieved using an infrared filter, a water-cooled plate, a vacuum hold-down system, and air flushing.

  4. Low power, scalable multichannel high voltage controller

    DOEpatents

    Stamps, James Frederick; Crocker, Robert Ward; Yee, Daniel Dadwa; Dils, David Wright

    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.

  5. Low power, scalable multichannel high voltage controller

    DOEpatents

    Stamps, James Frederick; Crocker, Robert Ward; Yee, Daniel Dadwa; Dils, David Wright

    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.

  6. High voltage electric substation performance in earthquakes

    SciTech Connect

    Eidinger, J.; Ostrom, D.; Matsuda, E.

    1995-12-31

    This paper examines the performance of several types of high voltage substation equipment in past earthquakes. Damage data is provided in chart form. This data is then developed into a tool for estimating the performance of a substation subjected to an earthquake. First, suggests are made about the development of equipment class fragility curves that represent the expected earthquake performance of different voltages and types of equipment. Second, suggestions are made about how damage to individual pieces of equipment at a substation likely affects the post-earthquake performance of the substation as a whole. Finally, estimates are provided as to how quickly a substation, at various levels of damage, can be restored to operational service after the earthquake.

  7. High-Voltage Digital-To-Analog Converter

    NASA Technical Reports Server (NTRS)

    Huston, Steven W.

    1990-01-01

    High-voltage 10-bit digital-to-analog converter operates under computer control to put out voltages up to 500 V at currents up to 35 mA. Circuit includes high-voltage power supply used to generate high-voltage square wave at frequency set by computer at value between 0.2 Hz and 10 Hz. Used to drive 0.02-microfarad, 1-kV capacitor at slewing rate of 1 V/microsecond to provide signal for robotic imaging system.

  8. High voltage design guide. Volume 4: Aircraft

    NASA Astrophysics Data System (ADS)

    Dunbar, W. G.

    1983-01-01

    This report supplies the theoretical background and design techniques needed by an engineer who is designing electrical insulation for high-voltage, high-power components, equipment, and systems for aircraft. A literature survey and abundant bibliography identify references that provide further data on the subjects of partial discharges, corona, field theory and plotting, voids and processes for applying insulation. Both gaseous and solid insulations are treated. Cryogenic and liquid design notes are included. Tests and test equipment for high voltage insulation and equipment are defined. Requirements of test plans and procedures for high-voltage, high-power equipment are identified and illustrated by examples. Suggestions for high-voltage specifications are provided. Very few of the Military and Government specifications deal with system voltages above 10kV, thus most aircraft high-voltage specifications will have to be derived from the power industry specifications and standards produced by ASTM, IEEE, and NEMA.

  9. HIGH VOLTAGE, HIGH CURRENT SPARK GAP SWITCH

    DOEpatents

    Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.

    1962-04-17

    A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)

  10. Living and Working Safely Around High-Voltage Power Lines.

    SciTech Connect

    United States. Bonneville Power Administration.

    2001-06-01

    High-voltage transmission lines can be just as safe as the electrical wiring in the homes--or just as dangerous. The crucial factor is ourselves: they must learn to behave safely around them. This booklet is a basic safety guide for those who live and work around power lines. It deals primarily with nuisance shocks due to induced voltages, and with potential electric shock hazards from contact with high-voltage lines. References on possible long-term biological effects of transmission lines are shown. In preparing this booklet, the Bonneville Power Administration has drawn on more than 50 years of experience with high-voltage transmission. BPA operates one of the world`s largest networks of long-distance, high-voltage lines. This system has more than 400 substations and about 15,000 miles of transmission lines, almost 4,400 miles of which are operated at 500,000 volts.

  11. High-Voltage CMOS Controller for Microfluidics.

    PubMed

    Khorasani, M; Behnam, M; van den Berg, L; Backhouse, C J; Elliott, D G

    2009-04-01

    A high-voltage microfluidic controller designed using DALSA semiconductor's 0.8-mum low-voltage/high-voltage complementary metal-oxide semiconductor/double diffused metal-oxide semiconductor process is presented. The chip's four high-voltage output drivers can switch 300 V, and the dc-dc boost converter can generate up to 68 V using external passive components. This integrated circuit represents an advancement in microfluidic technology when used in conjunction with a charge coupling device (CCD)-based optical system and a glass microfluidic channel, enabling a portable and cost-efficient platform for genetic analysis.

  12. High-voltage air-core pulse transformers

    SciTech Connect

    Rohwein, G. J.

    1981-01-01

    General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources. Consequently, the potential user must become thoroughly familiar with all aspects of design, fabrication and system application before he can produce a high performance transformer system. (LCL)

  13. High-voltage air-core pulse transformers

    SciTech Connect

    Rohwein, G.J.

    1981-08-01

    High voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The general types designed for high voltage pulse generation and energy transfer applications are described. Special emphasis is given to pulse charging systems which operate up to the multi-megavolt range. (WHK)

  14. High voltage MOSFET switching circuit

    DOEpatents

    McEwan, T.E.

    1994-07-26

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

  15. High voltage MOSFET switching circuit

    DOEpatents

    McEwan, Thomas E.

    1994-01-01

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

  16. Multijunction high-voltage solar cell

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.; Goradia, C.; Chai, A. T.

    1981-01-01

    Multijunction cell allows for fabrication of high-voltage solar cell on single semiconductor wafer. Photovoltaic energy source using cell is combined on wafer with circuit it is to power. Cell consists of many voltage-generating regions internally or externally interconnected to give desired voltage and current combination. For computer applications, module is built on silicon wafer with energy for internal information processing and readouts derived from external light source.

  17. Operation of NIST Josephson Array Voltage Standards

    PubMed Central

    Hamilton, Clark A.; Burroughs, Charles; Chieh, Kao

    1990-01-01

    This paper begins with a brief discussion of the physical principles and history of Josephson effect voltage standards. The main body of the paper deals with the practical details of the array design, cryoprobe construction, bias source requirements, adjustment of the system for optimum performance, calibration algorithms, and an assessment of error sources for the NIST-developed Josephson array standard. PMID:28179776

  18. High-Voltage, Asymmetric-Waveform Generator

    NASA Technical Reports Server (NTRS)

    Beegle, Luther W.; Duong, Tuan A.; Duong, Vu A.; Kanik, Isik

    2008-01-01

    The shapes of waveforms generated by commercially available analytical separation devices, such as some types of mass spectrometers and differential mobility spectrometers are, in general, inadequate and result in resolution degradation in output spectra. A waveform generator was designed that would be able to circumvent these shortcomings. It is capable of generating an asymmetric waveform, having a peak amplitude as large as 2 kV and frequency of several megahertz, which can be applied to a capacitive load. In the original intended application, the capacitive load would consist of the drift plates in a differential-mobility spectrometer. The main advantage to be gained by developing the proposed generator is that the shape of the waveform is made nearly optimum for various analytical devices requiring asymmetric-waveform such as differential-mobility spectrometers. In addition, this waveform generator could easily be adjusted to modify the waveform in accordance with changed operational requirements for differential-mobility spectrometers. The capacitive nature of the load is an important consideration in the design of the proposed waveform generator. For example, the design provision for shaping the output waveform is based partly on the principle that (1) the potential (V) on a capacitor is given by V=q/C, where C is the capacitance and q is the charge stored in the capacitor; and, hence (2) the rate of increase or decrease of the potential is similarly proportional to the charging or discharging current. The proposed waveform generator would comprise four functional blocks: a sine-wave generator, a buffer, a voltage shifter, and a high-voltage switch (see Figure 1). The sine-wave generator would include a pair of operational amplifiers in a feedback configuration, the parameters of which would be chosen to obtain a sinusoidal timing signal of the desired frequency. The buffer would introduce a slight delay (approximately equal to 20 ns) but would otherwise

  19. High Voltage Pulse Testing Survey.

    DTIC Science & Technology

    1985-10-01

    Vacuum 18 I. Direct Current Source 18 2. Pulse 20 3. Insulator Flashover 20 (a) Alumina 20 (b) Organic Materials 23 D...withstand voltage. 3. Insulator Flashover Flashover along insulating surfaces is less than it is along a parallel plate vacuum gap of similar dimensions...K. D. Srivastova, "The Effects of DC Prestress on Impulse Flashover of Insulators in Vacuum ," IEEE Trans on Elec Ins, Vol. EI-9, No. 3, pp.

  20. Near independence of OLED operating voltage on transport layer thickness

    SciTech Connect

    Swensen, James S.; Wang, Liang; Polikarpov, Evgueni; Rainbolt, James E.; Koech, Phillip K.; Cosimbescu, Lelia; Padmaperuma, Asanga B.

    2013-01-01

    We report organic light emitting devices (OLEDs) with weak drive voltage dependence on the thickness of the hole transport layer (HTL) for thicknesses up to 1150 Å using the N,N'-Bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (α-NPD) and N,N'-bis(3-methyl phenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'diamine (TPD), both of which have hole mobilities in the range of 2 × 10-3 cm2V-1s-1. Lower mobility HTL materials show larger operating voltage dependence on thickness. The near independence of the operating voltage for high mobility transport material thickness was only observed when the energy barrier for charge injection into the transport material was minimized. To ensure low injection barriers, a thin film of 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluorotetracyanoquinodimethane (F3TCNQ-Adl) was cast from solution onto the ITO surface. These results indicate that thick transport layers can be integrated into OLED stacks without the need for bulk conductivity doping.

  1. High-voltage pulsed generators for electro-discharge technologies

    NASA Astrophysics Data System (ADS)

    Kovalchuk, B. M.; Kharlov, A. V.; Kumpyak, E. V.; Sinebrykhov, V. A.

    2013-09-01

    A high-voltage pulse technology is one of effective techniques for the disintegration and milling of rocks, separation of ores and synthesized materials, recycling of building and elastoplastic materials. We present here the design and test results of two portable HV pulsed generators, designed for materials fragmentation, though some other technological applications are possible as well. Generator #1 consists of low voltage block, high voltage transformer, high voltage capacitive storage block, two electrode gas switch, fragmentation chamber and control system block. Technical characteristics of the #1 generator: stored energy in HV capacitors can be varied from 50 to 1000 J, output voltage up to 300 kV, voltage rise time ~ 50 ns, typical operation regime 1000 pulses bursts with a repetitive rate up to 10 Hz. Generator #2 is made on an eight stages Marx scheme with two capacitors (100 kV-400 nF) per stage, connected in parallel. Two electrode spark gap switches, operated in atmospheric air, are used in the Marx generator. Parameters of the generator: stored energy in capacitors 2÷8 kJ, amplitude of the output voltage 200÷400 kV, voltage rise time on a load 50÷100 ns, repetitive rate up to 0.5 Hz. The fragmentation process can be controlled within a wide range of parameters for both generators.

  2. High-voltage supplies for corona-electrostatic separators

    SciTech Connect

    Iuga, A.; Neamtu, V.; Suarasan, I.; Morar, R.; Dascalescu, L.

    1995-12-31

    The selection of the high-voltage supply can play an important role in the optimization of electrostatic separation processes. The present work aimed to evaluate the influence of the main high-voltage parameters (waveform, polarity, level) on the efficiency of electroseparation, in the case of insulation-metal granular mixtures. A roll-type laboratory electroseparator was employed for the experimental study and the tests were carried out with granular materials prelevated from the technological flow sheet of a recycling plant for electric wire scraps. The experiments shown the existence of a strong interdependence between the level of the operating voltage and the other electrical parameters. Although the full-wave rectifier allows for lower operating voltages than the half-wave rectifier, its general effectiveness in electroseparation processes is superior. The optimum operating voltage of an electroseparator seems to be slightly lower than the level at which the frequency of the spark discharges tends to exceed 60 min{sup {minus}1}. The oscillograms of the voltage and of the current across the separator proved to be of great use for studying the transition from corona to spark discharges. Good insulation-metal electroseparation can be achieved at either positive or negative polarity of the high-voltage supply, but negative electrode energization is recommended for most industry applications.

  3. Ultrasonic evaluation of high voltage circuit boards

    NASA Technical Reports Server (NTRS)

    Klima, S. J.; Riley, T. J.

    1976-01-01

    Preliminary observations indicate that an ultrasonic scanning technique may be useful as a quick, low cost, nondestructive method for judging the quality of circuit board materials for high voltage applications. Corona inception voltage tests were conducted on fiberglass-epoxy and fiberglass-polyimide high pressure laminates from 20 to 140 C. The same materials were scanned ultrasonically by utilizing the single transducer, through-transmission technique with reflector plate, and recording variations in ultrasonic energy transmitted through the board thickness. A direct relationship was observed between ultrasonic transmission level and corona inception voltage. The ultrasonic technique was subsequently used to aid selection of high quality circuit boards for the Communications Technology Satellite.

  4. High voltage, low inductance hydrogen thyratron study program, phase 5

    NASA Astrophysics Data System (ADS)

    Friedman, S.

    1983-08-01

    50 kv per stage dynamic breakdown voltage (DBV) was demonstrated in low inductance multistage hydrogen thyratrons for total voltages up to nearly 200 kv, at pressures consistent with a 10 ns current rise time. High peak current operation has been demonstrated up to 14 ka at 56 kv (the limits of our high current test kit). Bottom stage holdoff the per stage DBV are comparable to that of the best single stage thyratrons, bottom stage holdoff, stage voltage addition, and prefire problems are solved.

  5. Multiple high voltage output DC-to-DC power converter

    NASA Technical Reports Server (NTRS)

    Cronin, Donald L. (Inventor); Farber, Bertrand F. (Inventor); Gehm, Hartmut K. (Inventor); Goldin, Daniel S. (Inventor)

    1977-01-01

    Disclosed is a multiple output DC-to-DC converter. The DC input power is filtered and passed through a chopper preregulator. The chopper output is then passed through a current source inverter controlled by a squarewave generator. The resultant AC is passed through the primary winding of a transformer, with high voltages induced in a plurality of secondary windings. The high voltage secondary outputs are each solid-state rectified for passage to individual output loads. Multiple feedback loops control the operation of the chopper preregulator, one being responsive to the current through the primary winding and another responsive to the DC voltage level at a selected output.

  6. AlGaN/GaN high-electron-mobility transistor technology for high-voltage and low-on-resistance operation

    NASA Astrophysics Data System (ADS)

    Kuzuhara, Masaaki; Asubar, Joel T.; Tokuda, Hirokuni

    2016-07-01

    In this paper, we give an overview of the recent progress in GaN-based high-electron-mobility transistors (HEMTs) developed for mainstream acceptance in the power electronics field. The comprehensive investigation of AlGaN/GaN HEMTs fabricated on a free-standing semi-insulating GaN substrate reveals that an extracted effective lateral breakdown field of approximately 1 MV/cm is likely limited by the premature device breakdown originating from the insufficient structural and electrical quality of GaN buffer layers and/or the GaN substrate itself. The effective lateral breakdown field is increased to 2 MV/cm by using a highly resistive GaN substrate achieved by heavy Fe doping. Various issues relevant to current collapse are also discussed in the latter half of this paper, where a more pronounced reduction in current collapse is achieved by combining two different schemes (i.e., a prepassivation oxygen plasma treatment and a field plate structure) for intensifying the mitigating effect against current collapse. Finally, a novel approach to suppress current collapse is presented by introducing a three-dimensional field plate (3DFP) in AlGaN/GaN HEMTs, and its possibility of realizing true collapse-free operation is described.

  7. Detecting Faults In High-Voltage Transformers

    NASA Technical Reports Server (NTRS)

    Blow, Raymond K.

    1988-01-01

    Simple fixture quickly shows whether high-voltage transformer has excessive voids in dielectric materials and whether high-voltage lead wires too close to transformer case. Fixture is "go/no-go" indicator; corona appears if transformer contains such faults. Nests in wire mesh supported by cap of clear epoxy. If transformer has defects, blue glow of corona appears in mesh and is seen through cap.

  8. Spacecraft high-voltage power supply construction

    NASA Technical Reports Server (NTRS)

    Sutton, J. F.; Stern, J. E.

    1975-01-01

    The design techniques, circuit components, fabrication techniques, and past experience used in successful high-voltage power supplies for spacecraft flight systems are described. A discussion of the basic physics of electrical discharges in gases is included and a design rationale for the prevention of electrical discharges is provided. Also included are typical examples of proven spacecraft high-voltage power supplies with typical specifications for design, fabrication, and testing.

  9. Boeing's High Voltage Solar Tile Test Results

    NASA Technical Reports Server (NTRS)

    Reed, Brian J.; Harden, David E.; Ferguson, Dale C.; Snyder, David B.

    2002-01-01

    Real concerns of spacecraft charging and experience with solar array augmented electrostatic discharge arcs on spacecraft have minimized the use of high voltages on large solar arrays despite numerous vehicle system mass and efficiency advantages. Boeing's solar tile (patent pending) allows high voltage to be generated at the array without the mass and efficiency losses of electronic conversion. Direct drive electric propulsion and higher power payloads (lower spacecraft weight) will benefit from this design. As future power demand grows, spacecraft designers must use higher voltage to minimize transmission loss and power cable mass for very large area arrays. This paper will describe the design and discuss the successful test of Boeing's 500-Volt Solar Tile in NASA Glenn's Tenney chamber in the Space Plasma Interaction Facility. The work was sponsored by NASA's Space Solar Power Exploratory Research and Technology (SERT) Program and will result in updated high voltage solar array design guidelines being published.

  10. Efficient circuit triggers high-current, high-voltage pulses

    NASA Technical Reports Server (NTRS)

    Green, E. D.

    1964-01-01

    Modified circuit uses diodes to effectively disconnect the charging resistors from the circuit during the discharge cycle. Result is an efficient parallel charging, high voltage pulse modulator with low voltage rating of components.

  11. 30 CFR 75.826 - High-voltage trailing cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage trailing cables. 75.826 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution High-Voltage Longwalls § 75.826 High-voltage trailing cables. High-voltage trailing cables must: (a)...

  12. High voltage planar multijunction solar cell

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.; Chai, A. T.; Goradia, C. P. (Inventor)

    1982-01-01

    A high voltage multijunction solar cell is provided wherein a plurality of discrete voltage generating regions or unit cells are formed in a single generally planar semiconductor body. The unit cells are comprised of doped regions of opposite conductivity type separated by a gap or undiffused region. Metal contacts connect adjacent cells together in series so that the output voltages of the individual cells are additive. In some embodiments, doped field regions separated by a overlie the unit cells but the cells may be formed in both faces of the wafer.

  13. Programmable high voltage power supply with regulation confined to the high voltage section

    NASA Technical Reports Server (NTRS)

    Castell, Karen D. (Inventor); Ruitberg, Arthur P. (Inventor)

    1994-01-01

    A high voltage power supply in a dc-dc converter configuration includes a pre-regulator which filters and regulates the dc input and drives an oscillator which applies, in turn, a low voltage ac signal to the low side of a step-up high voltage transformer. The high voltage side of the transformer drives a voltage multiplier which provides a stepped up dc voltage to an output filter. The output voltage is sensed by a feedback network which then controls a regulator. Both the input and output of the regulator are on the high voltage side, avoiding isolation problems. The regulator furnishes a portion of the drive to the voltage multiplier, avoiding having a regulator in series with the load with its attendant, relatively high power losses. This power supply is highly regulated, has low power consumption, a low parts count and may be manufactured at low cost. The power supply has a programmability feature that allows for the selection of a large range of output voltages.

  14. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    NASA Technical Reports Server (NTRS)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources - a nominal 300-Volt high voltage input bus and a nominal 28-Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power supplies that provide power to the thruster auxiliary supplies, and two parallel 7.5 kilowatt power supplies that are capable of providing up to 15 kilowatts of total power at 300-Volts to 500-Volts to the thruster discharge supply. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall Effect Thruster. The performance of unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate the exceptional performance with full power efficiencies exceeding 97. With a space-qualified silicon carbide or similar high voltage, high efficiency power device, this design could evolve into a flight design for future missions that require high power electric propulsion systems.

  15. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    NASA Technical Reports Server (NTRS)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  16. Deep Space One High-Voltage Bus Management

    NASA Technical Reports Server (NTRS)

    Rachocki, Ken; Nieraeth, Donald

    1999-01-01

    The design of the High Voltage Power Converter Unit on DS1 allows both the spacecraft avionics and ion propulsion to operate in a stable manner near the PPP of the solar array. This approach relies on a fairly well-defined solar array model to determine the projected PPP. The solar array voltage set-points have to be updated every week to maintain operation near PPP. Stable operation even to the LEFT of the Peak Power Point is achievable so long as you do not change the operating power level of the ion engine. The next step for this technology is to investigate the use of onboard autonomy to determine the optimum SA voltage regulation set-point (i.e. near the PPP); this is for future missions that have one or more ion propulsion subsystems.

  17. Dc to ac converter operates efficiently at low input voltages

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Self-oscillating dc to ac converter with transistor switching to produce a square wave output is used for low and high voltage power sources. The converter has a high efficiency throughout a wide range of loads.

  18. Electro-optic high voltage sensor

    DOEpatents

    Davidson, James R.; Seifert, Gary D.

    2003-09-16

    A small sized electro-optic voltage sensor capable of accurate measurement of high voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation. A polarization beam displacer separates the input beam into two beams with orthogonal linear polarizations and causes one linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels effect elliptically polarizes the beam as it travels through the crystal. A reflector redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization. The system may include a detector for converting the output beams into electrical signals and a signal processor for determining the voltage based on an analysis of the output beams.

  19. Optimal high-voltage energization of corona-electrostatic separators

    SciTech Connect

    Iuga, A.; Neamtu, V.; Suarasan, I.; Morar, R.; Dascalescu, L.

    1998-03-01

    The selection of the high-voltage supply can play an important role in the optimization of electrostatic separation processes. This paper aims to evaluate the influence of the main high-voltage parameters (waveform, polarity, level) on the efficiency of electrostatic separation, in the case of insulation-metal granular mixtures. A roll-type laboratory high-tension separator was employed for the experimental study, and the tests were carried out with samples of granular materials taken from the technological flowsheet of a recycling plant for electric wire scraps. The oscillograms of the voltage and of the current across the separator proved to be of great use for studying the transition from corona to spark discharges. The experiments, performed under various operating conditions (roll speed, roll radius, high-voltage level, interelectrode distance), show the existence of a strong interdependence between these parameters, the frequency of spark discharges, and the efficiency of the separation process. The reported results suggest that monitoring the frequency of spark discharges, and the efficiency of the separation process. The reported results suggest that monitoring the frequency of the spark discharges could be of use for controlling the optimum operating voltage for a given electrostatic separation application. Although the full-wave rectifier allows for lower operating voltages than the half-wave rectifier, its general effectiveness in electrostatic separation processes is superior. Good insulation-metal electrostatic separation can be achieved at either positive or negative polarity of the high-voltage supply, but negative electrode energization is recommended for most industrial applications. The methodology proposed in this paper might be successfully employed for establishing the optimal operating conditions of electrode energization for other applications, such as electrostatic precipitation, plasma chemical purification of gases, or charge

  20. Compact high voltage solid state switch

    DOEpatents

    Glidden, Steven C.

    2003-09-23

    A compact, solid state, high voltage switch capable of high conduction current with a high rate of current risetime (high di/dt) that can be used to replace thyratrons in existing and new applications. The switch has multiple thyristors packaged in a single enclosure. Each thyristor has its own gate drive circuit that circuit obtains its energy from the energy that is being switched in the main circuit. The gate drives are triggered with a low voltage, low current pulse isolated by a small inexpensive transformer. The gate circuits can also be triggered with an optical signal, eliminating the trigger transformer altogether. This approach makes it easier to connect many thyristors in series to obtain the hold off voltages of greater than 80 kV.

  1. High-Voltage Isolation Transformer

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Ruitberg, A. P.

    1985-01-01

    Arcing and field-included surface erosion reduced by electrostatic shields around windings and ferromagnetic core of 80-kilovolt isolation transformer. Fabricated from high-resistivity polyurethane-based material brushed on critical surfaces, shields maintained at approximately half potential difference of windings.

  2. High Voltage Applications of Explosively Formed Fuses

    NASA Astrophysics Data System (ADS)

    Tasker, D. G.; Goforth, J. H.; Fowler, C. M.; Herrera, D. H.; King, J. C.; Lopez, E. A.; Martinez, E. C.; Oona, H.; Marsh, S. P.; Reinovsky, R. E.; Stokes, J.; Tabaka, L. J.; Torres, D. T.; Sena, F. C.; Kiuttu, G.; Degnan, J.

    2004-11-01

    At Los Alamos, we have primarily applied Explosively Formed Fuse (EFF) techniques to high current systems. In these systems, the EFF has interrupted currents from 19-25 MA, thus diverting the current to low inductance loads. The transferred current magnitude is determined by the ratio of storage inductance to load inductance and, with dynamic loads, the current has ranged from 12-20 MA. In a system with 18 MJ stored energy, the switch operates at a power of up to 6 TW. We are now investigating the use of the EFF technique to apply high voltages to high impedance loads in systems that are more compact. In these systems we are exploring circuits with EFF lengths from 43-100 cm, which have storage inductances large enough to apply 300-500 kV across high impedance loads. Experimental results and design considerations are presented. Using cylindrical EFF switches of 10 cm diameter and 43 cm length, currents of approximately 3 MA were interrupted producing ~200 kV. This indicates the switch had an effective resistance of ~100 mΩ where 150-200 mΩ was expected. To understand the lower performance, several parameters were studied including electrical conduction through the explosive products; current density; explosive initiation; insulator type and conductor thickness. The results show a number of interesting features, most notably that the primary mechanism of switch operation is mechanical and not electrical fusing of the conductor. Switches opening on a 1-10 μs time scale with resistances starting at 50 μΩ and increasing to perhaps 1 Ω now seem possible to construct using explosive charges as small as a few pounds.

  3. High Voltage Application of Explosively Formed Fuses

    SciTech Connect

    Tasker, D.G.; Goforth, J.H.; Fowler, C.M.; Lopez, E.M.; Oona, H.; Marsh, S.P.; King, J.C.; Herrera, D.H.; Torres, D.T.; Sena, F.C.; Martinez, E.C.; Reinovsky, R.E.; Stokes, J.L.; Tabaka, L.J.; Kiuttu, G.; Degnan, J.

    1998-10-18

    At Los Alamos, the authors have primarily applied Explosively Formed Fuse (EFF) techniques to high current systems. In these systems, the EFF has interrupted currents from 19 to 25 MA, thus diverting the current to low inductance loads. The magnitude of transferred current is determined by the ratio of storage inductance to load inductance, and with dynamic loads, the current has ranged from 12 to 20 MA. In a system with 18 MJ stored energy, the switch operates at a power up to 6 TW. The authors are now investigating the use of the EFF technique to apply high voltages to high impedance loads in systems that are more compact. In these systems, they are exploring circuits with EFF lengths from 43 to 100 cm, which have storage inductances large enough to apply 300 to 500 kV across high impedance loads. Experimental results and design considerations are presented. Using cylindrical EFF switches of 10 cm diameter and 43 cm length, currents of approximately 3 MA were interrupted producing {approximately}200 kV. This indicate s the switch had an effective resistance of {approximately}100 m{Omega} where 150--200 m{Omega} was expected. To understand the lower performance, several parameters were studied, including: electrical conduction through the explosive products; current density; explosive initiation; insulator type; conductor thickness; and so on. The results show a number of interesting features, most notably that the primary mechanism of switch operation is mechanical and not electrical fusing of the conductor. Switches opening on a 10 to 10 {micro}s time scale with resistances starting at 50 {micro}{Omega} and increasing to perhaps 1 {Omega} now seem possible to construct, using explosive charges as small as a few pounds.

  4. High Voltage Design Guide. Volume V. Spacecraft

    DTIC Science & Technology

    1983-01-01

    4. W. G. Dunbar, "Skylab High Voltage Systems Corona Assessment", 1 th Electrical/Electronics Insulation Conference, Chicago, Illinois, 1973. 5. 3. F ...and Composition of Interplanetary Dust Particles", Earth Planet, Sci. Lett. 30, pp 234, 1976. 13. D. K. Heier, "Brush/Slip Ring Selection for High...mai. a FEIINrS CATALOG NUMBER - F dAL-TR-82-2057 Volume V _____________ 4. TITLE (mnd S. kettle) U TYPE OF REPORT S, PERIOD COVERED High Voltage Design

  5. High Voltage Flux Compression Generators

    DTIC Science & Technology

    2008-04-02

    the generator: the armature radial expansion speed, the high explosive (HE) detonation speed, and the armature-stator helical contact speed. Clearly... detonation speeds, which are also the speed at which the self-similar expanding armature cone moves axially, are on the order of 8 to 9 mm/μs...product of detonation speed and the ratio of stator underside circumference to pitch, ( )prvv sc π2Δ= rr . For a typical circumference-to-pitch ratio

  6. High Voltage Water Breakdown Studies

    DTIC Science & Technology

    1998-01-01

    Terman [20] gives the following equation for a rectangle that has sides that are S1 by S2 and is made up of a rectangular bar that is b by c, L = 0.02339...Dielectrics," Proc. Tenth IEEE Pulsed Power Confer- ence, June, 1995, p. 574. (UNCLASSIFIED) 86 (20) Terman , F. E., Radio Engineers’ Handbook, McGraw-Hill Book...34 Conference Rec- ord, Eighth International Conference on Conduction and Breakdown in Dielectric Liquids, pp. 176-179, July, 1984. Lewis , T. J., High

  7. High-voltage electrocution causing bulbar dysfunction

    PubMed Central

    Parvathy, G.; Shaji, C. V.; Kabeer, K. A.; Prasanth, S. R.

    2016-01-01

    Electrical shock can result in neurological complications, involving both peripheral and central nervous systems, which may present immediately or later on. High-voltage electrical injuries are uncommonly reported and may predispose to both immediate and delayed neurologic complications. We report the case of a 68-year-old man who experienced a high-voltage electrocution injury, subsequently developed bulbar dysfunction and spontaneously recovered. We describe the development of bulbar palsy following a significant electrical injury, which showed no evidence of this on magnetic resonance imaging. High-voltage electrocution injuries are a serious problem with potential for both immediate and delayed neurologic sequelae. The existing literature has no reports on bulbar dysfunction following electrocution, apart from motor neuron disease. PMID:27365968

  8. High voltage stability performance of a gamma ray detection device

    NASA Astrophysics Data System (ADS)

    Abdullah, Nor Arymaswati; Lombigit, Lojius; Rahman, Nur Aira Abd

    2014-02-01

    An industrial grade digital radiation survey meter device is currently being developed at Malaysian Nuclear Agency. This device used a cylindrical type Geiger Mueller (GM) which acts as a detector. GM detector operates at relatively high direct current voltages depend on the type of GM tube. This thin/thick walled cylindrical type of GM tube operates at 450-650 volts range. Proper value and stability performance of high voltage are important parameters to ensure that this device give a reliable radiation dose measurement. This paper will present an assessment of the stability and performance of the high voltage supply for radiation detector. The assessment is performed using System Identification tools box in MATLAB and mathematical statistics.

  9. High voltage stability performance of a gamma ray detection device

    SciTech Connect

    Abdullah, Nor Arymaswati; Lombigit, Lojius; Rahman, Nur Aira Abd

    2014-02-12

    An industrial grade digital radiation survey meter device is currently being developed at Malaysian Nuclear Agency. This device used a cylindrical type Geiger Mueller (GM) which acts as a detector. GM detector operates at relatively high direct current voltages depend on the type of GM tube. This thin/thick walled cylindrical type of GM tube operates at 450-650 volts range. Proper value and stability performance of high voltage are important parameters to ensure that this device give a reliable radiation dose measurement. This paper will present an assessment of the stability and performance of the high voltage supply for radiation detector. The assessment is performed using System Identification tools box in MATLAB and mathematical statistics.

  10. A wiggler magnet for FEL low voltage operation

    SciTech Connect

    Al-Shamma`a, A.; Stuart, R.A.; Lucas, J.

    1995-12-31

    In low voltage FELs (ie, 200kV), operation is necessarily in the microwave frequency range for wiggler periods of the order of cms., so that a waveguide system is mandatory. Also, because of the relatively low velocity of the electron beam, the wiggle amplitude of the electron beam can be much larger than is normal for highly relativistic FELs. Both these factors mean that the electron trajectory must be carefully controlled to avoid beam collision with the waveguide walls. A wiggler system with half poles at entrance and exit is not an acceptable solution because of the offset is gives rise to the electron trajectory. Consequently, we have designed and constructed a wiggler magnet with exponential entrance and exit tapers for a minimal deflection and displacement of the electron beam. Simulations and experimental measurements showed that an on axis trajectory is easily obtainable.

  11. A compact, all solid-state LC high voltage generator

    NASA Astrophysics Data System (ADS)

    Fan, Xuliang; Liu, Jinliang

    2013-06-01

    LC generator is widely applied in the field of high voltage generation technology. A compact and all solid-state LC high voltage generator based on saturable pulse transformer is proposed in this paper. First, working principle of the generator is presented. Theoretical analysis and circuit simulation are used to verify the design of the generator. Experimental studies of the proposed LC generator with two-stage main energy storage capacitors are carried out. And the results show that the proposed LC generator operates as expected. When the isolation inductance is 27 μH, the output voltage is 1.9 times larger than the charging voltage on single capacitor. The multiplication of voltages is achieved. On the condition that the primary energy storage capacitor is charged to 857 V, the output voltage of the generator can reach to 59.5 kV. The step-up ratio is nearly 69. When self breakdown gas gap switch is used as main switch, the rise time of the voltage pulse on load resistor is 8.7 ns. It means that the series-wound inductance in the discharging circuit is very small in this system. This generator can be employed in two different applications.

  12. A compact, all solid-state LC high voltage generator.

    PubMed

    Fan, Xuliang; Liu, Jinliang

    2013-06-01

    LC generator is widely applied in the field of high voltage generation technology. A compact and all solid-state LC high voltage generator based on saturable pulse transformer is proposed in this paper. First, working principle of the generator is presented. Theoretical analysis and circuit simulation are used to verify the design of the generator. Experimental studies of the proposed LC generator with two-stage main energy storage capacitors are carried out. And the results show that the proposed LC generator operates as expected. When the isolation inductance is 27 μH, the output voltage is 1.9 times larger than the charging voltage on single capacitor. The multiplication of voltages is achieved. On the condition that the primary energy storage capacitor is charged to 857 V, the output voltage of the generator can reach to 59.5 kV. The step-up ratio is nearly 69. When self breakdown gas gap switch is used as main switch, the rise time of the voltage pulse on load resistor is 8.7 ns. It means that the series-wound inductance in the discharging circuit is very small in this system. This generator can be employed in two different applications.

  13. High voltage electrical amplifier having a short rise time

    DOEpatents

    Christie, David J.; Dallum, Gregory E.

    1991-01-01

    A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

  14. Modular high voltage power supply for chemical analysis

    DOEpatents

    Stamps, James F.; Yee, Daniel D.

    2007-01-09

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC--DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC--DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  15. Modular high voltage power supply for chemical analysis

    DOEpatents

    Stamps, James F.; Yee, Daniel D.

    2008-07-15

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  16. Modular high voltage power supply for chemical analysis

    DOEpatents

    Stamps, James F.; Yee, Daniel D.

    2010-05-04

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  17. Recommended practices for encapsulating high voltage assemblies

    NASA Technical Reports Server (NTRS)

    Tankisley, E. W.

    1974-01-01

    Preparation and encapsulation of high voltage assemblies are considered. Related problems in encapsulating are brought out in these instructions. A test sampling of four frequently used encapsulating compounds is shown in table form. The purpose of this table is to give a general idea of the working time available and the size of the container required for mixing and de-aerating.

  18. An Inexpensive Source of High Voltage

    ERIC Educational Resources Information Center

    Saraiva, Carlos

    2012-01-01

    As a physics teacher I like recycling old apparatus and using them for demonstrations in my classes. In physics laboratories in schools, sources of high voltage include induction coils or electronic systems that can be bought from companies that sell lab equipment. But these sources can be very expensive. In this article, I will explain how you…

  19. High Voltage Piezoelectric System for Generating Neutrons

    DTIC Science & Technology

    2013-06-01

    Piezoelectric transformer structural modeling - a review,” Ultrasonics , Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 54, pp...1 High Voltage Piezoelectric System for Generating Neutrons Brady Gall, Student Member, IEEE, Scott D. Kovaleski, Senior Member, IEEE, James A...Compact electrical neutron generators are a desir- able alternative to radioisotope neutron sources. A piezoelectric transformer system is presented

  20. Planar multijunction high voltage solar cells

    NASA Astrophysics Data System (ADS)

    Evans, J. C., Jr.; Chai, A. T.; Goradia, C.

    1980-01-01

    Technical considerations, preliminary results, and fabrication details are discussed for a family of high-voltage planar multi-junction (PMJ) solar cells which combine the attractive features of planar cells with conventional or interdigitated back contacts and the vertical multijunction (VMJ) solar cell. The PMJ solar cell is internally divided into many voltage-generating regions, called unit cells, which are internally connected in series. The key to obtaining reasonable performance from this device was the separation of top surface field regions over each active unit cell. Using existing solar cell fabricating methods, output voltages in excess of 20 volts per linear centimeter are possible. Analysis of the new device is complex, and numerous geometries are being studied which should provide substantial benefits in both normal sunlight usage as well as with concentrators.

  1. High-voltage pulsed generator for dynamic fragmentation of rocks.

    PubMed

    Kovalchuk, B M; Kharlov, A V; Vizir, V A; Kumpyak, V V; Zorin, V B; Kiselev, V N

    2010-10-01

    A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ∼50 ns, current amplitude of ∼6 kA with the 40 Ω active load, and ∼20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.

  2. High-voltage pulsed generator for dynamic fragmentation of rocks

    NASA Astrophysics Data System (ADS)

    Kovalchuk, B. M.; Kharlov, A. V.; Vizir, V. A.; Kumpyak, V. V.; Zorin, V. B.; Kiselev, V. N.

    2010-10-01

    A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ˜50 ns, current amplitude of ˜6 kA with the 40 Ω active load, and ˜20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.

  3. 30 CFR 77.810 - High-voltage equipment; grounding.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage equipment; grounding. 77.810... COAL MINES Surface High-Voltage Distribution § 77.810 High-voltage equipment; grounding. Frames, supporting structures, and enclosures of stationary, portable, or mobile high-voltage equipment shall...

  4. High voltage pulse generator. [Patent application

    DOEpatents

    Fasching, G.E.

    1975-06-12

    An improved high-voltage pulse generator is described which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of the first rectifier connected between the first and second capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. The output voltage can be readily increased by adding additional charging networks. The circuit allows the peak level of the output to be easily varied over a wide range by using a variable autotransformer in the charging circuit.

  5. Choice of operating voltage for a transmission electron microscope.

    PubMed

    Egerton, R F

    2014-10-01

    An accelerating voltage of 100-300kV remains a good choice for the majority of TEM or STEM specimens, avoiding the expense of high-voltage microscopy but providing the possibility of atomic resolution even in the absence of lens-aberration correction. For specimens thicker than a few tens of nm, the image intensity and scattering contrast are likely to be higher than at lower voltage, as is the visibility of ionization edges below 1000eV (as required for EELS elemental analysis). In thick (>100nm) specimens, higher voltage ensures less beam broadening and better spatial resolution for STEM imaging and EDX spectroscopy. Low-voltage (e.g. 30kV) TEM or STEM is attractive for a very thin (e.g. 10nm) specimen, as it provides higher scattering contrast and fewer problems for valence-excitation EELS. Specimens that are immune to radiolysis suffer knock-on damage at high current densities, and this form of radiation damage can be reduced or avoided by choosing a low accelerating voltage. Low-voltage STEM with an aberration-corrected objective lens (together with a high-angle dark-field detector and/or EELS) offers atomic resolution and elemental identification from very thin specimens. Conventional TEM can provide atomic resolution in low-voltage phase-contrast images but requires correction of chromatic aberration and preferably an electron-beam monochromator. Many non-conducting (e.g. organic) specimens damage easily by radiolysis and radiation damage then determines the TEM image resolution. For bright-field scattering contrast, low kV can provide slightly better dose-limited resolution if the specimen is very thin (a few nm) but considerably better resolution is possible from a thicker specimen, for which higher kV is required. Use of a phase plate in a conventional TEM offers the most dose-efficient way of achieving atomic resolution from beam-sensitive specimens.

  6. A high voltage nanosecond pulser with independently adjustable output voltage, pulse width, and pulse repetition frequency

    NASA Astrophysics Data System (ADS)

    Prager, James; Ziemba, Timothy; Miller, Kenneth; Carscadden, John; Slobodov, Ilia

    2014-10-01

    Eagle Harbor Technologies (EHT) is developing a high voltage nanosecond pulser capable of generating microwaves and non-equilibrium plasmas for plasma medicine, material science, enhanced combustion, drag reduction, and other research applications. The EHT nanosecond pulser technology is capable of producing high voltage (up to 60 kV) pulses (width 20-500 ns) with fast rise times (<10 ns) at high pulse repetition frequency (adjustable up to 100 kHz) for CW operation. The pulser does not require the use of saturable core magnetics, which allows for the output voltage, pulse width, and pulse repetition frequency to be fully adjustable, enabling researchers to explore non-equilibrium plasmas over a wide range of parameters. A magnetic compression stage can be added to improve the rise time and drive lower impedance loads without sacrificing high pulse repetition frequency operation. Work supported in part by the US Navy under Contract Number N00014-14-P-1055 and the US Air Force under Contract Number FA9550-14-C-0006.

  7. Background information on high voltage fields.

    PubMed Central

    Janes, D E

    1977-01-01

    The increased demand for power has led to higher voltages for overhead transmission lines. Environmentalists, governmental agencies, and some members of the scientific community have questioned if past biological effects research and experience with lower voltage lines provide adequate bases for predicting the possible health and environmental effects of the higher voltage lines. Only a small amount of work has been done to explore the possible effects, especially long term effects, of the exposure of biological systems to electric fields from transmission lines. Research in Western Europe and the United States has not identified any prompt or acute effects other than spark and electric discharge and no permanent effects. Contrasted with this are the studies of workers in Soviet and Spanish high voltage switchyards that report effects, such as excitability, headaches, drowsiness, fatique, and nausea, that are not found in Soviet line maintenance workers. The results of current and planned research, supported by both U.S. Government agencies and the private sector, should resolve a number of the present uncertanties and provide answers for the many questions concerning potential effects. PMID:598346

  8. High-Voltage Droplet Dispenser Developed

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; VanderWal, Randy L.

    2001-01-01

    Various techniques have been applied to deploying individual droplets for many applications, such as the study of the combustion of liquid fuels. Isolated droplet studies are useful in that they allow phenomena to be studied under well-controlled and simplified conditions. A high-voltage droplet dispenser has been developed that is extremely effective in dispensing a wide range of droplets. The dispenser is quite unique in that it utilizes a droplet bias voltage, as well as an ionization pulse, to release the droplet. The droplet is deployed from the end of a needle. A flat-tipped, stainless steel needle attached to a syringe dispenses a known value of liquid that hangs on the needle tip. Somewhat below the droplet is an annular ring electrode. A bias voltage, followed by a voltage pulse, is applied to attract the droplet sufficiently to pull it off the needle. The droplet and needle are oppositely charged relative to the annular electrode. The needle is negatively charged, and the annular ring is positively charged.

  9. High Voltage Design Guidelines: A Timely Update

    NASA Technical Reports Server (NTRS)

    Hillard, G. Barry; Kirkici, H.; Ensworth, Clint (Technical Monitor)

    2001-01-01

    The evolving state of high voltage systems and their increasing use in the space program have called for a revision of the High Voltage Design Guidelines, Marshall Space Flight Center technical document MSFC-STD-531, originally issued September 1978 (previously 50 M05189b, October 1972). These guidelines deal in depth with issues relating to the specification of materials, particularly electrical insulation, as well as design practices and test methods. Emphasis is on corona and Paschen breakdown as well as plasma effects for Low Earth Orbiting systems. We will briefly review the history of these guidelines as well as their immediate predecessors and discuss their range of applicability. In addition, this document has served as the basis for several derived works that became focused, program-specific HV guidelines. We will briefly review two examples, guidelines prepared for the X-33 program and for the Space Shuttle Electric Auxiliary Power Unit (EAPU) upgrade.

  10. Electro-optic high voltage sensor

    DOEpatents

    Davidson, James R.; Seifert, Gary D.

    2002-01-01

    A small sized electro-optic voltage sensor capable of accurate measurement of high levels of voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation into the sensor. A polarization beam displacer serves as a filter to separate the input beam into two beams with orthogonal linear polarizations. The beam displacer is oriented in such a way as to rotate the linearly polarized beams such that they enter a Pockels crystal having at a preferred angle of 45 degrees. The beam displacer is therefore capable of causing a linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels electro-optic effect induces a differential phase shift on the major and minor axes of the input beam as it travels through the Pockels crystal, which causes the input beam to be elliptically polarized. A reflecting prism redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization representing the major and minor axes. The system may include a detector for converting the output beams into electrical signals, and a signal processor for determining the voltage based on an analysis of the output beams. The output beams are amplitude modulated by the frequency of the electric field and the amplitude of the output beams is proportional to the magnitude of the electric field, which is related to the voltage being measured.

  11. High voltage spark carbon fiber detection system

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1980-01-01

    The pulse discharge technique was used to determine the length and density of carbon fibers released from fiber composite materials during a fire or aircraft accident. Specifications are given for the system which uses the ability of a carbon fiber to initiate spark discharge across a high voltage biased grid to achieve accurate counting and sizing of fibers. The design of the system was optimized, and prototype hardware proved satisfactory in laboratory and field tests.

  12. E-beam high voltage switching power supply

    DOEpatents

    Shimer, Daniel W.; Lange, Arnold C.

    1997-01-01

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360.degree./n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load.

  13. E-beam high voltage switching power supply

    DOEpatents

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

    1997-03-11

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360{degree}/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs.

  14. A Comparison of High-Voltage Switches

    SciTech Connect

    Chu, K.W.; Scott, G.L.

    1999-02-01

    This report summarizes our work on high-voltage switches during the past few years. With joint funding from the Department of Energy (DOE) and the Department of Defense (DOD), we tested a wide variety of switches to a common standard. This approach permitted meaningful comparisons between disparate switches. Most switches were purchased from commercial sources, though some were experimental devices. For the purposes of this report, we divided the switches into three generic types (gas, vacuum, and semiconductor) and selected data that best illustrates important strengths and weaknesses of each switch type. Test techniques that indicate the state of health of the switches are emphasized. For example, a good indicator of residual gas in a vacuum switch is the systematic variation of the switching delay in response to changes in temperature and/or operating conditions. We believe that the presentation of this kind of information will help engineers to select and to test switches for their particular applications. Our work was limited to switches capable of driving slappers. Also known as exploding-foil initiators, slappers are detonators that initiate a secondary explosive by direct impact with a small piece of matter moving at the detonation velocity (several thousands of meters per second). A slapper is desirable for enhanced safety (no primary explosive), but it also places extra demands on the capacitor-discharge circuit to deliver a fast-rising current pulse (greater than 10 A/ns) of several thousand amperes. The required energy is substantially less than one joule; but this energy is delivered in less than one microsecond, taking the peak power into the megawatt regime. In our study, the switches operated in the 1 kV to 3 kV range and were physically small, roughly 1 cm{sup 3} or less. Although a fuze functions only once in actual use, multiple-shot capability is important for production testing and for research work. For this reason, we restricted this report

  15. Energy harvesting in high voltage measuring techniques

    NASA Astrophysics Data System (ADS)

    Żyłka, Pawel; Doliński, Marcin

    2016-02-01

    The paper discusses selected problems related to application of energy harvesting (that is, generating electricity from surplus energy present in the environment) to supply autonomous ultra-low-power measurement systems applicable in high voltage engineering. As a practical example of such implementation a laboratory model of a remote temperature sensor is presented, which is self-powered by heat generated in a current-carrying busbar in HV- switchgear. Presented system exploits a thermoelectric harvester based on a passively cooled Peltier module supplying micro-power low-voltage dc-dc converter driving energy-efficient temperature sensor, microcontroller and a fibre-optic transmitter. Performance of the model in laboratory simulated conditions are presented and discussed.

  16. Organolead Halide Perovskites for Low Operating Voltage Multilevel Resistive Switching.

    PubMed

    Choi, Jaeho; Park, Sunghak; Lee, Joohee; Hong, Kootak; Kim, Do-Hong; Moon, Cheon Woo; Park, Gyeong Do; Suh, Junmin; Hwang, Jinyeon; Kim, Soo Young; Jung, Hyun Suk; Park, Nam-Gyu; Han, Seungwu; Nam, Ki Tae; Jang, Ho Won

    2016-08-01

    Organolead halide perovskites are used for low-operating-voltage multilevel resistive switching. Ag/CH3 NH3 PbI3 /Pt cells exhibit electroforming-free resistive switching at an electric field of 3.25 × 10(3) V cm(-1) for four distinguishable ON-state resistance levels. The migration of iodine interstitials and vacancies with low activation energies is responsible for the low-electric-field resistive switching via filament formation and annihilation.

  17. Hybrid-PIC Modeling of a High-Voltage, High-Specific-Impulse Hall Thruster

    NASA Technical Reports Server (NTRS)

    Smith, Brandon D.; Boyd, Iain D.; Kamhawi, Hani; Huang, Wensheng

    2013-01-01

    The primary life-limiting mechanism of Hall thrusters is the sputter erosion of the discharge channel walls by high-energy propellant ions. Because of the difficulty involved in characterizing this erosion experimentally, many past efforts have focused on numerical modeling to predict erosion rates and thruster lifespan, but those analyses were limited to Hall thrusters operating in the 200-400V discharge voltage range. Thrusters operating at higher discharge voltages (V(sub d) >= 500 V) present an erosion environment that may differ greatly from that of the lower-voltage thrusters modeled in the past. In this work, HPHall, a well-established hybrid-PIC code, is used to simulate NASA's High-Voltage Hall Accelerator (HiVHAc) at discharge voltages of 300, 400, and 500V as a first step towards modeling the discharge channel erosion. It is found that the model accurately predicts the thruster performance at all operating conditions to within 6%. The model predicts a normalized plasma potential profile that is consistent between all three operating points, with the acceleration zone appearing in the same approximate location. The expected trend of increasing electron temperature with increasing discharge voltage is observed. An analysis of the discharge current oscillations shows that the model predicts oscillations that are much greater in amplitude than those measured experimentally at all operating points, suggesting that the differences in oscillation amplitude are not strongly associated with discharge voltage.

  18. High Power, High Voltage FETs in Linear Applications: A User's Perspective

    SciTech Connect

    N. Greenough, E. Fredd, S. DePasquale

    2009-09-21

    The specifications of the current crop of highpower, high-voltage field-effect transistors (FETs) can lure a designer into employing them in high-voltage DC equipment. Devices with extremely low on-resistance and very high power ratings are available from several manufacturers. However, our experience shows that high-voltage, linear operation of these devices at near-continuous duty can present difficult reliability challenges at stress levels well-below their published specifications. This paper chronicles the design evolution of a 600 volt, 8 ampere shunt regulator for use with megawatt-class radio transmitters, and presents a final design that has met its reliability criteria.

  19. High Voltage Design Guide for Airborne Equipment

    DTIC Science & Technology

    1976-06-01

    500 380 210 140 50 800 770 530 500 360 210 140 85 780 670 530 480 360 220 140 125 870 630 560 520 350 220 140 114 4.1.2 High Voltage Cable. At high...radioactive source of ionizing radiation such as polonium sHould be placed near the equipment under test in the altitude chamber to insure a supply of...electrons in the critical gap volumcs. Polonium is recommenoed because it’is not as hard to handle as other gari~na sources like cobalt 60. 6.1

  20. High Voltage in Noble Liquids for High Energy Physics

    SciTech Connect

    Rebel, B.; Bernard, E.; Faham, C. H.; Ito, T. M.; Lundberg, B.; Messina, M.; Monrabal, F.; Pereverzev, S. P.; Resnati, F.; Rowson, P. C.; Soderberg, M.; Strauss, T.; Tomas, A.; Va'vra, J.; Wang, H.

    2014-08-22

    A workshop was held at Fermilab November 8-9, 2013 to discuss the challenges of using high voltage in noble liquids. The participants spanned the fields of neutrino, dark matter, and electric dipole moment physics. All presentations at the workshop were made in plenary sessions. This document summarizes the experiences and lessons learned from experiments in these fields at developing high voltage systems in noble liquids.

  1. Ultra-compact Marx-type high-voltage generator

    DOEpatents

    Goerz, David A.; Wilson, Michael J.

    2000-01-01

    An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

  2. High voltage processing of the SLC polarized electron gun

    SciTech Connect

    Saez, P.; Clendenin, J.; Garden, C.; Hoyt, E.; Klaisner, L.; Prescott, C.; Schultz, D.; Tang, H.

    1993-04-01

    The SLC polarized electron gun operates at 120 kV with very low dark current to maintain the ultra high vacuum (UHV). This strict requirement protects the extremely sensitive photocathode from contaminants caused by high voltage (HV) activity. Thorough HV processing is thus required x-ray sensitive photographic film, a nanoammeter in series with gun power supply, a radiation meter, a sensitive residual gas analyzer and surface x-ray spectrometry were used to study areas in the gun where HV activity occurred. By reducing the electric field gradients, carefully preparing the HV surfaces and adhering to very strict clean assembly procedures, we found it possible to process the gun so as to reduce both the dark current at operating voltage and the probability of HV discharge. These HV preparation and processing techniques are described.

  3. High voltage insulation of bushing for HTS power equipment

    NASA Astrophysics Data System (ADS)

    Kim, Woo-Jin; Choi, Jae-Hyeong; Kim, Sang-Hyun

    2012-12-01

    For the operation of high temperature superconducting (HTS) power equipments, it is necessary to develop insulating materials and high voltage (HV) insulation technology at cryogenic temperature of bushing. Liquid nitrogen (LN2) is an attractive dielectric liquid. Also, the polymer insulating materials are expected to be used as solid materials such as glass fiber reinforced plastic (GFRP), polytetra-fluoroethylene (PTFE, Teflon), Silicon (Si) rubber, aromatic polyamide (Nomex), EPDM/Silicon alloy compound (EPDM/Si). In this paper, the surface flashover characteristics of various insulating materials in LN2 are studied. These results are studied at both AC and impulse voltage under a non-uniform field. The use of GFRP and Teflon as insulation body for HTS bushing should be much desirable. Especially, GFRP is excellent material not only surface flashover characteristics but also mechanical characteristics at cryogenic temperature. The surface flashover is most serious problem for the shed design in LN2 and operation of superconducting equipments.

  4. Topologically protected loop flows in high voltage AC power grids

    NASA Astrophysics Data System (ADS)

    Coletta, T.; Delabays, R.; Adagideli, I.; Jacquod, Ph

    2016-10-01

    Geographical features such as mountain ranges or big lakes and inland seas often result in large closed loops in high voltage AC power grids. Sizable circulating power flows have been recorded around such loops, which take up transmission line capacity and dissipate but do not deliver electric power. Power flows in high voltage AC transmission grids are dominantly governed by voltage angle differences between connected buses, much in the same way as Josephson currents depend on phase differences between tunnel-coupled superconductors. From this previously overlooked similarity we argue here that circulating power flows in AC power grids are analogous to supercurrents flowing in superconducting rings and in rings of Josephson junctions. We investigate how circulating power flows can be created and how they behave in the presence of ohmic dissipation. We show how changing operating conditions may generate them, how significantly more power is ohmically dissipated in their presence and how they are topologically protected, even in the presence of dissipation, so that they persist when operating conditions are returned to their original values. We identify three mechanisms for creating circulating power flows, (i) by loss of stability of the equilibrium state carrying no circulating loop flow, (ii) by tripping of a line traversing a large loop in the network and (iii) by reclosing a loop that tripped or was open earlier. Because voltages are uniquely defined, circulating power flows can take on only discrete values, much in the same way as circulation around vortices is quantized in superfluids.

  5. Study of a High Voltage Ion Engine Power Supply

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A.; King, Roger J.; Mayer, Eric

    1996-01-01

    A complete laboratory breadboard version of a ion engine power converter was built and tested. This prototype operated on a line voltage of 80-120 Vdc, and provided output ratings of 1100 V at 1.8 kW, and 250 V at 20 mA. The high-voltage (HV) output voltage rating was revised from the original value of 1350 V at the beginning of the project. The LV output was designed to hold up during a 1-A surge current lasting up to 1 second. The prototype power converter included a internal housekeeping power supply which also operated from the line input. The power consumed in housekeeping was included in the overall energy budget presented for the ion engine converter. HV and LV output voltage setpoints were commanded through potentiometers. The HV converter itself reached its highest power efficiency of slightly over 93% at low line and maximum output. This would dip below 90% at high line. The no-load (rated output voltages, zero load current) power consumption of the entire system was less than 13 W. A careful loss breakdown shows that converter losses are predominately Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) conduction losses and HV rectifier snubbing losses, with the rectifier snubbing losses becoming predominant at high line. This suggests that further improvements in power efficiency could best be obtained by either developing a rectifier that was adequately protected against voltage overshoot with less snubbing, or by developing a pre-regulator to reduced the range of line voltage on the converter. The transient testing showed the converter to be fully protected against load faults, including a direct short-circuit from the HV output to the LV output terminals. Two currents sensors were used: one to directly detect any core ratcheting on the output transformer and re-initiate a soft start, and the other to directly detect a load fault and quickly shut down the converter for load protection. The finished converter has been extensively fault tested

  6. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

    SciTech Connect

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  7. A Spherical Electro Optic High Voltage Sensor

    DTIC Science & Technology

    1989-06-01

    electro - optic (EO) crystal is introduced for photonic measurement of pulsed high-voltage fields. A spherical shape is used in order to reduce electric field gradients in the vicinity of the sensor. The sensor is pure dielectric and is interrogated remotely using a laser. The sensor does not require the connection of any conducting components, which results in the highest electrical isolation. The spherical nature of the crystal coupled with the incident laser beam, and crossed polarizers (intensity modulation scheme). automatically produces interference figures. The

  8. Safe epoxy encapsulant for high voltage magnetics

    SciTech Connect

    Sanchez, R.O.; Archer, W.E.

    1998-01-01

    This paper describes the use of Formula 456, an aliphatic amine cured epoxy for impregnating coils and high voltage transformers. Sandia has evaluated a number of MDA-free epoxy encapsulants which relied on either anhydride or other aromatic amine curing agents. The use of aliphatic amine curing agents was more recently evaluated and has resulted in the definition of Formula 456 resin. Methylene dianiline (MDA) has been used for more than 20 years as the curing agent for various epoxy formulations throughout the Department of Energy and much of industry. Sandia National Laboratories began the process of replacing MDA with other formulations because of regulations imposed by OSHA on the use of MDA. OSHA has regulated MDA because it is a suspect carcinogen. Typically the elimination of OSHA-regulated materials provides a rare opportunity to qualify new formulations in a range of demanding applications. It was important to take full advantage of that opportunity, although the associated materials qualification effort was costly. Small high voltage transformers are one of those demanding applications. The successful implementation of the new formulation for high reliability transformers will be described. The test results that demonstrate the parts are qualified for use in DOE weapon systems will be presented.

  9. 30 CFR 75.813 - High-voltage longwalls; scope.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-voltage longwalls; scope. 75.813 Section 75.813 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution High-Voltage Longwalls § 75.813...

  10. 30 CFR 75.813 - High-voltage longwalls; scope.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage longwalls; scope. 75.813 Section 75.813 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution High-Voltage Longwalls § 75.813...

  11. High-voltage plasma interactions calculations using NASCAP/LEO

    NASA Technical Reports Server (NTRS)

    Mandell, M. J.; Katz, I.

    1990-01-01

    This paper reviews four previous simulations (two laboratory and two space-flight) of interactions of a high-voltage spacecraft with a plasma under low-earth orbit conditions, performed using a three-dimensional computer code NASCAP/LEO. Results show that NASCAP/LEO can perform meaningful simulations of high-voltage plasma interactions taking into account three-dimensional effects of geometry, spacecraft motion, and magnetic field. Two new calculations are presented: (1) for current collection by 1-mm pinholes in wires (showing that a pinhole in a wire can collect far more current than a similar pinhole in a flat plate); and (2) current collection by Charge-2 mother vehicle launched in December 1985. It is shown that the Charge-2 calculations predicted successfully ion collection at negative bias, the floating potential of a probe outside or inside the sheath under negative bias conditions, and magnetically limited electron collection under electron beam operation at high altitude.

  12. Improve Motor Operation at Off-Design Voltages - Motor Tip Sheet #9

    SciTech Connect

    2008-07-01

    Motors are designed to operate within +/- 10% of their nameplate rated voltages. When motors operate at conditions of over- or under-voltage, motor efficiency and other performance parameters are degraded.

  13. Efficient Low-Voltage Operation of a CW Gyrotron Oscillator at 233 GHz

    PubMed Central

    Hornstein, Melissa K.; Bajaj, Vikram S.; Griffin, Robert G.; Temkin, Richard J.

    2007-01-01

    The gyrotron oscillator is a source of high average power millimeter-wave through terahertz radiation. In this paper, we report low beam power and high-efficiency operation of a tunable gyrotron oscillator at 233 GHz. The low-voltage operating mode provides a path to further miniaturization of the gyrotron through reduction in the size of the electron gun, power supply, collector, and cooling system, which will benefit industrial and scientific applications requiring portability. Detailed studies of low-voltage operation in the TE2,3,1 mode reveal that the mode can be excited with less than 7 W of beam power at 3.5 kV. During CW operation with 3.5-kV beam voltage and 50-mA beam current, the gyrotron generates 12 W of RF power at 233.2 GHz. The EGUN electron optics code describes the low-voltage operation of the electron gun. Using gun-operating parameters derived from EGUN simulations, we show that a linear theory adequately predicts the low experimental starting currents. PMID:17687412

  14. Complete low power controller for high voltage power systems

    SciTech Connect

    Sumner, R.; Blanar, G.

    1997-12-31

    The MHV100 is a custom CMOS integrated circuit, developed for the AMS experiment. It provides complete control for a single channel high voltage (HV) generator and integrates all the required digital communications, D to A and A to D converters, the analog feedback loop and output drivers. This chip has been designed for use in both distributed high voltage systems or for low cost single channel high voltage systems. The output voltage and current range is determined by the external components.

  15. Control of Analyte Electrolysis in Electrospray Ionization Mass Spectrometry Using Repetitively Pulsed High Voltage

    SciTech Connect

    Kertesz, Vilmos; Van Berkel, Gary J

    2011-01-01

    Analyte electrolysis using a repetitively pulsed high voltage ion source was investigated and compared to that using a regular, continuously operating direct current high voltage ion source in electrospray ionization mass spectrometry. The extent of analyte electrolysis was explored as a function of the length and frequency of the high voltage pulse using the model compound reserpine in positive ion mode. Using +5 kV as the maximum high voltage amplitude, reserpine was oxidized to its 2, 4, 6 and 8-electron oxidation products when direct current high voltage was employed. In contrast, when using a pulsed high voltage, oxidation of reserpine was eliminated by employing the appropriate high voltage pulse length and frequency. This effect was caused by inefficient mass transport of the analyte to the electrode surface during the duration of the high voltage pulse and the subsequent relaxation of the emitter electrode/ electrolyte interface during the time period when the high voltage was turned off. This mode of ESI source operation allows for analyte electrolysis to be quickly and simply switched on or off electronically via a change in voltage pulse variables.

  16. Design of low-voltage bipolar operational amplifiers

    NASA Astrophysics Data System (ADS)

    Fonderie, Jeroen

    The design of input stages for low voltage Operational Amplifiers (OpAmps) is considered. The purpose of this design emanates from the objective of having a common mode input voltage range that reaches from one supply rail to the other, and designs that have this feature both at a 2 V and at a 1 V supply are discussed. Possible output stage configurations are analyzed. This discussion is restricted to output stages that have an output voltage range that also reaches from rail to rail. Further, the output stage should be able to supply a sufficiently large output current to the load that is externally connected to the OpAmp. The frequency response of the output stage is the focus of the discussion. The circuit parts that remain to complete the design of the OpAmp are discussed. These circuit parts are the intermediate stage, inserted between the input and output stage to boost the overall gain of the OpAmp, some implementations of the class AB current control circuit, circuitry to protect the output transistor from heavy saturation and from excessive power consumption, and, finally, the proportional to absolute temperature reference current generator. A detailed analysis of the frequency compensation techniques that can be used to stabilize the OpAmp is given. From this theory, design criteria to successfully implement the compensation method are derived. The experimental OpAmp designs and the measurements performed on these designs are described. Conclusions and suggestions for further research are given.

  17. High Voltage Power Transmission for Wind Energy

    NASA Astrophysics Data System (ADS)

    Kim, Young il

    The high wind speeds and wide available area at sea have recently increased the interests on offshore wind farms in the U.S.A. As offshore wind farms become larger and are placed further from the shore, the power transmission to the onshore grid becomes a key feature. Power transmission of the offshore wind farm, in which good wind conditions and a larger installation area than an onshore site are available, requires the use of submarine cable systems. Therefore, an underground power cable system requires unique design and installation challenges not found in the overhead power cable environment. This paper presents analysis about the benefit and drawbacks of three different transmission solutions: HVAC, LCC/VSC HVDC in the grid connecting offshore wind farms and also analyzed the electrical characteristics of underground cables. In particular, loss of HV (High Voltage) subsea power of the transmission cables was evaluated by the Brakelmann's theory, taking into account the distributions of current and temperature.

  18. High-Capacity, High-Voltage Composite Oxide Cathode Materials

    NASA Technical Reports Server (NTRS)

    Hagh, Nader M.

    2015-01-01

    This SBIR project integrates theoretical and experimental work to enable a new generation of high-capacity, high-voltage cathode materials that will lead to high-performance, robust energy storage systems. At low operating temperatures, commercially available electrode materials for lithium-ion (Li-ion) batteries do not meet energy and power requirements for NASA's planned exploration activities. NEI Corporation, in partnership with the University of California, San Diego, has developed layered composite cathode materials that increase power and energy densities at temperatures as low as 0 degC and considerably reduce the overall volume and weight of battery packs. In Phase I of the project, through innovations in the structure and morphology of composite electrode particles, the partners successfully demonstrated an energy density exceeding 1,000 Wh/kg at 4 V at room temperature. In Phase II, the team enhanced the kinetics of Li-ion transport and electronic conductivity at 0 degC. An important feature of the composite cathode is that it has at least two components that are structurally integrated. The layered material is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated and deliver a large amount of energy with stable cycling.

  19. High-voltage pixel sensors for ATLAS upgrade

    NASA Astrophysics Data System (ADS)

    Perić, I.; Kreidl, C.; Fischer, P.; Bompard, F.; Breugnon, P.; Clemens, J.-C.; Fougeron, D.; Liu, J.; Pangaud, P.; Rozanov, A.; Barbero, M.; Feigl, S.; Capeans, M.; Ferrere, D.; Pernegger, H.; Ristic, B.; Muenstermann, D.; Gonzalez Sevilla, S.; La Rosa, A.; Miucci, A.; Nessi, M.; Iacobucci, G.; Backhaus, M.; Hügging, Fabian; Krüger, H.; Hemperek, T.; Obermann, T.; Wermes, N.; Garcia-Sciveres, M.; Quadt, A.; Weingarten, J.; George, M.; Grosse-Knetter, J.; Rieger, J.; Bates, R.; Blue, A.; Buttar, C.; Hynds, D.

    2014-11-01

    The high-voltage (HV-) CMOS pixel sensors offer several good properties: a fast charge collection by drift, the possibility to implement relatively complex CMOS in-pixel electronics and the compatibility with commercial processes. The sensor element is a deep n-well diode in a p-type substrate. The n-well contains CMOS pixel electronics. The main charge collection mechanism is drift in a shallow, high field region, which leads to a fast charge collection and a high radiation tolerance. We are currently evaluating the use of the high-voltage detectors implemented in 180 nm HV-CMOS technology for the high-luminosity ATLAS upgrade. Our approach is replacing the existing pixel and strip sensors with the CMOS sensors while keeping the presently used readout ASICs. By intelligence we mean the ability of the sensor to recognize a particle hit and generate the address information. In this way we could benefit from the advantages of the HV sensor technology such as lower cost, lower mass, lower operating voltage, smaller pitch, smaller clusters at high incidence angles. Additionally we expect to achieve a radiation hardness necessary for ATLAS upgrade. In order to test the concept, we have designed two HV-CMOS prototypes that can be readout in two ways: using pixel and strip readout chips. In the case of the pixel readout, the connection between HV-CMOS sensor and the readout ASIC can be established capacitively.

  20. Radiofrequency exposure near high-voltage lines.

    PubMed Central

    Vignati, M; Giuliani, L

    1997-01-01

    Many epidemiologic studies suggest a relationship between incidence of diseases like cancer and leukemia and exposure to 50/60 Hz magnetic fields. Some studies suggest a relationship between leukemia incidence in populations residing near high-voltage lines and the distance to these lines. Other epidemiologic studies suggest a relationship between leukemia incidence and exposure to 50/60 Hz magnetic fields (measured or estimated) and distance from the main system (220 or 120 V). The present work does not question these results but is intended to draw attention to a possible concurrent cause that might also increase the incidence of this disease; the presence on an electric grid of radiofrequency currents used for communications and remote control. These currents have been detected on high- and medium-voltage lines. In some cases they are even used on the main system for remote reading of electric meters. This implies that radiofrequency (RF) magnetic fields are present near the electric network in addition to the 50/60 Hz fields. This intensity of these RF fields is low but the intensity of currents induced in the human body by exposure to magnetic fields increases with frequency. Because scientific research has not yet clarified whether the risk is related to the value of magnetic induction or to the currents this kind of exposure produces in the human body, it is reasonable to suggest that the presence of the RF magnetic fields must be considered in the context of epidemiologic studies. Images Figure 3. Figure 4. Figure 5. PMID:9467084

  1. High voltage supply for neutron tubes in well logging applications

    DOEpatents

    Humphreys, D. Russell

    1989-01-01

    A high voltage supply is provided for a neutron tube used in well logging. The "biased pulse" supply of the invention combines DC and "full pulse" techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

  2. Note: Complementary metal-oxide-semiconductor high voltage pulse generation circuits.

    PubMed

    Sun, Jiwei; Wang, Pingshan

    2013-10-01

    We present two types of on-chip pulse generation circuits. The first is based on CMOS pulse-forming-lines (PFLs). It includes a four-stage charge pump, a four-stacked-MOSFET switch and a 5 mm long PFL. The circuit is implemented in a 0.13 μm CMOS process. Pulses of ~1.8 V amplitude with ~135 ps duration on a 50 Ω load are obtained. The obtained voltage is higher than 1.6 V, the rated operating voltage of the process. The second is a high-voltage Marx generator which also uses stacked MOSFETs as high voltage switches. The output voltage is 11.68 V, which is higher than the highest breakdown voltage (~10 V) of the CMOS process. These results significantly extend high-voltage pulse generation capabilities of CMOS technologies.

  3. Note: Complementary metal-oxide-semiconductor high voltage pulse generation circuits

    NASA Astrophysics Data System (ADS)

    Sun, Jiwei; Wang, Pingshan

    2013-10-01

    We present two types of on-chip pulse generation circuits. The first is based on CMOS pulse-forming-lines (PFLs). It includes a four-stage charge pump, a four-stacked-MOSFET switch and a 5 mm long PFL. The circuit is implemented in a 0.13 μm CMOS process. Pulses of ˜1.8 V amplitude with ˜135 ps duration on a 50 Ω load are obtained. The obtained voltage is higher than 1.6 V, the rated operating voltage of the process. The second is a high-voltage Marx generator which also uses stacked MOSFETs as high voltage switches. The output voltage is 11.68 V, which is higher than the highest breakdown voltage (˜10 V) of the CMOS process. These results significantly extend high-voltage pulse generation capabilities of CMOS technologies.

  4. Advanced Gate Drive for the SNS High Voltage Converter Modulator

    SciTech Connect

    Nguyen, M.N.; Burkhart, C.; Kemp, M.A.; Anderson, D.E.; /Oak Ridge

    2009-05-07

    SLAC National Accelerator Laboratory is developing a next generation H-bridge switch plate [1], a critical component of the SNS High Voltage Converter Modulator [2]. As part of that effort, a new IGBT gate driver has been developed. The drivers are an integral part of the switch plate, which are essential to ensuring fault-tolerant, high-performance operation of the modulator. The redesigned driver improves upon the existing gate drive in several ways. The new gate driver has improved fault detection and suppression capabilities; suppression of shoot-through and over-voltage conditions, monitoring of dI/dt and Vce(sat) for fast over-current detection and suppression, and redundant power isolation are some of the added features. In addition, triggering insertion delay is reduced by a factor of four compared to the existing driver. This paper details the design and performance of the new IGBT gate driver. A simplified schematic and description of the construction are included. The operation of the fast over-current detection circuits, active IGBT over-voltage protection circuit, shoot-through prevention circuitry, and control power isolation breakdown detection circuit are discussed.

  5. 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.

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

    SciTech Connect

    Murty, B.V.

    2000-03-21

    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.

  7. A high voltage power supply for the AE-C and D low energy electron experiment

    NASA Technical Reports Server (NTRS)

    Gillis, J. A.

    1974-01-01

    A description is given of the electrical and mechanical design and operation of high voltage power supplies for space flight use. The supply was used to generate the spiraltron high voltage for low energy electron experiment on AE-C and D. Two versions of the supply were designed and built; one design is referred to as the low power version (AE-C) and the other as the high power version (AE-D). Performance is discussed under all operating conditions.

  8. Novel bandgap-based under-voltage-lockout methods with high reliability

    NASA Astrophysics Data System (ADS)

    Yongrui, Zhao; Xinquan, Lai

    2013-10-01

    Highly reliable bandgap-based under-voltage-lockout (UVLO) methods are presented in this paper. The proposed under-voltage state to signal conversion methods take full advantages of the high temperature stability characteristics and the enhancement low-voltage protection methods which protect the core circuit from error operation; moreover, a common-source stage amplifier method is introduced to expand the output voltage range. All of these methods are verified in a UVLO circuit fabricated with a 0.5 μm standard BCD process technology. The experimental result shows that the proposed bandgap method exhibits a good temperature coefficient of 20 ppm/°C, which ensures that the UVLO keeps a stable output until the under-voltage state changes. Moreover, at room temperature, the high threshold voltage VTH+ generated by the UVLO is 12.3 V with maximum drift voltage of ±80 mV, and the low threshold voltage VTH- is 9.5 V with maximum drift voltage of ±70 mV. Also, the low voltage protection method used in the circuit brings a high reliability when the supply voltage is very low.

  9. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

    PubMed

    Reghu, T; Mandloi, V; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  10. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications

    NASA Astrophysics Data System (ADS)

    Reghu, T.; Mandloi, V.; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  11. A High-Voltage Bipolar Transconductance Amplifier for Electrotactile Stimulation

    PubMed Central

    Schaning, Matthew A.; Kaczmarek, Kurt A.

    2008-01-01

    This article describes a high-performance transconductance amplifier specifically designed for electrotactile (electrocutaneous) stimulation. It enables voltages up to ±600 V to be produced at the output which will allow the psychophysiological performance associated with stimulation of the fingertip using various stimulation waveforms to be studied more thoroughly. The design has a transconductance of up to 20 mA/V, an 8.8-MΩ output resistance, and can provide output currents up to ±20 mA. A complete schematic diagram is presented along with a discussion of theory of operation and safety issues as well as performance and derating plots from the implemented design. PMID:18838369

  12. Method and system for a gas tube switch-based voltage source high voltage direct current transmission system

    SciTech Connect

    She, Xu; Chokhawala, Rahul Shantilal; Zhou, Rui; Zhang, Di; Sommerer, Timothy John; Bray, James William

    2016-12-13

    A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to "switch on" a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and "switch off" the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.

  13. An accurate continuous calibration system for high voltage current transformer

    SciTech Connect

    Tong Yue; Li Binhong

    2011-02-15

    A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

  14. Solid electrolyte: The key for high-voltage lithium batteries

    DOE PAGES

    Li, Juchuan; Ma, Cheng; Chi, Miaofang; ...

    2014-10-14

    A solid-state high-voltage (5 V) lithium battery is demonstrated to deliver a cycle life of 10 000 with 90% capacity retention. Furthermore, the solid electrolyte enables the use of high-voltage cathodes and Li anodes with minimum side reactions, leading to a high Coulombic efficiency of 99.98+%.

  15. False Operation of Static Random Access Memory Cells under Alternating Current Power Supply Voltage Variation

    NASA Astrophysics Data System (ADS)

    Sawada, Takuya; Takata, Hidehiro; Nii, Koji; Nagata, Makoto

    2013-04-01

    Static random access memory (SRAM) cores exhibit susceptibility against power supply voltage variation. False operation is investigated among SRAM cells under sinusoidal voltage variation on power lines introduced by direct RF power injection. A standard SRAM core of 16 kbyte in a 90 nm 1.5 V technology is diagnosed with built-in self test and on-die noise monitor techniques. The sensitivity of bit error rate is shown to be high against the frequency of injected voltage variation, while it is not greatly influenced by the difference in frequency and phase against SRAM clocking. It is also observed that the distribution of false bits is substantially random in a cell array.

  16. NASICON-Structured NaTi2(PO4)3@C Nanocomposite as the Low Operation-Voltage Anode Material for High-Performance Sodium-Ion Batteries.

    PubMed

    Wang, Dongxue; Liu, Qiang; Chen, Chaoji; Li, Malin; Meng, Xing; Bie, Xiaofei; Wei, Yingjin; Huang, Yunhui; Du, Fei; Wang, Chunzhong; Chen, Gang

    2016-01-27

    NASICON-type structured NaTi2(PO4)3 (NTP) has attracted wide attention as a promising anode material for sodium-ion batteries (SIBs), whereas it still suffer from poor rate capability and cycle stability due to the low electronic conductivity. Herein, the architecture, NTP nanoparticles embedded in the mesoporous carbon matrix, is designed and realized by a facile sol-gel method. Different than the commonly employed potentials of 1.5-3.0 V, the Na(+) storage performance is examined at low operation voltages between 0.01 and 3.0 V. The electrode demonstrates an improved capacity of 208 mAh g(-1), one of the highest capacities in the state-of-the-art titanium-based anode materials. Besides the high working plateau at 2.1 V, another one is observed at approximately 0.4 V for the first time due to further reduction of Ti(3+) to Ti(2+). Remarkably, the anode exhibits superior rate capability, whose capacity and corresponding capacity retention reach 56 mAh g(-1) and 68%, respectively, over 10000 cycles under the high current density of 20 C rate (4 A g(-1)). Worthy of note is that the electrode shows negligible capacity loss as the current densities increase from 50 to 100 C, which enables NTP@C nanocomposite as the prospective anode of SIBs with ultrahigh power density.

  17. A semi-floating gate transistor for low-voltage ultrafast memory and sensing operation.

    PubMed

    Wang, Peng-Fei; Lin, Xi; Liu, Lei; Sun, Qing-Qing; Zhou, Peng; Liu, Xiao-Yong; Liu, Wei; Gong, Yi; Zhang, David Wei

    2013-08-09

    As the semiconductor devices of integrated circuits approach the physical limitations of scaling, alternative transistor and memory designs are needed to achieve improvements in speed, density, and power consumption. We report on a transistor that uses an embedded tunneling field-effect transistor for charging and discharging the semi-floating gate. This transistor operates at low voltages (≤2.0 volts), with a large threshold voltage window of 3.1 volts, and can achieve ultra-high-speed writing operations (on time scales of ~1 nanosecond). A linear dependence of drain current on light intensity was observed when the transistor was exposed to light, so possible applications include image sensing with high density and performance.

  18. 30 CFR 75.804 - Underground high-voltage cables.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... § 75.804 Underground high-voltage cables. (a) Underground high-voltage cables used in resistance grounded systems shall be equipped with metallic shields around each power conductor with one or more ground conductors having a total cross sectional area of not less than one-half the power conductor,...

  19. High voltage switches having one or more floating conductor layers

    SciTech Connect

    Werne, Roger W.; Sampayan, Stephen; Harris, John Richardson

    2015-11-24

    This patent document discloses high voltage switches that include one or more electrically floating conductor layers that are isolated from one another in the dielectric medium between the top and bottom switch electrodes. The presence of the one or more electrically floating conductor layers between the top and bottom switch electrodes allow the dielectric medium between the top and bottom switch electrodes to exhibit a higher breakdown voltage than the breakdown voltage when the one or more electrically floating conductor layers are not present between the top and bottom switch electrodes. This increased breakdown voltage in the presence of one or more electrically floating conductor layers in a dielectric medium enables the switch to supply a higher voltage for various high voltage circuits and electric systems.

  20. Magnetic shielding of Hall thrusters at high discharge voltages

    SciTech Connect

    Mikellides, Ioannis G. Hofer, Richard R.; Katz, Ira; Goebel, Dan M.

    2014-08-07

    A series of numerical simulations and experiments have been performed to assess the effectiveness of magnetic shielding in a Hall thruster operating in the discharge voltage range of 300–700 V (I{sub sp} ≈ 2000–2700 s) at 6 kW, and 800 V (I{sub sp} ≈ 3000) at 9 kW. At 6 kW, the magnetic field topology with which highly effective magnetic shielding was previously demonstrated at 300 V has been retained for all other discharge voltages; only the magnitude of the field has been changed to achieve optimum thruster performance. It is found that magnetic shielding remains highly effective for all discharge voltages studied. This is because the channel is long enough to allow hot electrons near the channel exit to cool significantly upon reaching the anode. Thus, despite the rise of the maximum electron temperature in the channel with discharge voltage, the electrons along the grazing lines of force remain cold enough to eliminate or reduce significantly parallel gradients of the plasma potential near the walls. Computed maximum erosion rates in the range of 300–700 V are found not to exceed 10{sup −2} mm/kh. Such rates are ∼3 orders of magnitude less than those observed in the unshielded version of the same thruster at 300 V. At 9 kW and 800 V, saturation of the magnetic circuit did not allow for precisely the same magnetic shielding topology as that employed during the 6-kW operation since this thruster was not designed to operate at this condition. Consequently, the maximum erosion rate at the inner wall is found to be ∼1 order of magnitude higher (∼10{sup −1} mm/kh) than that at 6 kW. At the outer wall, the ion energy is found to be below the sputtering yield threshold so no measurable erosion is expected.

  1. High-voltage electrical survey advances using UV/IR

    NASA Astrophysics Data System (ADS)

    Ninedorf, Daniel A.; Stolper, Roel; Hart, Jaco

    2008-03-01

    Technology miniaturization has made new advancements in high voltage electrical surveying possible. A solar-blind ultraviolet image overlaid onto infrared, combined with a solar-blind ultraviolet image and then overlaid onto color visible in the same camera with a weight of 6 pounds provides the comparison images and portability to allow an operator to do on-the-spot analysis and repair priority assignment. The UV-VIS image provides the quickest location and identification. The UV-IR image allows analysis to determine if there is damage and the severity. This can be accomplished in just seconds thru menu selection: before it required two separate cameras. This presentation will provide examples of different images and analysis, with operating time from hand-held, laboratory, vehicle and aerial camera mounts.

  2. The Series Connected Buck Boost Regulator Concept for High Efficiency Light Weight DC Voltage Regulation

    NASA Technical Reports Server (NTRS)

    Birchenough, Arthur G.

    2003-01-01

    Improvements in the efficiency and size of DC-DC converters have resulted from advances in components, primarily semiconductors, and improved topologies. One topology, which has shown very high potential in limited applications, is the Series Connected Boost Unit (SCBU), wherein a small DC-DC converter output is connected in series with the input bus to provide an output voltage equal to or greater than the input voltage. Since the DC-DC converter switches only a fraction of the power throughput, the overall system efficiency is very high. But this technique is limited to applications where the output is always greater than the input. The Series Connected Buck Boost Regulator (SCBBR) concept extends partial power processing technique used in the SCBU to operation when the desired output voltage is higher or lower than the input voltage, and the implementation described can even operate as a conventional buck converter to operate at very low output to input voltage ratios. This paper describes the operation and performance of an SCBBR configured as a bus voltage regulator providing 50 percent voltage regulation range, bus switching, and overload limiting, operating above 98 percent efficiency. The technique does not provide input-output isolation.

  3. Electrical system architecture having high voltage bus

    DOEpatents

    Hoff, Brian Douglas [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL

    2011-03-22

    An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

  4. Integration Test of the High Voltage Hall Accelerator System Components

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Haag, Thomas; Huang, Wensheng; Pinero, Luis; Peterson, Todd; Dankanich, John

    2013-01-01

    NASA Glenn Research Center is developing a 4 kilowatt-class Hall propulsion system for implementation in NASA science missions. NASA science mission performance analysis was completed using the latest high voltage Hall accelerator (HiVHAc) and Aerojet-Rocketdyne's state-of-the-art BPT-4000 Hall thruster performance curves. Mission analysis results indicated that the HiVHAc thruster out performs the BPT-4000 thruster for all but one of the missions studied. Tests of the HiVHAc system major components were performed. Performance evaluation of the HiVHAc thruster at NASA Glenn's vacuum facility 5 indicated that thruster performance was lower than performance levels attained during tests in vacuum facility 12 due to the lower background pressures attained during vacuum facility 5 tests when compared to vacuum facility 12. Voltage-Current characterization of the HiVHAc thruster in vacuum facility 5 showed that the HiVHAc thruster can operate stably for a wide range of anode flow rates for discharge voltages between 250 and 600 volts. A Colorado Power Electronics enhanced brassboard power processing unit was tested in vacuum for 1,500 hours and the unit demonstrated discharge module efficiency of 96.3% at 3.9 kilowatts and 650 volts. Stand-alone open and closed loop tests of a VACCO TRL 6 xenon flow control module were also performed. An integrated test of the HiVHAc thruster, brassboard power processing unit, and xenon flow control module was performed and confirmed that integrated operation of the HiVHAc system major components. Future plans include continuing the maturation of the HiVHAc system major components and the performance of a single-string integration test.

  5. Planar LTCC transformers for high voltage flyback converters.

    SciTech Connect

    Schofield, Daryl; Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George; Abel, Dave

    2007-06-01

    This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.

  6. Bipolar high-repetition-rate high-voltage nanosecond pulser.

    PubMed

    Tian, Fuqiang; Wang, Yi; Shi, Hongsheng; Lei, Qingquan

    2008-06-01

    The pulser designed is mainly used for producing corona plasma in waste water treatment system. Also its application in study of dielectric electrical properties will be discussed. The pulser consists of a variable dc power source for high-voltage supply, two graded capacitors for energy storage, and the rotating spark gap switch. The key part is the multielectrode rotating spark gap switch (MER-SGS), which can ensure wider range modulation of pulse repetition rate, longer pulse width, shorter pulse rise time, remarkable electrical field distortion, and greatly favors recovery of the gap insulation strength, insulation design, the life of the switch, etc. The voltage of the output pulses switched by the MER-SGS is in the order of 3-50 kV with pulse rise time of less than 10 ns and pulse repetition rate of 1-3 kHz. An energy of 1.25-125 J per pulse and an average power of up to 10-50 kW are attainable. The highest pulse repetition rate is determined by the driver motor revolution and the electrode number of MER-SGS. Even higher voltage and energy can be switched by adjusting the gas pressure or employing N(2) as the insulation gas or enlarging the size of MER-SGS to guarantee enough insulation level.

  7. Bipolar high-repetition-rate high-voltage nanosecond pulser

    SciTech Connect

    Tian Fuqiang; Wang Yi; Shi Hongsheng; Lei Qingquan

    2008-06-15

    The pulser designed is mainly used for producing corona plasma in waste water treatment system. Also its application in study of dielectric electrical properties will be discussed. The pulser consists of a variable dc power source for high-voltage supply, two graded capacitors for energy storage, and the rotating spark gap switch. The key part is the multielectrode rotating spark gap switch (MER-SGS), which can ensure wider range modulation of pulse repetition rate, longer pulse width, shorter pulse rise time, remarkable electrical field distortion, and greatly favors recovery of the gap insulation strength, insulation design, the life of the switch, etc. The voltage of the output pulses switched by the MER-SGS is in the order of 3-50 kV with pulse rise time of less than 10 ns and pulse repetition rate of 1-3 kHz. An energy of 1.25-125 J per pulse and an average power of up to 10-50 kW are attainable. The highest pulse repetition rate is determined by the driver motor revolution and the electrode number of MER-SGS. Even higher voltage and energy can be switched by adjusting the gas pressure or employing N{sub 2} as the insulation gas or enlarging the size of MER-SGS to guarantee enough insulation level.

  8. E-beam high voltage switching power supply

    DOEpatents

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

    1996-10-15

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

  9. E-beam high voltage switching power supply

    DOEpatents

    Shimer, Daniel W.; Lange, Arnold C.

    1996-01-01

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

  10. 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).

  11. COTS Li-Ion Cells in High Voltage Batteries

    NASA Technical Reports Server (NTRS)

    Davies, Francis; Darcy, Eric; Jeevarajan, Judy; Cowles, Phil

    2003-01-01

    Testing at NASA JSC and COMDEV shows that Commercial Off the Shelf (COTS) Li Ion cells can not be used in high voltage batteries safely without considering the voltage stresses that may be put on the protective devices in them during failure modes.

  12. High precision, low disturbance calibration system for the CMS Barrel Electromagnetic Calorimeter High Voltage apparatus

    NASA Astrophysics Data System (ADS)

    Fasanella, G.

    2017-01-01

    The CMS Electromagnetic Calorimeter utilizes scintillation lead tungstate crystals, with avalanche photodiodes (APD) as photo-detectors in the barrel part. 1224 HV channels bias groups of 50 APD pairs, each at a voltage of about 380 V. The APD gain dependence on the voltage is 3%/V. A stability of better than 60 mV is needed to have negligible impact on the calorimeter energy resolution. Until 2015 manual calibrations were performed yearly. A new calibration system was deployed recently, which satisfies the requirement of low disturbance and high precision. The system is discussed in detail and first operational experience is presented.

  13. High voltage protection in active matrix flat-panel imagers

    NASA Astrophysics Data System (ADS)

    Lehnert, Joerg; Zhao, Wei

    2006-03-01

    Various direct and indirect active matrix flat-panel imagers (AMFPI) are being investigated for x-ray imaging. In both direct AMFPI and indirect AMFPI with avalanche gain, a bias potential up to several thousand volts is required to operate the photoconductor. Under the condition of a large amount of radiation exposure between subsequent readout, a potential >80 V could appear across the amorphous silicon (a-Si) thin film transistor (TFT) and cause permanent damage. The purpose of this paper is to investigate a simple pixel design for high voltage protection. The pixel electrode acts as an additional gate for the top channel of an a-Si TFT to drain excess image charge from the pixel electrode until an equilibrium is reached where the TFT channel current equals the detector signal current at a predetermined safe maximum value V Pmax for the pixel potential. This "dual-gate" TFT structure without additional protective device simplifies the TFT array design and improves yield. However special care is required to understand the characteristics of both the top and the bottom gates to ensure sufficient detector dynamic range as well as reliable high voltage protection. A physical model for dual-gate a-Si TFTs was developed and device parameters were determined by fitting the model to measured characteristics from a dual-gate TFT array. Our results showed that compared to the bottom (normal) gate, the protective gate has a shallower transfer characteristics (i.e. channel current as a function of gate voltage) due to a higher density of states in the top interface. Nevertheless it provides adequate protection of the TFT with V Pmax of ~40 V for typical radiographic exposures.

  14. Integrated high-voltage modulator for plasma immersion ion implantation with an RF plasma

    NASA Astrophysics Data System (ADS)

    Rogozin, A. I.; Astrelin, V. T.; Richter, E.; Möller, W.

    2003-08-01

    The present investigation focuses on further development of the plasma based high-voltage modulator for plasma immersion ion implantation devices. The modulator produces high-voltage pulses using grid controlled extraction of electrons from the plasma, which is used for the ion implantation. The operation features of the modulator in connection with a radio-frequency plasma are described. The device is applied to nitrogen ion implantations of stainless steel. The results indicate considerable hardness improvement, which confirms the practical utility of the high-voltage modulator.

  15. High-voltage field-controlled integrated thyristor

    NASA Astrophysics Data System (ADS)

    Grekhov, I. V.; Rozhkov, A. V.; Kostina, L. S.; Konovalov, A. V.; Fomenko, Yu. L.

    2013-01-01

    The design and technology of powerful field-controlled integrated thyristors, new energy-saving devices intended for converter equipment, are considered. The turn-on and turn-off current and voltage waveforms of the n+ p' N- n' p + microthyristor chip are presented, and turn-on and turn-off mechanisms are discussed. The development of local dynamic breakdown at turn-off is experimentally studied. The respective waveforms for this process are given, and the type of breakdown at a current density of about 150 A/cm2 is demonstrated. The current-voltage characteristics in the on state at room temperature and at 125°C indicate the temperature dependence changes sign at a current density above 60 A/cm2, becoming positive. This is significant for parallel operation of microthyristor chips in a module. It is shown that the static and dynamic characteristics of simple-in-design field-controlled integrated thyristors are highly competitive with those of insulated-gate bipolar transistors-basic devices of advanced high-power converter equipment.

  16. Understanding High Voltage Vacuum Insulators for Microsecond Pulses

    SciTech Connect

    J.B., J; D.A., G; T.L., H; E.J., L; R.D., S; L.K., T; G.E., V

    2007-08-15

    High voltage insulation is one of the main areas of pulsed power research and development since the surface of an insulator exposed to vacuum can fail electrically at an applied field more than an order or magnitude below the bulk dielectric strength of the insulator. This is troublesome for applications where high voltage conditioning of the insulator and electrodes is not practical and where relatively long pulses, on the order of several microseconds, are required. Here we give a summary of our approach to modeling and simulation efforts and experimental investigations for understanding flashover mechanism. The computational work is comprised of both filed and particle-in-cell modeling with state-of-the-art commercial codes. Experiments were performed in using an available 100-kV, 10-{micro}s pulse generator and vacuum chamber. The initial experiments were done with polyethylene insulator material in the shape of a truncated cone cut at +45{sup o} angle between flat electrodes with a gap of 1.0 cm. The insulator was sized so there were no flashovers or breakdowns under nominal operating conditions. Insulator flashover or gap closure was induced by introducing a plasma source, a tuft of velvet, in proximity to the insulator or electrode.

  17. Research of position measuring system for high voltage switchgear

    NASA Astrophysics Data System (ADS)

    Ji, Yilin; Qian, Zheng; Pan, Kaikai

    2016-01-01

    The contact position's accurate measurement is the key part of the realization of high voltage switchgear's on-line monitoring. Based on the position measurement, the speed and trip of the switchgear could also be obtained. Thus, the health level and the operation status can be evaluated. The insulation condition and the fault symptom can also be identified. In this paper, the on-line measuring principle for the contact position is presented at first. The indirect measuring method is adopted, and the incremental photoelectric encoder is utilized to realize the measurement of angular displacement. The position could be calculated by establishing the relationship between the angular displacement and the contact's linear displacement. After that, the technical difficulties of the on-line measuring system are demonstrated. The selection of encoder, the difficult parts of hardware design and software design are all discussed deeply. The lab test of the whole measuring system is processed at last, and the measuring results are satisfactory. It will provide powerful support for the realization of on-line monitoring equipment of the high voltage switchgear.

  18. Skylab high voltage electrical/electronic systems corona assessment.

    NASA Technical Reports Server (NTRS)

    Dunbar, W. G.

    1973-01-01

    Six significant design parameters which must be considered in the corona assessment include the operating voltage, radio frequency power, the 'pressure times spacing' relation, operating temperature, gases and contaminants in the environment, and configuration and field gradients. An equipment and experiments survey is presented, giving attention to corona-free equipment and equipment requiring detailed investigations.

  19. Understanding and Improving High Voltage Vacuum Insulators for Microsecond Pulses

    SciTech Connect

    Javedani, J B; Goerz, D A; Houck, T L; Lauer, E J; Speer, R D; Tully, L K; Vogtlin, G E; White, A D

    2007-03-05

    High voltage insulation is one of the main areas of pulsed power research and development, and dielectric breakdown is usually the limiting factor in attaining the highest possible performance in pulsed power devices. For many applications the delivery of pulsed power into a vacuum region is the most critical aspect of operation. The surface of an insulator exposed to vacuum can fail electrically at an applied field more than an order or magnitude below the bulk dielectric strength of the insulator. This mode of breakdown, called surface flashover, imposes serious limitations on the power flow into a vacuum region. This is especially troublesome for applications where high voltage conditioning of the insulator and electrodes is not practical and for applications where relatively long pulses, on the order of several microseconds, are required. The goal of this project is to establish a sound fundamental understanding of the mechanisms that lead to surface flashover, and then evaluate the most promising techniques to improve vacuum insulators and enable high voltage operation at stress levels near the intrinsic bulk breakdown limits of the material. The approach we proposed and followed was to develop this understanding through a combination of theoretical and computation methods coupled with experiments to validate and quantify expected behaviors. In this report we summarize our modeling and simulation efforts, theoretical studies, and experimental investigations. The computational work began by exploring the limits of commercially available codes and demonstrating methods to examine field enhancements and defect mechanisms at microscopic levels. Plasma simulations with particle codes used in conjunction with circuit models of the experimental apparatus enabled comparisons with experimental measurements. The large scale plasma (LSP) particle-in-cell (PIC) code was run on multiprocessor platforms and used to simulate expanding plasma conditions in vacuum gap regions

  20. High voltage high repetition rate pulse using Marx topology

    NASA Astrophysics Data System (ADS)

    Hakki, A.; Kashapov, N.

    2015-06-01

    The paper describes Marx topology using MOSFET transistors. Marx circuit with 10 stages has been done, to obtain pulses about 5.5KV amplitude, and the width of the pulses was about 30μsec with a high repetition rate (PPS > 100), Vdc = 535VDC is the input voltage for supplying the Marx circuit. Two Ferrite ring core transformers were used to control the MOSFET transistors of the Marx circuit (the first transformer to control the charging MOSFET transistors, the second transformer to control the discharging MOSFET transistors).

  1. High voltage bushing having weathershed and surrounding stress relief collar

    DOEpatents

    Cookson, Alan H.

    1981-01-01

    A high voltage electric bushing comprises a hollow elongated dielectric weathershed which encloses a high voltage conductor. A collar formed of high voltage dielectric material is positioned over the weathershed and is bonded thereto by an interface material which precludes moisture-like contaminants from entering between the bonded portions. The collar is substantially thicker than the adjacent weathershed which it surrounds, providing relief of the electric stresses which would otherwise appear on the outer surface of the weathershed. The collar may include a conductive ring or capacitive foil to further relieve electric stresses experienced by the bushing.

  2. Experimental Study of Arcing on High-voltage Solar Arrays

    NASA Technical Reports Server (NTRS)

    Vayner, Boris; Galofaro, Joel; Ferguson, Dale

    2005-01-01

    The main obstacle to the implementation of a high-voltage solar array in space is arcing on the conductor-dielectric junctions exposed to the surrounding plasma. One obvious solution to this problem would be the installation of fully encapsulated solar arrays which were not having exposed conductors at all. However, there are many technological difficulties that must be overcome before the employment of fully encapsulated arrays will turn into reality. An alternative solution to raise arc threshold by modifications of conventionally designed solar arrays looks more appealing, at least in the nearest future. A comprehensive study of arc inception mechanism [1-4] suggests that such modifications can be done in the following directions: i) to insulate conductor-dielectric junction from a plasma environment (wrapthrough interconnects); ii) to change a coverglass geometry (overhang); iii) to increase a coverglass thickness; iiii) to outgas areas of conductor-dielectric junctions. The operation of high-voltage array in LEO produces also the parasitic current power drain on the electrical system. Moreover, the current collected from space plasma by solar arrays determines the spacecraft floating potential that is very important for the design of spacecraft and its scientific apparatus. In order to verify the validity of suggested modifications and to measure current collection five different solar array samples have been tested in large vacuum chamber. Each sample (36 silicon based cells) consists of three strings containing 12 cells connected in series. Thus, arc rate and current collection can be measured on every string independently, or on a whole sample when strings are connected in parallel. The heater installed in the chamber provides the possibility to test samples under temperature as high as 80 C that simulates the LEO operational temperature. The experimental setup is described below.

  3. Summary of multiterminal high-voltage direct current transmission technology

    SciTech Connect

    Biggs, R.B.; Jewell, W.T.

    1984-05-01

    This report summarizes the present state of multiterminal (MT) high-voltage direct current (HVDC) power transmission. The purpose is to reassess the need for HVDC circuit breakers and to identify needed research for MT HVDC. The fundamentals of this technology are presented, and previous research and development is reviewed. Although no MT HVDC systems have yet been built, many concepts have been proposed. Some require a dc breaker, and others do not. Both options have advantages and disadvantages for various applications, so the selection will depend on the proposed application. Research is needed to define operating characteristics of various MT HVDC systems. In some applications, dc breakers will be useful, so research into HVDC interruption should continue. Also, dc fault detection and control algorithms for MT systems should be studied.

  4. Cryogenic CMOS cameras for high voltage monitoring in liquid argon

    NASA Astrophysics Data System (ADS)

    McConkey, N.; Spooner, N.; Thiesse, M.; Wallbank, M.; Warburton, T. K.

    2017-03-01

    The prevalent use of large volume liquid argon detectors strongly motivates the development of novel readout and monitoring technology which functions at cryogenic temperatures. This paper presents the development of a cryogenic CMOS camera system suitable for use inside a large volume liquid argon detector for online monitoring purposes. The characterisation of the system is described in detail. The reliability of such a camera system has been demonstrated over several months, and recent data from operation within the liquid argon region of the DUNE 35 t cryostat is presented. The cameras were used to monitor for high voltage breakdown inside the cryostat, with capability to observe breakdown of a liquid argon time projection chamber in situ. They were also used for detector monitoring, especially of components during cooldown.

  5. A compact, high-voltage pulsed charging system based on an air-core pulse transformer.

    PubMed

    Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Liu, Chebo; Yin, Yi

    2015-09-01

    Charging systems of pulsed power generators on mobile platforms are expected to be compact and provide high pulsed power, high voltage output, and high repetition rate. In this paper, a high-voltage pulsed charging system with the aforementioned characteristics is introduced, which can be applied to charge a high-voltage load capacitor. The operating principle of the system and the technical details of the components in the system are described in this paper. The experimental results show that a 600 nF load capacitor can be charged to 60 kV at 10 Hz by the high-voltage pulsed charging system for a burst of 0.5 s. The weight and volume of the system are 60 kg and 600 × 500 × 380 mm(3), respectively.

  6. A compact, high-voltage pulsed charging system based on an air-core pulse transformer

    NASA Astrophysics Data System (ADS)

    Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Liu, Chebo; Yin, Yi

    2015-09-01

    Charging systems of pulsed power generators on mobile platforms are expected to be compact and provide high pulsed power, high voltage output, and high repetition rate. In this paper, a high-voltage pulsed charging system with the aforementioned characteristics is introduced, which can be applied to charge a high-voltage load capacitor. The operating principle of the system and the technical details of the components in the system are described in this paper. The experimental results show that a 600 nF load capacitor can be charged to 60 kV at 10 Hz by the high-voltage pulsed charging system for a burst of 0.5 s. The weight and volume of the system are 60 kg and 600 × 500 × 380 mm3, respectively.

  7. Determining the mode of high voltage breakdowns in vacuum devices

    SciTech Connect

    Miller, H.C.; Furno, E.J.; Sturtz, J.P.

    1980-08-11

    Devices were constructed which were essentially vacuum diodes equipped with windows allowing observation of high voltage breakdowns. The waveform of the applied voltage was photographed, and the x-ray output was monitored to investigate electrical breakdown in these vacuum diodes. Results indicate that breakdowns may be divided into two types: (1) vacuum (interelectrode) breakdown - characterized by a diffuse moderately bright discharge, a relative slow and smooth voltage collapse, and a large burst of x-rays, and (2) surface (insulator) flashover - characterized by a bright discharge with a very bright filamentary core, a relatively fast and noisy voltage collapse and no x-ray burst. Useful information concerning the type of breakdown in a vacuum device can be obtained by monitoring the voltage (current) waveform and the x-ray output.

  8. Optical control system for high-voltage terminals

    DOEpatents

    Bicek, John J.

    1978-01-01

    An optical control system for the control of devices in the terminal of an electrostatic accelerator includes a laser that is modulated by a series of preselected codes produced by an encoder. A photodiode receiver is placed in the laser beam at the high-voltage terminal of an electrostatic accelerator. A decoder connected to the photodiode decodes the signals to provide control impulses for a plurality of devices at the high voltage of the terminal.

  9. Dynamics of laser-guided alternating current high voltage discharges

    NASA Astrophysics Data System (ADS)

    Daigle, J.-F.; Théberge, F.; Lassonde, P.; Kieffer, J.-C.; Fujii, T.; Fortin, J.; Châteauneuf, M.; Dubois, J.

    2013-10-01

    The dynamics of laser-guided alternating current high voltage discharges are characterized using a streak camera. Laser filaments were used to trigger and guide the discharges produced by a commercial Tesla coil. The streaking images revealed that the dynamics of the guided alternating current high voltage corona are different from that of a direct current source. The measured effective corona velocity and the absence of leader streamers confirmed that it evolves in a pure leader regime.

  10. Lithium-Ion Electrolytes with Improved Safety Tolerance to High Voltage Systems

    NASA Technical Reports Server (NTRS)

    Smart, Marshall C. (Inventor); Bugga, Ratnakumar V. (Inventor); Prakash, Surya G. (Inventor); Krause, Frederick C. (Inventor)

    2015-01-01

    The invention discloses various embodiments of electrolytes for use in lithium-ion batteries, the electrolytes having improved safety and the ability to operate with high capacity anodes and high voltage cathodes. In one embodiment there is provided an electrolyte for use in a lithium-ion battery comprising an anode and a high voltage cathode. The electrolyte has a mixture of a cyclic carbonate of ethylene carbonate (EC) or mono-fluoroethylene carbonate (FEC) co-solvent, ethyl methyl carbonate (EMC), a flame retardant additive, a lithium salt, and an electrolyte additive that improves compatibility and performance of the lithium-ion battery with a high voltage cathode. The lithium-ion battery is charged to a voltage in a range of from about 2.0 V (Volts) to about 5.0 V (Volts).

  11. Design & Fabrication of a High-Voltage Photovoltaic Cell

    SciTech Connect

    Felder, Jennifer; /North Carolina State U. /SLAC

    2012-09-05

    Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.

  12. Planar LTCC transformers for high voltage flyback converters: Part II.

    SciTech Connect

    Schofield, Daryl; Schare, Joshua M., Ph.D.; Slama, George; Abel, David

    2009-02-01

    This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.

  13. New High Voltage Ceramic Capacitors for Power Electronics

    NASA Astrophysics Data System (ADS)

    Laville, H.; Fabre, M.

    2014-08-01

    This paper presents the characteristics and performances of a new range of high voltage ceramic capacitors manufactured using a new ceramic material. This dielectric allows to get under working voltage the same capacitance values than using an X7R material with the advantage compared to X7R of a very low dissipation factor (less than 5.10-4). What makes these capacitors to be ideally suited for power applications where heat dissipation may be detrimental for performances and reliability.

  14. High voltage series connected tandem junction solar battery

    DOEpatents

    Hanak, Joseph J.

    1982-01-01

    A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

  15. Write operation in MRAM with voltage controlled magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Munira, Kamaram; Pandey, Sumeet; Sandhu, Gurtej

    In non-volatile Magnetic RAM, information is saved in the bistable configuration of the free layer in a magnetic tunnel junction (MTJ). New information can be written to the free layer through magnetic induction (Toggle MRAM) or manipulation of magnetization using electric currents (Spin Transfer Torque MRAM or STT-MRAM). Both of the writing methods suffer from a shortcoming in terms of energy efficiency. This limitation on energy performance is brought about by the need for driving relatively large electrical charge currents through the devices for switching. In STT-MRAM, the nonzero voltage drop across the resistive MTJ leads to significant power dissipation. An energy efficient way to write may be with the assistance of voltage controlled magnetic anisotropy (VCMA), where voltage applied across the MTJ creates an electric field that modulates the interfacial anisotropy between the insulator and free layer. However, VCMA cannot switch the free layer completely by 180 degree rotation of magnetization. It can lower the barrier between the two stable configurations or at best, cancel the barrier, allowing 90 degree rotation. A second mechanism, spin torque or magnetic field, is needed to direct the final switching destination.

  16. Plasma Interaction with International Space Station High Voltage Solar Arrays

    NASA Technical Reports Server (NTRS)

    Heard, John W.

    2002-01-01

    The International Space Station (ISS) is presently being assembled in low-earth orbit (LEO) operating high voltage solar arrays (-160 V max, -140 V typical with respect to the ambient atmosphere). At the station's present altitude, there exists substantial ambient plasma that can interact with the solar arrays. The biasing of an object to an electric potential immersed in plasma creates a plasma "sheath" or non-equilibrium plasma around the object to mask out the electric fields. A positively biased object can collect electrons from the plasma sheath and the sheath will draw a current from the surrounding plasma. This parasitic current can enter the solar cells and effectively "short out" the potential across the cells, reducing the power that can be generated by the panels. Predictions of collected current based on previous high voltage experiments (SAMPIE (Solar Array Module Plasma Interactions Experiment), PASP+ (Photovoltaic Array Space Power) were on the order of amperes of current. However, present measurements of parasitic current are on the order of several milliamperes, and the current collection mainly occurs during an "eclipse exit" event, i.e., when the space station comes out of darkness. This collection also has a time scale, t approx. 1000 s, that is much slower than any known plasma interaction time scales. The reason for the discrepancy between predictions and present electron collection is not understood and is under investigation by the PCU (Plasma Contactor Unit) "Tiger" team. This paper will examine the potential structure within and around the solar arrays, and the possible causes and reasons for the electron collection of the array.

  17. 46 CFR 111.12-7 - Voltage regulation and parallel operation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Voltage regulation and parallel operation. 111.12-7 Section 111.12-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111.12-7 Voltage regulation...

  18. 46 CFR 111.12-7 - Voltage regulation and parallel operation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Voltage regulation and parallel operation. 111.12-7 Section 111.12-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111.12-7 Voltage regulation...

  19. 46 CFR 111.12-7 - Voltage regulation and parallel operation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Voltage regulation and parallel operation. 111.12-7 Section 111.12-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111.12-7 Voltage regulation...

  20. 46 CFR 111.12-7 - Voltage regulation and parallel operation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Voltage regulation and parallel operation. 111.12-7 Section 111.12-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111.12-7 Voltage regulation...

  1. 46 CFR 111.12-7 - Voltage regulation and parallel operation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Voltage regulation and parallel operation. 111.12-7 Section 111.12-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111.12-7 Voltage regulation...

  2. High Input Voltage Discharge Supply for High Power Hall Thrusters Using Silicon Carbide Devices

    NASA Technical Reports Server (NTRS)

    Pinero, Luis R.; Scheidegger, Robert J.; Aulsio, Michael V.; Birchenough, Arthur G.

    2014-01-01

    A power processing unit for a 15 kW Hall thruster is under development at NASA Glenn Research Center. The unit produces up to 400 VDC with two parallel 7.5 kW discharge modules that operate from a 300 VDC nominal input voltage. Silicon carbide MOSFETs and diodes were used in this design because they were the best choice to handle the high voltage stress while delivering high efficiency and low specific mass. Efficiencies in excess of 97 percent were demonstrated during integration testing with the NASA-300M 20 kW Hall thruster. Electromagnet, cathode keeper, and heater supplies were also developed and will be integrated with the discharge supply into a vacuum-rated brassboard power processing unit with full flight functionality. This design could be evolved into a flight unit for future missions that requires high power electric propulsion.

  3. 30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad...

  4. 30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad...

  5. 30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad...

  6. 30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad...

  7. High voltage switch triggered by a laser-photocathode subsystem

    DOEpatents

    Chen, Ping; Lundquist, Martin L.; Yu, David U. L.

    2013-01-08

    A spark gap switch for controlling the output of a high voltage pulse from a high voltage source, for example, a capacitor bank or a pulse forming network, to an external load such as a high gradient electron gun, laser, pulsed power accelerator or wide band radar. The combination of a UV laser and a high vacuum quartz cell, in which a photocathode and an anode are installed, is utilized as triggering devices to switch the spark gap from a non-conducting state to a conducting state with low delay and low jitter.

  8. Methods for high-voltage bias testing of PV modules in hot and humid climate

    NASA Astrophysics Data System (ADS)

    Dhere, Neelkanth G.; Pethe, Shirish A.; Kaul, Ashwani

    2011-09-01

    The accelerated tests currently carried out on PV modules reduce the infant mortality as well as improve the production techniques during the manufacture of PV modules. However, the accelerated tests do not completely duplicate the real world operating conditions of PV modules. Hence it is essential to deploy PV modules in the field for extended periods in order to estimate the degradation, if any, as well as to elucidate the degradation mechanisms. Moreover, PV modules should be tested by specially designed tests in harsh climates. At Florida Solar Energy Center (FSEC) high-voltage bias testing of PV modules was carried out in hot and humid climate with the individual modules biased at +/- 600 V. It was observed that the leakage currents flowing from the PV circuit to the ground is directly proportional to the bias voltage. PV systems with maximum voltage of 1000 V are installed in Europe and elsewhere which means higher leakage currents will be produced in the PV modules. Based on this fact and the earlier observations, high voltage bias testing of c-Si PV modules specially designed for high voltage operation was carried out in hot and humid climate with the individual modules biased at +/-1500 V at FSEC and higher. This paper provides results of high voltage bias testing of PV modules. The results indicate that the test can be considered as reliable metric in determination of the long term performance of PV modules.

  9. Gaseous insulators for high voltage electrical equipment

    DOEpatents

    Christophorou, Loucas G.; James, David R.; Pace, Marshall O.; Pai, Robert Y.

    1979-01-01

    Gaseous insulators comprise compounds having high attachment cross sections for electrons having energies in the 0-1.3 electron volt range. Multi-component gaseous insulators comprise compounds and mixtures having overall high electron attachment cross sections in the 0-1.3 electron volt range and moderating gases having high cross sections for inelastic interactions with electrons of energies 1-4 electron volts. Suitable electron attachment components include hexafluorobutyne, perfluorobutene-2, perfluorocyclobutane, perfluorodimethylcyclobutane, perfluorocyclohexene, perfluoromethylcyclohexane, hexafluorobutadiene, perfluoroheptene-1 and hexafluoroazomethane. Suitable moderating gases include N.sub.2, CO, CO.sub.2 and H.sub.2. The gaseous insulating mixture can also contain SF.sub.6, perfluoropropane and perfluorobenzene.

  10. Gaseous insulators for high voltage electrical equipment

    DOEpatents

    Christophorou, Loucas G.; James, David R.; Pace, Marshall O.; Pai, Robert Y.

    1981-01-01

    Gaseous insulators comprise compounds having high attachment cross sections for electrons having energies in the 0-1.3 electron volt range. Multi-component gaseous insulators comprise compounds and mixtures having overall high electron attachment cross sections in the 0-1.3 electron volt range and moderating gases having high cross sections for inelastic interactions with electrons of energies 1-4 electron volts. Suitable electron attachment components include hexafluorobutyne, perfluorobutene-2, perfluorocyclobutane, perfluorodimethylcyclobutane, perfluorocyclohexene, perfluoromethylcyclohexane, hexafluorobutadiene, perfluoroheptene-1 and hexafluoroazomethane. Suitable moderating gases include N.sub.2, CO, CO.sub.2 and H.sub.2. The gaseous insulating mixture can also contain SF.sub.6, perfluoropropane and perfluorobenzene.

  11. Robustness of Self-Isolation High-Voltage Integrated Circuits against the Voltage Surge during Conductivity Modulation Delay in Free-Wheeling Diode

    NASA Astrophysics Data System (ADS)

    Yamazaki, Tomoyuki; Kumagai, Naoki; Nishiura, Akira; Fujihira, Tatsuhiko; Matsumoto, Takashi

    2007-02-01

    In this paper, we report on the robustness of self-isolation high-voltage integrated circuits (HVICs) against a voltage surge during a conductivity modulation delay in a free-wheeling diode (FWD) for the first time. Two types of voltage surge that have a negative voltage against the ground potential are applied to HVICs simultaneously in the conventional switching mode. The voltage surge activates parasitic bipolar transistors that may destroy the HVICs. In this study, the operation of parasitic bipolar transistors induced by the surge and the suppression of the action of these transistors were investigated, and the robustness of the self-isolation 1200 V HVICs against surge was verified experimentally.

  12. High performance Si nanowire field-effect-transistors based on a CMOS inverter with tunable threshold voltage.

    PubMed

    Van, Ngoc Huynh; Lee, Jae-Hyun; Sohn, Jung Inn; Cha, Seung Nam; Whang, Dongmok; Kim, Jong Min; Kang, Dae Joon

    2014-05-21

    We successfully fabricated nanowire-based complementary metal-oxide semiconductor (NWCMOS) inverter devices by utilizing n- and p-type Si nanowire field-effect-transistors (NWFETs) via a low-temperature fabrication processing technique. We demonstrate that NWCMOS inverter devices can be operated at less than 1 V, a significantly lower voltage than that of typical thin-film based complementary metal-oxide semiconductor (CMOS) inverter devices. This low-voltage operation was accomplished by controlling the threshold voltage of the n-type Si NWFETs through effective management of the nanowire (NW) doping concentration, while realizing high voltage gain (>10) and ultra-low static power dissipation (≤3 pW) for high-performance digital inverter devices. This result offers a viable means of fabricating high-performance, low-operation voltage, and high-density digital logic circuits using a low-temperature fabrication processing technique suitable for next-generation flexible electronics.

  13. Improved Lifetime High Voltage Switch Electrode.

    DTIC Science & Technology

    2014-09-26

    and T.R. Burkes, "Erosion of Spark Gap Electrodes", IEEE Trans. Plasma Sci., PS-8, 149, (1980). 5. L.B. Gordon, M. Kristiansen, M.O. Hagler, H.C...Kirbie, R.M. Ness, L.L. Hatfield and 3.N. Marx, "Material Studies in a High Energy Spark Gap", IEEE Trans. Plasma Sci., PS-10, 286, (1982). 6. A.L...identify by block number) Spark switches, electrodes, ion implantation. _. / 20. ABSTRACT (Cqntnu* on ,.as maide Ii necossery and Identify by block number

  14. Voltage-current and voltage-flux characteristics of asymmetric high TC DC SQUIDs

    NASA Astrophysics Data System (ADS)

    Novikov, I. L.; Greenberg, Ya. S.; Schultze, V.; Ijsselsteijn, R.; Meyer, H.-G.

    2009-01-01

    We report measurements of transfer functions and flux shifts of 20 on-chip high TC DC SQUIDs half of which were made purposely geometrically asymmetric. All of these SQUIDs were fabricated using standard high TC thin-film technology and they were single layer ones, having 140 nm thickness of YBa 2Cu 3O 7- x film deposited by laser ablation onto MgO bicrystal substrates with 24° misorientation angle. For every SQUID the parameters of its intrinsic asymmetry, i.e., the density of critical current and resistivity of every junction, were measured directly and independently. We showed that the main reason for the on-chip spreading of SQUIDs’ voltage-current and voltage-flux characteristics was the intrinsic asymmetry. We found that for SQUIDs with a relative large inductance ( L > 120 pH) both the voltage modulation and the transfer function were not very sensitive to the junctions asymmetry, whereas SQUIDs with smaller inductance ( L ≃ 65-75 pH) were more sensitive. The results obtained in the paper are important for the implementation in the sensitive instruments based on high TC SQUID arrays and gratings.

  15. Very Low-Voltage Operation of Ionic Liquid-Gated n-Type Organic Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Uemura, Takafumi; Yamagishi, Masakazu; Ono, Shimpei; Takeya, Jun

    2010-01-01

    n-Type organic field-effect transistors are operated with high transconductance at very low gate voltage using ionic-liquid electrolyte for the gating layers. Tetracyanoquinodimethane single crystals and C60 thin films are respectively interfaced with ionic liquid of 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide known for its low viscosity and high ionic conductivity, so that high-density electrons are rapidly accumulated in the semiconductor surfaces. The transistors are gated by high electric field confined to a molecular scale Helmholtz layer with the application of minimum gate voltages. The high-transconductance single-crystal device exhibits excellent air stability and the C60 thin-film transistor has realized the highest normalized transconductance among reported n-type organic transistors, together with remarkable improvement in threshold voltage as compared with that in conventional SiO2 devices.

  16. High-Voltage-Input Level Translator Using Standard CMOS

    NASA Technical Reports Server (NTRS)

    Yager, Jeremy A.; Mojarradi, Mohammad M.; Vo, Tuan A.; Blalock, Benjamin J.

    2011-01-01

    proposed integrated circuit would translate (1) a pair of input signals having a low differential potential and a possibly high common-mode potential into (2) a pair of output signals having the same low differential potential and a low common-mode potential. As used here, "low" and "high" refer to potentials that are, respectively, below or above the nominal supply potential (3.3 V) at which standard complementary metal oxide/semiconductor (CMOS) integrated circuits are designed to operate. The input common-mode potential could lie between 0 and 10 V; the output common-mode potential would be 2 V. This translation would make it possible to process the pair of signals by use of standard 3.3-V CMOS analog and/or mixed-signal (analog and digital) circuitry on the same integrated-circuit chip. A schematic of the circuit is shown in the figure. Standard 3.3-V CMOS circuitry cannot withstand input potentials greater than about 4 V. However, there are many applications that involve low-differential-potential, high-common-mode-potential input signal pairs and in which standard 3.3-V CMOS circuitry, which is relatively inexpensive, would be the most appropriate circuitry for performing other functions on the integrated-circuit chip that handles the high-potential input signals. Thus, there is a need to combine high-voltage input circuitry with standard low-voltage CMOS circuitry on the same integrated-circuit chip. The proposed circuit would satisfy this need. In the proposed circuit, the input signals would be coupled into both a level-shifting pair and a common-mode-sensing pair of CMOS transistors. The output of the level-shifting pair would be fed as input to a differential pair of transistors. The resulting differential current output would pass through six standoff transistors to be mirrored into an output branch by four heterojunction bipolar transistors. The mirrored differential current would be converted back to potential by a pair of diode-connected transistors

  17. Cleaning High-Voltage Equipment With Corncob Grit

    NASA Technical Reports Server (NTRS)

    Caveness, C.

    1986-01-01

    High electrical resistance of particles makes power shutdown unnecessary. New, inexpensive method of cleaning high-voltage electrical equipment uses plentiful agricultural product - corncob grit. Method removes dirt and debris from transformers, circuit breakers, and similar equipment. Suitable for utilities, large utility customers, and electrical-maintenance services.

  18. Interaction of high voltage surfaces with the space plasma

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.; Robinson, R. S.

    1980-01-01

    High voltage solar arrays provide spacecraft power while optimizing mass and power efficiency. Operating such arrays in the space plasma environment can result in anomalously large currents being collected through insulation defects. Two thicknesses of the insulating material were tested, with no effect found due to insulator thickness. In these tests the polyimide thickness was always much less than the pinhole diameter. The pinhole area was varied over an area range of more than 30:1. It was found that the current collected was independent of the pinhole area for hole diameters from 0.35 to 2.0 mm. Two types of adhesives were tried in two different configurations. The adhesives were chosen for their extreme difference in vacuum qualifications. Neither adhesive types nor configuration made a significant difference in current collection. The temperature of the insulating material was also varied. It was found that current collection decreased with increasing temperature. Tests were conducted to see if pinhole current collection decreased with time, as was indicated by the effects of several short tests. Current was collected for over four hours while the conductor potential was held constant at 1000 volts. A smooth decrease with time was not observed, but rather a roughly constant current collection with brief surges to high values. Tests were also conducted with the simulated solar cell biased negative. The current was found to be proportional to pinhole area.

  19. Descending vasa recta pericytes express voltage operated Na+ conductance in the rat

    PubMed Central

    Zhang, Zhong; Cao, Chunhua; Lee-Kwon, Whaseon; Pallone, Thomas L

    2005-01-01

    We studied the properties of a voltage-operated Na+ conductance in descending vasa recta (DVR) pericytes isolated from the renal outer medulla. Whole-cell patch-clamp recordings revealed a depolarization-induced, rapidly activating and rapidly inactivating inward current that was abolished by removal of Na+ but not Ca+ from the extracellular buffer. The Na+ current (INa) is highly sensitive to tetrodotoxin (TTX, Kd = 2.2 nm). At high concentrations, mibefradil (10 μm) and Ni+ (1 mm) blocked INa. INa was insensitive to nifedipine (10 μm). The L-type Ca+ channel activator FPL-64176 induced a slowly activating/inactivating inward current that was abolished by nifedipine. Depolarization to membrane potentials between 0 and 30 mV induced inactivation with a time constant of ∼1 ms. Repolarization to membrane potentials between −90 and −120 mV induced recovery from inactivation with a time constant of ∼11 ms. Half-maximal activation and inactivation occurred at −23.9 and −66.1 mV, respectively, with slope factors of 4.8 and 9.5 mV, respectively. The Na+ channel activator, veratridine (100 μm), reduced peak inward INa and prevented inactivation. We conclude that a TTX-sensitive voltage-operated Na+ conductance, with properties similar to that in other smooth muscle cells, is expressed by DVR pericytes. PMID:15975976

  20. High voltage electron microscopy of lunar samples

    NASA Technical Reports Server (NTRS)

    Fernandez-Moran, H.

    1973-01-01

    Lunar pyroxenes from Apollo 11, 12, 14, and 15 were investigated. The iron-rich and magnesium-rich pyroxene specimens were crushed to a grain size of ca. 50 microns and studied by a combination of X-ray and electron diffraction, electron microscopy, 57 Fe Mossbauer spectroscopy and X-ray crystallography techniques. Highly ordered, uniform electron-dense bands, corresponding to exsolution lamellae, with average widths of ca. 230A to 1000A dependent on the source specimen were observed. These were?qr separated by wider, less-dense interband spacings with average widths of ca. 330A to 3100A. In heating experiments, splitting of the dense bands into finer structures, leading finally to obliteration of the exsolution lamellae was recorded. The extensive exsolution is evidence for significantly slower cooling rates, or possibly annealing, at temperatures in the subsolidus range, adding evidence that annealing of rock from the surface of the moon took place at ca. 600 C. Correlation of the band structure with magnetic ordering at low temperatures and iron clustering within the bands was studied.

  1. The thermal regime around buried submarine high-voltage cables

    NASA Astrophysics Data System (ADS)

    Emeana, C. J.; Hughes, T. J.; Dix, J. K.; Gernon, T. M.; Henstock, T. J.; Thompson, C. E. L.; Pilgrim, J. A.

    2016-08-01

    The expansion of offshore renewable energy infrastructure and the need for trans-continental shelf power transmission require the use of submarine high-voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70 °C and are typically buried 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the heat flow pattern and potential effects on the sedimentary environments around such anomalously high heat sources in the near-surface sediments are poorly understood. We present temperature measurements from a 2-D laboratory experiment representing a buried submarine HV cable, and identify the thermal regimes generated within typical unconsolidated shelf sediments—coarse silt, fine sand and very coarse sand. We used a large (2 × 2.5 m2) tank filled with water-saturated spherical glass beads (ballotini) and instrumented with a buried heat source and 120 thermocouples to measure the time-dependent 2-D temperature distributions. The observed and corresponding Finite Element Method simulations of the steady state heat flow regimes and normalized radial temperature distributions were assessed. Our results show that the heat transfer and thus temperature fields generated from submarine HV cables buried within a range of sediments are highly variable. Coarse silts are shown to be purely conductive, producing temperature increases of >10 °C up to 40 cm from the source of 60 °C above ambient; fine sands demonstrate a transition from conductive to convective heat transfer between cf. 20 and 36 °C above ambient, with >10 °C heat increases occurring over a metre from the source of 55 °C above ambient; and very coarse sands exhibit dominantly convective heat transfer even at very low (cf. 7 °C) operating temperatures and reaching temperatures of up to 18 °C above ambient at a metre from the source at surface temperatures of only 18 °C. These findings are important for the surrounding near

  2. Copper wire theft and high voltage electrical burns

    PubMed Central

    Francis, Eamon C; Shelley, Odhran P

    2014-01-01

    High voltage electrical burns are uncommon. However in the midst of our economic recession we are noticing an increasing number of these injuries. Copper wire is a valuable commodity with physical properties as an excellent conductor of electricity making it both ubiquitous in society and prized on the black market. We present two consecutive cases referred to the National Burns Unit who sustained life threatening injuries from the alleged theft of high voltage copper wire and its omnipresence on an international scale. PMID:25356371

  3. Partial discharge in a high voltage experimental test assembly

    SciTech Connect

    Koss, R.J.; Brainard, J.P.

    1998-07-01

    This study was initiated when a new type of breakdown occurred in a high voltage experimental test assembly. An anomalous current pulse was observed, which indicated partial discharges, some leading to total breakdowns. High voltage insulator defects are shown along with their effect on the electrostatic fields in the breakdown region. OPERA electromagnetic field modeling software is used to calculate the fields and present a cause for the discharge. Several design modifications are investigated and one of the simplest resulted in a 25% decrease in the field at the discharge surface.

  4. High-Voltage, Low-Power BNC Feedthrough Terminator

    NASA Technical Reports Server (NTRS)

    Bearden, Douglas

    2012-01-01

    This innovation is a high-voltage, lowpower BNC (Bayonet Neill-Concelman) feedthrough that enables the user to terminate an instrumentation cable properly while connected to a high voltage, without the use of a voltage divider. This feedthrough is low power, which will not load the source, and will properly terminate the instrumentation cable to the instrumentation, even if the cable impedance is not constant. The Space Shuttle Program had a requirement to measure voltage transients on the orbiter bus through the Ground Lightning Measurement System (GLMS). This measurement has a bandwidth requirement of 1 MHz. The GLMS voltage measurement is connected to the orbiter through a DC panel. The DC panel is connected to the bus through a nonuniform cable that is approximately 75 ft (approximately equal to 23 m) long. A 15-ft (approximately equal to 5-m), 50-ohm triaxial cable is connected between the DC panel and the digitizer. Based on calculations and simulations, cable resonances and reflections due to mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. A voltage divider at the DC panel, and terminating the 50-ohm cable properly, would eliminate this issue. Due to implementation issues, an alternative design was needed to terminate the cable properly without the use of a voltage divider. Analysis shows how the cable resonances and reflections due to the mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. After simulating a dampening circuit located at the digitizer, simulations were performed to show how the cable resonances were dampened and the accuracy was improved significantly. Test cables built to verify simulations were accurate. Since the dampening circuit is low power, it can be packaged in a BNC feedthrough.

  5. Cardiac stimulation with high voltage discharge from stun guns.

    PubMed

    Nanthakumar, Kumaraswamy; Massé, Stephane; Umapathy, Karthikeyan; Dorian, Paul; Sevaptsidis, Elias; Waxman, Menashe

    2008-05-20

    The ability of an electrical discharge to stimulate the heart depends on the duration of the pulse, the voltage and the current density that reaches the heart. Stun guns deliver very short electrical pulses with minimal amount of current at high voltages. We discuss external stimulation of the heart by high voltage discharges and review studies that have evaluated the potential of stun guns to stimulate cardiac muscle. Despite theoretical analyses and animal studies which suggest that stun guns cannot and do not affect the heart, 3 independent investigators have shown cardiac stimulation by stun guns. Additional research studies involving people are needed to resolve the conflicting theoretical and experimental findings and to aid in the design of stun guns that are unable to stimulate the heart.

  6. High frequency capacitor-diode voltage multiplier dc-dc converter development

    NASA Technical Reports Server (NTRS)

    Kisch, J. J.; Martinelli, R. M.

    1977-01-01

    A power conditioner was developed which used a capacitor diode voltage multiplier to provide a high voltage without the use of a step-up transformer. The power conditioner delivered 1200 Vdc at 100 watts and was operated from a 120 Vdc line. The efficiency was in excess of 90 percent. The component weight was 197 grams. A modified boost-add circuit was used for the regulation. A short circuit protection circuit was used which turns off the drive circuit upon a fault condition, and recovers within 5 ms after removal of the short. High energy density polysulfone capacitors and high speed diodes were used in the multiplier circuit.

  7. Nuclear microprobe investigation of the effects of ionization and displacement damage in vertical, high voltage GaN diodes

    DOE PAGES

    Vizkelethy, G.; King, M. P.; Aktas, O.; ...

    2016-12-02

    Radiation responses of high-voltage, vertical gallium-nitride (GaN) diodes were investigated using Sandia National Laboratories’ nuclear microprobe. Effects of the ionization and the displacement damage were studied using various ion beams. We found that the devices show avalanche effect for heavy ions operated under bias well below the breakdown voltage. Here, the displacement damage experiments showed a surprising effect for moderate damage: the charge collection efficiency demonstrated an increase instead of a decrease for higher bias voltages.

  8. Connecting Renewables Directly to the Grid: Resilient Multi-Terminal HVDC Networks with High-Voltage High-Frequency Electronics

    SciTech Connect

    2012-01-23

    GENI Project: GE is developing electricity transmission hardware that could connect distributed renewable energy sources, like wind farms, directly to the grid—eliminating the need to feed the energy generated through intermediate power conversion stations before they enter the grid. GE is using the advanced semiconductor material silicon carbide (SiC) to conduct electricity through its transmission hardware because SiC can operate at higher voltage levels than semiconductors made out of other materials. This high-voltage capability is important because electricity must be converted to high-voltage levels before it can be sent along the grid’s network of transmission lines. Power companies do this because less electricity is lost along the lines when the voltage is high.

  9. High voltage and high current density vertical GaN power diodes

    SciTech Connect

    Fischer, A. J.; Dickerson, J. R.; Armstrong, A. M.; Moseley, M. W.; Crawford, M. H.; King, M. P.; Allerman, A. A.; Kaplar, R. J.; van Heukelom, M. S.; Wierer, J. J.

    2016-01-01

    We report on the realization of a GaN high voltage vertical p-n diode operating at > 3.9 kV breakdown with a specific on-resistance < 0.9 mΩ.cm2. Diodes achieved a forward current of 1 A for on-wafer, DC measurements, corresponding to a current density > 1.4 kA/cm2. An effective critical electric field of 3.9 MV/cm was estimated for the devices from analysis of the forward and reverse current-voltage characteristics. Furthermore this suggests that the fundamental limit to the GaN critical electric field is significantly greater than previously believed.

  10. High voltage and high current density vertical GaN power diodes

    DOE PAGES

    Fischer, A. J.; Dickerson, J. R.; Armstrong, A. M.; ...

    2016-01-01

    We report on the realization of a GaN high voltage vertical p-n diode operating at > 3.9 kV breakdown with a specific on-resistance < 0.9 mΩ.cm2. Diodes achieved a forward current of 1 A for on-wafer, DC measurements, corresponding to a current density > 1.4 kA/cm2. An effective critical electric field of 3.9 MV/cm was estimated for the devices from analysis of the forward and reverse current-voltage characteristics. Furthermore this suggests that the fundamental limit to the GaN critical electric field is significantly greater than previously believed.

  11. Harmonic resonance on parallel high voltage transmission lines

    SciTech Connect

    Harries, J.R.; Randall, J.L.

    1997-01-01

    The Bonneville Power Administration (BPA) has received complaints of telephone interference over a wide area of northwestern Washington State for several years. However, until 1995 investigations had proved inconclusive as either the source of the harmonics or the operating conditions changed whenever investigators arrived. The 2,100 Hz interference had been noticed at several optically isolated telephone exchanges. The area of complaint corresponded to electric service areas near the transmission line corridors of the BPA Custer-Monroe 500-kV lines. High 2,100 Hz field strength was measured near the 500-kV lines and also under lower voltage lines served from stations along the transmission line corridor. Tests and studies made with the Alternative Transients Program version of the Electromagnetic Transients Program (EMTP) were able to define the phenomena and isolate the source. Harmonic resonance has been observed, measured and modeled on parallel 500-kV lines that are about one wavelength at 2,100 Hz, the 35th harmonic. A seemingly small harmonic injection at one location on the system causes significant problems some distance away such as telephone interference.

  12. Wideband Electrostatic Vibration Energy Harvester (e-VEH) Having a Low Start-Up Voltage Employing a High-Voltage Integrated Interface

    NASA Astrophysics Data System (ADS)

    Dudka, A.; Basset, P.; Cottone, F.; Blokhina, E.; Galayko, D.

    2013-12-01

    This paper reports on an electrostatic Vibration Energy Harvester (e-VEH) system, for which the energy conversion process is initiated with a low bias voltage and is compatible with wideband stochastic external vibrations. The system employs the auto-synchronous conditioning circuit topology with the use of a novel dedicated integrated low-power high-voltage switch that is needed to connect the charge pump and flyback - two main parts of the used conditioning circuit. The proposed switch is designed and implemented in AMS035HV CMOS technology. Thanks to the proposed switch device, which is driven with a low-voltage ground-referenced logic, the e-VEH system may operate within a large voltage range, from a pre-charge low voltage up to several tens volts. With such a high-voltage e-VEH operation, it is possible to obtain a strong mechanical coupling and a high rate of vibration energy conversion. The used transducer/resonator device is fabricated with a batch-processed MEMS technology. When excited with stochastic vibrations having an acceleration level of 0.8 g rms distributed in the band 110-170 Hz, up to 0.75 μW of net electrical power has been harvested with our system. This work presents an important milestone in the challenge of designing a fully integrated smart conditioning interface for the capacitive e-VEHs.

  13. Low-voltage-operated organic one-time programmable memory using printed organic thin-film transistors and antifuse capacitors.

    PubMed

    Jung, Soon-Won; Na, Bock Soon; Park, Chan Woo; Koo, Jae Bon

    2014-11-01

    We demonstrate an organic one-time programmable memory cell formed entirely at plastic-compatible temperatures. All the processes are performed at below 130 degrees C. Our memory cell consists of a printed organic transistor and an organic capacitor. Inkjet-printed organic transistors are fabricated by using high-k polymer dielectric blends comprising poly(vinylidenefluoride-trifluoroethylene) [P(VDF-TrFE)] and poly(methyl methacrylate) (PMMA) for low-voltage operation. P(NDI2OD-T2) transistors have a high field-effect mobility of 0.2 cm2/Vs and a low operation gate voltage of less than 10 V. The operation voltage effectively decreases owing to the high permittivity of the P(VDF-TrFE):PMMA blended film. The data in the memory cell are programmed by electrically breaking the organic capacitor. The organic capacitor acts like an antifuse capacitor, because it is initially open, and it becomes permanently short-circuited by applying a high voltage. The organic memory cells are programmed with 4 V, and they are read out with 2 V. The memory data are read out by sensing the current in the memory cell. The printed organic one-time programmable memory is suitable for applications storing small amount of data, such as low-cost radio-frequency identification (RFID) tag.

  14. 59. View of high voltage (4160 volts alternating current) electric ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. View of high voltage (4160 volts alternating current) electric load center and motor control center at mezzanine level in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  15. High voltage gas insulated transmission line with continuous particle trapping

    DOEpatents

    Cookson, Alan H.; Dale, Steinar J.

    1983-01-01

    This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.

  16. Laboratory 15 kV high voltage solar array facility

    NASA Technical Reports Server (NTRS)

    Kolecki, J. C.; Gooder, S. T.

    1976-01-01

    The laboratory high voltage solar array facility is a photoelectric power generating system. Consisting of nine modules with over 23,000 solar cells, the facility is capable of delivering more than a kilowatt of power. The physical and electrical characteristics of the facility are described.

  17. The design and development of a high voltage power supply

    NASA Technical Reports Server (NTRS)

    Ting, R.

    1974-01-01

    A high voltage circuit system was redesigned, breadboarded, and tested to meet revised specification requirements. Circuit component subassemblies are described and include the firing unit, regulator, dc to dc converter, and output and trigger circuits. Design changes, tests, and equipment fabrication are outlined chronologically by month. A list of design specifications is included.

  18. Treatment of spider bites by high voltage direct current.

    PubMed

    Osborn, C D

    1991-06-01

    Between September 7, 1988, and January 15, 1991, 147 cases of confirmed (19) and suspected spider bites have been treated by high voltage direct current (HVDC) shocks. Venom damage to tissue was arrested at the time of treatment. Pain and systemic symptoms usually improved within 15 minutes. Lesion excision or grafts have not been necessary in any of the 127 cases with completed followup.

  19. Current isolating epitaxial buffer layers for high voltage photodiode array

    DOEpatents

    Morse, Jeffrey D.; Cooper, Gregory A.

    2002-01-01

    An array of photodiodes in series on a common semi-insulating substrate has a non-conductive buffer layer between the photodiodes and the semi-insulating substrate. The buffer layer reduces current injection leakage between the photodiodes of the array and allows optical energy to be converted to high voltage electrical energy.

  20. High voltage electrical insulation coating for refractory materials

    NASA Technical Reports Server (NTRS)

    Lent, W. E.

    1972-01-01

    Formula and process have been developed for coating refractory metal surfaces with high voltage electrical insulation for use at temperatures to 600 C. Coatings were specifically developed as an insulation for the surface of a perforated, molybdenum, ion-accelerator grid, but are not limited to this application.

  1. [Fatal electric arc accidents due to high voltage].

    PubMed

    Strauch, Hansjürg; Wirth, Ingo

    2004-01-01

    The frequency of electric arc accidents has been successfully reduced owing to preventive measures taken by the professional association. However, the risk of accidents has continued to exist in private setting. Three fatal electric arc accidents caused by high voltage are reported with reference to the autopsy findings.

  2. [Research on sterilization of pathogens by high electrostatic voltage method].

    PubMed

    Wang, X; Wu, Y; Ni, X; Xia, B; Xu, J; Du, Q

    1992-10-01

    An experimental research has been carried out on the sterilization of four kinds of pathogens by high electrostatic method along with an inquiry into the influence of voltage waveform and the treated time on sterilization. It is concluded that pathogens can be killed efficiently by corona discharge field.

  3. A high-voltage cardiac stimulator for field shocks of a whole heart in a bath

    NASA Astrophysics Data System (ADS)

    Mashburn, David N.; Hinkson, Stephen J.; Woods, Marcella C.; Gilligan, Jonathan M.; Holcomb, Mark R.; Wikswo, John P.

    2007-10-01

    Defibrillators are a critical tool for treating heart disease; however, the mechanisms by which they halt fibrillation are still not fully understood and are the subject of ongoing research. Clinical defibrillators do not provide the precise control of shock timing, duration, and voltage or other features needed for detailed scientific inquiry, and there are few, if any, commercially available units designed for research applications. For this reason, we have developed a high-voltage, programmable, capacitive-discharge stimulator optimized to deliver defibrillation shocks with precise timing and voltage control to an isolated animal heart, either in air or in a bath. This stimulator is capable of delivering voltages of up to 500V and energies of nearly 100J with timing accuracy of a few microseconds and with rise and fall times of 5μs or less and is controlled only by two external timing pulses and a control computer that sets the stimulation parameters via a LABVIEW interface. Most importantly, the stimulator has circuits to protect the high-voltage circuitry and the operator from programming and input-output errors. This device has been tested and used successfully in field shock experiments on rabbit hearts as well as other protocols requiring high voltage.

  4. 30 CFR 75.833 - Handling high-voltage trailing cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Handling high-voltage trailing cables. 75.833... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution High-Voltage Longwalls § 75.833 Handling high-voltage trailing cables. (a) Cable handling. (1)...

  5. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable...

  6. 30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage powerlines; clearances above... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad...

  7. 30 CFR 77.807 - Installation of high-voltage transmission cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Installation of high-voltage transmission... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807 Installation of high-voltage transmission cables. High-voltage transmission cables shall be installed or placed so as to afford...

  8. 30 CFR 75.810 - High-voltage trailing cables; splices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage trailing cables; splices. 75.810... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.810 High-voltage trailing cables; splices. In the case of high-voltage cables used as...

  9. Large space system - Charged particle environment interaction technology. [effects on high voltage solar array performance

    NASA Technical Reports Server (NTRS)

    Stevens, N. J.; Roche, J. C.; Grier, N. T.

    1979-01-01

    Large high-voltage space power systems proposed for future applications in both low earth orbit and geosynchronous altitudes must operate in the space charged-particle environment with possible interactions between this environment and the high-voltage surfaces. The paper reviews the ground experimental work to provide indicators for the interactions that could exist in the space power system. A preliminary analytical model of a large space power system is constructed using the existing NASA Charging Analyzer Program, and its performance in geosynchronous orbit is evaluated. The analytical results are used to illustrate the regions where detrimental interactions could exist and to establish areas where future technology is required.

  10. Methods, systems and apparatus for controlling third harmonic voltage when operating a multi-space machine in an overmodulation region

    DOEpatents

    Perisic, Milun; Kinoshita, Michael H; Ranson, Ray M; Gallegos-Lopez, Gabriel

    2014-06-03

    Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector. By modifying the reference voltage vector, voltage command signals that control a five-phase inverter module can be optimized to increase output voltages generated by the five-phase inverter module.

  11. Mixed voltage VLSI design

    NASA Technical Reports Server (NTRS)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    A technique for minimizing the power dissipated in a Very Large Scale Integration (VLSI) chip by lowering the operating voltage without any significant penalty in the chip throughput even though low voltage operation results in slower circuits. Since the overall throughput of a VLSI chip depends on the speed of the critical path(s) in the chip, it may be possible to sustain the throughput rates attained at higher voltages by operating the circuits in the critical path(s) with a high voltage while operating the other circuits with a lower voltage to minimize the power dissipation. The interface between the gates which operate at different voltages is crucial for low power dissipation since the interface may possibly have high static current dissipation thus negating the gains of the low voltage operation. The design of a voltage level translator which does the interface between the low voltage and high voltage circuits without any significant static dissipation is presented. Then, the results of the mixed voltage design using a greedy algorithm on three chips for various operating voltages are presented.

  12. Nanoscopic voltage distribution of operating cascade laser devices in cryogenic temperature.

    PubMed

    Dhar, R S; Ban, D

    2016-06-01

    A nanoscopic exploratory measurement technique to measure voltage distribution across an operating semiconductor device in cryogenic temperature has been developed and established. The cross-section surface of the terahertz (THz) quantum cascade laser (QCL) has been measured that resolves the voltage distribution at nanometer scales. The electric field dissemination across the active region of the device has been attained under the device's lasing conditions at cryogenic temperature of 77 K.

  13. Next generation KATRIN high precision voltage divider for voltages up to 65kV

    NASA Astrophysics Data System (ADS)

    Bauer, S.; Berendes, R.; Hochschulz, F.; Ortjohann, H.-W.; Rosendahl, S.; Thümmler, T.; Schmidt, M.; Weinheimer, C.

    2013-10-01

    The KATRIN (KArlsruhe TRItium Neutrino) experiment aims to determine the mass of the electron antineutrino with a sensitivity of 200 meV by precisely measuring the electron spectrum of the tritium beta decay. This will be done by the use of a retarding spectrometer of the MAC-E-Filter type. To achieve the desired sensitivity the stability of the retarding potential of -18.6 kV has to be monitored with a precision of 3 ppm over at least two months. Since this is not feasible with commercial devices, two ppm-class high voltage dividers were developed, following the concept of the standard divider for DC voltages of up to 100 kV of the Physikalisch-Technische Bundesanstalt (PTB). In order to reach such high accuracies different effects have to be considered. The two most important ones are the temperature dependence of resistance and leakage currents, caused by insulators or corona discharges. For the second divider improvements were made concerning the high-precision resistors and the thermal design of the divider. The improved resistors are the result of a cooperation with the manufacturer. The design improvements, the investigation and the selection of the resistors, the built-in ripple probe and the calibrations at PTB will be reported here. The latter demonstrated a stability of about 0.1 ppm/month over a period of two years.

  14. Challenges and approaches for high-voltage spinel lithium-ion batteries.

    PubMed

    Kim, Jung-Hyun; Pieczonka, Nicholas P W; Yang, Li

    2014-07-21

    Lithium-ion (Li-ion) batteries have been developed for electric vehicle (EV) applications, owing to their high energy density. Recent research and development efforts have been devoted to finding the next generation of cathode materials for Li-ion batteries to extend the driving distance of EVs and lower their cost. LiNi(0.5)Mn(1.5)O(4) (LNMO) high-voltage spinel is a promising candidate for a next-generation cathode material based on its high operating voltage (4.75 V vs. Li), potentially low material cost, and excellent rate capability. Over the last decade, much research effort has focused on achieving a fundamental understanding of the structure-property relationship in LNMO materials. Recent studies, however, demonstrated that the most critical barrier for the commercialization of high-voltage spinel Li-ion batteries is electrolyte decomposition and concurrent degradative reactions at electrode/electrolyte interfaces, which results in poor cycle life for LNMO/graphite full cells. Despite scattered reports addressing these processes in high-voltage spinel full cells, they have not been consolidated into a systematic review article. With this perspective, emphasis is placed herein on describing the challenges and the various approaches to mitigate electrolyte decomposition and other degradative reactions in high-voltage spinel cathodes in full cells.

  15. BANSHEE: High-voltage repetitively pulsed electron-beam driver

    SciTech Connect

    VanHaaften, F.

    1992-01-01

    BANSHEE (Beam Accelerator for a New Source of High-Energy Electrons) this is a high-voltage modulator is used to produce a high-current relativistic electron beam for high-power microwave tube development. The goal of the BANSHEE research is first to achieve a voltage pulse of 700--750 kV with a 1-{mu}s pulse width driving a load of {approximately}100 {Omega}, the pulse repetition frequency (PRF) of a few hertz. The ensuing goal is to increase the pulse amplitude to a level approaching 1 MV. We conducted tests using half the modulator with an output load of 200 {Omega}, up to a level of {approximately}650 kV at a PRF of 1 Hz and 525 kV at a PRF of 5 Hz. We then conducted additional testing using the complete system driving a load of {approximately}100 {Omega}.

  16. BANSHEE: High-voltage repetitively pulsed electron-beam driver

    SciTech Connect

    VanHaaften, F.

    1992-08-01

    BANSHEE (Beam Accelerator for a New Source of High-Energy Electrons) this is a high-voltage modulator is used to produce a high-current relativistic electron beam for high-power microwave tube development. The goal of the BANSHEE research is first to achieve a voltage pulse of 700--750 kV with a 1-{mu}s pulse width driving a load of {approximately}100 {Omega}, the pulse repetition frequency (PRF) of a few hertz. The ensuing goal is to increase the pulse amplitude to a level approaching 1 MV. We conducted tests using half the modulator with an output load of 200 {Omega}, up to a level of {approximately}650 kV at a PRF of 1 Hz and 525 kV at a PRF of 5 Hz. We then conducted additional testing using the complete system driving a load of {approximately}100 {Omega}.

  17. Stable electrolyte for high voltage electrochemical double-layer capacitors

    SciTech Connect

    Ruther, Rose E.; Sun, Che -Nan; Holliday, Adam; Cheng, Shiwang; Delnick, Frank M.; Zawodzinski, Thomas A.; Nanda, Jagjit

    2016-12-28

    A simple electrolyte consisting of NaPF6 salt in 1,2-dimethoxyethane (DME) can extend the voltage window of electric double-layer capacitors (EDLCs) to >3.5 V. DME does not passivate carbon electrodes at very negative potentials (near Na/Na+), extending the practical voltage window by about 1.0 V compared to standard, non-aqueous electrolytes based on acetonitrile. The voltage window is demonstrated in two- and three-electrode cells using a combination of electrochemical impedance spectroscopy (EIS), charge-discharge cycling, and measurements of leakage current. DME-based electrolytes cannot match the high conductivity of acetonitrile solutions, but they can satisfy applications that demand high energy density at moderate power. The conductivity of NaPF6 in DME is comparable to commercial lithium-ion battery electrolytes and superior to most ionic liquids. Lastly, factors that limit the voltage window and EDLC energy density are discussed, and strategies to further boost energy density are proposed.

  18. High Transmembrane Voltage Raised by Close Contact Initiates Fusion Pore.

    PubMed

    Bu, Bing; Tian, Zhiqi; Li, Dechang; Ji, Baohua

    2016-01-01

    Membrane fusion lies at the heart of neuronal communication but the detailed mechanism of a critical step, fusion pore initiation, remains poorly understood. Here, through atomistic molecular dynamics simulations, a transient pore formation induced by a close contact of two apposed bilayers is firstly reported. Such a close contact gives rise to a high local transmembrane voltage that induces the transient pore formation. Through simulations on two apposed bilayers fixed at a series of given distances, the process in which two bilayers approaching to each other under the pulling force from fusion proteins for membrane fusion was mimicked. Of note, this close contact induced fusion pore formation is contrasted with previous reported electroporation under ad hoc applied external electric field or ionic charge in-balance. We show that the transmembrane voltage increases with the decrease of the distance between the bilayers. Below a critical distance, depending on the lipid composition, the local transmembrane voltage can be sufficiently high to induce the transient pores. The size of these pores is approximately 1~2 nm in diameter, which is large enough to allow passing of neurotransmitters. A resealing of the membrane pores resulting from the neutralization of the transmembrane voltage by ions through the pores was then observed. We also found that the membrane tension can either prolong the lifetime of transient pores or cause them to dilate for full collapse. This result provides a possible mechanism for fusion pore formation and regulation of pathway of fusion process.

  19. High Transmembrane Voltage Raised by Close Contact Initiates Fusion Pore

    PubMed Central

    Bu, Bing; Tian, Zhiqi; Li, Dechang; Ji, Baohua

    2016-01-01

    Membrane fusion lies at the heart of neuronal communication but the detailed mechanism of a critical step, fusion pore initiation, remains poorly understood. Here, through atomistic molecular dynamics simulations, a transient pore formation induced by a close contact of two apposed bilayers is firstly reported. Such a close contact gives rise to a high local transmembrane voltage that induces the transient pore formation. Through simulations on two apposed bilayers fixed at a series of given distances, the process in which two bilayers approaching to each other under the pulling force from fusion proteins for membrane fusion was mimicked. Of note, this close contact induced fusion pore formation is contrasted with previous reported electroporation under ad hoc applied external electric field or ionic charge in-balance. We show that the transmembrane voltage increases with the decrease of the distance between the bilayers. Below a critical distance, depending on the lipid composition, the local transmembrane voltage can be sufficiently high to induce the transient pores. The size of these pores is approximately 1~2 nm in diameter, which is large enough to allow passing of neurotransmitters. A resealing of the membrane pores resulting from the neutralization of the transmembrane voltage by ions through the pores was then observed. We also found that the membrane tension can either prolong the lifetime of transient pores or cause them to dilate for full collapse. This result provides a possible mechanism for fusion pore formation and regulation of pathway of fusion process. PMID:28018169

  20. Stable electrolyte for high voltage electrochemical double-layer capacitors

    DOE PAGES

    Ruther, Rose E.; Sun, Che -Nan; Holliday, Adam; ...

    2016-12-28

    A simple electrolyte consisting of NaPF6 salt in 1,2-dimethoxyethane (DME) can extend the voltage window of electric double-layer capacitors (EDLCs) to >3.5 V. DME does not passivate carbon electrodes at very negative potentials (near Na/Na+), extending the practical voltage window by about 1.0 V compared to standard, non-aqueous electrolytes based on acetonitrile. The voltage window is demonstrated in two- and three-electrode cells using a combination of electrochemical impedance spectroscopy (EIS), charge-discharge cycling, and measurements of leakage current. DME-based electrolytes cannot match the high conductivity of acetonitrile solutions, but they can satisfy applications that demand high energy density at moderate power.more » The conductivity of NaPF6 in DME is comparable to commercial lithium-ion battery electrolytes and superior to most ionic liquids. Lastly, factors that limit the voltage window and EDLC energy density are discussed, and strategies to further boost energy density are proposed.« less

  1. The Thermal Regime Around Buried Submarine High-Voltage Cables

    NASA Astrophysics Data System (ADS)

    Emeana, C. J.; Dix, J.; Henstock, T.; Gernon, T.; Thompson, C.; Pilgrim, J.

    2015-12-01

    The expansion of offshore renewable energy infrastructure and the desire for "trans-continental shelf" power transmission, all require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70oC and are typically buried at depths of 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the thermal properties of near surface shelf sediments are poorly understood and this increases the uncertainty in determining the required cable current ratings, cable reliability and the potential effects on the sedimentary environments. We present temperature measurements from a 2D laboratory experiment, designed to represent a buried, submarine HV cable. We used a large (2.5 m-high) tank, filled with water-saturated ballotini and instrumented with 120 thermocouples, which measured the time-dependent 2D temperature distributions around the heat source. The experiments use a buried heat source to represent a series of realistic cable surface temperatures with the aim for identifying the thermal regimes generated within typical non-cohesive shelf sediments: coarse silt, fine sand and very coarse sand. The steady state heat flow regimes, and normalised and radial temperature distributions were assessed. Our results show that at temperatures up to 60°C above ambient, the thermal regimes are conductive for the coarse silt sediments and convective for the very coarse sand sediments even at 7°C above ambient. However, the heat flow pattern through the fine sand sediment shows a transition from conductive to convective heat flow at a temperature of approximately 20°C above ambient. These findings offer an important new understanding of the thermal regimes associated with submarine HV cables buried in different substrates and has huge impacts on cable ratings as the IEC 60287 standard only considers conductive heat flow as well as other potential near surface impacts.

  2. Investigation Of The High-Voltage Discharge On The Surface Of Gas-Liquid System

    NASA Astrophysics Data System (ADS)

    Nguyen-Kuok, Shi; Morgunov, Aleksandr; Malakhov, Yury; Korotkikh, Ivan

    2016-09-01

    This paper describes an experimental setup for study of physical processes in the high-voltage discharge on the surface of gas-liquid system at atmospheric pressure. Measurements of electrical and optical characteristics of the high-voltage discharge in gas, at the surface of the gas-liquid system and in the electrolyte are obtained. The parameters of the high-voltage discharge and the conditions for its stable operation are presented. Investigations with various electrolytes and cathode assemblies of various materials and sizes were carried out. The installation can be used for the processing and recycling of industrial and chemical liquid waste. Professor of Laboratory of Plasma Physics, National Research University MPEI, Krasnokazarmennya Str.14, 111250, Moscow, Russia.

  3. Study of seismic response and vibration control of High voltage electrical equipment damper based on TMD

    NASA Astrophysics Data System (ADS)

    Liu, Chuncheng; Wang, Chongyang; Mao, Long; Zha, Chuanming

    2016-11-01

    Substation high voltage electrical equipment such as mutual inductor, circuit interrupter, disconnecting switch, etc., has played a key role in maintaining the normal operation of the power system. When the earthquake disaster, the electrical equipment of the porcelain in the transformer substation is the most easily to damage, causing great economic losses. In this paper, using the method of numerical analysis, the establishment of a typical high voltage electrical equipment of three dimensional finite element model, to study the seismic response of a typical SF6 circuit breaker, at the same time, analysis and contrast the installation ring tuned mass damper (TMD damper for short), by changing the damper damping coefficient and the mass block, install annular TMD vibration control effect is studied. The results of the study for guiding the seismic design of high voltage electrical equipment to provide valuable reference.

  4. High-voltage suicidal electrocution with multiple exit wounds.

    PubMed

    Das, Siddhartha; Patra, Ambika Prasad; Shaha, Kusa Kumar; Sistla, Sarath Chandra; Jena, Manoj Kumar

    2013-03-01

    Poisoning, hanging, and burning are the usual methods adopted by people to commit suicide. Suicide by electrocution and that too high voltage is one of the rarest methods adopted for the purpose. We report the case of a young man who committed suicide by climbing up a 25-ft-high electric pole. The deceased was a regular alcoholic and was under severe depression for a long time because of his personal problems. He survived for more than 2 days after the incident. His serum urea and creatinine levels were elevated, so were the creatine kinase total and creatine kinase-MB level. The method adopted and the findings make this case a rare scientific report. Moreover, to the best of our knowledge, this is the first reported case in an English scientific literature of a high-voltage suicidal electrocution with multiple exit wounds. The circumstances surrounding the manner of electrocution and the features of electric injuries are presented and discussed.

  5. High-voltage terminal test of a test stand for a 1-MV electrostatic accelerator

    NASA Astrophysics Data System (ADS)

    Park, Sae-Hoon; Kim, Yu-Seok

    2015-10-01

    The Korea Multipurpose Accelerator Complex has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source and accelerating tube will be installed in a high-pressure vessel. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz radio-frequency power supply, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. The results of the 300-kV high-voltage terminal tests are presented in this paper.

  6. Stable Josephson reference voltages between 0. 1 and 1. 3 V for high-precision voltage standards

    SciTech Connect

    Niemeyer, J.; Grimm, L.; Meier, W.; Hinken, J.H.; Vollmer, E.

    1985-12-01

    A new series array of 1440 Josephson tunnel junctions has been developed and tested as a reference voltage standard. It yields microwave induced quantized voltage steps up to 1.3 V. The steps are usually stable for more than 5 h with a microwave driving frequency of either 70 or 90 GHz. A high-resolution comparison of a constant voltage step at the 1-V level with the electromotive force of a saturated Weston cell is described. The comparison shows that the step voltage is constant to within +- 1 nV over the full step width.

  7. Stable Josephson reference voltages between 0.1 and 1.3 V for high precision voltage standards

    NASA Astrophysics Data System (ADS)

    Niemeyer, J.; Grimm, L.; Meier, W.; Hinken, J. H.; Vollmer, E.

    1985-12-01

    A new series array of 1440 Josephson tunnel junctions has been developed and tested as a reference voltage standard. It yields microwave induced quantized voltage steps up to 1.3 V. The steps are usually stable for more than 5 h with a microwave driving frequency of either 70 or 90 GHz. A high-resolution comparison of a constant voltage step at the 1-V level with the electromotive force of a saturated Weston cell is described. The comparison shows that the step voltage is constant to within + or - 1 nV over the full step width.

  8. Working group report on advanced high-voltage high-power and energy-storage space systems

    NASA Technical Reports Server (NTRS)

    Cohen, H. A.; Cooke, D. L.; Evans, R. W.; Hastings, D.; Jongeward, G.; Laframboise, J. G.; Mahaffey, D.; Mcintyre, B.; Pfizer, K. A.; Purvis, C.

    1986-01-01

    Space systems in the future will probably include high-voltage, high-power energy-storage and -production systems. Two such technologies are high-voltage ac and dc systems and high-power electrodynamic tethers. The working group identified several plasma interaction phenomena that will occur in the operation of these power systems. The working group felt that building an understanding of these critical interaction issues meant that several gaps in our knowledge had to be filled, and that certain aspects of dc power systems have become fairly well understood. Examples of these current collection are in quiescent plasmas and snap over effects. However, high-voltage dc and almost all ac phenomena are, at best, inadequately understood. In addition, there is major uncertainty in the knowledge of coupling between plasmas and large scale current flows in space plasmas. These gaps in the knowledge are addressed.

  9. 250 kV 6 mA compact Cockcroft-Walton high-voltage power supply.

    PubMed

    Ma, Zhan-Wen; Su, Xiao-Dong; Lu, Xiao-Long; Wei, Zhen; Wang, Jun-Run; Huang, Zhi-Wu; Miao, Tian-You; Su, Tong-Ling; Yao, Ze-En

    2016-08-01

    A compact power supply system for a compact neutron generator has been developed. A 4-stage symmetrical Cockcroft-Walton circuit is adopted to produce 250 kV direct current high-voltage. A 2-stage 280 kV isolation transformer system is used to drive the ion source power supply. For a compact structure, safety, and reliability during the operation, the Cockcroft-Walton circuit and the isolation transformer system are enclosed in an epoxy vessel containing the transformer oil whose size is about ∅350 mm × 766 mm. Test results indicate that the maximum output voltage of the power supply is 282 kV, and the stability of the output voltage is better than 0.63% when the high voltage power supply is operated at 250 kV, 6.9 mA with the input voltage varying ±10%.

  10. 250 kV 6 mA compact Cockcroft-Walton high-voltage power supply

    NASA Astrophysics Data System (ADS)

    Ma, Zhan-Wen; Su, Xiao-Dong; Lu, Xiao-Long; Wei, Zhen; Wang, Jun-Run; Huang, Zhi-Wu; Miao, Tian-You; Su, Tong-Ling; Yao, Ze-En

    2016-08-01

    A compact power supply system for a compact neutron generator has been developed. A 4-stage symmetrical Cockcroft-Walton circuit is adopted to produce 250 kV direct current high-voltage. A 2-stage 280 kV isolation transformer system is used to drive the ion source power supply. For a compact structure, safety, and reliability during the operation, the Cockcroft-Walton circuit and the isolation transformer system are enclosed in an epoxy vessel containing the transformer oil whose size is about ∅350 mm × 766 mm. Test results indicate that the maximum output voltage of the power supply is 282 kV, and the stability of the output voltage is better than 0.63% when the high voltage power supply is operated at 250 kV, 6.9 mA with the input voltage varying ±10%.

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

    DOEpatents

    Shimer, Daniel W.; Lange, Arnold C.

    1995-01-01

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

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

    DOEpatents

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

    1995-05-23

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

  13. Comprehensive behavioral model of dual-gate high voltage JFET and pinch resistor

    NASA Astrophysics Data System (ADS)

    Banáš, Stanislav; Paňko, Václav; Dobeš, Josef; Hanyš, Petr; Divín, Jan

    2016-09-01

    Many analog technologies operate in large voltage range and therefore include at least one or more high voltage devices built from low doped layers. Such devices exhibit effects not covered by standard compact models, namely pinching (depletion) effects, in high voltage FETs often called quasisaturation. For example, the conventional compact JFET model is insufficient and oversimplified. Its scalability is controlled by the area factor, which only multiplies currents and capacitances but does not take into account existing 3-D effects. Also the optional second independent gate is missing. Therefore, the customized four terminal (4T) model written in Verilog-A (FitzPatrick and Miller, 2007; Sagdeo, 2007) was developed. It converges very well, its simulation speed is comparable with conventional compact models, and contains all required phenomena, including parasitic effects as, for example, impact ionization. This model has universal usage for many types of devices in various high voltage technologies such as stand-alone voltage dependent resistor, pinch resistor, drift area of power FET, part of special high side or start-up devices, and dual-gate JFET.

  14. A high voltage method for measuring low capacitance for tomography.

    PubMed

    Lu, Decai; Shao, Fuqun; Guo, Zhiheng

    2009-05-01

    Low capacitance measurement is involved in many industrial applications, especially in the applications of electrical capacitance tomography (ECT). Most of the low capacitance measurement circuits employ an ac-based method or a charge/discharge method because of high sensitivity, high resolution, and immunity to stray capacitance; and its excitation or charge voltage are not more than 20 V. When ECT techniques for large industrial equipment such as blast furnaces or grain barns are explored, the existing methods for measuring low capacitance have some limitations. This paper proposes a high excitation voltage ac-based method for measuring low capacitance to improve the resolution of measurement. The method uses a high excitation voltage of several hundred volts and a transformer ratio arms as the C/V transducer. Experimental results indicate that the new method has a resolution of 0.005 fF, a good stability (about 0.003 fF over 4 h) and linearity (0.9992).

  15. High Voltage, Fast-Switching Module for Active Control of Magnetic Fields and Edge Plasma Currents

    NASA Astrophysics Data System (ADS)

    Ziemba, Timothy; Miller, Kenneth; Prager, James; Slobodov, Ilia

    2016-10-01

    Fast, reliable, real-time control of plasma is critical to the success of magnetic fusion science. High voltage and current supplies are needed to mitigate instabilities in all experiments as well as disruption events in large scale tokamaks for steady-state operation. Silicon carbide (SiC) MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities; however, these devices are limited to 1.2-1.7 kV devices. As fusion enters the long-pulse and burning plasma eras, efficiency of power switching will be important. Eagle Harbor Technologies (EHT), Inc. developing a high voltage SiC MOSFET module that operates at 10 kV. This switch module utilizes EHT gate drive technology, which has demonstrated the ability to increase SiC MOSFET switching efficiency. The module will allow more rapid development of high voltage switching power supplies at lower cost necessary for the next generation of fast plasma feedback and control. EHT is partnering with the High Beta Tokamak group at Columbia to develop detailed high voltage module specifications, to ensure that the final product meets the needs of the fusion science community.

  16. Ion back-bombardment of GaAs photocathodes inside dc high voltage electron guns

    SciTech Connect

    Joseph Grames; Philip Adderley; Joshua Brittian; Daniel Charles; James Clark; John Hansknecht; Benard Poelker; Marcy Stutzman; Kenneth Surles-law

    2005-05-01

    DC high voltage GaAs photoguns are key components at accelerator facilities worldwide. New experiments and new accelerator facilities demand improved performance from these guns, in particular higher current operation and longer photocathode operating lifetime. This conference submission explores bulk GaAs photocathode lifetime as a function of beam current, active photocathode area, laser spot size and the vacuum of the gun and beam line. Lifetime measurements were made at 100 microamps, a beam current relevant for accelerators like CEBAF, and at beam currents of 1 milliamps and 5 milliamps, a regime that is interesting for high current Free Electron Laser (FEL) and Energy Recovery Linac (ERL) operation.

  17. Design and validation of a high-voltage levitation circuit for electrostatic accelerometers

    SciTech Connect

    Li, G.; Wu, S. C.; Zhou, Z. B.; Bai, Y. Z.; Hu, M.; Luo, J.

    2013-12-15

    A simple high-voltage circuit with a voltage range of 0 to 900 V and an open-loop bandwidth of 11 kHz is realized by using an operational amplifier and a MOSFET combination. The circuit is used for the levitation of a test mass of 71 g, suspended below the top-electrodes with a gap distance of 57 μm, so that the performance of an electrostatic accelerometer can be tested on the ground. The translation noise of the accelerometer, limited by seismic noise, is about 4 × 10{sup −8} m/s{sup 2}/Hz{sup 1/2} at 0.1 Hz, while the high-voltage coupling noise is one-order of magnitude lower.

  18. Criteria to estimate the voltage unbalances due to high-speed railway demands

    SciTech Connect

    Chen, T.H. . Dept. of Electrical Engineering and Technology)

    1994-08-01

    This paper has presented simple criteria to estimate the voltage unbalances due to high-speed railway demands that are generally single-phase loads. Feeding traction loads from the public power system may lead to some voltage unbalance on the latter and consequently affect the operation of its energy-supply system and other equipment connected with it. Three transformer connection schemes that are commonly used in power-supply systems for the high-speed railway are discussed and compared. The estimating criteria have been derived and represented by simple formula that can be easily applied to evaluate this voltage unbalance. The results are of value to related engineers and consultants especially during periods of planning and design.

  19. Static reactive power compensators for high-voltage power systems. Final report

    SciTech Connect

    Not Available

    1981-04-01

    A study conducted to summarize the role of static reactive power compensators for high voltage power system applications is described. This information should be useful to the utility system planning engineer in applying static var systems (SVS) to high voltage as (HVAC) systems. The static var system is defined as a form of reactive power compensator. The general need for reactive power compensation in HVAC systems is discussed, and the static var system is compared to other devices utilized to provide reactive power compensation. Examples are presented of applying SVS for specific functions, such as the prevention of voltage collapse. The operating principles of commercially available SVS's are discussed in detail. The perormance and active power loss characteristics of SVS types are compared.

  20. Design and validation of a high-voltage levitation circuit for electrostatic accelerometers.

    PubMed

    Li, G; Wu, S C; Zhou, Z B; Bai, Y Z; Hu, M; Luo, J

    2013-12-01

    A simple high-voltage circuit with a voltage range of 0 to 900 V and an open-loop bandwidth of 11 kHz is realized by using an operational amplifier and a MOSFET combination. The circuit is used for the levitation of a test mass of 71 g, suspended below the top-electrodes with a gap distance of 57 μm, so that the performance of an electrostatic accelerometer can be tested on the ground. The translation noise of the accelerometer, limited by seismic noise, is about 4 × 10(-8) m/s(2)/Hz(1/2) at 0.1 Hz, while the high-voltage coupling noise is one-order of magnitude lower.

  1. A High-Voltage UWB Coupled-Line Directional Coupler for Radar

    NASA Astrophysics Data System (ADS)

    Farr, Everett G.; Atchley, Lanney M.; Ellibee, Donald E.; Lawry, Dean I.

    The simplest method of building ultra-wideband (UWB) radar systems requires two antennas, one each for transmission and reception. To save space, it would be preferable to use a single antenna, so a UWB, high-voltage directional coupler is needed. In support of that goal, we develop here coupled-line directional couplers. We begin by describing the time-domain theory of operation of such couplers, and we optimize the impedances for maximum return signal. We then design, build and test two versions of high-voltage coupled-line directional couplers. We incorporate the directional couplers into a low-voltage UWB radar system, and we observe scattering back from a comer reflector. We identify possible improvements to the directional couplers and the UWB radar system.

  2. Highly-Efficient and Modular Medium-Voltage Converters

    DTIC Science & Technology

    2015-09-28

    operation of the MMC-based adjustable-speed drive system is the large magnitude of the submodule (SM) capacitor volt- age ripple due to the inverse ...5), the peak-to-peak ripple of the SM capacitor voltages has an inverse depen- dency on the ac-side frequency and a direct dependency on the ac-side...line) 109 V Rated electrical frequency fr 120 Hz ^load 0.22 n Aoad 6.03 mH Number of poles pairs (P/2) 2 Table 3: MMC Parameters Quantity Value

  3. Development of the Fast Scintillation Detector with Programmable High Voltage Adjustment Suitable for Moessbauer Spectroscopy

    SciTech Connect

    Prochazka, R.; Frydrych, J.; Pechousek, J.

    2010-07-13

    This work is focused on a development of a compact fast scintillation detector suitable for Moessbauer spectroscopy (low energy X-ray/{gamma}-ray detection) where high counting rates are inevitable. Optimization of this part was necessary for a reliable function, better time resolution and to avoid a detector pulses pile-up effect. The pile-up effect decreases the measurement performance, significantly depends on the source activity and also on the pulse duration. Our new detection unit includes a fast scintillation crystal YAP:Ce, an R6095 photomultiplier tube, a high voltage power supply socket C9028-01 assembly, an AD5252 digital potentiometer with an I2C interface and an AD8000 ultra fast operation preamplifier. The main advantages of this solution lie in a short pulse duration (less than 200 ns), stable operation for high activities, programmable gain of the high voltage supply and compact design in the aluminum housing.

  4. Pulse Evaluation of High Voltage SiC Diodes

    DTIC Science & Technology

    2007-06-01

    Different packaging options were also explored. The first group of diodes was encased in hard, caramel - colored , high temperature epoxy which...16-21 June 2013., The original document contains color images. 14. ABSTRACT The U. S. Army Research Laboratory (ARL) is evaluating silicon carbide...individually at increasing voltage and current levels until failure in order to narrow down the peak current limitation of the devices

  5. Low operating voltage n-channel organic field effect transistors using lithium fluoride/PMMA bilayer gate dielectric

    SciTech Connect

    Kumar, S.; Dhar, A.

    2015-10-15

    Highlights: • Alternative to chemically crosslinking of PMMA to achieve low leakage in provided. • Effect of LiF in reducing gate leakage through the OFET device is studied. • Effect of gate leakage on transistor performance has been investigated. • Low voltage operable and low temperature processed n-channel OFETs were fabricated. - Abstract: We report low temperature processed, low voltage operable n-channel organic field effect transistors (OFETs) using N,N′-Dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C{sub 8}) organic semiconductor and poly(methylmethacrylate) (PMMA)/lithium fluoride (LiF) bilayer gate dielectric. We have studied the role of LiF buffer dielectric in effectively reducing the gate leakage through the device and thus obtaining superior performance in contrast to the single layer PMMA dielectric devices. The bilayer OFET devices had a low threshold voltage (V{sub t}) of the order of 5.3 V. The typical values of saturation electron mobility (μ{sub s}), on/off ratio and inverse sub-threshold slope (S) for the range of devices made were estimated to be 2.8 × 10{sup −3} cm{sup 2}/V s, 385, and 3.8 V/decade respectively. Our work thus provides a potential substitution for much complicated process of chemically crosslinking PMMA to achieve low leakage, high capacitance, and thus low operating voltage OFETs.

  6. Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized

    NASA Technical Reports Server (NTRS)

    Adell, Philippe C.; Mojarradi, Mohammad; DelCastillo, Linda Y.; Vo, Tuan A.

    2011-01-01

    A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that uses a unique combination of 0.25 micrometer CMOS (complementary metal oxide semiconductor) transistors and high-voltage lateral DMOS (diffusion metal oxide semiconductor) device with high breakdown voltage (greater than 650 V). The high-voltage requirements are achieved by stacking a number of DMOS devices within one module, while two modules can be placed in series to achieve higher voltages. Besides the high-voltage requirements, a second generation prototype is currently being developed to provide improved switching capabilities (rise time and fall time for full range of target voltages and currents), the ability to scale the output voltage to a desired value with good accuracy (few percent) up to 10 kV, to cover a wide range of high-voltage applications. In addition, to ensure miniaturization, long life, and high reliability, the assemblies will require intensive high-voltage electrostatic modeling (optimized E-field distribution throughout the module) to complete the proposed packaging approach and test the applicability of using advanced materials in a space-like environment (temperature and pressure) to help prevent potential arcing and corona due to high field regions. Finally, a single-event effect evaluation would have to be performed and single-event mitigation methods implemented at the design and system level or developed to ensure complete radiation hardness of the module.

  7. High voltage systems (tube-type microwave)/low voltage system (solid-state microwave) power distribution

    NASA Technical Reports Server (NTRS)

    Nussberger, A. A.; Woodcock, G. R.

    1980-01-01

    SPS satellite power distribution systems are described. The reference Satellite Power System (SPS) concept utilizes high-voltage klystrons to convert the onboard satellite power from dc to RF for transmission to the ground receiving station. The solar array generates this required high voltage and the power is delivered to the klystrons through a power distribution subsystem. An array switching of solar cell submodules is used to maintain bus voltage regulation. Individual klystron dc voltage conversion is performed by centralized converters. The on-board data processing system performs the necessary switching of submodules to maintain voltage regulation. Electrical power output from the solar panels is fed via switch gears into feeder buses and then into main distribution buses to the antenna. Power also is distributed to batteries so that critical functions can be provided through solar eclipses.

  8. Chandra Probes High-Voltage Auroras on Jupiter

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Scientists have obtained new insight into the unique power source for many of Jupiter's auroras, the most spectacular and active auroras in the Solar System. Extended monitoring of the giant planet with NASA's Chandra X-ray Observatory detected the presence of highly charged particles crashing into the atmosphere above its poles. X-ray spectra measured by Chandra showed that the auroral activity was produced by ions of oxygen and other elements that were stripped of most of their electrons. This implies that these particles were accelerated to high energies in a multimillion-volt environment above the planet's poles. The presence of these energetic ions indicates that the cause of many of Jupiter's auroras is different from auroras produced on Earth or Saturn. Chandra X-ray Image of Jupiter Chandra X-ray Image of Jupiter "Spacecraft have not explored the region above the poles of Jupiter, so X-ray observations provide one of the few ways to probe that environment," said Ron Elsner of the NASA Marshall Space Flight Center in Huntsville, Alabama, and lead author on a recently published paper describing these results in the Journal for Geophysical Research. "These results will help scientists to understand the mechanism for the power output from Jupiter's auroras, which are a thousand times more powerful than those on Earth." Electric voltages of about 10 million volts, and currents of 10 million amps - a hundred times greater than the most powerful lightning bolts - are required to explain the X-ray observations. These voltages would also explain the radio emission from energetic electrons observed near Jupiter by the Ulysses spacecraft. Schematic of Jupiter's Auroral Activity Production Schematic of Jupiter's Auroral Activity Production On Earth, auroras are triggered by solar storms of energetic particles, which disturb Earth's magnetic field. Gusts of particles from the Sun can also produce auroras on Jupiter, but unlike Earth, Jupiter has another way of producing

  9. Arcing and discharges in high-voltage subsystems of Space Station

    NASA Technical Reports Server (NTRS)

    Singh, N.

    1988-01-01

    Arcing and other types of electrical discharges are likely to occur in high-voltage subsystems of the Space Station. Results from ground and space experiments on the arcing of solar cell arrays are briefly reviewed, showing that the arcing occurs when the conducting interconnects in the arrays are at negative potential above a threshold, which decreases with the increasing plasma density. Furthermore, above the threshold voltages the arcing rate increases with the plasma density. At the expected operating voltages (approximately 200 V) in the solar array for the space station, arcing is expected to occur even in the ambient ionospheric plasma. If the ionization of the contaminants increases the plasma density near the high-voltage systems, the adverse effects of arcing on the solar arrays and the space station are likely to be enhanced, In addition to arcing other discharge processes are likely to occur in high-voltage subsystems. For example, Paschen discharge is likely to occur when the neutral density N sub n greater that 10 to the 12th cu cm, the corresponding neutral pressure P greater than 3 x 10 to the -5 Torr.

  10. Zero Voltage Soft Switching Duty Cycle Pulse Modulated High Frequency Inverter-Fed

    NASA Astrophysics Data System (ADS)

    Ishitobi, Manabu; Matsushige, Takayuki; Nakaoka, Mutsuo; Bessyo, Daisuke; Omori, Hideki; Terai, Haruo

    The utility grid voltage of commercial AC power source in Japan and USA is 100V, but in other Asian and European countries, it is 220V. In recent years, in Japan 200V outputted single-phase three-wire system begins to be used for high power applications. In 100V utility AC power applications and systems, an active voltage clamped quasi-resonant inverter circuit topology sing IGBTs has been effectively used so far for the consumer microwave oven. In this paper, presented is a half bridge type voltage-clamped asymmetrical soft switching PWM high-frequency inverter type AC-DC converter using IGBTs which is designed for consumer magnetron drive used as the consumer microwave oven in 200V utility AC power system. The zero voltage soft switching inverter treated here can use the same power rated switching semiconductor devices and three-winding high frequency transformer as those of the active voltage clamped quasi-resonant inverter using the IGBTs that has already been used for 100V utility AC power source. The operating performances of the voltage source single ended push pull (SEPP) type soft switching PWM inverter are evaluated and discussed for 100V and 200V common use consumer microwave oven. The harmonic line current components in the utility AC power side of the AC-DC power converter with ZVS-PWM SEPP inverter are reduced and improved on the basis of sine wave like pulse frequency modulation and sine wave like pulse width modulation for the utility AC voltage source.

  11. High-Voltage, High-Power Gaseous Electronics Switch For Electric Grid Power Conversion

    NASA Astrophysics Data System (ADS)

    Sommerer, Timothy J.

    2014-05-01

    We are developing a high-voltage, high-power gas switch for use in low-cost power conversion terminals on the electric power grid. Direct-current (dc) power transmission has many advantages over alternating current (ac) transmission, but at present the high cost of ac-dc power interconversion limits the use of dc. The gas switch we are developing conducts current through a magnetized cold cathode plasma in hydrogen or helium to reach practical current densities > 1 A/cm2. Thermal and sputter damage of the cathode by the incident ion flux is a major technical risk, and is being addressed through use of a ``self-healing'' liquid metal cathode (eg, gallium). Plasma conditions and cathode sputtering loss are estimated by analyzing plasma spectral emission. A particle-in-cell plasma model is used to understand various aspects of switch operation, including the conduction phase (where plasma densities can exceed 1013 cm-3), the switch-open phase (where the high-voltage must be held against gas breakdown on the left side of Paschen's curve), and the switching transitions (especially the opening process, which is initiated by forming an ion-matrix sheath adjacent to a control grid). The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000298.

  12. Fiber optic current monitor for high-voltage applications

    DOEpatents

    Renda, G.F.

    1992-04-21

    A current monitor which derives its power from the conductor being measured for bidirectionally measuring the magnitude of current (from DC to above 50 khz) flowing through a conductor across which a relatively high level DC voltage is applied, includes a pair of identical transmitter modules connected in opposite polarity to one another in series with the conductor being monitored, for producing from one module a first light signal having an intensity directly proportional to the magnitude of current flowing in one direction through the conductor during one period of time, and from the other module a second light signal having an intensity directly proportional to the magnitude of current flowing in the opposite direction through the conductor during another period of time, and a receiver located in a safe area remote from the high voltage area for receiving the first and second light signals, and converting the same to first and second voltage signals having levels indicative of the magnitude of current being measured at a given time. 6 figs.

  13. Loss Reduction on Adoption of High Voltage LT Less Distribution

    NASA Astrophysics Data System (ADS)

    Tiwari, Deepika; Adhikari, Nikhileshwar Prasad; Gupta, Amit; Bajpai, Santosh Kumar

    2016-06-01

    In India there is a need to improve the quality of the electricity distribution process which has increased varying from year to year. In distribution networks, the limiting factor to load carrying capacity is generally the voltage reduction. High voltage distribution system (HVDS) is one of the steps to reduce line losses in electrical distribution network. It helps to reduce the length of low tension (LT) lines and makes the power available close to the users. The high voltage power distribution system reduces the probability of power theft by hooking HVDS suggests an increase in installation of small capacity single-phase transformers in the network which again save considerable energy. This paper is compared to existing conventional low tension distribution network with HVDS. The paper gives a clear picture of reduction in distribution losses with adoption of HVDS system. Losses Reduction of 11 kV Feeder in Nuniya (India) with adoption of HVDS have been worked out/ quantified and benefits thereby in generating capacity have discussed.

  14. Fiber optic current monitor for high-voltage applications

    DOEpatents

    Renda, George F.

    1992-01-01

    A current monitor which derives its power from the conductor being measured for bidirectionally measuring the magnitude of current (from DC to above 50 khz) flowing through a conductor across which a relatively high level DC voltage is applied, includes a pair of identical transmitter modules connected in opposite polarity to one another in series with the conductor being monitored, for producing from one module a first light signal having an intensity directly proportional to the magnitude of current flowing in one direction through the conductor during one period of time, and from the other module a second light signal having an intensity directly proportional to the magnitude of current flowing in the opposite direction through the conductor during another period of time, and a receiver located in a safe area remote from the high voltage area for receiving the first and second light signals, and converting the same to first and second voltage signals having levels indicative of the magnitude of current being measured at a given time.

  15. Modeling of High-voltage Breakdown in Helium

    NASA Astrophysics Data System (ADS)

    Xu, Liang; Khrabrov, Alexander; Kaganovich, Igor; Sommerer, Timothy

    2016-09-01

    We investigate the breakdown in extremely high reduced electric fields (E/N) between parallel-plate electrodes in helium. The left branch of the Paschen curve in the voltage range of 20-350kV and inter-electrode gap range of 0.5-3.5cm is studied analytically and with Monte-Carlo/PIC simulations. The model incorporates electron, ion, and fast neutral species whose energy-dependent anisotropic scattering, as well as backscattering at the electrodes, is carefully taken into account. Our model demonstrates that (1) anisotropic scattering is indispensable for producing reliable results at such high voltage and (2) due to the heavy species backscattered at cathode, breakdown can occur even without electron- and ion-induced ionization of the background gas. Fast atoms dominate in the breakdown process more and more as the applied voltage is increased, due to their increasing ionization cross-section and to the copious flux of energetic fast atoms generated in charge-exchange collisions.

  16. Switch contact device for interrupting high current, high voltage, AC and DC circuits

    DOEpatents

    Via, Lester C.; Witherspoon, F. Douglas; Ryan, John M.

    2005-01-04

    A high voltage switch contact structure capable of interrupting high voltage, high current AC and DC circuits. The contact structure confines the arc created when contacts open to the thin area between two insulating surfaces in intimate contact. This forces the arc into the shape of a thin sheet which loses heat energy far more rapidly than an arc column having a circular cross-section. These high heat losses require a dramatic increase in the voltage required to maintain the arc, thus extinguishing it when the required voltage exceeds the available voltage. The arc extinguishing process with this invention is not dependent on the occurrence of a current zero crossing and, consequently, is capable of rapidly interrupting both AC and DC circuits. The contact structure achieves its high performance without the use of sulfur hexafluoride.

  17. High-speed, high-voltage pulse generation using avalanche transistor.

    PubMed

    Yong-Sheng, Gou; Bai-Yu, Liu; Yong-Lin, Bai; Jun-Jun, Qin; Xiao-Hong, Bai; Bo, Wang; Bing-Li, Zhu; Chuan-Dong, Sun

    2016-05-01

    In this work, the conduction mechanism of avalanche transistors was demonstrated and the operation condition for generating high-speed pulse using avalanche transistors was illustrated. Based on the above analysis, a high-speed and high-voltage pulse (HHP) generating circuit using avalanche transistors was designed, and its working principle and process were studied. To improve the speed of the output pulse, an approach of reducing the rise time of the leading edge is proposed. Methods for selecting avalanche transistor and reducing the parasitic inductance and capacitance of printed circuit board (PCB) were demonstrated. With these instructions, a PCB with a tapered transmission line was carefully designed and manufactured. Output pulse with amplitude of 2 kV and rise time of about 200 ps was realized with this PCB mounted with avalanche transistors FMMT417, indicating the effectiveness of the HHP generating circuit design.

  18. High-speed, high-voltage pulse generation using avalanche transistor

    NASA Astrophysics Data System (ADS)

    Yong-sheng, Gou; Bai-yu, Liu; Yong-lin, Bai; Jun-jun, Qin; Xiao-hong, Bai; Bo, Wang; Bing-li, Zhu; Chuan-dong, Sun

    2016-05-01

    In this work, the conduction mechanism of avalanche transistors was demonstrated and the operation condition for generating high-speed pulse using avalanche transistors was illustrated. Based on the above analysis, a high-speed and high-voltage pulse (HHP) generating circuit using avalanche transistors was designed, and its working principle and process were studied. To improve the speed of the output pulse, an approach of reducing the rise time of the leading edge is proposed. Methods for selecting avalanche transistor and reducing the parasitic inductance and capacitance of printed circuit board (PCB) were demonstrated. With these instructions, a PCB with a tapered transmission line was carefully designed and manufactured. Output pulse with amplitude of 2 kV and rise time of about 200 ps was realized with this PCB mounted with avalanche transistors FMMT417, indicating the effectiveness of the HHP generating circuit design.

  19. High voltage space plasma interactions. [charging the solar power satellites

    NASA Technical Reports Server (NTRS)

    Mccoy, J. E.

    1980-01-01

    Two primary problems resulted from plasma interactions; one of concern to operations in geosynchronous orbit (GEO), the other in low orbits (LEO). The two problems are not the same. Spacecraft charging has become widely recognized as a problem, particularly for communications satellites operating in GEO. The very thin thermal plasmas at GEO are insufficient to bleed off voltage buildups due to higher energy charged particle radiation collected on outer surfaces. Resulting differential charging/discharging causes electrical transients, spurious command signals and possible direct overload damage. An extensive NASA/Air Force program has been underway for several years to address this problem. At lower altitudes, the denser plasmas of the plasmasphere/ionosphere provide sufficient thermal current to limit such charging to a few volts or less. Unfortunately, these thermal plasma currents which solve the GEO spacecraft charging problem can become large enough to cause just the opposite problem in LEO.

  20. A low-voltage high-speed electronic switch based on piezoelectric transduction

    NASA Astrophysics Data System (ADS)

    Newns, Dennis; Elmegreen, Bruce; Hu Liu, Xiao; Martyna, Glenn

    2012-04-01

    We propose a novel digital switch, the piezoelectronic transistor or PET. Based on properties of known materials, we predict that a nanometer-scale PET can operate at low voltages and relatively high speeds, exceeding the capabilities of any conventional field effect transistor (FET). Depending on the degree to which these attributes can be simultaneously achieved, the device has a broad array of potential applications in digital logic. The PET is a 3-terminal switch in which a gate voltage is applied to a piezoelectric (PE), resulting in expansion compressing a piezoresistive (PR) material comprising the channel, which then undergoes a continuous, reversible insulator-metal transition. The channel becomes conducting in response to the gate voltage. A high piezoelectric coefficient PE, e.g., a relaxor piezoelectric, leads to low voltage operation. Suitable channel materials manifesting a pressure-induced metal-insulator transition can be found amongst rare earth chalcogenides, transition metal oxides, and among others. Mechanical requirements include a high PE/PR area ratio to step up pressure, a rigid surround material to constrain the PE and PR external boundaries normal to the strain axis, and a void space to enable free motion of the component side walls. Using static mechanical modeling and dynamic electro-acoustic simulations, we optimize device structure and materials and predict performance.

  1. High voltage design structure for high temperature superconducting device

    DOEpatents

    Tekletsadik, Kasegn D.

    2008-05-20

    In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

  2. Highly tunable local gate controlled complementary graphene device performing as inverter and voltage controlled resistor.

    PubMed

    Kim, Wonjae; Riikonen, Juha; Li, Changfeng; Chen, Ya; Lipsanen, Harri

    2013-10-04

    Using single-layer CVD graphene, a complementary field effect transistor (FET) device is fabricated on the top of separated back-gates. The local back-gate control of the transistors, which operate with low bias at room temperature, enables highly tunable device characteristics due to separate control over electrostatic doping of the channels. Local back-gating allows control of the doping level independently of the supply voltage, which enables device operation with very low VDD. Controllable characteristics also allow the compensation of variation in the unintentional doping typically observed in CVD graphene. Moreover, both p-n and n-p configurations of FETs can be achieved by electrostatic doping using the local back-gate. Therefore, the device operation can also be switched from inverter to voltage controlled resistor, opening new possibilities in using graphene in logic circuitry.

  3. Extremum seeking-based optimization of high voltage converter modulator rise-time

    SciTech Connect

    Scheinker, Alexander; Bland, Michael; Krstic, Miroslav; Audia, Jeff

    2013-02-01

    We digitally implement an extremum seeking (ES) algorithm, which optimizes the rise time of the output voltage of a high voltage converter modulator (HVCM) at the Los Alamos Neutron Science Center (LANSCE) HVCM test stand by iteratively, simultaneously tuning the first 8 switching edges of each of the three phase drive waveforms (24 variables total). We achieve a 50 μs rise time, which is reduction in half compared to the 100 μs achieved at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. Considering that HVCMs typically operate with an output voltage of 100 kV, with a 60Hz repetition rate, the 50 μs rise time reduction will result in very significant energy savings. The ES algorithm will prove successful, despite the noisy measurements and cost calculations, confirming the theoretical results that the algorithm is not affected by noise whose frequency components are independent of the perturbing frequencies.

  4. Partial discharge measurements on a high voltage direct current mass impregnated paper cable

    SciTech Connect

    Jeroense, M.J.P.; Kreuger, F.H.

    1996-12-31

    Partial discharge measurement has been a good tool for the quality assurance of cables under alternating voltage. With the growing interest in High Voltage Direct Current cables it seems therefore logical to extend this technique for use at direct voltage. The paper describes this technique as used on a HVDC cable with mass impregnated paper. The different phases of operation (no load, full load, cooling phase, etc.) are characterized by a different discharge behavior. Special attention is given to the dangerous cooling phase. Models have been developed which can explain the discharge patterns that were measured. This paper gives an insight in the electrical behavior of a HVDC cable with mass impregnated paper insulation.

  5. Field emission studies toward improving the performance of DC high voltage photoelectron guns

    NASA Astrophysics Data System (ADS)

    BastaniNejad, Mahzad

    Field emission is the main mechanism that prevents DC high voltage photoemission electron guns from operating at the very high bias voltages required to produce low emittance beams. Gas conditioning is shown to eliminate field emission from cathode electrodes used inside DC high voltage photoelectron guns. Measurements and simulation results indicate that gas conditioning eliminates field emission from cathode electrodes via two mechanisms: sputtering and implantation, with the benefits of implantation reversed by heating the electrode. The field emission characteristics of 5 stainless steel electrodes varied significantly upon the initial application of voltage but improved to nearly the same level after helium and krypton gas conditioning, exhibiting less than 10 pA field emission at - 225kV bias voltage with a 50 mm cathode/anode gap, corresponding to a field strength ˜ 13 MV/m. Field emission could be reduced with either krypton or helium, but there were conditions related to gas choice, voltage and field strength that were more favorable than others. The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. Out of 8 electrodes (6 niobium and 2 stainless steel), the best niobium electrode performed better than the best stainless steel electrodes. Large grain niobium exhibited no measurable field emission (< 10 pA) at 225 kV with 20 mm cathode/anode gap, corresponding to a field strength of 18.7 MV/m. Surface evaluation of all electrodes suggested no correlation between the surface roughness and the field emission current. Removing surface particulate contaminations and protrusions using an effective polishing and cleaning technique helps to prevent field emission. Mechanical polishing using silicon carbide paper and diamond paste is a common method of obtaining a mirror like surface finish on the cathode electrodes. However, it sometimes results rolled

  6. Experimental validation of a high voltage pulse measurement method.

    SciTech Connect

    Cular, Stefan; Patel, Nishant Bhupendra; Branch, Darren W.

    2013-09-01

    This report describes X-cut lithium niobates (LiNbO3) utilization for voltage sensing by monitoring the acoustic wave propagation changes through LiNbO3 resulting from applied voltage. Direct current (DC), alternating current (AC) and pulsed voltage signals were applied to the crystal. Voltage induced shift in acoustic wave propagation time scaled quadratically for DC and AC voltages and linearly for pulsed voltages. The measured values ranged from 10 - 273 ps and 189 ps 2 ns for DC and non-DC voltages, respectively. Data suggests LiNbO3 has a frequency sensitive response to voltage. If voltage source error is eliminated through physical modeling from the uncertainty budget, the sensors U95 estimated combined uncertainty could decrease to ~0.025% for DC, AC, and pulsed voltage measurements.

  7. Method for reducing fuel cell output voltage to permit low power operation

    DOEpatents

    Reiser, Carl A.; Landau, Michael B.

    1980-01-01

    Fuel cell performance is degraded by recycling a portion of the cathode exhaust through the cells and, if necessary, also reducing the total air flow to the cells for the purpose of permitting operation below a power level which would otherwise result in excessive voltage.

  8. Real time diagnostic for operation at a CW low voltage FEL

    SciTech Connect

    Balfour, C.; Shaw, A.; Mayhew, S.E.

    1995-12-31

    At Liverpool University, a system for single user control of an FEL has been designed to satisfy the low voltage FEL (ie 200kV) operational requirements. This system incorporates many aspects of computer automation for beam diagnostics, radiation detection and vacuum system management. In this paper the results of the development of safety critical control systems critical control systems are reported.

  9. High Voltage Power Supply Design Guide for Space

    NASA Technical Reports Server (NTRS)

    Bever, Renate S.; Ruitberg, Arthur P.; Kellenbenz, Carl W.; Irish, Sandra M.

    2006-01-01

    This book is written for newcomers to the topic of high voltage (HV) in space and is intended to replace an earlier (1970s) out-of-print document. It discusses the designs, problems, and their solutions for HV, mostly direct current, electric power, or bias supplies that are needed for space scientific instruments and devices, including stepping supplies. Output voltages up to 30kV are considered, but only very low output currents, on the order of microamperes. The book gives a brief review of the basic physics of electrical insulation and breakdown problems, especially in gases. It recites details about embedment and coating of the supplies with polymeric resins. Suggestions on HV circuit parts follow. Corona or partial discharge testing on the HV parts and assemblies is discussed both under AC and DC impressed test voltages. Electric field analysis by computer on an HV device is included in considerable detail. Finally, there are many examples given of HV power supplies, complete with some of the circuit diagrams and color photographs of the layouts.

  10. The advantages of the high voltage solar array for electric propulsion

    NASA Technical Reports Server (NTRS)

    Sater, B. L.

    1973-01-01

    The high voltage solar array (HVSA) offers improvements in efficiency, weight, and reliability for the electric propulsion power system. The basic HVSA technology involves designing the solar array to deliver power in the form required by the ion thruster. This paper delves into conventional power processes and problems associated with ion thruster operation using SERT II experience for examples. In this light, the advantages of the HVSA concept for electric propulsion are presented. Tests conducted operating the SERT II thruster system in conjunction with HVSA are discussed. Thruster operation was observed to be normal and in some respects improved.

  11. Digital radiology using active matrix readout of amorphous selenium: detectors with high voltage protection.

    PubMed

    Zhao, W; Law, J; Waechter, D; Huang, Z; Rowlands, J A

    1998-04-01

    A flat-panel x-ray imaging detector is being investigated for digital radiography and fluoroscopy. The detector uses a layer of amorphous selenium (a-Se) to convert x rays to a charge image, which is then electronically read out with a two-dimensional array of thin film transistors (TFTs). In order to sensitize the a-Se layer to x rays, a high voltage (of the order of several thousand volts) is applied to its top surface. The TFTs, which are at the bottom surface of the a-Se layer, are not subjected to any high voltage under normal radiological operational conditions since the pixel potential is < 10 V. However under a fault condition where these two events occur simultaneously: (1) suspended detector scan; and (2) an x-ray exposure more than ten times higher than normal, the voltage on the TFTs could rise to a damaging value. This paper describes a method for protecting the TFTs from high voltage damage under this fault condition. It employs a dual-gate TFT structure, one gate is for scanning control and the other is connected to the pixel electrode for high voltage protection. Before the pixel potential reaches a damaging value, the protection gate turns on the TFT automatically and drains excess charge away from the pixel thus providing a safe pixel saturation potential. In this paper, the characteristic curves of dual-gate TFTs are studied both theoretically and experimentally. The pixel x-ray response for imaging detectors with high voltage protection are predicted, and it is shown that with practical TFT designs the detector can provide a safe pixel saturation potential as well as satisfy the dynamic range required for diagnostic x-ray imaging applications.

  12. Pickup impact on high-voltage multifinger LDMOS-SCR with low trigger voltage and high failure current

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Jin, Xiangliang; Wang, Yang; Zhou, Acheng

    2015-12-01

    The impact of inserting P+ pickup on high-voltage multi-finger laterally diffused metal-oxide-semiconductor-silicon-controlled rectifier (LDMOS-SCR) has been studied in this article. Four-finger LDMOS-SCR structures with finger length of 50 μm using 0.5 μm 18 V complementarily diffused metal oxide semiconductor (CDMOS) process were fabricated and tested. Theoretical analysis is carried out to make detailed comparisons between LDMOS-SCR with and without P+ pickup. It verifies that the multi-finger LDMOS-SCR with P+ pickup has greater electrostatic discharge (ESD) robustness and effectiveness. Furthermore, transmission line pulse (TLP) test has been done and the results show that the trigger voltage (Vt1) of the LDMOS-SCR with P+ pickup remarkably decreases from 46.19 to 35.39 V and the second breakdown current (It2) effectively increases from 8.13 to 10.08 A.

  13. Low-voltage operation of n-type organic field-effect transistors with ionic liquid

    NASA Astrophysics Data System (ADS)

    Uemura, T.; Yamagishi, M.; Ono, S.; Takeya, J.

    2009-09-01

    High performance n-type organic field-effect transistors are developed to achieve high transconductance and low-threshold voltage using ionic-liquid electrolyte for intense electrostatic gating. Tetracyanoquinodimethane single crystals and C60 thin films are interfaced with ionic liquid of 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide known for its low viscosity and high ionic conductivity, so that high-density electrons are rapidly accumulated in the semiconductor surfaces with the application of minimum gate voltages, forming 1-nm thick electric double layers to concentrate electric field as high as 1 MV/cm. The C60 transistor shows the highest normalized transconductance among reported n-type organic transistors, together with minimum threshold voltage.

  14. Curing system for high voltage cross linked cables

    DOEpatents

    Bahder, George; Katz, Carlos; Bopp, Louis A.

    1978-01-01

    This invention makes extruded, vulcanized, high voltage cables insulated with thermosetting compounds at much higher rates of production and with superior insulation of reduced thickness and with reduced cavities or voids in the insulation. As the cable comes from an extruder, it passes into a curing chamber with a heat booster that quickly raises the insulation to a temperature at which it is cured much more quickly than with steam heating of the prior art. A high temperature liquid in contact with the insulation maintains the high temperature; and because of the greater curing heat, the cable can travel through the curing chamber at a faster rate and into a cooling tube where it contacts with a cooling liquid under high pressure. The insulation compound is treated to reduce the size of cavities; and the high pressure maintained by the curing and cooling mediums prevent expansion of cavities before the insulation is set.

  15. DEMONSTRATION BULLETIN: HIGH VOLTAGE ELECTRON BEAM TECHNOLOGY - HIGH VOLTAGE ENVIRONMENTAL APPLICATIONS, INC.

    EPA Science Inventory

    The high energy electron beam irradiation technology is a low temperature method for destroying complex mixtures of hazardous organic chemicals in solutions containing solids. The system consists of a computer-automated, portable electron beam accelerator and a delivery system. T...

  16. Relationship between the blue response and open-circuit voltage of high performance silicon solar cells

    NASA Technical Reports Server (NTRS)

    Green, M. A.; Blakers, A. W.

    1983-01-01

    The relationship between the response at blue wavelengths and the open-circuit voltage of high performance silicon solar cells with a virtually 'transparent' emitter is analyzed. It is shown that a one-dimensional cell model cannot simultaneously model the optical collection properties and operating characteristics of such cells. The analysis highlights the importance of surface conditions and shows that previous conclusions regarding bounds on Auger coefficients imposed by correlating these parameters must be treated with caution.

  17. Investigation into the High Voltage Shutdown of the Oxygen Generator System in the International Space Station

    NASA Technical Reports Server (NTRS)

    Carpenter, Joyce E.; Gentry, Gregory J.; Diderich, Greg S.; Roy, Robert J.; Golden, John L.; VanKeuren, Steve; Steele, John W.; Rector, Tony J.; Varsik, Jerome D.; Montefusco, Daniel J.; Wilson, Mark E.; Worthy, Erica S.

    2012-01-01

    The Oxygen Generation System (OGS) Hydrogen Dome Assembly Orbital Replacement Unit (ORU) serial number 00001 suffered a cell stack high-voltage shutdown on July 5, 2010. The Hydrogen Dome Assembly ORU was removed and replaced with the on-board spare ORU serial number 00002 to maintain OGS operation. The Hydrogen Dome Assembly ORU was returned from ISS on STS-133/ULF-5 in March 2011 with test, teardown and evaluation (TT&E) and failure analysis to follow.

  18. Novel High-Voltage, High-Power Piezoelectric Transformer Developed and Demonstrated for Space Communications Applications

    NASA Technical Reports Server (NTRS)

    Carazo, Alfredo V.; Wintucky, Edwin G.

    2004-01-01

    Improvements in individual piezoelectric transformer (PT) performance and the combination of these PTs in a unique modular topology under a Phase I contract with the NASA Glenn Research Center have enabled for the first time the simultaneous achievement of both high voltage and high power at much higher levels than previously obtained with any PT. Feasibility was demonstrated by a prototype transformer (called a Tap-Soner), which is shown in the preceding photograph as part of a direct-current to direct-current (dc-dc) converter having two outputs rated at 1.5 kV/5 W and 4.5 kV/20 W. The power density of 3.5 W/cm3 is significantly lower than for magnetic transformers with the same voltage and power output. This development, which is being done under a Small Business Innovation Research (SBIR) contract by Face Electronics, LC (Norfolk, VA), is based on improvements in the materials and design of Face's basic patented Transoner-T3 PT, shown in the left in the following figure. The T3 PT is most simply described as a resonant multilayer transducer where electrical energy at the input section is efficiently mechanically coupled to the output section, which then vibrates in a fundamental longitudinal mode to generate a high gain in voltage. The piezoelectric material used is a modified lead-zirconium-titanate-based ceramic. One of the significant improvements in PT design was the incorporation of a symmetrical double input layer, shown on the right in the following figure, which eliminated the lossy bending vibration modes characteristic of a single input layer. The performance of the improved PT was optimized to 1.5 kV/5 W. The next step was devising a way to combine the individual PTs in a modular circuit topology needed to achieve the desired high voltage and power output. Since the optimum performance of the individual PT occurs at resonance, the most efficient operation of the modular transformer was achieved by using a separate drive circuit for each PT. The

  19. A SiC NMOS Linear Voltage Regulator for High-Temperature Applications

    SciTech Connect

    Valle-Mayorga, JA; Rahman, A; Mantooth, HA

    2014-05-01

    The first SiC integrated circuit linear voltage regulator is reported. The voltage regulator uses a 20-V supply and generates an output of 15 V, adjustable down to 10 V. It was designed for loads of up to 2 A over a temperature range of 25-225 degrees C. It was, however, successfully tested up to 300 degrees C. The voltage regulator demonstrated load regulations of 1.49% and 9% for a 2-A load at temperatures of 25 and 300 degrees C, respectively. However, the load regulation is less than 2% up to 300 degrees C for a 1-A load. The line regulation with a 2-A load at 25 and 300 degrees C was 17 and 296 mV/V, respectively. The regulator was fabricated in a Cree 4H-SiC 2-mu m experimental process and consists of 1000, 32/2-mu m NMOS depletion MOSFETs as the pass device, an integrated error amplifier with enhancement MOSFETs, and resistor loads, and uses external feedback and compensation networks to ensure operational integrity. It was designed to be integrated with high-voltage vertical power MOSFETs on the same SiC substrate. It also serves as a guide to future attempts for voltage regulation in any type of integrated SiC circuitry.

  20. A novel ZVS high voltage power supply for micro-channel plate photomultiplier tubes

    NASA Astrophysics Data System (ADS)

    Pei, Chengquan; Tian, Jinshou; Liu, Zhen; Qin, Hong; Wu, Shengli

    2017-04-01

    A novel resonant high voltage power supply (HVPS) with zero voltage switching (ZVS), to reduce the voltage stress on switching devices and improve conversion efficiency, is proposed. The proposed HVPS includes a drive circuit, a transformer, several voltage multiplying circuits, and a regulator circuit. The HVPS contains several secondary windings that can be precisely regulated. The proposed HVPS performed better than the traditional resistor voltage divider, which requires replacing matching resistors resulting in resistor dispersibility in the Micro-Channel Plate (MCP). The equivalent circuit of the proposed HVPS was established and the operational principle analyzed. The entire switching element can achieve ZVS, which was validated by a simulation and experiments. The properties of this HVPS were tested including minimum power loss (240 mW), maximum power loss (1 W) and conversion efficiency (85%). The results of this research are that the proposed HVPS was suitable for driving the micro-channel plate photomultiplier tube (MCP-PMT). It was therefore adopted to test the MCP-PMT, which will be used in Daya Bay reactor neutrino experiment II in China.

  1. Preliminary chaotic model of snapover on high voltage solar cells

    NASA Technical Reports Server (NTRS)

    Mackey, Willie R.

    1995-01-01

    High voltage power systems in space will interact with the space plasma in a variety of ways. One of these, snapover, is characterized by sudden enlargement of the current collection area across normally insulating surfaces generating enhanced electron current collection. Power drain on solar array power systems results from this enhanced current collection. Optical observations of the snapover phenomena in the laboratory indicates a functional relation between glow area and bia potential as a consequence of the fold/cusp bifurcation in chaos theory. Successful characterizations of snapover as a chaotic phenomena may provide a means of snapover prevention and control through chaotic synchronization.

  2. High-voltage R-F feedthrough bushing

    DOEpatents

    Grotz, G.F.

    1982-09-03

    Described is a multi-element, high voltage radio frequency bushing for transmitting rf energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

  3. Self-monitoring high voltage transmission line suspension insulator

    DOEpatents

    Stemler, Gary E.; Scott, Donald N.

    1981-01-01

    A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.

  4. Schottky bipolar I-MOS: An I-MOS with Schottky electrodes and an open-base BJT configuration for reduced operating voltage

    NASA Astrophysics Data System (ADS)

    Kannan, N.; Kumar, M. Jagadesh

    2017-04-01

    In this paper, we have proposed a novel impact ionization MOS (I-MOS) structure, called the Schottky bipolar I-MOS, with Schottky source and drain electrodes and utilizing the open-base bipolar junction transistor (BJT) configuration for achieving reduction in the operating voltage of the I-MOS transistor. We report, using 2-D simulations, a low operating voltage (∼1.1 V) and a low subthreshold swing (∼3.6 mV/Decade). For the corresponding p-i-n I-MOS, the operating voltage is ∼5.5 V. The operating voltage of the Schottky bipolar I-MOS is the lowest reported operating voltage for silicon based I-MOS transistors. The nearly 80% reduction in the operating voltage of the Schottky bipolar I-MOS makes it suitable for applications requiring low operating voltages. The Schottky bipolar I-MOS is also expected to have an improved reliability over the p-i-n I-MOS since high energy carriers, induced by impact ionization near the drain, do not have to pass under the gate region in the channel. The use of Schottky contacts instead of heavily doped source and drain regions and the low channel doping level reduces the required thermal budget for device fabrication. The low operating voltage, low subthreshold swing and possibly improved reliability of the Schottky bipolar I-MOS, makes it a potential solution for applications where steep subthreshold slope transistors are being explored as alternative to the conventional MOS transistor.

  5. High voltage studies of inverted-geometry ceramic insulators for a 350 kV DC polarized electron gun

    SciTech Connect

    Hernandez-Garcia, C.; Poelker, M.; Hansknecht, J.

    2016-02-01

    Jefferson Lab is constructing a 350 kV direct current high voltage photoemission gun employing a compact inverted-geometry insulator. This photogun will produce polarized electron beams at an injector test facility intended for low energy nuclear physics experiments, and to assist the development of new technology for the Continuous Electron Beam Accelerator Facility. A photogun operating at 350kV bias voltage reduces the complexity of the injector design, by eliminating the need for a graded-beta radio frequency “capture” section employed to boost lower voltage beams to relativistic speed. However, reliable photogun operation at 350 kV necessitates solving serious high voltage problems related to breakdown and field emission. This study focuses on developing effective methods to avoid breakdown at the interface between the insulator and the commercial high voltage cable that connects the photogun to the high voltage power supply. Three types of inverted insulators were tested, in combination with two electrode configurations. Our results indicate that tailoring the conductivity of the insulator material, and/or adding a cathode triple-junction screening electrode, effectively serves to increase the hold-off voltage from 300kV to more than 375kV. In conclusion, electrostatic field maps suggest these configurations serve to produce a more uniform potential gradient across the insulator.

  6. High voltage studies of inverted-geometry ceramic insulators for a 350 kV DC polarized electron gun

    DOE PAGES

    Hernandez-Garcia, C.; Poelker, M.; Hansknecht, J.

    2016-02-01

    Jefferson Lab is constructing a 350 kV direct current high voltage photoemission gun employing a compact inverted-geometry insulator. This photogun will produce polarized electron beams at an injector test facility intended for low energy nuclear physics experiments, and to assist the development of new technology for the Continuous Electron Beam Accelerator Facility. A photogun operating at 350kV bias voltage reduces the complexity of the injector design, by eliminating the need for a graded-beta radio frequency “capture” section employed to boost lower voltage beams to relativistic speed. However, reliable photogun operation at 350 kV necessitates solving serious high voltage problems relatedmore » to breakdown and field emission. This study focuses on developing effective methods to avoid breakdown at the interface between the insulator and the commercial high voltage cable that connects the photogun to the high voltage power supply. Three types of inverted insulators were tested, in combination with two electrode configurations. Our results indicate that tailoring the conductivity of the insulator material, and/or adding a cathode triple-junction screening electrode, effectively serves to increase the hold-off voltage from 300kV to more than 375kV. In conclusion, electrostatic field maps suggest these configurations serve to produce a more uniform potential gradient across the insulator.« less

  7. Optimizing the CEBAF Injector for Beam Operation with a Higher Voltage Electron Gun

    SciTech Connect

    F.E. Hannon, A.S. Hofler, R. Kazimi

    2011-03-01

    Recent developments in the DC gun technology used at CEBAF have allowed an increase in operational voltage from 100kV to 130kV. In the near future this will be extended further to 200kV with the purchase of a new power supply. The injector components and layout at this time have been designed specifically for 100kV operation. It is anticipated that with an increase in gun voltage and optimization of the layout and components for 200kV operation, that the electron bunch length and beam brightness can be improved upon. This paper explores some upgrade possibilities for a 200kV gun CEBAF injector through beam dynamic simulations.

  8. Radiation damage in high voltage silicon solar cells

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Brandhorst, H., Jr.; Swartz, C. K.; Weizer, V. G.

    1980-01-01

    Three high open-circuit voltage cell designs based on 0.1 ohm-cm p-type silicon were irradiated with 1 MeV electrons and their performance determined to fluences as high as 10 to the 15th power/sq cm. Of the three cell designs, radiation induced degradation was greatest in the high-low emitter (HLE cell). The diffused and ion implanted cells degraded approximately equally but less than the HLE cell. Degradation was greatest in an HLE cell exposed to X-rays before electron irradiation. The cell regions controlling both short-circuit current and open-circuit voltage degradation were defined in all three cell types. An increase in front surface recombination velocity accompanied time dependent degradation of an HLE cell after X-irradiation. It was speculated that this was indirectly due to a decrease in positive charge at the silicon-oxide interface. Modifications aimed at reducing radiation induced degradation are proposed for all three cell types.

  9. A complementary organic inverter of porphyrazine thin films: low-voltage operation using ionic liquid gate dielectrics.

    PubMed

    Fujimoto, Takuya; Miyoshi, Yasuhito; Matsushita, Michio M; Awaga, Kunio

    2011-05-28

    We studied a complementary organic inverter consisting of a p-type semiconductor, metal-free phthalocyanine (H(2)Pc), and an n-type semiconductor, tetrakis(thiadiazole)porphyrazine (H(2)TTDPz), operated through the ionic-liquid gate dielectrics of N,N-diethyl-N-methyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide (DEME-TFSI). This organic inverter exhibits high performance with a very low operation voltage below 1.0 V and a dynamic response up to 20 Hz.

  10. 30 CFR 77.704-1 - Work on high-voltage lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on high-voltage lines. 77.704-1 Section 77... MINES Grounding § 77.704-1 Work on high-voltage lines. (a) No high-voltage line shall be regarded as... provided in § 77.103) that such high-voltage line has been deenergized and grounded. Such qualified...

  11. 30 CFR 75.511 - Low-, medium-, or high-voltage distribution circuits and equipment; repair.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low-, medium-, or high-voltage distribution... Electrical Equipment-General § 75.511 Low-, medium-, or high-voltage distribution circuits and equipment; repair. No electrical work shall be performed on low-, medium-, or high-voltage distribution circuits...

  12. 30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers; record of...

  13. 30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers; record of...

  14. 30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers; record of...

  15. 30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers; record of...

  16. 30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers; record of...

  17. 30 CFR 75.511 - Low-, medium-, or high-voltage distribution circuits and equipment; repair.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Low-, medium-, or high-voltage distribution... Electrical Equipment-General § 75.511 Low-, medium-, or high-voltage distribution circuits and equipment; repair. No electrical work shall be performed on low-, medium-, or high-voltage distribution circuits...

  18. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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. High-voltage circuits entering the underground area of any coal mine shall be protected by suitable circuit breakers of adequate interrupting...

  19. 78 FR 20949 - Proposed Collection; Comment Request; High-Voltage Continuous Mining Machines Standards for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... Safety and Health Administration Proposed Collection; Comment Request; High-Voltage Continuous Mining... collection maintains the safe use of high-voltage continuous mining machines in underground coal mines by... high-voltage continuous mining machine standards for underground coal mines. MSHA is...

  20. 30 CFR 18.53 - High-voltage longwall mining systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-voltage longwall mining systems. 18.53..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage...

  1. 30 CFR 18.53 - High-voltage longwall mining systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-voltage longwall mining systems. 18.53..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage...

  2. 30 CFR 18.53 - High-voltage longwall mining systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-voltage longwall mining systems. 18.53..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage...

  3. 30 CFR 18.53 - High-voltage longwall mining systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-voltage longwall mining systems. 18.53..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage...

  4. 30 CFR 75.511 - Low-, medium-, or high-voltage distribution circuits and equipment; repair.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Low-, medium-, or high-voltage distribution... Electrical Equipment-General § 75.511 Low-, medium-, or high-voltage distribution circuits and equipment; repair. No electrical work shall be performed on low-, medium-, or high-voltage distribution circuits...

  5. 30 CFR 75.511 - Low-, medium-, or high-voltage distribution circuits and equipment; repair.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Low-, medium-, or high-voltage distribution... Electrical Equipment-General § 75.511 Low-, medium-, or high-voltage distribution circuits and equipment; repair. No electrical work shall be performed on low-, medium-, or high-voltage distribution circuits...

  6. 30 CFR 75.511 - Low-, medium-, or high-voltage distribution circuits and equipment; repair.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Low-, medium-, or high-voltage distribution... Electrical Equipment-General § 75.511 Low-, medium-, or high-voltage distribution circuits and equipment; repair. No electrical work shall be performed on low-, medium-, or high-voltage distribution circuits...

  7. 30 CFR 75.705-2 - Repairs to energized surface high-voltage lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Repairs to energized surface high-voltage lines. 75.705-2 Section 75.705-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... Repairs to energized surface high-voltage lines. An energized high-voltage surface line may be...

  8. 30 CFR 75.802 - Protection of high-voltage circuits extending underground.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of high-voltage circuits extending... LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.802 Protection of high-voltage circuits extending underground. (a) Except...

  9. 30 CFR 77.704-10 - Tying into energized high-voltage surface circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tying into energized high-voltage surface... AREAS OF UNDERGROUND COAL MINES Grounding § 77.704-10 Tying into energized high-voltage surface circuits. If the work of forming an additional circuit by tying into an energized high-voltage surface line...

  10. 30 CFR 75.807 - Installation of high-voltage transmission cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Installation of high-voltage transmission... LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.807 Installation of high-voltage transmission cables. All underground...

  11. 30 CFR 75.705-10 - Tying into energized high-voltage surface circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tying into energized high-voltage surface....705-10 Tying into energized high-voltage surface circuits. If the work of forming an additional circuit by tying into an energized high-voltage surface line is performed from the ground, any...

  12. 30 CFR 75.705-1 - Work on high-voltage lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on high-voltage lines. 75.705-1 Section 75... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.705-1 Work on high-voltage lines. (a) Section 75.705 specifically prohibits work on energized high-voltage lines underground;...

  13. 30 CFR 75.811 - High-voltage underground equipment; grounding.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage underground equipment; grounding... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.811 High-voltage underground equipment; grounding. Frames, supporting structures...

  14. Low power, high voltage power supply with fast rise/fall time

    NASA Technical Reports Server (NTRS)

    Bearden, Douglas B. (Inventor)

    2007-01-01

    A low power, high voltage power supply system includes a high voltage power supply stage and a preregulator for programming the power supply stage so as to produce an output voltage which is a predetermined fraction of a desired voltage level. The power supply stage includes a high voltage, voltage doubler stage connected to receive the output voltage from the preregulator and for, when activated, providing amplification of the output voltage to the desired voltage level. A first feedback loop is connected between the output of the preregulator and an input of the preregulator while a second feedback loop is connected between the output of the power supply stage and the input of the preregulator.

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

    PubMed Central

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

    2012-01-01

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

  16. Low Power, High Voltage Power Supply with Fast Rise/Fall Time

    NASA Technical Reports Server (NTRS)

    Bearden, Douglas B. (Inventor)

    2007-01-01

    A low power, high voltage power supply system includes a high voltage power supply stage and a preregulator for programming the power supply stage so as to produce an output voltage which is a predetermined fraction of a desired voltage level. The power supply stage includes a high voltage, voltage doubler stage connected to receive the output voltage from the preregulator and for, when activated, providing amplification of the output voltage to the desired voltage level. A first feedback loop is connected between the output of the preregulator and an input of the preregulator while a second feedback loop is connected between the output of the power supply stage and the input of the preregulator.

  17. Parallel input parallel output high voltage bi-directional converters for driving dielectric electro active polymer actuators

    NASA Astrophysics Data System (ADS)

    Thummala, P.; Zhang, Z.; Andersen, M. A. E.; Rahimullah, S.

    2014-03-01

    Dielectric electroactive polymer (DEAP) actuators are capacitive devices which provide mechanical motions when charged electrically. The charging characteristics of a DEAP actuator depends on its size, voltage applied to its electrodes, and its operating frequency. The main idea of this paper is to design and implement driving circuits for the DEAP actuators for their use in various applications. This paper presents implementation of parallel input, parallel output, high voltage (~2.5 kV) bi-directional DC-DC converters for driving the DEAP actuators. The topology is a bidirectional flyback DC-DC converter incorporating commercially available high voltage MOSFETs (4 kV) and high voltage diodes (5 kV). Although the average current of the aforementioned devices is limited to 300 mA and 150 mA, respectively, connecting the outputs of multiple converters in parallel can provide a scalable design. This enables operating the DEAP actuators in various static and dynamic applications e.g. positioning, vibration generation or damping, and pumps. The proposed idea is experimentally verified by connecting three high voltage converters in parallel to operate a single DEAP actuator. The experimental results with both film capacitive load and the DEAP actuator are shown for a maximum charging voltage of 2 kV.

  18. Topics in recent studies with high-voltage electron microscopes.

    PubMed

    Mori, Hirotaro

    2011-01-01

    In this article, topics in recent studies with high-voltage electron microscopes (HVEMs) are reviewed. High-voltage electron microscopy possesses a number of advantages that cannot be afforded by conventional electron microscopy, thus providing a unique microscopy technique in both materials science and biological science. One of these advantages is the capability of continuously observing phenomena using a variety of electron microscopy techniques simultaneously with the introduction of the displacement of atoms from lattice points. This has enabled in-depth studies on such fundamental subjects as the crystalline-to-amorphous-to-crystalline transition, the motion properties of point defects and the one-dimensional diffusion of dislocation loops. Electron tomography studies using HVEMs take advantage of the large observable thickness of a specimen. In addition, by combining different advantages, a number of advanced applications in materials science have been carried out, including analyses of the atomic structure of a reduction-induced reconstructed surface and the atomic mechanism behind the self-catalytic vapor-liquid-solid growth of an oxide nanowire. As long as excellent and invaluable studies that cannot be carried out without HVEMs appear in succession, it is necessary to make the utmost efforts to improve these microscopes.

  19. Operational stability enhancement of low-voltage organic field-effect transistors based on bilayer polymer dielectrics

    NASA Astrophysics Data System (ADS)

    She, Xiao-Jian; Liu, Jie; Zhang, Jing-Yu; Gao, Xu; Wang, Sui-Dong

    2013-09-01

    Bilayer polymer dielectrics consisting of hydrophobic thin layers on high-k polyvinylalcohol (PVA) are utilized to realize p-type and n-type low-voltage organic field-effect transistors (OFETs), which show superior mobility and operational stability compared with the devices with PVA single-layer dielectric. The OFETs with top layers containing discrete π-groups, such as polystyrene (PS) and poly(2-vinyl naphthalene) (PVN), show stronger bias stress instability than those with π-group free polymethylmethacrylate (PMMA), and it is ascribed to slow charge trapping into the π-groups under bias stress. By integrating p-type and n-type low-voltage OFETs based on PMMA/PVA bilayer dielectric, a low-power high-stability complementary inverter is achieved.

  20. Cryogenic lifetime tests on a commercial epoxy resin high voltage bushing

    SciTech Connect

    Schwenterly, S W; Pleva, Ed; Ha, Tam T

    2012-06-12

    High-temperature superconducting (HTS) power devices operating in liquid nitrogen frequently require high-voltage bushings to carry the current leads from the superconducting windings to the room temperature grid connections. Oak Ridge National Laboratory is collaborating with Waukesha Electric Systems, SuperPower, and Southern California Edison to develop and demonstrate an HTS utility power transformer. Previous dielectric high voltage tests in support of this program have been carried out in test cryostats with commercial epoxy resin bushings from Electro Composites Inc. (ECI). Though the bushings performed well in these short-term tests, their long-term operation at high voltage in liquid nitrogen needs to be verified for use on the utility grid. Long-term tests are being carried out on a sample 28-kV-class ECI bushing. The bushing has a monolithic cast, cycloaliphatic resin body and is fire- and shatter-resistant. The test cryostat is located in an interlocked cage and is energized at 25 kVac around the clock. Liquid nitrogen (LN) is automatically refilled every 9.5 hours. Partial discharge, capacitance, and leakage resistance tests are periodically performed to check for deviations from factory values. At present, over 2400 hours have been accumulated with no changes in these parameters. The tests are scheduled to run for four to six months.

  1. Cryogenic lifetime tests on a commercial epoxy resin high voltage bushing

    NASA Astrophysics Data System (ADS)

    Schwenterly, S. W.; Pleva, E. F.; Ha, T. T.

    2012-06-01

    High-temperature superconducting (HTS) power devices operating in liquid nitrogen frequently require high-voltage bushings to carry the current leads from the superconducting windings to the room temperature grid connections. Oak Ridge National Laboratory (ORNL) is collaborating with Waukesha Electric Systems (WES), SuperPower (SP), and Southern California Edison (SCE) to develop and demonstrate an HTS utility power transformer. Previous dielectric high voltage tests in support of this program have been carried out in test cryostats with commercial epoxy resin bushings from Electro Composites Inc. (ECI). Though the bushings performed well in these short-term tests, their long-term operation at high voltage in liquid nitrogen (LN) needs to be verified for use on the utility grid. Long-term tests are being carried out on a sample 28-kV-rms-class ECI bushing. The bushing has a monolithic cast, cycloaliphatic resin body and is fire- and shatter-resistant. The test cryostat is located in an interlocked cage and is continuously energized at 25 kVac rms. LN is automatically refilled every 9.5 hours. Partial discharge, capacitance, and leakage resistance tests are periodically performed to check for deviations from factory values. At present, over 2400 hours have been accumulated with no changes in these parameters. The tests are scheduled to run for four to six months.

  2. The Effect of Current-Limiting Reactors on the Tripping of Short Circuits in High-Voltage Electrical Equipment

    SciTech Connect

    Volkov, M. S.; Gusev, Yu. P. Monakov, Yu. V.; Cho, Gvan Chun

    2016-01-15

    The insertion of current-limiting reactors into electrical equipment operating at a voltage of 110 and 220 kV produces a change in the parameters of the transient recovery voltages at the contacts of the circuit breakers for disconnecting short circuits, which could be the reason for the increase in the duration of the short circuit, damage to the electrical equipment and losses in the power system. The results of mathematical modeling of the transients, caused by tripping of the short circuit in a reactive electric power transmission line are presented, and data are given on the negative effect of a current-limiting resistor on the rate of increase and peak value of the transient recovery voltages. Methods of ensuring the standard requirements imposed on the parameters of the transient recovery voltages when using current-limiting reactors in the high-voltage electrical equipment of power plants and substations are proposed and analyzed.

  3. High-voltage scanning ion microscope: Beam optics and design

    NASA Astrophysics Data System (ADS)

    Magilin, D.; Ponomarev, A.; Rebrov, V.; Ponomarov, A.

    2015-05-01

    This article is devoted to the conceptual design of a compact high-voltage scanning ion microscope (HVSIM). In an HVSIM design, the ion optical system is based on a high-brightness ion source. Specifically, the ion optical system is divided into two components: an ion injector and a probe-forming system (PFS) that consists of an accelerating tube and a multiplet of quadrupole lenses. The crossover is formed and controlled by the injector, which acts as an object collimator, and is focused on the image plane by the PFS. The ion microprobe has a size of 0.1 μm and an energy of 2 MeV. When the influence of the chromatic and third-order aberrations is theoretically taken into account, the HVSIM forms an ion microprobe.

  4. Propylene based systems for high voltage cable insulation applications

    NASA Astrophysics Data System (ADS)

    Hosier, I. L.; Cozzarini, L.; Vaughan, A. S.; Swingler, S. G.

    2009-08-01

    Crosslinked polyethylene (XLPE) remains the material of choice for extruded high voltage cables, possessing excellent thermo-mechanical and electrical properties. However, it is not easily recyclable posing questions as to its long term sustainability. Whilst both polyethylene and polypropylene are widely recycled and provide excellent dielectric properties, polypropylene has significantly better mechanical integrity at high temperatures than polyethylene. However, while isotactic polypropylene is too stiff at room temperature for incorporation into a cable system, previous studies by the authors have indicated that this limitation can be overcome by using a propylene-ethylene copolymer. Whilst these previous studies considered unrelated systems, the current study aims to quantify the usefulness of a series of related random propylene-ethylene co-polymers and assesses their potential for replacing XLPE.

  5. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    SciTech Connect

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  6. High Voltage Dielectrophoretic and Magnetophoretic Hybrid Integrated Circuit / Microfluidic Chip

    PubMed Central

    Issadore, David; Franke, Thomas; Brown, Keith A.; Hunt, Thomas P.; Westervelt, Robert M.

    2010-01-01

    A hybrid integrated circuit (IC) / microfluidic chip is presented that independently and simultaneously traps and moves microscopic objects suspended in fluid using both electric and magnetic fields. This hybrid chip controls the location of dielectric objects, such as living cells and drops of fluid, on a 60 × 61 array of pixels that are 30 × 38 μm2 in size, each of which can be individually addressed with a 50 V peak-to-peak, DC to 10 MHz radio frequency voltage. These high voltage pixels produce electric fields above the chip’s surface with a magnitude , resulting in strong dielectrophoresis (DEP) forces . Underneath the array of DEP pixels there is a magnetic matrix that consists of two perpendicular sets of 60 metal wires running across the chip. Each wire can be sourced with 120 mA to trap and move magnetically susceptible objects using magnetophoresis (MP). The DEP pixel array and magnetic matrix can be used simultaneously to apply forces to microscopic objects, such as living cells or lipid vesicles, that are tagged with magnetic nanoparticles. The capabilities of the hybrid IC / microfluidic chip demonstrated in this paper provide important building blocks for a platform for biological and chemical applications. PMID:20625468

  7. High Voltage Dielectrophoretic and Magnetophoretic Hybrid Integrated Circuit / Microfluidic Chip.

    PubMed

    Issadore, David; Franke, Thomas; Brown, Keith A; Hunt, Thomas P; Westervelt, Robert M

    2009-12-01

    A hybrid integrated circuit (IC) / microfluidic chip is presented that independently and simultaneously traps and moves microscopic objects suspended in fluid using both electric and magnetic fields. This hybrid chip controls the location of dielectric objects, such as living cells and drops of fluid, on a 60 × 61 array of pixels that are 30 × 38 μm(2) in size, each of which can be individually addressed with a 50 V peak-to-peak, DC to 10 MHz radio frequency voltage. These high voltage pixels produce electric fields above the chip's surface with a magnitude , resulting in strong dielectrophoresis (DEP) forces . Underneath the array of DEP pixels there is a magnetic matrix that consists of two perpendicular sets of 60 metal wires running across the chip. Each wire can be sourced with 120 mA to trap and move magnetically susceptible objects using magnetophoresis (MP). The DEP pixel array and magnetic matrix can be used simultaneously to apply forces to microscopic objects, such as living cells or lipid vesicles, that are tagged with magnetic nanoparticles. The capabilities of the hybrid IC / microfluidic chip demonstrated in this paper provide important building blocks for a platform for biological and chemical applications.

  8. Piezoelectric transformer and modular connections for high power and high voltage power supplies

    NASA Technical Reports Server (NTRS)

    Vazquez Carazo, Alfredo (Inventor)

    2006-01-01

    A modular design for combining piezoelectric transformers is provided for high voltage and high power conversion applications. The input portions of individual piezoelectric transformers are driven for a single power supply. This created the vibration and the conversion of electrical to electrical energy from the input to the output of the transformers. The output portions of the single piezoelectric transformers are combining in series and/or parallel to provide multiple outputs having different rating of voltage and current.

  9. Atmospheric pressure microplasmas in ZnO nanoforests under high voltage stress

    NASA Astrophysics Data System (ADS)

    Noor, Nafisa; Manthina, Venkata; Cil, Kadir; Adnane, Lhacene; Agrios, Alexander G.; Gokirmak, Ali; Silva, Helena

    2015-09-01

    Atmospheric pressure ZnO microplasmas have been generated by high amplitude single pulses and DC voltages applied using micrometer-separated probes on ZnO nanoforests. The high voltage stress triggers plasma breakdown and breakdown in the surrounding air followed by sublimation of ZnO resulting in strong blue and white light emission with sharp spectral lines and non-linear current-voltage characteristics. The nanoforests are made of ZnO nanorods (NRs) grown on fluorine doped tin oxide (FTO) glass, poly-crystalline silicon and bulk p-type silicon substrates. The characteristics of the microplasmas depend strongly on the substrate and voltage parameters. Plasmas can be obtained with pulse durations as short as ˜1 μs for FTO glass substrate and ˜100 ms for the silicon substrates. Besides enabling plasma generation with shorter pulses, NRs on FTO glass substrate also lead to better tunability of the operating gas temperature. Hot and cold ZnO microplasmas have been observed with these NRs on FTO glass substrate. Sputtering of nanomaterials during plasma generation in the regions surrounding the test area has also been noticed and result in interesting ZnO nanostructures (`nano-flowers' and `nano-cauliflowers'). A practical way of generating atmospheric pressure ZnO microplasmas may lead to various lighting, biomedical and material processing applications.

  10. Design and power management of an offshore medium voltage DC microgrid realized through high voltage power electronics technologies and control

    NASA Astrophysics Data System (ADS)

    Grainger, Brandon Michael

    The growth in the electric power industry's portfolio of Direct Current (DC) based generation and loads have captured the attention of many leading research institutions. Opportunities for using DC based systems have been explored in electric ship design and have been a proven, reliable solution for transmitting bulk power onshore and offshore. To integrate many of the renewable resources into our existing AC grid, a number of power conversions through power electronics are required to condition the equipment for direct connection. Within the power conversion stages, there is always a requirement to convert to or from DC. The AC microgrid is a conceptual solution proposed for integrating various types of renewable generation resources. The fundamental microgrid requirements include the capability of operating in islanding mode and/or grid connected modes. The technical challenges associated with microgrids include (1) operation modes and transitions that comply with IEEE1547 without extensive custom engineering and (2) control architecture and communication. The Medium Voltage DC (MVDC) architecture, explored by the University of Pittsburgh, can be visualized as a special type of DC microgrid. This dissertation is multi-faceted, focused on many design aspects of an offshore DC microgrid. The focal points of the discussion are focused on optimized high power, high frequency magnetic material performance in electric machines, transformers, and DC/DC power converters---all components found within offshore, power system architectures. A new controller design based upon model reference control is proposed and shown to stabilize the electric motor drives (modeled as constant power loads), which serve as the largest power consuming entities in the microgrid. The design and simulation of a state-of-the-art multilevel converter for High Voltage DC (HVDC) is discussed and a component sensitivity analysis on fault current peaks is explored. A power management routine is

  11. A high frequency active voltage doubler in standard CMOS using offset-controlled comparators for inductive power transmission.

    PubMed

    Lee, Hyung-Min; Ghovanloo, Maysam

    2013-06-01

    In this paper, we present a fully integrated active voltage doubler in CMOS technology using offset-controlled high speed comparators for extending the range of inductive power transmission to implantable microelectronic devices (IMD) and radio-frequency identification (RFID) tags. This active voltage doubler provides considerably higher power conversion efficiency (PCE) and lower dropout voltage compared to its passive counterpart and requires lower input voltage than active rectifiers, leading to reliable and efficient operation with weakly coupled inductive links. The offset-controlled functions in the comparators compensate for turn-on and turn-off delays to not only maximize the forward charging current to the load but also minimize the back current, optimizing PCE in the high frequency (HF) band. We fabricated the active voltage doubler in a 0.5-μm 3M2P std . CMOS process, occupying 0.144 mm(2) of chip area. With 1.46 V peak AC input at 13.56 MHz, the active voltage doubler provides 2.4 V DC output across a 1 kΩ load, achieving the highest PCE = 79% ever reported at this frequency. In addition, the built-in start-up circuit ensures a reliable operation at lower voltages.

  12. A High Frequency Active Voltage Doubler in Standard CMOS Using Offset-Controlled Comparators for Inductive Power Transmission

    PubMed Central

    Lee, Hyung-Min; Ghovanloo, Maysam

    2014-01-01

    In this paper, we present a fully integrated active voltage doubler in CMOS technology using offset-controlled high speed comparators for extending the range of inductive power transmission to implantable microelectronic devices (IMD) and radio-frequency identification (RFID) tags. This active voltage doubler provides considerably higher power conversion efficiency (PCE) and lower dropout voltage compared to its passive counterpart and requires lower input voltage than active rectifiers, leading to reliable and efficient operation with weakly coupled inductive links. The offset-controlled functions in the comparators compensate for turn-on and turn-off delays to not only maximize the forward charging current to the load but also minimize the back current, optimizing PCE in the high frequency (HF) band. We fabricated the active voltage doubler in a 0.5-μm 3M2P std. CMOS process, occupying 0.144 mm2 of chip area. With 1.46 V peak AC input at 13.56 MHz, the active voltage doubler provides 2.4 V DC output across a 1 kΩ load, achieving the highest PCE = 79% ever reported at this frequency. In addition, the built-in start-up circuit ensures a reliable operation at lower voltages. PMID:23853321

  13. Charge and fluence lifetime measurements of a dc high voltage GaAs photogun at high average current

    SciTech Connect

    J. Grames, R. Suleiman, P.A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, M.L. Stutzman

    2011-04-01

    GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a) operating with the drive laser beam positioned away from the electrostatic center of the photocathode, (b) limiting the photocathode active area to eliminate photoemission from regions of the photocathode that do not support efficient beam delivery, (c) using a large drive laser beam to distribute ion damage over a larger area, and (d) by applying a relatively low bias voltage to the anode to repel ions created within the downstream beam line. A combination of these techniques provided the best total charge extracted lifetimes in excess of 1000 C at dc beam currents up to 9.5 mA, using green light illumination of bulk GaAs inside a 100 kV photogun.

  14. Flexible and internal series-connected supercapacitors with high working voltage using ultralight porous carbon nanofilms

    NASA Astrophysics Data System (ADS)

    Li, Xiaoyan; Zhou, Man; Wang, Jun; Ge, Fengyan; Zhao, Yaping; Komarneni, Sridhar; Cai, Zaisheng

    2017-02-01

    Highly flexible carbon nanofibers with hierarchical nanostructure, which provide an excellent distribution of differently functionalized-carbon nanotubes and terephthalic acid, were prepared cost-effectively and demonstrated as binder-free electrodes. Symmetric solid-state supercapacitors were then fabricated and could be operated reversibly in the voltage range of 0-1.8 V with excellent electrochemical performance due to the hierarchical porosity and hybrid architecture. Furthermore, internal series-connected supercapacitors based on the prepared porous carbon nanofibers were designed and fabricated. Such supercapacitors were found to be flexible enough to be rolled up or twisted with constant capacitive performance at a high working voltage of up to 3.6 V and exhibited a 38.9% increase in energy density than that of the single-cell supercapacitor. This one-step approach leads to simplicity of operation and economical efficiency for fabricating lightweight supercapacitors with high working voltage and energy density, which may be beneficial for the development of flexible and wearable energy storage devices.

  15. Ultra High Voltage Propellant Isolators and Insulators for JIMO Ion Thrusters

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Gaier, James R.; Hung, Ching-Cheh; Walters, Patty A.; Sechkar, Ed; Panko, Scott; Kamiotis, Christina A.

    2004-01-01

    Within NASA's Project Prometheus, high specific impulse ion thrusters for electric propulsion of spacecraft for the proposed Jupiter Icy Moon Orbiter (JIMO) mission to three of Jupiter's moons: Callisto, Ganymede and Europa will require high voltage operation to meet mission propulsion. The anticipated approx.6,500 volt net ion energy will require electrical insulation and propellant isolation which must exceed that used successfully by the NASA Solar Electric Propulsion Technology Readiness (NSTAR) Deep Space 1 mission thruster by a factor of approx.6. Xenon propellant isolator prototypes that operate at near one atmosphere and prototypes that operate at low pressures (<100 Torr) have been designed and are being tested for suitability to the JIMO mission requirements. Propellant isolators must be durable to Paschen breakdown, sputter contamination, high temperature, and high voltage while operating for factors longer duration than for the Deep Space 1 Mission. Insulators used to mount the thrusters as well as those needed to support the ion optics have also been designed and are under evaluation. Isolator and insulator concepts, design issues, design guidelines, fabrication considerations and performance issues are presented. The objective of the investigation was to identify candidate isolators and insulators that are sufficiently robust to perform durably and reliably during the proposed JIMO mission.

  16. Threshold-voltage modulated phase change heterojunction for application of high density memory

    SciTech Connect

    Yan, Baihan; Tong, Hao Qian, Hang; Miao, Xiangshui

    2015-09-28

    Phase change random access memory is one of the most important candidates for the next generation non-volatile memory technology. However, the ability to reduce its memory size is compromised by the fundamental limitations inherent in the CMOS technology. While 0T1R configuration without any additional access transistor shows great advantages in improving the storage density, the leakage current and small operation window limit its application in large-scale arrays. In this work, phase change heterojunction based on GeTe and n-Si is fabricated to address those problems. The relationship between threshold voltage and doping concentration is investigated, and energy band diagrams and X-ray photoelectron spectroscopy measurements are provided to explain the results. The threshold voltage is modulated to provide a large operational window based on this relationship. The switching performance of the heterojunction is also tested, showing a good reverse characteristic, which could effectively decrease the leakage current. Furthermore, a reliable read-write-erase function is achieved during the tests. Phase change heterojunction is proposed for high-density memory, showing some notable advantages, such as modulated threshold voltage, large operational window, and low leakage current.

  17. 76 FR 72203 - Voltage Coordination on High Voltage Grids; Notice of Reliability Workshop Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... improvements to dispatch and voltage control software could improve reliability and market efficiency. This... existing and emerging software to improve coordination and optimization of the Bulk-Power System from a... free 1-(866) 208- 3372 (voice) or (202) 208-1659 (TTY), or send a FAX to (202) 208-2106 with...

  18. 76 FR 70721 - Voltage Coordination on High Voltage Grids; Notice of Staff Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-15

    ... software could improve reliability and market efficiency. The workshop will address how entities currently coordinate economic dispatch and voltage control and the capability of existing and emerging software to... email to accessibility@ferc.gov or call toll free 1-(866) 208- 3372 (voice) or (202) 208-1659 (TTY),...

  19. High-voltage, low-inductance gas switch

    SciTech Connect

    Gruner, Frederick R.; Stygar, William A.

    2016-03-22

    A low-inductance, air-insulated gas switch uses a de-enhanced annular trigger ring disposed between two opposing high voltage electrodes. The switch is DC chargeable to 200 kilovolts or more, triggerable, has low jitter (5 ns or less), has pre-fire and no-fire rates of no more than one in 10,000 shots, and has a lifetime of greater than 100,000 shots. Importantly, the switch also has a low inductance (less than 60 nH) and the ability to conduct currents with less than 100 ns rise times. The switch can be used with linear transformer drives or other pulsed-power systems.

  20. Preliminary Chaotic Model of Snapover on High Voltage Solar Cells

    NASA Technical Reports Server (NTRS)

    Mackey, Willie R.

    1995-01-01

    High voltage power systems in space will interact with the space plasma in a variety of ways. One of these, Snapover, is characterized by a sudden enlargement of the electron current collection area across normally insulating surfaces. A power drain on solar array power systems will results from this enhanced current collection. Optical observations of the snapover phenomena in the laboratory indicates a functional relation between bia potential and surface glow area. This paper shall explore the potential benefits of modeling the relation between current and bia potential as an aspect of bifurcation analysis in chaos theory. Successful characterizations of snapover as a chaotic phenomena may provide a means of snapover prevention and control through chaotic synchronization.

  1. Analysis of lifetime control in high-voltage IGBTs

    NASA Astrophysics Data System (ADS)

    Yuan, X.; Udrea, F.; Coulbeck, L.; Waind, P. R.; Amaratunga, G. A. J.

    2002-01-01

    This paper discusses the effectiveness of the lifetime control technology in high-voltage insulated gate bipolar transistors (IGBTs) by using both numerical simulations and a two-dimensional on-state analytical model specifically developed for IGBTs with local lifetime killing. A comprehensive study of the static and dynamic performance of IGBTs using lifetime control technology in comparison with IGBTs featuring reduced anode injection efficiency structures is made. We show for the first time that IGBTs with low anode injection efficiency have similar or better on-state/switching trade-off when compared to equivalent IGBTs using lifetime control technology. We also show that both the local lifetime control and the low anode injection efficiency techniques are superior to full irradiation. The low anode injection efficiency is particularly better than the local lifetime control technique when applied to punch-though IGBTs while no difference between the two is found in non-punch-though IGBTs.

  2. Monolithic high voltage nonlinear transmission line fabrication process

    DOEpatents

    Cooper, G.A.

    1994-10-04

    A process for fabricating sequential inductors and varistor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varistor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process. 6 figs.

  3. Monolithic high voltage nonlinear transmission line fabrication process

    DOEpatents

    Cooper, Gregory A.

    1994-01-01

    A process for fabricating sequential inductors and varactor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varactor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process.

  4. LEO high voltage solar array arcing response model, continuation 5

    NASA Technical Reports Server (NTRS)

    Metz, Roger N.

    1989-01-01

    The modeling of the Debye Approximation electron sheaths in the edge and strip geometries was completed. Electrostatic potentials in these sheaths were compared to NASCAP/LEO solutions for similar geometries. Velocity fields, charge densities and particle fluxes to the biased surfaces were calculated for all cases. The major conclusion to be drawn from the comparisons of our Debye Approximation calculations with NASCAP-LEO output is that, where comparable biased structures can be defined and sufficient resolution obtained, these results are in general agreement. Numerical models for the Child-Langmuir, high-voltage electron sheaths in the edge and strip geometries were constructed. Electrostatic potentials were calculated for several cases in each of both geometries. Velocity fields and particle fluxes were calculated. The self-consistent solution process was carried through one cycle and output electrostatic potentials compared to NASCAP-type input potentials.

  5. Concept design of the high voltage transmission system for the collider tunnel

    NASA Astrophysics Data System (ADS)

    Norman, L. S.

    1992-03-01

    In order to provide electrical service to the Superconducting Super Collider Laboratory (SSCL) 54-mile-circumference collider of 125 MVA at 69 kV or 155 MVA at 138 kV of distributed power, it must be demonstrated that the concept design for a high-voltage transmission system can meet the distribution requirements of the collider electrical system with its cryogenic system's large motor loads and its pulsed power technical systems. It is a practical design, safe for operating personnel and cost-effective. The normal high-voltage transmission techniques of overhead and underground around the 54-mile collider tunnel could not be applied because of technical and physical constraints, or was environmentally unacceptable. The approach taken to solve these problems is the installation of 69-kV or 138-kV exposed solid dielectric transmission cable inside the collider tunnel with the superconducting magnets, cryogenic piping, electrical medium, and low-voltage distribution systems, and electronic/instrumentation wiring systems. This mixed-use approach has never been attempted in a collider tunnel. Research into all aspects of the engineering and installation problems and consultation with transmission cable manufacturers, electrical utilities, and European entities with similar installations--such as the Channel Tunnel--demonstrate that the concept design is feasible and practical. This paper presents a history of the evolution of the concept design. Design studies are underway to determine the system configuration and voltages. Included in this report are tunnel transmission cable system considerations and evaluation of solid dielectric high-voltage cable design.

  6. A high-voltage rechargeable magnesium-sodium hybrid battery

    DOE PAGES

    Li, Yifei; An, Qinyou; Cheng, Yingwen; ...

    2017-02-13

    There is a growing global demand for safe and low-cost energy storage technology which triggers strong interests in novel battery concepts beyond state-of-art Li-ion batteries. We report a high-voltage rechargeable Mg–Na hybrid battery featuring dendrite-free deposition of Mg anode and Na-intercalation cathode as a low-cost and safe alternative to Li-ion batteries for large-scale energy storage. A prototype device using a Na3V2(PO4)3 cathode, a Mg anode, and a Mg–Na dual salt electrolyte exhibits the highest voltage (2.60 V vs. Mg) and best rate performance (86% capacity retention at 10 C rate) among reported hybrid batteries. Synchrotron radiation-based X-ray absorption near edgemore » structure (XANES), atomic-pair distribution function (PDF), and high-resolution X-ray diffraction (HRXRD) studies reveal the chemical environment and structural change of Na3V2(PO4)3 cathode during the Na ion insertion/deinsertion process. XANES study shows a clear reversible shift of vanadium K-edge and HRXRD and PDF studies reveal a reversible two-phase transformation and V–O bond length change during cycling. The energy density of the hybrid cell could be further improved by developing electrolytes with a higher salt concentration and wider electrochemical window. Our work represents a significant step forward for practical safe and low-cost hybrid batteries.« less

  7. High-voltage supply for neutron tubes in well-logging applications

    DOEpatents

    Humphreys, D.R.

    1982-09-15

    A high voltage supply is provided for a neutron tube used in well logging. The biased pulse supply of the invention combines DC and full pulse techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

  8. High voltage and high specific capacity dual intercalating electrode Li-ion batteries

    NASA Technical Reports Server (NTRS)

    West, William C. (Inventor); Blanco, Mario (Inventor)

    2010-01-01

    The present invention provides high capacity and high voltage Li-ion batteries that have a carbonaceous cathode and a nonaqueous electrolyte solution comprising LiF salt and an anion receptor that binds the fluoride ion. The batteries can comprise dual intercalating electrode Li ion batteries. Methods of the present invention use a cathode and electrode pair, wherein each of the electrodes reversibly intercalate ions provided by a LiF salt to make a high voltage and high specific capacity dual intercalating electrode Li-ion battery. The present methods and systems provide high-capacity batteries particularly useful in powering devices where minimizing battery mass is important.

  9. Evaluation of high temperature dielectric films for high voltage power electronic applications

    NASA Technical Reports Server (NTRS)

    Suthar, J. L.; Laghari, J. R.

    1992-01-01

    Three high temperature films, polyimide, Teflon perfluoroalkoxy and poly-P-xylene, were evaluated for possible use in high voltage power electronic applications, such as in high energy density capacitors, cables and microelectronic circuits. The dielectric properties, including permittivity and dielectric loss, were obtained in the frequency range of 50 Hz to 100 kHz at temperatures up to 200 C. The dielectric strengths at 60 Hz were determined as a function of temperature to 250 C. Confocal laser microscopy was performed to diagnose for voids and microimperfections within the film structure. The results obtained indicate that all films evaluated are capable of maintaining their high voltage properties, with minimal degradation, at temperatures up to 200 C. However, above 200 C, they lose some of their electrical properties. These films may therefore become viable candidates for high voltage power electronic applications at high temperatures.

  10. Nonlinear high voltage transmission line for transversely excited CO{sub 2} lasers

    SciTech Connect

    Ishi, Akira; Yasuoka, Koichi; Tamagawa, Tohru

    1995-12-31

    A high voltage Pulse with the risetime less than a few hundreds nanoseconds and the amplitude of several tens kilovolts is required to establish stable glow discharge excitation in high power pulsed gas lasers. To make the high voltage pulse fast, we have developed a nonlinear high voltage transmission line for transversely excited CO{sub 2} lasers. Fig.1 shows the electrical circuit of switching unit, pulse sharpening unit with nonlinear high voltage transmission line and discharge electrodes for TE-CO{sub 2} laser. The nonlinear high voltage transmission line is a 15-step LC ladder circuit that consists of linear inductors (L=6 {mu}H) and nonlinear BaTiO{sub 3} capacitors. Fig.2 shows a capacitance dependence on applied voltages. If an LC ladder circuit is constructed using a capacitor with the characteristics, the transmission velocity is fast at the high-voltage section and is slow at the low-voltage section. High voltage pulse with slow risetime is expected to be sharpen. The voltage and the current waveforms of the discharge measured at the point {open_quotes}c{close_quotes}. The risetime of 1{mu}s of the input voltage pulse was compressed to less than 200 ns at the output terminal of the LC ladder circuit and the outout pulse was applied to the discharge gap of the laser.

  11. Circuit for monitoring temperature of high-voltage equipment

    DOEpatents

    Jacobs, Martin E.

    1976-01-01

    This invention relates to an improved circuit for measuring temperature in a region at high electric potential and generating a read-out of the same in a region at lower potential. The circuit is specially designed to combine high sensitivity, stability, and accuracy. A major portion of the circuit situated in the high-potential region can take the form of an integrated circuit. The preferred form of the circuit includes an input section which is situated in the high-potential region and comprises a temperature-compensated thermocouple circuit for sensing temperature, an oscillator circuit for generating a train of ramp voltages whose rise time varies inversely with the thermocouple output, a comparator and switching circuit for converting the oscillator output to pulses whose frequency is proportional to the thermocouple output, and a light-emitting diode which is energized by these pulses. An optical coupling transmits the light pulses generated by the diode to an output section of the circuit, situated in a region at ground. The output section comprises means for converting the transmitted pulses to electrical pulses of corresponding frequency, means for amplifying the electrical pulses, and means for displaying the frequency of the same. The preferred embodiment of the overall circuit is designed so that the frequency of the output signal in hertz and tenths of hertz is equal to the sensed temperature in degrees and tenths of degrees.

  12. High voltage series resonant inverter ion engine screen supply. [SCR series resonant inverter for space applications

    NASA Technical Reports Server (NTRS)

    Biess, J. J.; Inouye, L. Y.; Shank, J. H.

    1974-01-01

    A high-voltage, high-power LC series resonant inverter using SCRs has been developed for an Ion Engine Power Processor. The inverter operates within 200-400Vdc with a maximum output power of 2.5kW. The inverter control logic, the screen supply electrical and mechanical characteristics, the efficiency and losses in power components, regulation on the dual feedback principle, the SCR waveforms and the component weight are analyzed. Efficiency of 90.5% and weight density of 4.1kg/kW are obtained.

  13. High voltage solar cell power generating system for regulated solar array development

    NASA Technical Reports Server (NTRS)

    Levy, E., Jr.; Hoffman, A. C.

    1973-01-01

    A laboratory solar power system regulated by on-panel switches has been delivered for operating high power (3 kw), high voltage (15,000 volt) loads (communication tubes, ion thrusters). The modular system consists of 26 solar arrays, each with an integral light source and cooling system. A typical array contains 2560 series-connected cells. Each light source consists of twenty 500 watt tungsten iodide lamps providing plus or minus 5 per cent uniformity at one solar constant. An array temperature of less than 40 C is achieved using an infrared filter, a water cooled plate, a vacuum hold-down system, and air flushing.

  14. Transmembrane potentials during high voltage shocks in ischemic cardiac tissue.

    PubMed

    Holley, L K; Knisley, S B

    1997-01-01

    Transmembrane, voltage sensitive fluorescent dye (TMF) recording techniques have shown that high voltage shocks (HVS), typically used in defibrillation, produce either hyper- or depolarization of the transmembrane potential (TMP) when delivered in the refractory period of an action potential (AP) in normal cardiac tissue (NT). Further, HVS produce an extension of the AP, which has been hypothesized as a potential mechanism for electrical defibrillation. We examined whether HVS modify TMP of ischemic tissue (IT) in a similar manner. In seven Langendorff rabbit hearts, recordings of APs were obtained in both NT and IT with TMF using di-4-ANEPPS, and diacetylmonoxime (23 microM) to avoid motion artifacts. Local ischemia was produced by occlusion of the LAD, HVS of either biphasic (5 + 5 ms) or (3 + 2 ms) or monophasic shapes (5 ms) were delivered at varying times (20%-90%) of the paced AP. Intracardiac ECG and TMF recordings of the TMP were each amplified, recorded, and digitized at a frequency of 1 kHz. The paced AP in IT was triangular in shape with no obvious phase 3 plateau, typically seen in NT. There was normally a reduced AP amplitude (expressed as fractional fluorescence) in IT (2.6% +/- 1.79%) compared to 3.8% +/- 0.66% in NT, and shortened AP duration (137 +/- 42 vs 171 +/- 11 ms). One hundred-Volt HVS delivered during the refractory period of paced AP in IT in five rabbits, elicited a depolarization response of the TMP with an amplitude up to three times greater than the paced AP. This is in contrast to NT where the 100-V HVS produced hyperpolarization in four hearts, and only a slight depolarization response in one heart. These results suggest that HVS, typically delivered by a defibrillation shock, modify TMPs in a significantly different manner for ischemic cells, which may influence success in defibrillation.

  15. High-Voltage Power Supply With Fast Rise and Fall Times

    NASA Technical Reports Server (NTRS)

    Bearden, Douglas B.; Acker, Richard M.; Kapuslka, Robert E.

    2007-01-01

    A special-purpose high-voltage power supply can be electronically switched on and off with fast rise and fall times, respectively. The output potential is programmable from 20 to 1,250 V. An output current of 50 A can be sustained at 1,250 V. The power supply was designed specifically for electronically shuttering a microchannel plate in an x-ray detector that must operate with exposure times as short as 1 ms. The basic design of the power supply is also adaptable to other applications in which there are requirements for rapid slewing of high voltages. The power-supply circuitry (see figure) includes a preregulator, which is used to program the output at 1/30 of the desired output potential. After the desired voltage has been set, the outputs of a pulse width modulator (PWM) are enabled and used to amplify the preregulator output potential by 30. The amplification is achieved by use of two voltage doublers with a transformer that has two primary and two secondary windings. A resistor is used to limit the current by controlling the drive voltage of two field-effect transistors (FETs) during turn-on of the PWM. A pulse transformer is used to turn on four FETs to short-circuit four output capacitors when the outputs of the PWM have been disabled. The most notable aspects of the performance of the power supply are a rise time of only 80 s and a fall time of only 60 s at a load current of 50 A or less. Another notable aspect is that the application of a 0-to-5-V square wave to a shutdown pin of the PWM causes the production of a 0-to-1,250-V square wave at the output terminals.

  16. Design and Development of a Series Switch for High Voltage in RF Heating

    NASA Astrophysics Data System (ADS)

    Patel, Himanshu K.; Shah, Deep; Thacker, Mauli; Shah, Atman

    2013-02-01

    Plasma is the fourth state of matter. To sustain plasma in its ionic form very high temperature is essential. RF heating systems are used to provide the required temperature. Arching phenomenon in these systems can cause enormous damage to the RF tube. Heavy current flows across the anode-cathode junction, which need to be suppressed in minimal time for its protection. Fast-switching circuit breakers are used to cut-off the load from the supply in cases of arching. The crowbar interrupts the connection between the high voltage power supply (HVPS) and the RF tube for a temporary period between which the series switch has to open. The crowbar shunts the current across the load but in the process leads to short circuiting the HVPS. Thus, to protect the load as well as the HVPS a series switch is necessary. This paper presents the design and development of high voltage Series Switch for the high power switching applications. Fiber optic based Optimum triggering scheme is designed and tested to restrict the time delay well within the stipulated limits. The design is well supported with the experimental results for the whole set-up along with the series switch at various voltage level before its approval for operation at 5.2 kV.

  17. Intracellular calcium affects prestin's voltage operating point indirectly via turgor-induced membrane tension

    NASA Astrophysics Data System (ADS)

    Song, Lei; Santos-Sacchi, Joseph

    2015-12-01

    Recent identification of a calmodulin binding site within prestin's C-terminus indicates that calcium can significantly alter prestin's operating voltage range as gauged by the Boltzmann parameter Vh (Keller et al., J. Neuroscience, 2014). We reasoned that those experiments may have identified the molecular substrate for the protein's tension sensitivity. In an effort to understand how this may happen, we evaluated the effects of turgor pressure on such shifts produced by calcium. We find that the shifts are induced by calcium's ability to reduce turgor pressure during whole cell voltage clamp recording. Clamping turgor pressure to 1kPa, the cell's normal intracellular pressure, completely counters the calcium effect. Furthermore, following unrestrained shifts, collapsing the cells abolishes induced shifts. We conclude that calcium does not work by direct action on prestin's conformational state. The possibility remains that calcium interaction with prestin alters water movements within the cell, possibly via its anion transport function.

  18. A High-Voltage-Tolerant and Precise Charge-Balanced Neuro-Stimulator in Low Voltage CMOS Process.

    PubMed

    Luo, Zhicong; Ker, Ming-Dou

    2016-12-01

    This paper presents a 4 × VDD neuro-stimulator in a 0.18- μm 1.8 V/3.3 V CMOS process. The self-adaption bias technique and stacked MOS configuration are used to prevent transistors from the electrical overstress and gate-oxide reliability issue. A high-voltage-tolerant level shifter with power-on protection is used to drive the neuro-stimulator The reliability measurement of up to 100 million periodic cycles with 3000- μA biphasic stimulations in 12-V power supply has verified that the proposed neuro-stimulator is robust. Precise charge balance is achieved by using a novel current memory cell with the dual calibration loops and leakage current compensation. The charge mismatch is down to 0.25% over all the stimulus current ranges (200-300 μA) The residual average dc current is less than 6.6 nA after shorting operation.

  19. Low-jitter, high-voltage, infrared, laser-triggered, vacuum switch

    SciTech Connect

    Earley, L.M.; Barnes, G.A.

    1991-01-01

    A laser-triggered, high-voltage vacuum switch using a triggering pellet embedded in the cathode has been developed. The switch was constructed with tungsten electrodes and used either KC1 or Poco graphite pellets. An aperture in the anode allowed the laser beam to strike the pellet on the cathode surface. Reliable triggering was achieved with only 200 {mu}J of laser energy at a wavelength of 1064 nm. The switch was operated with an A-K gap voltage ranging from 5- to 30-kV with switching currents up to 15 kA peak. The delay time of the switch vaired from 70 {plus minus} 3 ns at 25 kv to 500 {plus minus} 100 ns at 5 kV. 6 refs., 6 figs., 2 tabs.

  20. Next Generation IGBT Switch Plate Development for the SNS High Voltage Converter Modulator

    SciTech Connect

    Kemp, Mark A.; Burkhart, Craig; Nguyen, Minh N.; Anderson, David E.; /Oak Ridge

    2008-09-18

    The RF source High Voltage Converter Modulator (HVCM) systems installed on the Spallation Neutron Source (SNS) have operated well in excess of 200,000 hours, during which time numerous failures have occurred. An improved Insulated Gate Bipolar Transistor (IGBT) switch plate is under development to help mitigate these failures. The new design incorporates two significant improvements. The IGBTs are upgraded to 4500 V, 1200 A, press-pack devices, which increase the voltage margin, facilitate better cooling, and eliminate explosive disassembly of the package in the event of device failure. The upgrade to an advanced IGBT gate drive circuit decreases switching losses and improves fault-condition response. The upgrade design and development status will be presented.

  1. A high-DC-voltage GaAs photoemission gun: Transverse emittance and momentum spread measurements

    SciTech Connect

    Engwall, D.; Bohn, C.; Cardman, L.

    1997-06-01

    We have built a high-DC-voltage photoemission gun and a diagnostic beamline permitting us to measure rms transverse emittance ({epsilon}{sub x}) and rms momentum spread ({delta}) of short-duration electron pulses produced by illuminating the cathode with light from a mode-locked, frequency-doubled Nd:YLF laser. The electron gun is a GaAs photocathode source designed to operate at 500kV. We have measured {epsilon}{sub x} and {delta} for conditions ranging from emittance-dominated to space-charge-dominated. We report these measurements as functions of microbunch charge for different beam radii, pulse lengths, and voltages/field gradients at the cathode, and compare them with PARMELA calculations.

  2. Thyratron characteristics under high di/dt and high-repetition-rate operation

    SciTech Connect

    Ball, D.; Hill, J.; Kan, T.

    1981-05-11

    Power conditioning systems for high peak and average power, high repetition rate discharge excited lasers involve operation of modulator components in unconventional regimes. Reliable operation of switches and energy storage elements under high voltage and high di/dt conditions is a pacing item for laser development at the present time. To test and evaluate these components a Modulator Component Test Facility (MCTF) was constructed. The MCTF consists of a command charge system, energy storage capacitors, thyratron switch with inverse thyratron protection, and a resistive load. The modulator has initially been operated at voltages up to 60 kV at 600 Hz. Voltage, current, and calorimetric diagnostics are provided for major modulator components. Measurements of thyratron characteristics under high di/dt operation are presented. Commutation energy loss and di/dt have been measured as functions of the tube hydrogen pressure.

  3. Note: Repetitive operation of the capacitor bank of the low-voltage miniature plasma focus at 50 Hz.

    PubMed

    Shukla, Rohit; Shyam, Anurag

    2013-10-01

    We have already reported the low-voltage operation of a plasma focus describing the operation of plasma focus at 4.2 kV which proposes possibility of making a repetitive system using compact driving source. Another recent article describes that the same capacitor-bank can drive the plasma focus for a measured ~5 × 10(4) neutrons per shot at 5 kV and 59 kA current. In the present work, repetitive operation of the capacitor-bank of plasma focus is done and that too is being reported at a very high repetition rate of 50 Hz using very simple scheme of charging and triggering the bank. The bank is continuously discharged to burst duration of 20 s in this configuration admeasuring a thousand shots.

  4. Note: Repetitive operation of the capacitor bank of the low-voltage miniature plasma focus at 50 Hz

    NASA Astrophysics Data System (ADS)

    Shukla, Rohit; Shyam, Anurag

    2013-10-01

    We have already reported the low-voltage operation of a plasma focus describing the operation of plasma focus at 4.2 kV which proposes possibility of making a repetitive system using compact driving source. Another recent article describes that the same capacitor-bank can drive the plasma focus for a measured ˜5 × 104 neutrons per shot at 5 kV and 59 kA current. In the present work, repetitive operation of the capacitor-bank of plasma focus is done and that too is being reported at a very high repetition rate of 50 Hz using very simple scheme of charging and triggering the bank. The bank is continuously discharged to burst duration of 20 s in this configuration admeasuring a thousand shots.

  5. A miniature high-efficiency fully digital adaptive voltage scaling buck converter

    NASA Astrophysics Data System (ADS)

    Li, Hangbiao; Zhang, Bo; Luo, Ping; Zhen, Shaowei; Liao, Pengfei; He, Yajuan; Li, Zhaoji

    2015-09-01

    A miniature high-efficiency fully digital adaptive voltage scaling (AVS) buck converter is proposed in this paper. The pulse skip modulation with flexible duty cycle (FD-PSM) is used in the AVS controller, which simplifies the circuit architecture (<170 gates) and greatly saves the die area and the power consumption. The converter is implemented in a 0.13-μm one-poly-eight-metal (1P8 M) complementary metal oxide semiconductor process and the active on-chip area of the controller is only 0.003 mm2, which is much smaller. The measurement results show that when the operating frequency of the digital load scales dynamically from 25.6 MHz to 112.6 MHz, the supply voltage of which can be scaled adaptively from 0.84 V to 1.95 V. The controller dissipates only 17.2 μW, while the supply voltage of the load is 1 V and the operating frequency is 40 MHz.

  6. 29 CFR 1926.1410 - Power line safety (all voltages)-equipment operations closer than the Table A zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Power line safety (all voltages)-equipment operations... FOR CONSTRUCTION Cranes and Derricks in Construction § 1926.1410 Power line safety (all voltages... an energized power line is prohibited, except where the employer demonstrates that all of...

  7. High-Voltage LED Light Engine with Integrated Driver

    SciTech Connect

    Soer, Wouter

    2016-02-29

    LED luminaires have seen dramatic changes in cost breakdown over the past few years. The LED component cost, which until recently was the dominant portion of luminaire cost, has fallen to a level of the same order as the other luminaire components, such as the driver, housing, optics etc. With the current state of the technology, further luminaire performance improvement and cost reduction is realized most effectively by optimization of the whole system, rather than a single component. This project focuses on improving the integration between LEDs and drivers. Lumileds has developed a light engine platform based on low-cost high-power LEDs and driver topologies optimized for integration with these LEDs on a single substrate. The integration of driver and LEDs enables an estimated luminaire cost reduction of about 25% for targeted applications, mostly due to significant reductions in driver and housing cost. The high-power LEDs are based on Lumileds’ patterned sapphire substrate flip-chip (PSS-FC) technology, affording reduced die fabrication and packaging cost compared to existing technology. Two general versions of PSS-FC die were developed in order to create the desired voltage and flux increments for driver integration: (i) small single-junction die (0.5 mm2), optimal for distributed lighting applications, and (ii) larger multi-junction die (2 mm2 and 4 mm2) for high-power directional applications. Two driver topologies were developed: a tapped linear driver topology and a single-stage switch-mode topology, taking advantage of the flexible voltage configurations of the new PSS-FC die and the simplification opportunities enabled by integration of LEDs and driver on the same board. A prototype light engine was developed for an outdoor “core module” application based on the multi-junction PSS-FC die and the single-stage switch-mode driver. The light engine meets the project efficacy target of 128 lm/W at a luminous flux

  8. Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thrusters anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization.

  9. Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thruster's anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization and acceleration zones upstream shifting as a function of increased background pressure.

  10. Improvement of high-voltage staircase drive circuit waveform for high-intensity therapeutic ultrasound

    NASA Astrophysics Data System (ADS)

    Tamano, Satoshi; Jimbo, Hayato; Azuma, Takashi; Yoshizawa, Shin; Fujiwara, Keisuke; Itani, Kazunori; Umemura, Shin-Ichiro

    2016-07-01

    Recently, in the treatment of diseases such as cancer, noninvasive or low-invasive modality, such as high-intensity focused ultrasound (HIFU), has been put into practice as an alternative to open surgery. HIFU induces thermal ablation of the target tissue to be treated. To improve the efficiency of HIFU, we have proposed a “triggered-HIFU” technique, which uses the combination of a short-duration, high-voltage transmission and a long-duration, medium-voltage transmission. In this method, the transmission device must endure high peak voltage for the former and the high time-average power for the latter. The triggered-HIFU sequence requires electronic scanning of the HIFU focus to maximize its thermal efficiency. Therefore, the transmission device must drive an array transducer with the number of elements on the order of a hundred or more, which requires that each part of the device that drives each element must be compact. The purpose of this work is to propose and construct such a transmission device by improving the staircase drive circuit, which we previously proposed. The main point of improvement is that both N and P MOSFETs are provided for each staircase voltage level instead of only one of them. Compared with the previous ultrasonic transmission circuit, high-voltage spikes were significantly reduced, the power consumption was decreased by 26.7%, and the transmission circuit temperature rise was decreased by 14.5 °C in the triggered-HIFU heating mode.

  11. Integration Testing of a Modular Discharge Supply for NASA's High Voltage Hall Accelerator Thruster

    NASA Technical Reports Server (NTRS)

    Pinero, Luis R.; Kamhawi, hani; Drummond, Geoff

    2010-01-01

    NASA s In-Space Propulsion Technology Program is developing a high performance Hall thruster that can fulfill the needs of future Discovery-class missions. The result of this effort is the High Voltage Hall Accelerator thruster that can operate over a power range from 0.3 to 3.5 kW and a specific impulse from 1,000 to 2,800 sec, and process 300 kg of xenon propellant. Simultaneously, a 4.0 kW discharge power supply comprised of two parallel modules was developed. These power modules use an innovative three-phase resonant topology that can efficiently supply full power to the thruster at an output voltage range of 200 to 700 V at an input voltage range of 80 to 160 V. Efficiencies as high as 95.9 percent were measured during an integration test with the NASA103M.XL thruster. The accuracy of the master/slave current sharing circuit and various thruster ignition techniques were evaluated.

  12. High voltage power supply with modular series resonant inverters

    DOEpatents

    Dreifuerst, G.R.; Merritt, B.T.

    1995-07-18

    A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.

  13. High voltage power supply with modular series resonant inverters

    DOEpatents

    Dreifuerst, Gary R.; Merritt, Bernard T.

    1995-01-01

    A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.

  14. Photoconductivity of high-voltage space insulating materials

    NASA Technical Reports Server (NTRS)

    Coffey, H. T.; Nanevicz, J. E.; Adamo, R. C.

    1975-01-01

    The dark and photoconductivities of four high voltage spacecraft insulators, Kapton-H, FEP Teflon, Parylene, and fused quartz, were studied under a variety of conditions intended to simulate a space environment. All measurements were made in a vacuum of less than .00001 torr while the temperature was varied from 22 C to 100 C. Some of the samples used employed conventional deposited metal electrodes--others employed electrodes composed either of an electron beam or a plasma formed by ionization of the residual gas in the test chamber. Test results show: (1) Kapton had unusual conduction properties; it conductivity decreased by more than an order of magnitude when heated at 100 C in a vacuum, but ultimately attained a stable and reproducible value. (2) Both Teflon and fused quartz had high dark resistivities but low photoresistivities when exposed to UV. Optical-density measurements revealed that both materials transmitted UV with little attenuation. (3) Parylene was found to have a low but relatively stable resistivity--comparatively minor changes occurred upon heating or illuminating the sample. Optical-density measurements showed that Parylene was absorbent in the UV and would prevent photoemission from the metal electrode on the back surface.

  15. Evaluation of Epoxy Nanocomposites for High Voltage Insulation

    NASA Astrophysics Data System (ADS)

    Iyer, Ganpathy

    Polymeric materials containing nanometer (nm) size particles are being introduced to provide compact shapes for low and medium voltage insulation equipment. The nanocomposites may provide superior electrical performance when compared with those available currently, such as lower dielectric losses and increased dielectric strength, tracking and erosion resistance, and surface hydrophobicity. All of the above mentioned benefits can be achieved at a lower filler concentration (< 10%) than conventional microfillers (40-60%). Also, the uniform shapes of nanofillers provide a better electrical stress distribution as compared to irregular shaped microcomposites which can have high internal electric stress, which could be a problem for devices with active electrical parts. Improvement in electrical performance due to addition of nanofillers in an epoxy matrix has been evaluated in this work. Scanning Electron Microscopy (SEM) was done on the epoxy samples to confirm uniform dispersion of nano-sized fillers as good filler dispersion is essential to realize the above stated benefits. Dielectric spectroscopy experiments were conducted over a wide range of frequencies as a function of temperature to understand the role of space charge and interfaces in these materials. The experiment results demonstrate significant reduction in dielectric losses in samples containing nanofillers. High voltage experiments such as corona resistance tests were conducted over 500 hours to monitor degradation in the samples due to corona. These tests revealed improvements in partial discharge endurance of nanocomposite samples. These improvements could not be adequately explained using a macroscopic quantity such as thermal conductivity. Thermo gravimetric analysis (TGA) showed higher weight loss initiation temperatures for nanofilled samples which is in agreement with the corona resistance experimental results. Theoretical models have also been developed in this work to complement the results of

  16. A current to voltage converter for cryogenics using a CMOS operational amplifier

    NASA Astrophysics Data System (ADS)

    Hayashi, K.; Saitoh, K.; Shibayama, Y.; Shirahama, K.

    2009-02-01

    We have constructed a versatile current to voltage (I-V) converter operating at liquid helium temperature, using a commercially available all-CMOS OPamp. It is valuable for cryogenic measurements of electrical current of nano-pico amperes, for example, in scanning probe microscopy. The I-V converter is thermally linked to liquid helium bath and self-heated up to 10.7 K. We have confirmed its capability of a transimpedance gain of 106 V/A and a bandwidth from DC to 200 kHz. In order to test the practical use for a frequency-modulation atomic force microscope, we have measured the resonance frequency shift of a quartz tuning fork at 32 kHz. In the operation of the I-V converter close to the sensor at liquid helium temperature, the signal-to-noise ratio has been improved to a factor of 13.6 compared to the operation at room temperature.

  17. Crosslinkable high k polymer dielectrics for low voltage organic field-effect transistor memories (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Wu, Hung-Chin; Hung, Chih-Chien; Chiu, Yu-Cheng; Tung, Shih-Huang; Chen, Wen-Chang

    2016-09-01

    High Performance organic field-effect transistor (OFET) memory devices were successfully prepared using new dielectric materials, poly(N-(hydroxymethyl)acrylamide-co-5 -(9-(5-(diethylamino)pentyl)-2-(4-vinylphenyl)-9H-fluorene (P(NMA-co-F6NSt)), which contained chemical cross-linkable segment (NMA) and hole trapping building block (F6NSt). The high k characteristics of P(NMA-co-F6NSt)) led to a low voltage operation, a small power consumption, and a good digital information storage capacity. Such P(NMA-co-F6NSt) dielectrics in OFET memories with variant NMA/F6NSt molar ratios (100/0 (P1), 95/5 (P2), 80/20 (P3), and 67/33 (P4)) showed excellent insulating properties and good charge storage performance under a low operating voltage below ±5V, due to the tightly network structures after crosslinking and well-dispersed trapping cites (i.e. fluorene moieties). P3-based memory device, in particular, exhibited largest memory window of 4.13 V among the studied polymers, and possessed stable data retention stability over 104 s with a high on/off current ratio (i.e. 104) and good endurance characteristics of more than 200 write-read-write-erase (WRER) cycles. The above results suggested that a high-performance OFET memory device could be facilely achieved using the novel synthesized high-k copolymers.

  18. A HIGH CURRENT, HIGH VOLTAGE SOLID-STATE PULSE GENERATOR FOR THE NIF PLASMA ELECTRODE POCKELS CELL

    SciTech Connect

    Arnold, P A; Barbosa, F; Cook, E G; Hickman, B C; Akana, G L; Brooksby, C A

    2007-07-27

    A high current, high voltage, all solid-state pulse modulator has been developed for use in the Plasma Electrode Pockels Cell (PEPC) subsystem in the National Ignition Facility. The MOSFET-switched pulse generator, designed to be a more capable plug-in replacement for the thyratron-switched units currently deployed in NIF, offers unprecedented capabilities including burst-mode operation, pulse width agility and a steady-state pulse repetition frequency exceeding 1 Hz. Capable of delivering requisite fast risetime, 17 kV flattop pulses into a 6 {Omega} load, the pulser employs a modular architecture characteristic of the inductive adder technology, pioneered at LLNL for use in acceleration applications, which keeps primary voltages low (and well within the capabilities of existing FET technology), reduces fabrication costs and is amenable to rapid assembly and quick field repairs.

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

    NASA Astrophysics Data System (ADS)

    Béthoux, O.; Cathelin, J.

    2010-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

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

  1. High precision high voltage divider and its application to electron beam ion traps

    SciTech Connect

    Chen, W. D.; Xiao, J.; Shen, Y.; Fu, Y. Q.; Meng, F. C.; Chen, C. Y.; Zou, Y.; Hutton, R.

    2008-12-15

    A high precision high voltage divider has been developed for the electron beam ion trap in Shanghai. The uncertainty caused by the temperature coefficient of resistance (TCR) and the voltage coefficient of resistance has been studied in detail and was minimized to the level of ppm (10{sup -6}) range. Once the TCR was matched between the resistors, the precision of the dividing ratio finally reached the ppm range also. We measured the delay of the divider caused by the capacitor introduced to minimize voltage ripple to be 2.35 ms. Finally we applied the divider to an experiment to measure resonant energies for some dielectronic recombination processes for highly charged xenon ions. The final energies include corrections for both space charge and fringe field effects are mostly under 0.03%.

  2. Experimental Evaluation and Comparison of Thermal Conductivity of High-Voltage Insulation Materials for Vacuum Electronic Devices

    NASA Astrophysics Data System (ADS)

    Suresh, C.; Srikrishna, P.

    2017-03-01

    Vacuum electronic devices operate with very high voltage differences between their sub-assemblies which are separated by very small distances. These devices also emit large amounts of heat that needs to be dissipated. Hence, there exists a requirement for high-voltage insulators with good thermal conductivity for voltage isolation and efficient heat dissipation. However, these voltage insulators are generally poor conductors of heat. In the present work, an effort has been made to obtain good high-voltage insulation materials with substantial improvement in their thermal conductivity. New mixtures of composites were formed by blending varying percentages (by volumes) of aluminum nitride powders with that of neat room-temperature vulcanizing (RTV) silicone elastomer compound. In this work, a thermal conductivity test setup has been devised for the quantification of the thermal conductivity of the insulators. The thermal conductivities and high-voltage isolation capabilities of various blended composites were quantified and were compared with that of neat RTV to evaluate the relative improvement.

  3. A 70 kV solid-state high voltage pulse generator based on saturable pulse transformer.

    PubMed

    Fan, Xuliang; Liu, Jinliang

    2014-02-01

    High voltage pulse generators are widely applied in many fields. In recent years, solid-state and operating at repetitive mode are the most important developing trends of high voltage pulse generators. A solid-state high voltage pulse generator based on saturable pulse transformer is proposed in this paper. The proposed generator is consisted of three parts. They are charging system, triggering system, and the major loop. Saturable pulse transformer is the key component of the whole generator, which acts as a step-up transformer and main switch during working process of this generator. The circuit and working principles of the proposed pulse generator are introduced first in this paper, and the saturable pulse transformer used in this generator is introduced in detail. Circuit of the major loop is simulated to verify the design of the system. Demonstration experiments are carried out, and the results show that when the primary energy storage capacitor is charged to a high voltage, such as 2.5 kV, a voltage with amplitude of 86 kV can be achieved on the secondary winding. The magnetic core of saturable pulse transformer is saturated deeply and the saturable inductance of the secondary windings is very small. The switch function of the saturable pulse transformer can be realized ideally. Therefore, a 71 kV output voltage pulse is formed on the load. Moreover, the magnetic core of the saturable pulse transformer can be reset automatically.

  4. Application of high voltage electric field (HVEF) drying technology in potato chips

    NASA Astrophysics Data System (ADS)

    Bai, Yaxiang; Shi, Hua; Yang, Yaxin

    2013-03-01

    In order to improve the drying efficiency and qualities of vegetable by high voltage electric field (HVEF), potato chips as a representative of vegetable was dried using a high voltage electric drying systems at 20°C. The shrinkage rate, water absorption and rehydration ratio of dried potato chips were measured. The results indicated that the drying rate of potato chips was significantly improved in the high voltage electric drying systems. The shrinkage rate of potato chips dried by high voltage electric field was 1.1% lower than that by oven drying method. And the rehydration rate of high voltage electric field was 24.6% higher than that by oven drying method. High voltage electric field drying is very advantageous and can be used as a substitute for traditional drying method.

  5. Flash Memory Featuring Low-Voltage Operation by Crystalline ZrTiO4 Charge-Trapping Layer

    NASA Astrophysics Data System (ADS)

    Shen, Yung-Shao; Chen, Kuen-Yi; Chen, Po-Chun; Chen, Teng-Chuan; Wu, Yung-Hsien

    2017-03-01

    Crystalline ZrTiO4 (ZTO) in orthorhombic phase with different plasma treatments was explored as the charge-trapping layer for low-voltage operation flash memory. For ZTO without any plasma treatment, even with a high k value of 45.2, it almost cannot store charges due the oxygen vacancies-induced shallow-level traps that make charges easy to tunnel back to Si substrate. With CF4 plasma treatment, charge storage is still not improved even though incorporated F atoms could introduce additional traps since the F atoms disappear during the subsequent thermal annealing. On the contrary, nevertheless the k value degrades to 40.8, N2O plasma-treated ZTO shows promising performance in terms of 5-V hysteresis memory window by ±7-V sweeping voltage, 2.8-V flatband voltage shift by programming at +7 V for 100 μs, negligible memory window degradation with 105 program/erase cycles and 81.8% charge retention after 104 sec at 125 °C. These desirable characteristics are ascribed not only to passivation of oxygen vacancies-related shallow-level traps but to introduction of a large amount of deep-level bulk charge traps which have been proven by confirming thermally excited process as the charge loss mechanism and identifying traps located at energy level beneath ZTO conduction band by 0.84 eV~1.03 eV.

  6. A new aluminium-ion battery with high voltage, high safety and low cost.

    PubMed

    Sun, Haobo; Wang, Wei; Yu, Zhijing; Yuan, Yan; Wang, Shuai; Jiao, Shuqiang

    2015-07-28

    A new kind of Al-ion battery with carbon paper as the cathode, high-purity Al foil as the anode and ionic liquid as the electrolyte is proposed in this work. The significance of the presented battery is going to be an extremely high average voltage plateau of ca. 1.8 V vs. Al(3+)/Al.

  7. A Fusing Switch for Fault Suppression in the SNS High Voltage Converter Modulators

    SciTech Connect

    Kemp, Mark A.; Burkhart, Craig; Nguyen, Minh N.; Anderson, David E.; /Oak Ridge

    2009-08-03

    The High Voltage Converter Modulators (HVCMs) at the Spallation Neutron Source (SNS) have operated in excess of a combined 250,000 hours. Performance and reliability improvements to the HVCM are ongoing to increase modulator availability as accelerator system demands increase. There is a relatively large amount of energy storage in the HVCMs, {approx}180 kJ. This energy has the potential to dump into unsuppressed faults, cause damage, and increase the time to repair. The 'fusing switch' concept involves isolation of this stored energy from the location of the most common faults. This paper introduces this concept and its application to the HVCMs.

  8. High performance low voltage organic field effect transistors on plastic substrate for amplifier circuits

    NASA Astrophysics Data System (ADS)

    Houin, G.; Duez, F.; Garcia, L.; Cantatore, E.; Torricelli, F.; Hirsch, L.; Belot, D.; Pellet, C.; Abbas, M.

    2016-09-01

    The high performance air stable organic semiconductor small molecule dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) was chosen as active layer for field effect transistors built to realize flexible amplifier circuits. Initial device on rigid Si/SiO2 substrate showed appreciable performance with hysteresis-free characteristics. A number of approaches were applied to simplify the process, improve device performance and decrease the operating voltage: they include an oxide interfacial layer to decrease contact resistance; a polymer passivation layer to optimize semiconductor/dielectric interface and an anodized high-k oxide as dielectric layer for low voltage operation. The devices fabricated on plastic substrate yielded excellent electrical characteristics, showing mobility of 1.6 cm2/Vs, lack of hysteresis, operation below 5 V and on/off current ratio above 105. An OFET model based on variable ranging hopping theory was used to extract the relevant parameters from the transfer and output characteristics, which enabled us to simulate our devices achieving reasonable agreement with the measurements

  9. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap

    SciTech Connect

    Maxson, Jared; Bazarov, Ivan; Dunham, Bruce; Dobbins, John; Liu, Xianghong; Smolenski, Karl

    2014-09-15

    A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.

  10. Method and apparatus for connecting high voltage leads to a high temperature super-conducting transformer

    DOEpatents

    Golner, Thomas M.; Mehta, Shirish P.

    2005-07-26

    A method and apparatus for connecting high voltage leads to a super-conducting transformer is provided that includes a first super-conducting coil set, a second super-conducting coil set, and a third super-conducting coil set. The first, second and third super-conducting coil sets are connected via an insulated interconnect system that includes insulated conductors and insulated connectors that are utilized to connect the first, second, and third super-conducting coil sets to the high voltage leads.

  11. Design of a high voltage stimulator chip for a stroke rehabilitation system.

    PubMed

    Zeng, Lei; Yi, Xin; Lu, Sheng; Lou, Yuan; Jiang, Jianfei; Qu, Hongen; Lan, Ning; Wang, Guoxing

    2013-01-01

    This paper describes the design of an 8-channel high voltage stimulator chip for rehabilitation of stroke patients through surface stimulation, which requires high stimulation currents and high compliance voltage. The chip gets stimulation control data through its Serial Peripheral Interface (SPI), and can accordingly generate biphasic stimulation currents with different amplitudes, duration, frequencies and polarities independently for each channel. The current driver is implemented with thick oxide devices with a supply voltage up to 90V. The chip is designed in a 0.35εm X-FAB high voltage process.

  12. High voltage holding in the negative ion sources with cesium deposition

    SciTech Connect

    Belchenko, Yu.; Abdrashitov, G.; Ivanov, A.; Sanin, A.; Sotnikov, O.

    2016-02-15

    High voltage holding of the large surface-plasma negative ion source with cesium deposition was studied. It was found that heating of ion-optical system electrodes to temperature >100 °C facilitates the source conditioning by high voltage pulses in vacuum and by beam shots. The procedure of electrode conditioning and the data on high-voltage holding in the negative ion source with small cesium seed are described. The mechanism of high voltage holding improvement by depletion of cesium coverage is discussed.

  13. The effect of the dc bias voltage on the x-ray bremsstrahlung and beam intensities of medium and highly charged ions of argon

    SciTech Connect

    Rodrigues, G.; Lakshmy, P. S.; Kanjilal, D.; Roy, A.; Baskaran, R.

    2010-02-15

    X-ray bremsstrahlung measurements from the 18 GHz High Temperature Superconducting Electron Cyclotron Resonance Ion Source, Pantechnik-Delhi Ion Source were measured as a function of negative dc bias voltage, keeping all other source operating parameters fixed and the extraction voltage in the off condition. The optimization of medium and highly charged ions of argon with similar source operating parameters is described. It is observed that the high temperature component of the electron is altered significantly with the help of bias voltage, and the electron population has to be maximized for obtaining higher current.

  14. The effect of the dc bias voltage on the x-ray bremsstrahlung and beam intensities of medium and highly charged ions of argon.

    PubMed

    Rodrigues, G; Lakshmy, P S; Baskaran, R; Kanjilal, D; Roy, A

    2010-02-01

    X-ray bremsstrahlung measurements from the 18 GHz High Temperature Superconducting Electron Cyclotron Resonance Ion Source, Pantechnik-Delhi Ion Source were measured as a function of negative dc bias voltage, keeping all other source operating parameters fixed and the extraction voltage in the off condition. The optimization of medium and highly charged ions of argon with similar source operating parameters is described. It is observed that the high temperature component of the electron is altered significantly with the help of bias voltage, and the electron population has to be maximized for obtaining higher current.

  15. Performance, stability and operation voltage optimization of screen-printed aqueous supercapacitors

    PubMed Central

    Lehtimäki, Suvi; Railanmaa, Anna; Keskinen, Jari; Kujala, Manu; Tuukkanen, Sampo; Lupo, Donald

    2017-01-01

    Harvesting micropower energy from the ambient environment requires an intermediate energy storage, for which printed aqueous supercapacitors are well suited due to their low cost and environmental friendliness. In this work, a systematic study of a large set of devices is used to investigate the effect of process variability and operating voltage on the performance and stability of screen printed aqueous supercapacitors. The current collectors and active layers are printed with graphite and activated carbon inks, respectively, and aqueous NaCl used as the electrolyte. The devices are characterized through galvanostatic discharge measurements for quantitative determination of capacitance and equivalent series resistance (ESR), as well as impedance spectroscopy for a detailed study of the factors contributing to ESR. The capacitances are 200–360 mF and the ESRs 7.9–12.7 Ω, depending on the layer thicknesses. The ESR is found to be dominated by the resistance of the graphite current collectors and is compatible with applications in low-power distributed electronics. The effects of different operating voltages on the capacitance, leakage and aging rate of the supercapacitors are tested, and 1.0 V found to be the optimal choice for using the devices in energy harvesting applications. PMID:28382962

  16. Reduction of voltage-operated potassium currents by levetiracetam: a novel antiepileptic mechanism of action?

    PubMed

    Madeja, Michael; Margineanu, Doru Georg; Gorji, Ali; Siep, Elke; Boerrigter, Paul; Klitgaard, Henrik; Speckmann, Erwin-Josef

    2003-10-01

    Levetiracetam (ucb L059; Keppra) is a novel antiepileptic drug. Its effects on action potential generation and voltage-operated potassium currents were studied in acutely isolated hippocampal CA1 neurones from rat and guinea pig, using the patch-clamp technique in the whole-cell configuration. (i) Levetiracetam reduced repetitive action potential generation and affected the single action potential. Levetiracetam, 100 microM, decreased the total number of action potentials and reduced the total depolarisation area of repetitive action potentials by 21%. Furthermore, levetiracetam increased the duration of the first action potential slightly, prolonged that of the second action potential by 13% and decreased the slope of rise by 23%. (ii) Levetiracetam decreased the voltage-operated potassium current. Without effect on sodium and A-type potassium currents, levetiracetam, 100 microM, reduced the delayed rectifier current by 26%. The concentration of half-maximal block was 47 microM for guinea pig and 6 microM for rat neurones. Thus, the reduction of repetitive action potential generation by levetiracetam can be attributed, unexpectedly, to a moderate reduction of the delayed rectifier potassium current, as supported by a simulation of action potential generation. This suggests that a reduction of potassium currents may contribute to the antiepileptic effect(s) of levetiracetam.

  17. Performance and Environmental Test Results of the High Voltage Hall Accelerator Engineering Development Unit

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Haag, Thomas; Huang, Wensheng; Shastry, Rohit; Pinero, Luis; Peterson, Todd; Mathers, Alex

    2012-01-01

    NASA Science Mission Directorate's In-Space Propulsion Technology Program is sponsoring the development of a 3.5 kW-class engineering development unit Hall thruster for implementation in NASA science and exploration missions. NASA Glenn and Aerojet are developing a high fidelity high voltage Hall accelerator that can achieve specific impulse magnitudes greater than 2,700 seconds and xenon throughput capability in excess of 300 kilograms. Performance, plume mappings, thermal characterization, and vibration tests of the high voltage Hall accelerator engineering development unit have been performed. Performance test results indicated that at 3.9 kW the thruster achieved a total thrust efficiency and specific impulse of 58%, and 2,700 sec, respectively. Thermal characterization tests indicated that the thruster component temperatures were within the prescribed material maximum operating temperature limits during full power thruster operation. Finally, thruster vibration tests indicated that the thruster survived the 3-axes qualification full-level random vibration test series. Pre and post-vibration test performance mappings indicated almost identical thruster performance. Finally, an update on the development progress of a power processing unit and a xenon feed system is provided.

  18. A Complex Permittivity Based Sensor for the Electrical Characterization of High-Voltage Transformer Oils

    PubMed Central

    Dervos, Constantine T.; Paraskevas, Christos D.; Skafidas, Panayotis D.; Vassiliou, Panayota

    2005-01-01

    This work investigates the use of a specially designed cylindrical metal cell, in order to obtain complex permittivity and tanδ data of highly insulating High Voltage (HV) transformer oil samples. The data are obtained at a wide range of frequencies and operation temperatures to demonstrate the polarization phenomena and the thermally stimulated effects. Such complex permittivity measurements may be utilized as a criterion for the service life prediction of oil field electrical equipment (OFEE). Therefore, by one set of measurements on a small oil volume, data may be provided on the impending termination, or continuation of the transformer oil service life. The oil incorporating cell, attached to the appropriate measuring units, could be described as a complex permittivity sensor. In this work, the acquired dielectric data from a great number of operating distribution network power transformers were correlated to corresponding physicochemical ones to demonstrate the future potential employment of the proposed measuring technique.

  19. A new class of high force, low-voltage, compliant actuation system

    SciTech Connect

    RODGERS,M. STEVEN; KOTA,SRIDHAR; HETRICK,JOEL; LI,ZHE; JENSEN,BRIAN D.; KRYGOWSKI,THOMAS W.; MILLER,SAMUEL L.; BARNES,STEPHEN MATTHEW; BURG,MICHAEL STANLEY

    2000-04-10

    Although many actuators employing electrostatic comb drives have been demonstrated in a laboratory environment, widespread acceptance in mass produced microelectromechanical systems (MEMS) may be limited due to issues associated with low drive force, large real estate demands, high operating voltages, and reliability concerns due to stiction. On the other hand, comb drives require very low drive currents, offer predictable response, and are highly compatible with the fabrication technology. The expand the application space and facilitate the widespread deployment of self-actuated MEMS, a new class of advanced actuation systems has been developed that maintains the highly desirable aspects of existing components, while significantly diminishing the issues that could impede large scale acceptance. In this paper, the authors will present low-voltage electrostatic actuators that offer a dramatic increase in force over conventional comb drive designs. In addition, these actuators consume only a small fraction of the chip area previously used, yielding significant gains in power density. To increase the stroke length of these novel electrostatic actuators, the authors have developed highly efficient compliant stroke amplifiers. The coupling of compact, high-force actuators with fully compliant displacement multipliers sets a new paradigm for highly integrated microelectromechanical systems.

  20. Degradation of Photovoltaic Modules Under High Voltage Stress in the Field: Preprint

    SciTech Connect

    del Cueto, J. A.; Rummel, S. R.

    2010-08-01

    The degradation in performance for eight photovoltaic (PV) modules stressed at high voltage (HV) is presented. Four types of modules--tandem-junction and triple-junction amorphous thin-film silicon, plus crystalline and polycrystalline silicon modules--were tested, with a pair of each biased at opposite polarities. They were deployed outdoors between 2001 and 2009 with their respective HV leakage currents through the module encapsulation continuously monitored with a data acquisition system, along with air temperature and relative humidity. For the first 5 years, all modules were biased continuously at fixed 600 VDC, day and night. In the last 2 years, the modules were step-bias stressed cyclically up and down in voltage between 10 and 600 VDC, in steps of tens to hundreds of volts. This allowed characterization of leakage current versus voltage under a large range of temperature and moisture conditions, facilitating determination of leakage paths. An analysis of the degradation is presented, along with integrated leakage charge. In HV operation: the bulk silicon modules degraded either insignificantly or at rates of 0.1%/yr higher than modules not biased at HV; for the thin-film silicon modules, the added loss rates are insignificant for one type, or 0.2%/yr-0.6%/yr larger for the other type.

  1. Extremum seeking-based optimization of high voltage converter modulator rise-time

    DOE PAGES

    Scheinker, Alexander; Bland, Michael; Krstic, Miroslav; ...

    2013-02-01

    We digitally implement an extremum seeking (ES) algorithm, which optimizes the rise time of the output voltage of a high voltage converter modulator (HVCM) at the Los Alamos Neutron Science Center (LANSCE) HVCM test stand by iteratively, simultaneously tuning the first 8 switching edges of each of the three phase drive waveforms (24 variables total). We achieve a 50 μs rise time, which is reduction in half compared to the 100 μs achieved at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. Considering that HVCMs typically operate with an output voltage of 100 kV, with a 60Hz repetitionmore » rate, the 50 μs rise time reduction will result in very significant energy savings. The ES algorithm will prove successful, despite the noisy measurements and cost calculations, confirming the theoretical results that the algorithm is not affected by noise whose frequency components are independent of the perturbing frequencies.« less

  2. Electric Power High-Voltage Transmission Lines: Design Options, Cost, and Electric and Magnetic Field Levels

    SciTech Connect

    Stoffel, J. B.; Pentecost, E. D.; Roman, R. D.; Traczyk, P. A.

    1994-11-01

    The aim of this report is to provide background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist preparers and reviewers of the section on alternatives in environmental documents. This report will give the reviewing individual a better appreciation of the factors affecting EMF strengths near high-voltage transmission lines and the approaches that might be used to reduce EMF impacts on humans and other biological species in the vicinity of high-voltage overhead or underground alternating-current (ac) or direct-current (dc) transmission lines.

  3. Observation of Dust Stream Formation Produced by Low Current, High Voltage Cathode Spots

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2004-01-01

    Macro-particle acceleration driven by low current, high voltage cathode spots has been investigated. The phenomenon was observed to occur when nanometer and micrometer-sized particles in the presence of a discharge plasma were exposed to a high voltage pulse. The negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provides the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. The particle impact craters observed at the surface of downstream witness badges were documented using SEM and light microscopy.

  4. Ultra-High Voltage 4H-SiC Bi-Directional Insulated Gate Bipolar Transistors

    NASA Astrophysics Data System (ADS)

    Chowdhury, Sauvik

    4H- Silicon Carbide (4H-SiC) is an attractive material for power semiconductor devices due to its large bandgap, high critical electric field and high thermal conductivity compared to Silicon (Si). For ultra-high voltage applications (BV > 10 kV), 4H-SiC Insulated Gate Bipolar Transistors (IGBTs) are favored over unipolar transistors due to lower conduction losses. With improvements in SiC materials and processing technology, promising results have been demonstrated in the area of conventional unidirectional 4H-SiC IGBTs, with breakdown voltage ratings up to 27 kV. This research presents the experimental demonstration of the world's first high voltage bi-directional power transistors in 4H-SiC. Traditionally, four (two IGBTs and two diodes) or two (two reverse blocking IGBTs) semiconductor devices are necessary to yield a bidirectional switch. With a monolithically integrated bidirectional switch as presented here, the number of semiconductor devices is reduced to only one, which results in increased reliability and reduced cost of the overall system. Additionally, by using the unique dual gate operation of BD-IGBTs, switching losses can be reduced to a small fraction of that in conventional IGBTs, resulting in increased efficiency. First, the performance limits of SiC IGBTs are calculated by using analytical methods. The performance benefits of SiC IGBTs over SiC unipolar devices and Si IGBTs are quantified. Numerical simulations are used to optimize the unit cell and edge termination structures for a 15 kV SiC BD-IGBT. The effect of different device parameters on BD-IGBT static and switching performance are quantified. Second, the process technology necessary for the fabrication of high voltage SiC BD-IGBTs is optimized. The effect of different process steps on parameters such as breakdown voltage, carrier lifetime, gate oxide reliability, SiO2-SiC interface charge density is quantified. A carrier lifetime enhancement process has been optimized for lightly doped

  5. High-voltage, high-power, solid-state remote power controllers for aerospace applications

    NASA Technical Reports Server (NTRS)

    Sturman, J. C.

    1985-01-01

    Two general types of remote power controller (RPC) that combine the functions of a circuit breaker and a switch were developed for use in direct-current (dc) aerospace systems. Power-switching devices used in these designs are the relatively new gate-turnoff thyristor (GTO) and poweer metal-oxide-semiconductor field-effect transistors (MOSFET). The various RPC's can switch dc voltages to 1200 V and currents to 100 A. Seven different units were constructed and subjected to comprehensive laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times to limit voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout and microsecond tripout for large overloads. The basic circuits developed can be used to build switchgear limited only by the ratings of the switching device used.

  6. Fast Rise Time and High Voltage Nanosecond Pulses at High Pulse Repetition Frequency

    NASA Astrophysics Data System (ADS)

    Miller, Kenneth E.; Ziemba, Timothy; Prager, James; Picard, Julian; Hashim, Akel

    2015-09-01

    Eagle Harbor Technologies (EHT), Inc. is conducting research to decrease the rise time and increase the output voltage of the EHT Nanosecond Pulser product line, which allows for independently, user-adjustable output voltage (0 - 20 kV), pulse width (20 - 500 ns), and pulse repetition frequency (0 - 100 kHz). The goals are to develop higher voltage pulses (50 - 60 kV), decrease the rise time from 20 to below 10 ns, and maintain the high pulse repetition capabilities. These new capabilities have applications to pseudospark generation, corona production, liquid discharges, and nonlinear transmission line driving for microwave production. This work is supported in part by the US Navy SBIR program.

  7. Photocathode lifetime improvement by using a pulsed high voltage on the photocathode gun of the polarized electron source at NIKHEF

    NASA Astrophysics Data System (ADS)

    van den Putte, M. J. J.; de Jager, C. W.; Militsyn, B. L.; Shatunov, Yu. M.; Tokarev, Yu. F.

    1998-02-01

    The first result on a dramatic improvement of the photocathode lifetime of the polarized electron source at NIKHEF is presented. The improvement was obtained after replacing the original DC power supply with a pulsed power supply for the photocathode gun high voltage. The pulsed high voltage power supply provides a negative Gauss-like pulse, with an amplitude of 100 kV, and a full-width of 600 μs, with repetition rates up to 10 Hz. Contrary to using DC high voltage, no deterioration of the vacuum in the acceleration chamber is observed. A photocathode lifetime of 180 h has been measured, using a strained layer InGaAsP photocathode. The lifetime is independent of whether or not the photocathode gun is operated at the pulsing rate of 1 Hz.

  8. Effects of elevation change on mental stress in high-voltage transmission tower construction workers.

    PubMed

    Hsu, Feng-Wen; Lin, Chiuhsiang Joe; Lee, Yung-Hui; Chen, Hung-Jen

    2016-09-01

    High-voltage transmission tower construction is a high-risk operation due to the construction site locations, extreme climatic factors, elevated working surfaces, and narrow working space. To comprehensively enhance our understanding of the psychophysiological phenomena of workers in extremely high tower constructions, we carried out a series of field experiments to test and compare three working surface heights in terms of frequency-domain heart rate variability (HRV) measurements. Twelve experienced male workers participated in this experiment. The dependent variables, namely, heart rate (HR), normalized low-frequency power (nLF), normalized high-frequency power (nHF), and LF-to-HF power ratio (LF/HF), were measured with the Polar RS800CX heart rate monitor. The experimental results indicated that the task workload was similar between working surface heights. Tower construction workers perceived an increased level of mental stress as working surface height increased.

  9. A High-Voltage SOI CMOS Exciter Chip for a Programmable Fluidic Processor System.

    PubMed

    Current, K W; Yuk, K; McConaghy, C; Gascoyne, P R C; Schwartz, J A; Vykoukal, J V; Andrews, C

    2007-06-01

    A high-voltage (HV) integrated circuit has been demonstrated to transport fluidic droplet samples on programmable paths across the array of driving electrodes on its hydrophobically coated surface. This exciter chip is the engine for dielectrophoresis (DEP)-based micro-fluidic lab-on-a-chip systems, creating field excitations that inject and move fluidic droplets onto and about the manipulation surface. The architecture of this chip is expandable to arrays of N X N identical HV electrode driver circuits and electrodes. The exciter chip is programmable in several senses. The routes of multiple droplets may be set arbitrarily within the bounds of the electrode array. The electrode excitation waveform voltage amplitude, phase, and frequency may be adjusted based on the system configuration and the signal required to manipulate a particular fluid droplet composition. The voltage amplitude of the electrode excitation waveform can be set from the minimum logic level up to the maximum limit of the breakdown voltage of the fabrication technology. The frequency of the electrode excitation waveform can also be set independently of its voltage, up to a maximum depending upon the type of droplets that must be driven. The exciter chip can be coated and its oxide surface used as the droplet manipulation surface or it can be used with a top-mounted, enclosed fluidic chamber consisting of a variety of materials. The HV capability of the exciter chip allows the generated DEP forces to penetrate into the enclosed chamber region and an adjustable voltage amplitude can accommodate a variety of chamber floor thicknesses. This demonstration exciter chip has a 32 x 32 array of nominally 100 V electrode drivers that are individually programmable at each time point in the procedure to either of two phases: 0deg and 180deg with respect to the reference clock. For this demonstration chip, while operating the electrodes with a 100-V peak-to-peak periodic waveform, the maximum HV electrode

  10. Radio-frequency powered glow discharge device and method with high voltage interface

    DOEpatents

    Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

    1994-06-28

    A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

  11. Radio-frequency powered glow discharge device and method with high voltage interface

    DOEpatents

    Duckworth, Douglas C.; Marcus, R. Kenneth; Donohue, David L.; Lewis, Trousdale A.

    1994-01-01

    A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

  12. High Power/High Voltage Rechargeable Batteries Open New Opportunities for Space Missions

    NASA Astrophysics Data System (ADS)

    Borthomieu, Y.; Brochard, P.; Lagattu, B.; Netchev, K.

    2008-09-01

    Scientific missions probes, new generation of launchers and satellites are increasingly requesting high power (permanent or pulses). The introduction of a range of rechargeable cells capable of delivering up and receiving high current addresses these needs and opens new horizons for future space missions power supply.Moreover, high power is often linked to high voltage and such need becomes more and more common for space & defence applications. The aim of the high voltage is to carry reasonable current in the harness of the electrical systems.This paper presents Saft answers to these demands, for existing launchers and also for in development ones, as well as for other markets with similar needs, such as military equipment or underwater vehicles.

  13. High Voltage EEE Parts for EMA/EHA Applications on Manned Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Griffin, Trent; Young, David

    2011-01-01

    The objective of this paper is an assessment of high voltage electronic components required for high horsepower electric thrust vector control (TVC) systems for human spaceflight launch critical application. The scope consists of creating of a database of available Grade 1 electrical, electronic and electromechanical (EEE) parts suited to this application, a qualification path for potential non-Grade 1 EEE parts that could be used in these designs, and pathfinder testing to validate aspects of the proposed qualification plan. Advances in the state of the art in high power electric power systems enable high horsepower electric actuators, such as the electromechnical actuator (EMA) and the electro-hydrostatic actuator (EHA), to be used in launch vehicle TVC systems, dramaticly reducing weight, complexity and operating costs. Designs typically use high voltage insulated gate bipolar transistors (HV-IGBT). However, no Grade 1 HV-IGBT exists and it is unlikely that market factors alone will produce such high quality parts. Furthermore, the perception of risk, the lack of qualification methodoloy, the absence of manned space flight heritage and other barriers impede the adoption of commercial grade parts onto the critical path. The method of approach is to identify high voltage electronic component types and key parameters for parts currently used in high horsepower EMA/EHA applications, to search for higher quality substitutes and custom manufacturers, to create a database for these parts, and then to explore ways to qualify these parts for use in human spaceflight launch critical application, including grossly derating and possibly treating hybrid parts as modules. This effort is ongoing, but results thus far include identification of over 60 HV-IGBT from four manufacturers, including some with a high reliability process flow. Voltage ranges for HV-IGBT have been identified, as has screening tests used to characterize HV-IGBT. BSI BS ISO 21350 Space systems Off

  14. High voltage-power frequency electrical heating in-situ conversion technology of oil shale

    NASA Astrophysics Data System (ADS)

    Sun, Youhong; Yang, Yang; Lopatin, Vladimir; Guo, Wei; Liu, Baochang; Yu, Ping; Gao, Ke; Ma, Yinlong

    2014-05-01

    With the depletion of conventional energy sources,oil shale has got much attention as a new type of energy resource,which is rich and widespread in the world.The conventional utilization of oil shale is mainly focused on resorting to produce shale oil and fuel gas with low extraction efficiency about one in a million due to many shortcomings and limitations.And the in-situ conversion of oil shale,more environmentally friendly,is still in the experimental stage.High voltage-power frequency electrical heating in-situ conversion of oil shale is a new type of in-situ pyrolysis technology.The main equipment includes a high voltage-power frequency generator and interior reactor. The high voltage-power frequency generator can provide a voltage between 220-8000 V which can be adjusted in real time according to the actual situation.Firstly,high voltage is used to breakdown the oil shale to form a dendritic crack between two electrodes providing a conductive channel inside the oil shale rock.And then the power frequency(220V) is used to generate the electric current for heating the internal surface of conductive channel,so that the energy can be transmitted to the surrounding oil shale.When the temperature reaches 350 degree,the oil shale begins to pyrolysis.In addition,the temperature in the conductive channel can be extremely high with high voltage,which makes the internal surface of conductive channel graphitization and improves its heat conduction performance.This technology can successfully make the oil shale pyrolysis, based on a lot of lab experiments,and also produce the combustible shale oil and fuel gas.Compared to other in-situ conversion technology,this method has the following advantages: high speed of heating oil shale,the equipment underground is simple,and easy to operate;it can proceed without the limitation of shale thickness, and can be used especially in the thin oil shale reservoir;the heating channel is parallel to the oil shale layers,which has more

  15. Design Guide: Designing and Building High Voltage Power Supplies. Volume 2

    DTIC Science & Technology

    1988-08-01

    surface was stressed at a voltage of over 45-kV/cm impulse and 35 V/cm de. However. the atmosphere was sulfur hexafluoride, and such high voltage -stress...3.3.3.4 Surface Surrounding Void 77 3.3.3.5 Temperature Effects 77 3.3.3.6 Impressed Voltage 78 3.3.4 Surface Flashover 84 3.3.4.1 Temperature Effect on...Interconnects, and Surfaces 182 5.2.5.1 Terminal Boards and Su~pports 182 5.2.5.2 High Voltage Leads 184 5.2.5.3 Lead Terminals 187 5.2.5.4

  16. 30 CFR 18.54 - High-voltage continuous mining machines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-voltage continuous mining machines. 18.54..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of...

  17. 30 CFR 18.54 - High-voltage continuous mining machines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-voltage continuous mining machines. 18.54..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of...

  18. 30 CFR 18.54 - High-voltage continuous mining machines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-voltage continuous mining machines. 18.54..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of...

  19. 30 CFR 18.54 - High-voltage continuous mining machines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-voltage continuous mining machines. 18.54..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of...

  20. 30 CFR 18.54 - High-voltage continuous mining machines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage continuous mining machines. 18.54..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of...