High-frequency high-voltage high-power DC-to-DC converters

NASA Technical Reports Server (NTRS)

Wilson, T. G.; Owen, H. A.; Wilson, P. M.

1982-01-01

A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

High-frequency high-voltage high-power DC-to-DC converters

NASA Astrophysics Data System (ADS)

Wilson, T. G.; Owen, H. A.; Wilson, P. M.

1982-09-01

A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

Beyond voltage-gated ion channels: Voltage-operated membrane proteins and cellular processes.

PubMed

Zhang, Jianping; Chen, Xingjuan; Xue, Yucong; Gamper, Nikita; Zhang, Xuan

2018-04-18

Voltage-gated ion channels were believed to be the only voltage-sensitive proteins in excitable (and some non-excitable) cells for a long time. Emerging evidence indicates that the voltage-operated model is shared by some other transmembrane proteins expressed in both excitable and non-excitable cells. In this review, we summarize current knowledge about voltage-operated proteins, which are not classic voltage-gated ion channels as well as the voltage-dependent processes in cells for which single voltage-sensitive proteins have yet to be identified. Particularly, we will focus on the following. (1) Voltage-sensitive phosphoinositide phosphatases (VSP) with four transmembrane segments homologous to the voltage sensor domain (VSD) of voltage-gated ion channels; VSPs are the first family of proteins, other than the voltage-gated ion channels, for which there is sufficient evidence for the existence of the VSD domain; (2) Voltage-gated proton channels comprising of a single voltage-sensing domain and lacking an identified pore domain; (3) G protein coupled receptors (GPCRs) that mediate the depolarization-evoked potentiation of Ca 2+ mobilization; (4) Plasma membrane (PM) depolarization-induced but Ca 2+ -independent exocytosis in neurons. (5) Voltage-dependent metabolism of phosphatidylinositol 4,5-bisphosphate (PtdIns[4,5]P 2 , PIP 2 ) in the PM. These recent discoveries expand our understanding of voltage-operated processes within cellular membranes. © 2018 Wiley Periodicals, Inc.

Surface interactions and high-voltage current collection

NASA Technical Reports Server (NTRS)

Mandell, M. J.; Katz, I.

1985-01-01

Spacecraft of the future will be larger and have higher power requirements than any flown to date. For several reasons, it is desirable to operate a high power system at high voltage. While the optimal voltages for many future missions are in the range 500 to 5000 volts, the highest voltage yet flown is approximately 100 volts. The NASCAP/LEO code is being developed to embody the phenomenology needed to model the environmental interactions of high voltage spacecraft. Some plasma environment are discussed. The treatment of the surface conductivity associated with emitted electrons and some simulations by NASCAP/LEO of ground based high voltage interaction experiments are described.

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

High voltage testing for the Majorana Demonstrator

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

Abgrall, N.; Arnquist, Isaac J.; Avignone, F. T.

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,more » 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.« less

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.

OB's high voltage laboratory

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

Not Available

1966-01-01

The January issue of Hi-Tension News provides a detailed description of the advanced surge test facilities and procedures in daily operation at the OB High Voltage Laboratory in Barberton, Ohio. Technical competences achieved in this laboratory contribute to the essential factors of design confirmation to basic studies of ehv insulation systems, conductor and hardware performance, and optimum tower construction. Known throughout the industry for authenticity of its full scale, all weather outdoor testing, OB's High Voltage Laboratory is a full-fledged participant in the NEMA-sponsored program to make testing facilities available on a cooperative basis.

The high voltage homopolar generator

NASA Astrophysics Data System (ADS)

Price, J. H.; Gully, J. H.; Driga, M. D.

1986-11-01

System and component design features of proposed high voltage homopolar generator (HVHPG) are described. The system is to have an open circuit voltage of 500 V, a peak output current of 500 kA, 3.25 MJ of stored inertial energy and possess an average magnetic-flux density of 5 T. Stator assembly components are discussed, including the stator, mount structure, hydrostatic bearings, main and motoring brushgears and rotor. Planned operational procedures such as monitoring the rotor to full speed and operation with a superconducting field coil are delineated.

Electrical safety for high voltage arrays

NASA Technical Reports Server (NTRS)

Marshall, N. A.

1983-01-01

A number of key electrical safety requirements for the high voltage arrays of central station photovoltaic power systems are explored. The suitability of representative industrial DC power switchgear for control and fault protection was evaluated. Included were AC/DC circuit breakers, electromechanical contactors and relays, load interruptors, cold disconnect devices, sectionalizing switches, and high voltage DC fuses. As appropriate, steady state and transient characteristics were analyzed. Failure modes impacting upon operation and maintenance safety were also identified, as were the voltage withstand and current interruption levels.

SABRE modification to a higher voltage high impedance inductive voltage adder (IVA)

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

Mazarakis, M.G.; Smith, D.L.; Poukey, J.W.

The SABRE accelerator was originally designed to operate as low impedance voltage adder with 40-ohm maximum output impedance in negative polarity operation and approximately 20 ohm in positive polarity. Because of the low impedance and higher than expected energy losses in the pulse forming network, the operating input cavity voltage is of the order of 800 kV which limits the total output voltage to {approximately} 8 MV for negative polarity and 5 to 6 MV for positive polarity. The modifications presented here aim to increase the output voltage in both polarities. A new high impedance central electrode was designed capablemore » of operating both in negative and positive polarities, and the number of pulse forming lines feeding the inductively isolated cavities was reduced to half. These modifications were recently tested in positive polarity. An increase in the total accelerating voltage from 5.5 MV to 9 MV was observed while stressing all components to the level required to achieve 12 MV in negative polarity. In these experiments only 65% of the usual operating intermediate store capacitor voltage was necessary (1.7 MV instead of 2.6 MV). Currently, the device is reconfigured for negative polarity tests. The cavities are rotated by 180{degree} and a 17-inch spool is added at the base of the cantilevered center electrode (cathode electrode). Positive and negative polarity results are presented and compared with simulations.« less

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

PubMed

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

2011-11-22

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.

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

Experimental validation of prototype high voltage bushing

NASA Astrophysics Data System (ADS)

Shah, Sejal; Tyagi, H.; Sharma, D.; Parmar, D.; M. N., Vishnudev; Joshi, K.; Patel, K.; Yadav, A.; Patel, R.; Bandyopadhyay, M.; Rotti, C.; Chakraborty, A.

2017-08-01

Prototype High voltage bushing (PHVB) is a scaled down configuration of DNB High Voltage Bushing (HVB) of ITER. It is designed for operation at 50 kV DC to ensure operational performance and thereby confirming the design configuration of DNB HVB. Two concentric insulators viz. Ceramic and Fiber reinforced polymer (FRP) rings are used as double layered vacuum boundary for 50 kV isolation between grounded and high voltage flanges. Stress shields are designed for smooth electric field distribution. During ceramic to Kovar brazing, spilling cannot be controlled which may lead to high localized electrostatic stress. To understand spilling phenomenon and precise stress calculation, quantitative analysis was performed using Scanning Electron Microscopy (SEM) of brazed sample and similar configuration modeled while performing the Finite Element (FE) analysis. FE analysis of PHVB is performed to find out electrical stresses on different areas of PHVB and are maintained similar to DNB HV Bushing. With this configuration, the experiment is performed considering ITER like vacuum and electrical parameters. Initial HV test is performed by temporary vacuum sealing arrangements using gaskets/O-rings at both ends in order to achieve desired vacuum and keep the system maintainable. During validation test, 50 kV voltage withstand is performed for one hour. Voltage withstand test for 60 kV DC (20% higher rated voltage) have also been performed without any breakdown. Successful operation of PHVB confirms the design of DNB HV Bushing. In this paper, configuration of PHVB with experimental validation data is presented.

System for instrumenting and manipulating apparatuses in high voltage

DOEpatents

Jordan, Kevin

2016-06-07

A system for energizing, operating and manipulating apparatuses in high voltage systems. The system uses a dielectric gas such as SF.sub.6 as a driving power supply for a pneumatic motor which ultimately charges a battery or other energy storage device. The stored energy can then be used for instrumentation equipment, or to power any electrical equipment, in the high voltage deck. The accompanying method provides for the use of the SF6 system for operating an electrical device in a high-voltage environment.

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.

Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

NASA Technical Reports Server (NTRS)

Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

1982-01-01

Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

NASA Astrophysics Data System (ADS)

Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

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.

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

PubMed

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

2007-02-01

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 TE(2) (,) (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.

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

Programmable high-output-impedance, large-voltage compliance, microstimulator for low-voltage biomedical applications.

PubMed

Farahmand, Sina; Maghami, Mohammad Hossein; Sodagar, Amir M

2012-01-01

This paper reports on the design of a programmable, high output impedance, large voltage compliance microstimulator for low-voltage biomedical applications. A 6-bit binary-weighted digital to analog converter (DAC) is used to generate biphasic stimulus current pulses. A compact current mirror with large output voltage compliance and high output resistance conveys the current pulses to the target tissue. Designed and simulated in a standard 0.18µm CMOS process, the microstimulator circuit is capable of delivering a maximum stimulation current of 160µA to a 10-kΩ resistive load. Operated at a 1.8-V supply voltage, the output stage exhibits a voltage compliance of 1.69V and output resistance of 160MΩ at full scale stimulus current. Layout of the core microelectrode circuit measures 25.5µm×31.5µm.

Design and realization of high voltage disconnector condition monitoring system

NASA Astrophysics Data System (ADS)

Shi, Jinrui; Xu, Tianyang; Yang, Shuixian; Li, Buoyang

2017-08-01

The operation status of the high voltage disconnector directly affects the safe and stable operation of the power system. This article uses the wireless frequency hopping communication technology of the communication module to achieve the temperature acquisition of the switch contacts and high voltage bus, to introduce the current value of the loop in ECS, and judge the operation status of the disconnector by considering the ambient temperature, calculating the temperature rise; And through the acquisition of the current of drive motor in the process of switch closing and opening, and fault diagnosis of the disconnector by analyzing the change rule of the drive motor current, the condition monitoring of the high voltage disconnector is realized.

High Voltage TAL Performance

NASA Technical Reports Server (NTRS)

Jacobson, David T.; Jankovsky, Robert S.; Rawlin, Vincent K.; Manzella, David H.

2001-01-01

The performance of a two-stage, anode layer Hall thruster was evaluated. Experiments were conducted in single and two-stage configurations. In single-stage configuration, the thruster was operated with discharge voltages ranging from 300 to 1700 V. Discharge specific impulses ranged from 1630 to 4140 sec. Thruster investigations were conducted with input power ranging from 1 to 8.7 kW, corresponding to power throttling of nearly 9: 1. An extensive two-stage performance map was generated. Data taken with total voltage (sum of discharge and accelerating voltage) constant revealed a decrease in thruster efficiency as the discharge voltage was increased. Anode specific impulse values were comparable in the single and two-stage configurations showing no strong advantage for two-stage operation.

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

Influence of high-power nonlinear consumers on electric energy losses in mining high-voltage power line

NASA Astrophysics Data System (ADS)

Averbukh, M. A.; Prasol, D. A.

2018-03-01

The article elucidates the influence of high-power nonlinear consumers on electric energy losses in a mining high-voltage power line. The object of the study was a fragment of a power supply system of a mining enterprise with hoists. The investigation has assessed the electric energy losses conditioned by nonsinusoidal currents and voltages of the power line over a single hoist operation cycle. Also, the total electric energy losses in a high-voltage power line of a mining enterprise was calculated. The energy losses due to nonsinusoidal currents and voltages over single operation cycle of the cage hoist amount to 36.358 kWh. The presence of such losses increases total technological power and energy losses in the mining high-voltage power line by approximately 5-15%. The total energy losses in the components of the mining enterprise high-voltage power line caused by nonsinusoidal voltage are significant and lead to additional expenses of the company.

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.

Neutron-induced single event burnout in high voltage electronics

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

Normand, E.; Wert, J.L.; Oberg, D.L.

Energetic neutrons with an atmospheric neutron spectrum, which were demonstrated to induce single event burnout in power MOSFETs, have been shown to induce burnout in high voltage (>3,000V) electronics when operated at voltages as low as 50% of rated voltage. The laboratory failure rates correlate well with field failure rates measured in Europe.

Resonant-Type Smooth Impact Drive Mechanism Actuator Operating at Lower Input Voltages

NASA Astrophysics Data System (ADS)

Morita, Takeshi; Nishimura, Takuma; Yoshida, Ryuichi; Hosaka, Hiroshi

2013-07-01

We report on the design and fabrication of a resonant-type smooth impact drive mechanism (SIDM) actuator based on a multilayered piezoelectric ceramic transducer. Conventional SIDMs use off-resonant sawtooth-shaped displacement in developing stick-slip motion of a slider, but require large input voltages for high-speed operation. In contrast, in resonant-type SIDMs, a quasi-sawtooth-shaped displacement is obtained by combining two resonant vibrational modes. This driving principle enables low input voltage operations. In combining the modes, their frequency ratio must be 1:2. To design and optimize the stator transducer to generate sawtooth-shaped displacements, a transfer matrix method was adopted. With a preload of 270 mN, the no-load speed was 40 mm/s under a driving voltage of 1.6 V (peak to peak). This input voltage was one-sixth that of previous SIDMs for the same performance. Concurrently, heat generation was significantly reduced because dielectric losses were suppressed under the lower input voltage operation.

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.

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.

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.

Physicochemical assessment criteria for high-voltage pulse capacitors

NASA Astrophysics Data System (ADS)

Darian, L. A.; Lam, L. Kh.

2016-12-01

In the paper, the applicability of decomposition products of internal insulation of high-voltage pulse capacitors is considered (aging is the reason for decomposition products of internal insulation). Decomposition products of internal insulation of high-voltage pulse capacitors can be used to evaluate their quality when in operation and in service. There have been three generations of markers of aging of insulation as in the case with power transformers. The area of applicability of markers of aging of insulation for power transformers has been studied and the area can be extended to high-voltage pulse capacitors. The research reveals that there is a correlation between the components and quantities of markers of aging of the first generation (gaseous decomposition products of insulation) dissolved in insulating liquid and the remaining life of high-voltage pulse capacitors. The application of markers of aging to evaluate the remaining service life of high-voltage pulse capacitor is a promising direction of research, because the design of high-voltage pulse capacitors keeps stability of markers of aging of insulation in high-voltage pulse capacitors. It is necessary to continue gathering statistical data concerning development of markers of aging of the first generation. One should also carry out research aimed at estimation of the remaining life of capacitors using markers of the second and the third generation.

Physicochemical assessment criteria for high-voltage pulse capacitors

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

Darian, L. A., E-mail: LDarian@rambler.ru; Lam, L. Kh.

In the paper, the applicability of decomposition products of internal insulation of high-voltage pulse capacitors is considered (aging is the reason for decomposition products of internal insulation). Decomposition products of internal insulation of high-voltage pulse capacitors can be used to evaluate their quality when in operation and in service. There have been three generations of markers of aging of insulation as in the case with power transformers. The area of applicability of markers of aging of insulation for power transformers has been studied and the area can be extended to high-voltage pulse capacitors. The research reveals that there is amore » correlation between the components and quantities of markers of aging of the first generation (gaseous decomposition products of insulation) dissolved in insulating liquid and the remaining life of high-voltage pulse capacitors. The application of markers of aging to evaluate the remaining service life of high-voltage pulse capacitor is a promising direction of research, because the design of high-voltage pulse capacitors keeps stability of markers of aging of insulation in high-voltage pulse capacitors. It is necessary to continue gathering statistical data concerning development of markers of aging of the first generation. One should also carry out research aimed at estimation of the remaining life of capacitors using markers of the second and the third generation.« less

A magnesium–sodium hybrid battery with high operating voltage

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

Dong, Hui; Li, Yifei; Liang, Yanliang

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.

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.

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.

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.

Special features of large-size resistors for high-voltage pulsed installations

NASA Astrophysics Data System (ADS)

Minakova, N. N.; Ushakov, V. Ya.

2017-12-01

Many structural materials in pulsed power engineering operate under extreme conditions. For example, in high-voltage electrophysical installations among which there are multistage high-voltage pulse generators (HVPG), rigid requirements are imposed on characteristics of solid-state resistors that are more promising in comparison with widely used liquid resistors. Materials of such resistors shall be able to withstand strong electric fields, operate at elevated temperatures, in transformer oil, etc. Effective charge of high-voltage capacitors distributed over the HVPG steps (levels) requires uniform voltage distribution along the steps of the installation that can be obtained using large-size resistors. For such applications, polymer composite materials are considered rather promising. They can work in transformer oil and have small mass in comparison with bulky resistors on inorganic basis. This allows technical solutions already developed and implemented in HVPG with liquid resistors to be employed. This paper is devoted to the solution of some tasks related to the application of filled polymers in high-voltage engineering.

Surface voltage gradient role in high voltage solar array-plasma interaction: Center Director's discretionary fund

NASA Technical Reports Server (NTRS)

Carruth, M. R., Jr.

1985-01-01

A large amount of experimental and analytical effort has been directed toward understanding the plasma sheath growth and discharge phenomena which lead to high voltage solar array-space plasma interactions. An important question which has not been addressed is how the surface voltage gradient on such an array may affect these interactions. The results of this study indicate that under certain conditions, the voltage gradient should be taken into account when evaluating the effect on a solar array operating in a plasma environment.

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

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

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 reserpinemore » 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.« less

Statistical characteristics of transient enclosure voltage in ultra-high-voltage gas-insulated switchgear

NASA Astrophysics Data System (ADS)

Cai, Yuanji; Guan, Yonggang; Liu, Weidong

2017-06-01

Transient enclosure voltage (TEV), which is a phenomenon induced by the inner dielectric breakdown of SF6 during disconnector operations in a gas-insulated switchgear (GIS), may cause issues relating to shock hazard and electromagnetic interference to secondary equipment. This is a critical factor regarding the electromagnetic compatibility of ultra-high-voltage (UHV) substations. In this paper, the statistical characteristics of TEV at UHV level are collected from field experiments, and are analyzed and compared to those from a repeated strike process. The TEV waveforms during disconnector operations are recorded by a self-developed measurement system first. Then, statistical characteristics, such as the pulse number, duration of pulses, frequency components, magnitude and single pulse duration, are extracted. The transmission line theory is introduced to analyze the TEV and is validated by the experimental results. Finally, the relationship between the TEV and the repeated strike process is analyzed. This proves that the pulse voltage of the TEV is proportional to the corresponding breakdown voltage. The results contribute to the definition of the standard testing waveform of the TEV, and can aid the protection of electronic devices in substations by minimizing the threat of this phenomenon.

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

30 CFR 75.705-3 - Work on energized high-voltage surface lines; reporting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on energized high-voltage surface lines... Work on energized high-voltage surface lines; reporting. Any operator designating and assigning qualified persons to perform repairs on energized high-voltage surface lines under the provisions of § 75...

Technical Trend of Environment-friendly High Voltage Vacuum Circuit Breaker (VCB)

NASA Astrophysics Data System (ADS)

Okubo, Hitoshi

Vacuum Circuit Breakers (VCBs) have widely been used for low and medium voltage level, because of their high current interruption performance, maintenance free operations and environment-friendly characteristics. The VCB is now going to be applied to higher voltage systems for transmission and substation use. In this paper, the recent technical trend and future perspectives of high voltage VCBs are described, as well as their technical background.

A low knee voltage and high breakdown voltage of 4H-SiC TSBS employing poly-Si/Ni Schottky scheme

NASA Astrophysics Data System (ADS)

Kim, Dong Young; Seok, Ogyun; Park, Himchan; Bahng, Wook; Kim, Hyoung Woo; Park, Ki Cheol

2018-02-01

We report a low knee voltage and high breakdown voltage 4H-SiC TSBS employing poly-Si/Ni dual Schottky contacts. A knee voltage was significantly improved from 0.75 to 0.48 V by utilizing an alternative low work-function material of poly-Si as an anode electrode. Also, reverse breakdown voltage was successfully improved from 901 to 1154 V due to a shrunk low-work-function Schottky region by a proposed self-align etching process between poly-Si and SiC. SiC TSBS with poly-Si/Ni dual Schottky scheme is a suitable structure for high-efficiency rectification and high-voltage blocking operation.

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

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.

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.

High-voltage compatible, full-depleted CCD

DOEpatents

Holland, Stephen Edward

2007-09-18

A charge coupled device for detecting electromagnetic and particle radiation is described. The device includes a high-resistivity semiconductor substrate, buried channel regions, gate electrode circuitry, and amplifier circuitry. For good spatial resolution and high performance, especially when operated at high voltages with full or nearly full depletion of the substrate, the device can also include a guard ring positioned near channel regions, a biased channel stop, and a biased polysilicon electrode over the channel stop.

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.

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.

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.

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.

Trap Healing for High-Performance Low-Voltage Polymer Transistors and Solution-Based Analog Amplifiers on Foil.

PubMed

Pecunia, Vincenzo; Nikolka, Mark; Sou, Antony; Nasrallah, Iyad; Amin, Atefeh Y; McCulloch, Iain; Sirringhaus, Henning

2017-06-01

Solution-processed semiconductors such as conjugated polymers have great potential in large-area electronics. While extremely appealing due to their low-temperature and high-throughput deposition methods, their integration in high-performance circuits has been difficult. An important remaining challenge is the achievement of low-voltage circuit operation. The present study focuses on state-of-the-art polymer thin-film transistors based on poly(indacenodithiophene-benzothiadiazole) and shows that the general paradigm for low-voltage operation via an enhanced gate-to-channel capacitive coupling is unable to deliver high-performance device behavior. The order-of-magnitude longitudinal-field reduction demanded by low-voltage operation plays a fundamental role, enabling bulk trapping and leading to compromised contact properties. A trap-reduction technique based on small molecule additives, however, is capable of overcoming this effect, allowing low-voltage high-mobility operation. This approach is readily applicable to low-voltage circuit integration, as this work exemplifies by demonstrating high-performance analog differential amplifiers operating at a battery-compatible power supply voltage of 5 V with power dissipation of 11 µW, and attaining a voltage gain above 60 dB at a power supply voltage below 8 V. These findings constitute an important milestone in realizing low-voltage polymer transistors for solution-based analog electronics that meets performance and power-dissipation requirements for a range of battery-powered smart-sensing applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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).

DC High Voltage Conditioning of Photoemission Guns at Jefferson Lab FEL

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

Hernandez-Garcia, C.; Benson, S. V.; Biallas, G.

2009-08-04

DC high voltage photoemission electron guns with GaAs photocathodes have been used to produce polarized electron beams for nuclear physics experiments for about 3 decades with great success. In the late 1990s, Jefferson Lab adopted this gun technology for a free electron laser (FEL), but to assist with high bunch charge operation, considerably higher bias voltage is required compared to the photoguns used at the Jefferson Lab Continuous Electron Beam Accelerator Facility. The FEL gun has been conditioned above 400 kV several times, albeit encountering non-trivial challenges with ceramic insulators and field emission from electrodes. Recently, high voltage processing withmore » krypton gas was employed to process very stubborn field emitters. This work presents a summary of the high voltage techniques used to high voltage condition the Jefferson Lab FEL photoemission gun.« less

Recent advances of high voltage AlGaN/GaN power HFETs

NASA Astrophysics Data System (ADS)

Uemoto, Yasuhiro; Ueda, Tetsuzo; Tanaka, Tsuyoshi; Ueda, Daisuke

2009-02-01

We review our recent advances of GaN-based high voltage power transistors. These are promising owing to low on-state resistance and high breakdown voltage taking advantages of superior material properties. However, there still remain a couple of technical issues to be solved for the GaN devices to replace the existing Si-based power devices. The most critical issue is to achieve normally-off operation which is strongly desired for the safety operation, however, it has been very difficult because of the built-in polarization electric field. Our new device called GIT (Gate Injection Transistor) utilizing conductivity modulation successfully achieves the normally-off operation keeping low on-state resistance. The fabricated GIT on a Si substrate exhibits threshold voltage of +1.0V. The obtained on-state resistance and off-state breakdown voltage were 2.6mΩ•cm2 and 800V, respectively. Remaining technical issue is to further increase the breakdown voltage. So far, the reported highest off-state breakdown voltage of AlGaN/GaN HFETs has been 1900V. Overcoming these issues by a novel device structure, we have demonstrated the world highest breakdown voltages of 10400V using thick poly-crystalline AlN as a passivation film and Via-holes through sapphire which enable very efficient layout of the lateral HFET array avoiding any undesired breakdown of passivation films. Since conventional wet or dry etching cannot be used for chemically stable sapphire, high power pulsed laser is used to form the via-holes. The presented GaN power devices demonstrate that GaN is advantageous for high voltage power switching applications replacing currently used Si-based power MOSFETs and IGBTs.

Digitally gain controlled linear high voltage amplifier for laboratory applications.

PubMed

Koçum, C

2011-08-01

The design of a digitally gain controlled high-voltage non-inverting bipolar linear amplifier is presented. This cost efficient and relatively simple circuit has stable operation range from dc to 90 kHz under the load of 10 kΩ and 39 pF. The amplifier can swing up to 360 V(pp) under these conditions and it has 2.5 μs rise time. The gain can be changed by the aid of JFETs. The amplifiers have been realized using a combination of operational amplifiers and high-voltage discrete bipolar junction transistors. The circuit details and performance characteristics are discussed.

18/20 T high magnetic field scanning tunneling microscope with fully low voltage operability, high current resolution, and large scale searching ability.

PubMed

Li, Quanfeng; Wang, Qi; Hou, Yubin; Lu, Qingyou

2012-04-01

We present a home-built 18/20 T high magnetic field scanning tunneling microscope (STM) featuring fully low voltage (lower than ±15 V) operability in low temperatures, large scale searching ability, and 20 fA high current resolution (measured by using a 100 GOhm dummy resistor to replace the tip-sample junction) with a bandwidth of 3.03 kHz. To accomplish low voltage operation which is important in achieving high precision, low noise, and low interference with the strong magnetic field, the coarse approach is implemented with an inertial slider driven by the lateral bending of a piezoelectric scanner tube (PST) whose inner electrode is axially split into two for enhanced bending per volt. The PST can also drive the same sliding piece to inertial slide in the other bending direction (along the sample surface) of the PST, which realizes the large area searching ability. The STM head is housed in a three segment tubular chamber, which is detachable near the STM head for the convenience of sample and tip changes. Atomic resolution images of a graphite sample taken under 17.6 T and 18.0001 T are presented to show its performance. © 2012 American Institute of Physics

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.

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.

30 CFR 77.807-3 - Movement of equipment; minimum distance from high-voltage lines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... high-voltage lines. 77.807-3 Section 77.807-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-3 Movement of equipment; minimum distance from high-voltage lines. When any part of any equipment operated on the surface of any...

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.

High-voltage, high-current, solid-state closing switch

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

Focia, Ronald Jeffrey

2017-08-22

A high-voltage, high-current, solid-state closing switch uses a field-effect transistor (e.g., a MOSFET) to trigger a high-voltage stack of thyristors. The switch can have a high hold-off voltage, high current carrying capacity, and high time-rate-of-change of current, di/dt. The fast closing switch can be used in pulsed power applications.

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.

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.

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.

30 CFR 77.807-2 - Booms and masts; minimum distance from high-voltage lines.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-voltage lines. 77.807-2 Section 77.807-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-2 Booms and masts; minimum distance from high-voltage lines. The booms and masts of equipment operated on the surface of any...

High Voltage Design Concepts for Launch Vehicles and Orbital Spacecraft Applications

NASA Technical Reports Server (NTRS)

Hall, David K.; Kirkici, Hulya; Hillard, G. Barry; Schweickart, Daniel; Dunbar, Bill

2000-01-01

With the advent of design concepts such as, electromechanical actuation and "more electric" initiatives, has come the need for electrical power buses and electronic equipment to operate at higher than normal dc voltages to meet power requirements while keeping current levels to manageable levels. This new bus voltage has been typically 270 Volts dc nominal for launch vehicles, and 120 Volt dc for the International Space Station. This paper will discuss the new design applications for high voltage dc power in existing and future launch vehicles and spacecraft and the potential problems associated therewith. These new applications must be operational from lift-off, ascent, on orbit and descent in all of the pressure and temperature conditions for each, i.e. through the "Paschen region" twice. This paper will also attempt to stimulate an interest in the academic and professional communities to support and conduct research needed for design data applicable to high voltage dc usage.

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

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

NASA Technical Reports Server (NTRS)

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

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%.

High-performance, low-operating voltage, and solution-processable organic field-effect transistor with silk fibroin as the gate dielectric

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

Shi, Leilei; Xu, Xinjun, E-mail: xuxj@mater.ustb.edu.cn, E-mail: lidong@mater.ustb.edu.cn; Ma, Mingchao

2014-01-13

We report the use of silk fibroin as the gate dielectric material in solution-processed organic field-effect transistors (OFETs) with poly(3-hexylthiophene) (P3HT) as the semiconducting layer. Such OFETs exhibit a low threshold of −0.77 V and a low-operating voltage (0 to −3 V) compatible with the voltage level commonly-used in current electronic industry. The carrier mobility of such OFETs is as high as 0.21 cm{sup 2} V{sup −1} s{sup −1} in the saturation regime, comparable to the best value of P3HT-based OFETs with dielectric layer that is not solution-processed. The high-performance of this kind of OFET is related with the high contentmore » of β strands in fibroin dielectric which leads to an array of fibers in a highly ordered structure, thus reducing the trapping sites at the semiconductor/dielectric interface.« less

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.

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

Completely explosive ultracompact high-voltage nanosecond pulse-generating system

NASA Astrophysics Data System (ADS)

Shkuratov, Sergey I.; Talantsev, Evgueni F.; Baird, Jason; Rose, Millard F.; Shotts, Zachary; Altgilbers, Larry L.; Stults, Allen H.

2006-04-01

A conventional pulsed power technology has been combined with an explosive pulsed power technology to produce an autonomous high-voltage power supply. The power supply contained an explosive-driven high-voltage primary power source and a power-conditioning stage. The ultracompact explosive-driven primary power source was based on the physical effect of shock-wave depolarization of high-energy Pb (Zr52Ti48)O3 ferroelectric material. The volume of the energy-carrying ferroelectric elements in the shock-wave ferroelectric generators (SWFEGs) varied from 1.2 to 2.6cm3. The power-conditioning stage was based on the spiral vector inversion generator (VIG). The SWFEG-VIG system demonstrated successful operation and good performance. The amplitude of the output voltage pulse of the SWFEG-VIG system exceeded 90kV, with a rise time of 5.2ns.

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.

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.

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.

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.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2006-03-14

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2008-03-25

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

NASCAP modelling of high-voltage power system interactions with space charged-particle environments

NASA Technical Reports Server (NTRS)

Stevens, N. J.; Roche, J. C.; Mandell, M. J.

1979-01-01

A simple space power system operating in geosynchronous orbit was analyzed. This system consisted of two solar array wings and a central body. Each solar array wing was considered to be divided into three regions operating at 2000 volts. The center body was considered to be an electrical ground with the array voltages both positive and negative relative to ground. The system was analyzed for both a normal environment and a moderate geomagnetic substorm environment. Initial results indicate a high probability of arcing at the interconnects on the negative operating voltage wing. The dielectric strength of the substrate may be exceeded giving rise to breakdown in the bulk of the material. The geomagnetic substorm did not seem to increase the electrical gradients at the interconnects on the negative operating voltage wing but did increase the gradients on the positive operating voltage wing which could result in increased coupling current losses.

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

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

Ma, Zhan-Wen; Su, Xiao-Dong; Wei, Zhen

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 themore » 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%.« less

High-mobility and low-operating voltage organic thin film transistor with epoxy based siloxane binder as the gate dielectric

NASA Astrophysics Data System (ADS)

Tewari, Amit; Gandla, Srinivas; Pininti, Anil Reddy; Karuppasamy, K.; Böhm, Siva; Bhattacharyya, Arup R.; McNeill, Christopher R.; Gupta, Dipti

2015-09-01

This paper reports the fabrication of pentacene-based organic thin-film transistors using a dielectric material, Dynasylan ®SIVO110. The devices exhibit excellent performance characterized by a low threshold voltage of -1.4 V (operating voltage: 0 to -4 V) together with a mobility of 1.9 cm2 V-1s-1. These results are promising because it uses only a single layer of dielectric without performing any intermediate treatment. The reason is attributed to the high charge storage capacity of the dielectric (κ ˜ 20.02), a low interfacial trap density (2.56 × 1011cm-2), and favorable pentacene film morphology consisting of large and interconnected grains having an average size of 234 nm.

Coordinative Voltage Control Strategy with Multiple Resources for Distribution Systems of High PV Penetration: Preprint

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

Zhu, Xiangqi; Zhang, Yingchen

This paper presents an optimal voltage control methodology with coordination among different voltage-regulating resources, including controllable loads, distributed energy resources such as energy storage and photovoltaics (PV), and utility voltage-regulating devices such as voltage regulators and capacitors. The proposed methodology could effectively tackle the overvoltage and voltage regulation device distortion problems brought by high penetrations of PV to improve grid operation reliability. A voltage-load sensitivity matrix and voltage-regulator sensitivity matrix are used to deploy the resources along the feeder to achieve the control objectives. Mixed-integer nonlinear programming is used to solve the formulated optimization control problem. The methodology has beenmore » tested on the IEEE 123-feeder test system, and the results demonstrate that the proposed approach could actively tackle the voltage problem brought about by high penetrations of PV and improve the reliability of distribution system operation.« less

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.

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.

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.cm 2. Diodes achieved a forward current of 1 A for on-wafer, DC measurements, corresponding to a current density > 1.4 kA/cm 2. 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.

Ion properties in a Hall current thruster operating at high voltage

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

Garrigues, L., E-mail: laurent.garrigues@laplace.univ-tlse.fr

2016-04-28

Operation of a 5 kW-class Hall current Thruster for various voltages from 400 V to 800 V and a xenon mass flow rate of 6 mg s{sup −1} have been studied with a quasi-neutral hybrid model. In this model, anomalous electron transport is fitted from ion mean velocity measurements, and energy losses due to electron–wall interactions are used as a tuned parameter to match expected electron temperature strength for same class of thruster. Doubly charged ions production has been taken into account and detailed collisions between heavy species included. As the electron temperature increases, the main channel of Xe{sup 2+} ion production becomes stepwisemore » ionization of Xe{sup +} ions. For an applied voltage of 800 V, the mass utilization efficiency is in the range of 0.8–1.1, and the current fraction of doubly charged ions varies between 0.1 and 0.2. Results show that the region of ion production of each species is located at the same place inside the thruster channel. Because collision processes mean free path is larger than the acceleration region, each type of ions experiences same potential drop, and ion energy distributions of singly and doubly charged are very similar.« less

Analysis of a modular generator for high-voltage, high-frequency pulsed applications, using low voltage semiconductors (< 1 kV) and series connected step-up (1:10) transformers.

PubMed

Redondo, L M; Fernando Silva, J; Margato, E

2007-03-01

This article discusses the operation of a modular generator topology, which has been developed for high-frequency (kHz), high-voltage (kV) pulsed applications. The proposed generator uses individual modules, each one consisting of a pulse circuit based on a modified forward converter, which takes advantage of the required low duty cycle to operate with a low voltage clamp reset circuit for the step-up transformer. This reduces the maximum voltage on the semiconductor devices of both primary and secondary transformer sides. The secondary winding of each step-up transformer is series connected, delivering a fraction of the total voltage. Each individual pulsed module is supplied via an isolation transformer. The assembled modular laboratorial prototype, with three 5 kV modules, 800 V semiconductor switches, and 1:10 step-up transformers, has 80% efficiency, and is capable of delivering, into resistive loads, -15 kV1 A pulses with 5 micros width, 10 kHz repetition rate, with less than 1 micros pulse rise time. Experimental results for resistive loads are presented and discussed.

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.

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

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

She, Xu; Chokhawala, Rahul Shantilal; Zhou, Rui

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 themore » 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.« less

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.

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. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

C-H surface diamond field effect transistors for high temperature (400 °C) and high voltage (500 V) operation

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

Kawarada, H., E-mail: kawarada@waseda.jp; Institute of Nano-Science and Nano-Engineering, Waseda University, Shinjuku, Tokyo 169-8555; Kagami Memorial Laboratory for Material Science and Technology, Waseda University, Shinjuku, Tokyo 169-0051

2014-07-07

By forming a highly stable Al{sub 2}O{sub 3} gate oxide on a C-H bonded channel of diamond, high-temperature, and high-voltage metal-oxide-semiconductor field-effect transistor (MOSFET) has been realized. From room temperature to 400 °C (673 K), the variation of maximum drain-current is within 30% at a given gate bias. The maximum breakdown voltage (V{sub B}) of the MOSFET without a field plate is 600 V at a gate-drain distance (L{sub GD}) of 7 μm. We fabricated some MOSFETs for which V{sub B}/L{sub GD} > 100 V/μm. These values are comparable to those of lateral SiC or GaN FETs. The Al{sub 2}O{sub 3} was deposited on the C-Hmore » surface by atomic layer deposition (ALD) at 450 °C using H{sub 2}O as an oxidant. The ALD at relatively high temperature results in stable p-type conduction and FET operation at 400 °C in vacuum. The drain current density and transconductance normalized by the gate width are almost constant from room temperature to 400 °C in vacuum and are about 10 times higher than those of boron-doped diamond FETs.« less

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...-Voltage Longwalls § 75.826 High-voltage trailing cables. High-voltage trailing cables must: (a) Meet existing trailing cable requirements and the approval requirements of the high-voltage continuous mining...

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.

Low voltage operation of IGZO thin film transistors enabled by ultrathin Al2O3 gate dielectric

NASA Astrophysics Data System (ADS)

Ma, Pengfei; Du, Lulu; Wang, Yiming; Jiang, Ran; Xin, Qian; Li, Yuxiang; Song, Aimin

2018-01-01

An ultrathin, 5 nm, Al2O3 film grown by atomic-layer deposition was used as a gate dielectric for amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). The Al2O3 layer showed a low surface roughness of 0.15 nm, a low leakage current, and a high breakdown voltage of 6 V. In particular, a very high gate capacitance of 720 nF/cm2 was achieved, making it possible for the a-IGZO TFTs to not only operate at a low voltage of 1 V but also exhibit desirable properties including a low threshold voltage of 0.3 V, a small subthreshold swing of 100 mV/decade, and a high on/off current ratio of 1.2 × 107. Furthermore, even under an ultralow operation voltage of 0.6 V, well-behaved transistor characteristics were still observed with an on/off ratio as high as 3 × 106. The electron transport through the Al2O3 layer has also been analyzed, indicating the Fowler-Nordheim tunneling mechanism.

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.

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.

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.

High-performance, low-voltage, and easy-operable bending actuator based on aligned carbon nanotube/polymer composites.

PubMed

Chen, Luzhuo; Liu, Changhong; Liu, Ke; Meng, Chuizhou; Hu, Chunhua; Wang, Jiaping; Fan, Shoushan

2011-03-22

In this work, we show that embedding super-aligned carbon nanotube sheets into a polymer matrix (polydimethylsiloxane) can remarkably reduce the coefficient of thermal expansion of the polymer matrix by two orders of magnitude. Based on this unique phenomenon, we fabricated a new kind of bending actuator through a two-step method. The actuator is easily operable and can generate an exceptionally large bending actuation with controllable motion at very low driving DC voltages (<700 V/m). Furthermore, the actuator can be operated without electrolytes in the air, which is superior to conventional carbon nanotube actuators. Proposed electrothermal mechanism was discussed and confirmed by our experimental results. The exceptional bending actuation performance together with easy fabrication, low-voltage, and controllable motion demonstrates the potential ability of using this kind of actuator in various applicable areas, such as artificial muscles, microrobotics, microsensors, microtransducers, micromanipulation, microcantilever for medical applications, and so on.

Temperature controlled high voltage regulator

DOEpatents

Chiaro, Jr., Peter J.; Schulze, Gerald K.

2004-04-20

A temperature controlled high voltage regulator for automatically adjusting the high voltage applied to a radiation detector is described. The regulator is a solid state device that is independent of the attached radiation detector, enabling the regulator to be used by various models of radiation detectors, such as gas flow proportional radiation detectors.

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 and...

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 and...

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 and...

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 and...

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 be...

High Voltage, Solid-State Switch for Fusion Science Applications

NASA Astrophysics Data System (ADS)

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

2017-10-01

Eagle Harbor Technologies, Inc. is developing a series stack of solid-state switches to produce a single high voltage switch that can be operated at over 35 kV. During the Phase I program, EHT developed two high voltage switch modules: one with isolated power gate drive and a second with inductively coupled gate drive. These switches were tested at 15 kV and up to 300 A at switching frequencies up to 500 kHz for 10 ms bursts. Robust switching was demonstrated for both IGBTs and SiC MOSFETs. During the Phase II program, EHT will develop a higher voltage switch (>35 kV) that will be suitable for high pulsed and average power applications. EHT will work with LTX to utilize these switches to design, build, and test a pulsed magnetron driver that will be delivered to LTX before the completion of the program. EHT will present data from the Phase I program as well as preliminary results from the start of the Phase II program. With support of DOE SBIR.

Comparison of high-voltage ac and pulsed operation of a surface dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Williamson, James M.; Trump, Darryl D.; Bletzinger, Peter; Ganguly, Biswa N.

2006-10-01

A surface dielectric barrier discharge (DBD) in atmospheric pressure air was excited either by low frequency (0.3-2 kHz) high-voltage ac or by short, high-voltage pulses at repetition rates from 50 to 600 pulses s-1. The short-pulse excited discharge was more diffuse and did not have the pronounced bright multiple cathode spots observed in the ac excited discharge. The discharge voltage, current and average power deposited into the discharge were calculated for both types of excitation. As a measure of plasma-chemical efficiency, the ozone number density was measured by UV absorption as a function of average deposited power. The density of ozone produced by ac excitation did not increase so rapidly as that produced by short-pulse excitation as a function of average power, with a maximum measured density of ~3 × 1015 cm-3 at 25 W. The maximum ozone production achieved by short-pulse excitation was ~8.5 × 1015 cm-3 at 20 W, which was four times greater than that achieved by ac excitation at the same power level.

Modular high voltage power supply for chemical analysis

DOEpatents

Stamps, James F [Livermore, CA; Yee, Daniel D [Dublin, CA

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.

Modular high voltage power supply for chemical analysis

DOEpatents

Stamps, James F [Livermore, CA; Yee, Daniel D [Dublin, CA

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.

Modular high voltage power supply for chemical analysis

DOEpatents

Stamps, James F [Livermore, CA; Yee, Daniel D [Dublin, CA

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.

Electronic Current Transducer (ECT) for high voltage dc lines

NASA Astrophysics Data System (ADS)

Houston, J. M.; Peters, P. H., Jr.; Summerayes, H. R., Jr.; Carlson, G. J.; Itani, A. M.

1980-02-01

The development of a bipolar electronic current transducer (ECT) for measuring the current in a high voltage dc (HVDC) power line at line potential is discussed. The design and construction of a free standing ECT for use on a 400 kV line having a nominal line current of 2000 A is described. Line current is measured by a 0.0001 ohm shunt whose voltage output is sampled by a 14 bit digital data link. The high voltage interface between line and ground is traversed by optical fibers which carry digital light signals as far as 300 m to a control room where the digital signal is converted back to an analog representation of the shunt voltage. Two redundant electronic and optical data links are used in the prototype. Power to operate digital and optical electronics and temperature controlling heaters at the line is supplied by a resistively and capacitively graded 10 stage cascade of ferrite core transformers located inside the hollow, SF6 filled, porcelain support insulator. The cascade is driven by a silicon controlled rectifier inverter which supplies about 100 W of power at 30 kHz.

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

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.

Incorporating voltage security into the planning, operation and monitoring of restructured electric energy markets

NASA Astrophysics Data System (ADS)

Nair, Nirmal-Kumar

As open access market principles are applied to power systems, significant changes are happening in their planning, operation and control. In the emerging marketplace, systems are operating under higher loading conditions as markets focus greater attention to operating costs than stability and security margins. Since operating stability is a basic requirement for any power system, there is need for newer tools to ensure stability and security margins being strictly enforced in the competitive marketplace. This dissertation investigates issues associated with incorporating voltage security into the unbundled operating environment of electricity markets. It includes addressing voltage security in the monitoring, operational and planning horizons of restructured power system. This dissertation presents a new decomposition procedure to estimate voltage security usage by transactions. The procedure follows physical law and uses an index that can be monitored knowing the state of the system. The expression derived is based on composite market coordination models that have both PoolCo and OpCo transactions, in a shared stressed transmission grid. Our procedure is able to equitably distinguish the impacts of individual transactions on voltage stability, at load buses, in a simple and fast manner. This dissertation formulates a new voltage stability constrained optimal power flow (VSCOPF) using a simple voltage security index. In modern planning, composite power system reliability analysis that encompasses both adequacy and security issues is being developed. We have illustrated the applicability of our VSCOPF into composite reliability analysis. This dissertation also delves into the various applications of voltage security index. Increasingly, FACT devices are being used in restructured markets to mitigate a variety of operational problems. Their control effects on voltage security would be demonstrated using our VSCOPF procedure. Further, this dissertation investigates

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 High-voltage...

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 High-voltage...

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.

High Efficiency Single Output ZVS-ZCS Voltage Doubled Flyback Converter

NASA Astrophysics Data System (ADS)

Kaliyaperumal, Deepa; Saju, Hridya Merin; Kumar, M. Vijaya

2016-06-01

A switch operating at high switching frequency increases the switching losses of the converter resulting in lesser efficiency. Hence this paper proposes a new topology which has resonant switches [zero voltage switching (ZVS)] in the primary circuit to eliminate the above said disadvantages, and voltage doubler zero current switching (ZCS) circuit in the secondary to double the output voltage, and hence the output power, power density and efficiency. The design aspects of the proposed topology for a single output of 5 V at 50 kHz, its simulation and hardware results are discussed in detail. The analysis of the results obtained from a 2.5 W converter reveals the superiority of the proposed converter.

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.

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.

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.

Increase the threshold voltage of high voltage GaN transistors by low temperature atomic hydrogen treatment

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

Erofeev, E. V., E-mail: erofeev@micran.ru; Fedin, I. V.; Kutkov, I. V.

High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping levelmore » makes it possible to attain a threshold voltage of GaN transistors close to V{sub th} = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to V{sub th} = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation.« less

Modeling of high composition AlGaN channel high electron mobility transistors with large threshold voltage

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

Bajaj, Sanyam, E-mail: bajaj.10@osu.edu; Hung, Ting-Hsiang; Akyol, Fatih

2014-12-29

We report on the potential of high electron mobility transistors (HEMTs) consisting of high composition AlGaN channel and barrier layers for power switching applications. Detailed two-dimensional (2D) simulations show that threshold voltages in excess of 3 V can be achieved through the use of AlGaN channel layers. We also calculate the 2D electron gas mobility in AlGaN channel HEMTs and evaluate their power figures of merit as a function of device operating temperature and Al mole fraction in the channel. Our models show that power switching transistors with AlGaN channels would have comparable on-resistance to GaN-channel based transistors for the samemore » operation voltage. The modeling in this paper shows the potential of high composition AlGaN as a channel material for future high threshold enhancement mode transistors.« less

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.

The development of high-voltage repetitive low-jitter corona stabilized triggered switch

NASA Astrophysics Data System (ADS)

Geng, Jiuyuan; Yang, Jianhua; Cheng, Xinbing; Yang, Xiao; Chen, Rong

2018-04-01

The high-power switch plays an important part in a pulse power system. With the trend of pulse power technology toward modularization, miniaturization, and accuracy control, higher requirements on electrical trigger and jitter of the switch have been put forward. A high-power low-jitter corona-stabilized triggered switch (CSTS) is designed in this paper. This kind of CSTS is based on corona stabilized mechanism, and it can be used as a main switch of an intense electron-beam accelerator (IEBA). Its main feature was the use of an annular trigger electrode instead of a traditional needle-like trigger electrode, taking main and side trigger rings to fix the discharging channels and using SF6/N2 gas mixture as its operation gas. In this paper, the strength of the local field enhancement was changed by a trigger electrode protrusion length Dp. The differences of self-breakdown voltage and its stability, delay time jitter, trigger requirements, and operation range of the switch were compared. Then the effect of different SF6/N2 mixture ratio on switch performance was explored. The experimental results show that when the SF6 is 15% with the pressure of 0.2 MPa, the hold-off voltage of the switch is 551 kV, the operating range is 46.4%-93.5% of the self-breakdown voltage, the jitter is 0.57 ns, and the minimum trigger voltage requirement is 55.8% of the peak. At present, the CSTS has been successfully applied to an IEBA for long time operation.

The development of high-voltage repetitive low-jitter corona stabilized triggered switch.

PubMed

Geng, Jiuyuan; Yang, Jianhua; Cheng, Xinbing; Yang, Xiao; Chen, Rong

2018-04-01

The high-power switch plays an important part in a pulse power system. With the trend of pulse power technology toward modularization, miniaturization, and accuracy control, higher requirements on electrical trigger and jitter of the switch have been put forward. A high-power low-jitter corona-stabilized triggered switch (CSTS) is designed in this paper. This kind of CSTS is based on corona stabilized mechanism, and it can be used as a main switch of an intense electron-beam accelerator (IEBA). Its main feature was the use of an annular trigger electrode instead of a traditional needle-like trigger electrode, taking main and side trigger rings to fix the discharging channels and using SF 6 /N 2 gas mixture as its operation gas. In this paper, the strength of the local field enhancement was changed by a trigger electrode protrusion length Dp. The differences of self-breakdown voltage and its stability, delay time jitter, trigger requirements, and operation range of the switch were compared. Then the effect of different SF 6 /N 2 mixture ratio on switch performance was explored. The experimental results show that when the SF 6 is 15% with the pressure of 0.2 MPa, the hold-off voltage of the switch is 551 kV, the operating range is 46.4%-93.5% of the self-breakdown voltage, the jitter is 0.57 ns, and the minimum trigger voltage requirement is 55.8% of the peak. At present, the CSTS has been successfully applied to an IEBA for long time operation.

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

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

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).

Series asymmetric supercapacitors based on free-standing inner-connection electrodes for high energy density and high output voltage

NASA Astrophysics Data System (ADS)

Tao, Jiayou; Liu, Nishuang; Rao, Jiangyu; Ding, Longwei; Al Bahrani, Majid Raissan; Li, Luying; Su, Jun; Gao, Yihua

2014-11-01

Asymmetric supercapacitors (ASCs) based on free-standing membranes with high energy density and high output voltage are reported. MnO2 nanowire/carbon nanotube (CNT) composites and MoO3 nanobelt/CNT composites are selected as the anode and the cathode materials of the devices, respectively. The ASC has a high volumetric capacitance of 50.2 F cm-3 at a scan rate of 2 mV s-1 and a high operation voltage window of 2.0 V. Especially, after a middle layer with an inner-connection structure was inserted between the anode and the cathode, the output voltage of the whole device can achieve 4.0 V. The full cell of series ASCs (SASC) with an inner-connection middle layer has a high energy density of 28.6 mW h cm-3 at a power density of 261.4 mW cm-3, and exhibits excellent cycling performance of 99.6% capacitance retention over 10 000 cycles. This strategy of designing the hybridized structure for SASCs provides a promising route for next-generation SCs with high energy density and high output voltage.Asymmetric supercapacitors (ASCs) based on free-standing membranes with high energy density and high output voltage are reported. MnO2 nanowire/carbon nanotube (CNT) composites and MoO3 nanobelt/CNT composites are selected as the anode and the cathode materials of the devices, respectively. The ASC has a high volumetric capacitance of 50.2 F cm-3 at a scan rate of 2 mV s-1 and a high operation voltage window of 2.0 V. Especially, after a middle layer with an inner-connection structure was inserted between the anode and the cathode, the output voltage of the whole device can achieve 4.0 V. The full cell of series ASCs (SASC) with an inner-connection middle layer has a high energy density of 28.6 mW h cm-3 at a power density of 261.4 mW cm-3, and exhibits excellent cycling performance of 99.6% capacitance retention over 10 000 cycles. This strategy of designing the hybridized structure for SASCs provides a promising route for next-generation SCs with high energy density and high

High voltage electrical injuries.

PubMed

Kaloudová, Y; Sín, R; Rihová, H; Brychta, R; Suchánek, I; Martincová, A

2006-01-01

Between 1999 and 2005, a total of 41 patients were hospitalized at the Burn Centre of Brno University Hospital with high voltage electrical injuries, representing 6.06% of the total number of patients treated at the Burn Intensive Care Unit (ICU) for extensive burn trauma. The average age of patients with serious electrotraumas was 27.29 years. The youngest patient was 9 years old, the oldest 64 years. Lethality amounted to 17.07% of the total number of patients. The article clearly shows the sinister dimension (a frighteningly high number of cases) of high voltage electrical injuries suffered outside work context in the vicinity of railway tracks and affecting in particular the youngest age groups--children.

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.

Absolute Determination of High DC Voltages by Means of Frequency Measurement

NASA Astrophysics Data System (ADS)

Peier, Dirk; Schulz, Bernd

1983-01-01

A novel absolute measuring procedure is presented for the definition of fixed points of the voltage in the 100 kV range. The method is based on transit time measurements with accelerated electrons. By utilizing the selective interaction of a monoenergetic electron beam with the electromagnetic field of a special cavity resonator, the voltage is referred to fundamental constants and the base unit second. Possible balance voltages are indicated by a current detector. Experimental investigations are carried out with resonators in the normal conducting range. With a copper resonator operating at the temperature of boiling nitrogen (77 K), the relative uncertainty of the voltage points is estimated to be +/- 4 × 10-4. The technically realizable uncertainty can be reduced to +/- 1 × 10-5 by the proposed application of a superconducting niobium resonator. Thus this measuring device becomes suitable as a primary standard for the high-voltage range.

Cavallo's multiplier for in situ generation of high voltage

NASA Astrophysics Data System (ADS)

Clayton, S. M.; Ito, T. M.; Ramsey, J. C.; Wei, W.; Blatnik, M. A.; Filippone, B. W.; Seidel, G. M.

2018-05-01

A classic electrostatic induction machine, Cavallo's multiplier, is suggested for in situ production of very high voltage in cryogenic environments. The device is suitable for generating a large electrostatic field under conditions of very small load current. Operation of the Cavallo multiplier is analyzed, with quantitative description in terms of mutual capacitances between electrodes in the system. A demonstration apparatus was constructed, and measured voltages are compared to predictions based on measured capacitances in the system. The simplicity of the Cavallo multiplier makes it amenable to electrostatic analysis using finite element software, and electrode shapes can be optimized to take advantage of a high dielectric strength medium such as liquid helium. A design study is presented for a Cavallo multiplier in a large-scale, cryogenic experiment to measure the neutron electric dipole moment.

Daikin Advanced Lithium Ion Battery Technology – High Voltage Electrolyte - REVISED

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

Sunstrom, Joseph; Hendershot, Ron E.

An evaluation of high voltage electrolytes which contain fluorochemicals as solvents/additive has been completed with the objective of formulating a safe, stable electrolyte capable of operation to 4.6 V. Stable cycle performance has been demonstrated in LiNi1/3Mn1/3Co1/3O2 (NMC111)/graphite cells to 4.5 V. The ability to operate at high voltage results in significant energy density gain (>30%) which would manifest as longer battery life resulting in higher range for electric vehicles. Alternatively, a higher energy density battery can be made smaller without sacrificing existing energy. In addition, the fluorinated electrolytes examined showed better safety performance when tested in abuse conditions. Themore » results are promising for future advanced battery development for vehicles as well as other applications.« less

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

Code of Federal Regulations, 2010 CFR

2010-07-01

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

High Energy Density Li-ion Cells for EV’s Based on Novel, High Voltage Cathode Material Systems

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

Kepler, Keith D.; Slater, Michael

This Li-ion cell technology development project had three objectives: to develop advanced electrode materials and cell components to enable stable high-voltage operation; to design and demonstrate a Li-ion cell using these materials that meets the PHEV40 performance targets; and to design and demonstrate a Li-ion cell using these materials that meets the EV performance targets. The major challenge to creating stable high energy cells with long cycle life is system integration. Although materials that can give high energy cells are known, stabilizing them towards long-term cycling in the presence of other novel cell components is a major challenge. The majormore » technical barriers addressed by this work include low cathode specific energy, poor electrolyte stability during high voltage operation, and insufficient capacity retention during deep discharge for Si-containing anodes. Through the course of this project, Farasis was able to improve capacity retention of NCM materials for 4.4+ V operation, through both surface treatment and bulk-doping approaches. Other material advances include increased rate capability and of HE-NCM materials through novel synthesis approach, doubling the relative capacity at 1C over materials synthesized using standard methods. Silicon active materials proved challenging throughout the project and ultimately were the limiting factor in the energy density vs. cycle life trade off. By avoiding silicon anodes for the lower energy PHEV design, we manufactured cells with intermediate energy density and long cycle life under high voltage operation for PHEV applications. Cells with high energy density for EV applications were manufactured targeting a 300 Wh/kg design and were able to achieve > 200 cycles.« less

Cryogenic lifetime tests on a commercial epoxy resin high voltage bushing

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

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 bemore » 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.« less

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.

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.

E-beam high voltage switching power supply

DOEpatents

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

1996-10-15

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

E-beam high voltage switching power supply

DOEpatents

Shimer, Daniel W.; Lange, Arnold C.

1996-01-01

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

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

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

Li, G.; Wu, S. C.; Zhou, Z. B.

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 ofmore » magnitude lower.« less

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 offers improvements in efficiency, weight, and reliability for the electric propulsion power system. Conventional power processes and problems associated with ion thruster operation using SERT 2 experience are discussed and the advantages of the HVSA concept for electric propulsion are presented. Tests conducted operating the SERT 2 thruster system in conjunction with HVSA are reported. Thruster operation was observed to be normal and in some respects improved.

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.

A Consideration of Stable Operating Power Limits of HVDC System Composed of Voltage Source Converters

NASA Astrophysics Data System (ADS)

Konishi, Hiroo; Takahashi, Choei; Kishibe, Hideto; Sato, Hiromichi

The stable operating power limits of a small scale HVDC system composed of voltage source converters (VSC-HVDC system) are analyzed with a simple model. The VSC-HVDC system could operate where the AC system must be somewhat larger in capacity than the VSC-HVDC system capacity. The stable operating power limits were between one and two times the SCR (short circuit ratio). When the inverter of the VSC-HVDC system was operated with lead reactive (capacitive) power control conditions, the stable operating limits were increased through AC voltage stabilization. When the inverter was a STATCOM operation, it could operate regardless of the SCR but regions within allowable AC voltage variations.

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... High-Voltage Longwalls § 75.833 Handling high-voltage trailing cables. (a) Cable handling. (1) Miners must not handle energized trailing cables unless they are wearing high-voltage insulating gloves, which...

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.

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

NASA Technical Reports Server (NTRS)

Callis, Charles P.

1987-01-01

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

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.

30 CFR 75.804 - Underground high-voltage cables.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Underground high-voltage cables. 75.804 Section... § 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...

30 CFR 75.804 - Underground high-voltage cables.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Underground high-voltage cables. 75.804 Section... § 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...

30 CFR 75.804 - Underground high-voltage cables.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Underground high-voltage cables. 75.804 Section... § 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...

Train surfing and other high voltage trauma: differences in injury-related mechanisms and operative outcomes after fasciotomy, amputation and soft-tissue coverage.

PubMed

Lumenta, David Benjamin; Vierhapper, Martin Friedrich; Kamolz, Lars-Peter; Keck, Maike; Frey, Manfred

2011-12-01

In the context of scarce reports on train surfers among high voltage electric injuries, we conducted a retrospective review between January 1994 and December 2008. After matching for inclusion criteria we reviewed patient records of 37 true high voltage injuries (12 train surfers [TS] and 25 other high voltage injuries [HV]). TS were significantly younger (TS 15.8 years vs. HV 33.3 years, p<0.0001), and had a greater %TBSA (TS 49.7%TBSA vs. HV 21.5%TBSA, p=0.0003) without affecting the median length-of-stay (TS 52 days vs. HV 49 days) or number of operations (TS 4 vs. HV 3). TS had different injury patterns, with a higher percentage of affected extremities (TS 72.9% vs. HV 52.0%, p=0.0468) and associated injuries (TS 58% vs. HV 20%, n.s.) than HV. Both groups demonstrated comparable fasciotomy (TS 71.4% vs. HV 55.8%) and amputation rates (TS 17.1% vs. HV 15.4%). While TS required less flaps (TS 3/12 vs. HV 18/25; p=0.0153), soft-tissue reconstruction revealed an overall low incidence of complication rates (one partial pedicled flap loss and two total free flap losses). Train surfers have proven to be a distinct group of patients among high-voltage injuries notably as a result of a younger age, a shorter electric contact duration and higher velocity-induced trauma. With a possibly declining trend of train surfing-related accidents in an aging society, it will be interesting to see if emerging economies will face comparable phenomena, for which prevention strategies remain key. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

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

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.

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.

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

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

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

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

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

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.

Hybrid permeable metal-base transistor with large common-emitter current gain and low operational voltage.

PubMed

Feng, Chengang; Yi, Mingdong; Yu, Shunyang; Hümmelgen, Ivo A; Zhang, Tong; Ma, Dongge

2008-04-01

We demonstrate the suitability of N,N'-diphenyl-N,N'-bis(1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine (NPB), an organic semiconductor widely used in organic light-emitting diodes (OLEDs), for high-gain, low operational voltage nanostructured vertical-architecture transistors, which operate as permeable-base transistors. By introducing vanadium oxide (V2O5) between the injecting metal and NPB layer at the transistor emitter, we reduced the emitter operational voltage. The addition of two Ca layers, leading to a Ca/Ag/Ca base, allowed to obtain a large value of common-emitter current gain, but still retaining the permeable-base transistor character. This kind of vertical devices produced by simple technologies offer attractive new possibilities due to the large variety of available molecular semiconductors, opening the possibility of incorporating new functionalities in silicon-based devices.

Series asymmetric supercapacitors based on free-standing inner-connection electrodes for high energy density and high output voltage.

PubMed

Tao, Jiayou; Liu, Nishuang; Rao, Jiangyu; Ding, Longwei; Al Bahrani, Majid Raissan; Li, Luying; Su, Jun; Gao, Yihua

2014-12-21

Asymmetric supercapacitors (ASCs) based on free-standing membranes with high energy density and high output voltage are reported. MnO(2) nanowire/carbon nanotube (CNT) composites and MoO(3) nanobelt/CNT composites are selected as the anode and the cathode materials of the devices, respectively. The ASC has a high volumetric capacitance of 50.2 F cm(-3) at a scan rate of 2 mV s(-1) and a high operation voltage window of 2.0 V. Especially, after a middle layer with an inner-connection structure was inserted between the anode and the cathode, the output voltage of the whole device can achieve 4.0 V. The full cell of series ASCs (SASC) with an inner-connection middle layer has a high energy density of 28.6 mW h cm(-3) at a power density of 261.4 mW cm(-3), and exhibits excellent cycling performance of 99.6% capacitance retention over 10,000 cycles. This strategy of designing the hybridized structure for SASCs provides a promising route for next-generation SCs with high energy density and high output voltage.

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.

2017-07-01

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.

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.

New controller for high voltage converter modulator at spallation neutron source

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

Wezensky, Mark W; Brown, David L; Lee, Sung-Woo

2017-01-01

The Spallation Neutron Source (SNS) has developed a new control system for the High Voltage Convertor Modulator (HVCM) at the SNS to replace the original control system which is approaching obsolescence. The original system was based on controllers for similar high voltage systems that were already in use [1]. The new controller, based on National Instruments PXI/FlexRIO Field Programmable Gate Array (FPGA) platform, offers enhancements such as modular construction, flexibility and non-proprietary software. The new controller also provides new capabilities like various methods for modulator pulse flattening, waveform capture, and first fault detection. This paper will discuss the design ofmore » the system, including the human machine interface, based on lessons learned at the SNS and other projects. It will also discuss performance and other issues related to its operation in an accelerator facility which requires high availability. To date, 73% of the operational HVCMs have been upgraded to with the new controller, and the remainder are scheduled for completion by mid-2017.« less

Multijunction high voltage concentrator solar cells

NASA Technical Reports Server (NTRS)

Valco, G. J.; Kapoor, V. J.; Evans, J. C.; Chai, A.-T.

1981-01-01

The standard integrated circuit technology has been developed to design and fabricate new innovative planar multi-junction solar cell chips for concentrated sunlight applications. This 1 cm x 1 cm cell consisted of several voltage generating regions called unit cells which were internally connected in series within a single chip resulting in high open circuit voltages. Typical open-circuit voltages of 3.6 V and short-circuit currents of 90 ma were obtained at 80 AM1 suns. A dramatic increase in both short circuit current and open circuit voltage with increased light levels was observed.

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.

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.

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

Experimental results on plasma interactions with large surfaces at high voltages

NASA Technical Reports Server (NTRS)

Grier, N. T.

1980-01-01

Multikilowatt power levels for future payloads can be more efficiently generated using solar arrays operating in the kilovolt range. This implies that large areas of the array at high operating voltages will be exposed to the space plasma environment. The resulting interactions of these high voltage surfaces with space plasma environments can seriously impact the performance of the satellite system. The plasma-surface interaction phenomena were studied in tests performed in two separate vacuum chambers, a 4.6 m diameter by 19.2 long chamber and a 20 m diameter by 27.4 m long chamber. The generated plasma density was approximately 1x10 to the 4th power/cu cm. Ten solar array panels, each with areas of 1400 sq cm were used in the tests. Nine of the solar panels were tested as a composite unit in the form of a 3x3 solar panel matrix. The results from all the tests confirmed small sample tests results: insulators were found to enhance the plasma coupling current for high positive bias and arcing was found to occur at high negative bias.

High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

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

Hernandez-Garcia, C.; Bullard, D.; Hannon, F.

The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain <10 MV/m at the desired operating voltage aiming at little or no field emission once conditioned. Typical electrode surface preparation involves diamond-paste polishing by skilled personnel, requiring several weeks of effort per electrode. In this work, we describe a centrifugal barrel-polishing techniquemore » commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (~11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Here, tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.« less

High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

DOE PAGES

Hernandez-Garcia, C.; Bullard, D.; Hannon, F.; ...

2017-09-11

The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain <10 MV/m at the desired operating voltage aiming at little or no field emission once conditioned. Typical electrode surface preparation involves diamond-paste polishing by skilled personnel, requiring several weeks of effort per electrode. In this work, we describe a centrifugal barrel-polishing techniquemore » commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (~11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Here, tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.« less

High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

NASA Astrophysics Data System (ADS)

Hernandez-Garcia, C.; Bullard, D.; Hannon, F.; Wang, Y.; Poelker, M.

2017-09-01

The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain <10 MV/m at the desired operating voltage aiming at little or no field emission once conditioned. Typical electrode surface preparation involves diamond-paste polishing by skilled personnel, requiring several weeks of effort per electrode. In this work, we describe a centrifugal barrel-polishing technique commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (˜11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.

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.

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.

Threshold-voltage modulated phase change heterojunction for application of high density memory

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

Yan, Baihan; Tong, Hao, E-mail: tonghao@hust.edu.cn; Qian, Hang

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-raymore » 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.« less

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

DOEpatents

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

1995-05-23

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

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

DOEpatents

Shimer, Daniel W.; Lange, Arnold C.

1995-01-01

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

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.

Liquid Nitrogen as Fast High Voltage Switching Medium

NASA Astrophysics Data System (ADS)

Dickens, J.; Neuber, A.; Haustein, M.; Krile, J.; Krompholz, H.

2002-12-01

Compact pulsed power systems require new switching technologies. For high voltages, liquid nitrogen seems to be a suitable switching medium, with high hold-off voltage, low dielectric constant, and no need for pressurized systems as in high pressure gas switches. The discharge behavior in liquid nitrogen, such as breakdown voltages, formative times, current rise as function of voltage, recovery, etc. are virtually unknown, however. The phenomenology of breakdown in liquid nitrogen is investigated with high speed (temporal resolution < 1 ns) electrical and optical diagnostics, in a coaxial system with 50-Ohm impedance. Discharge current and voltage are determined with transmission line type current sensors and capacitive voltage dividers. The discharge luminosity is measured with photomultiplier tubes. Preliminary results of self-breakdown investigations (gap 1 mm, breakdown voltage 44 kV, non-boiling supercooled nitrogen) show a fast (2 ns) transition from an unknown current level to several mA, a long-duration (100 ns) phase with constant current superimposed by ns-spikes, and a final fast transition to the impedance limited current during several nanoseconds. The optical measurements will be expanded toward spectroscopy and high speed photography with the aim of clarifying the overall breakdown mechanisms, including electronic initiation, bubble formation, bubble dynamics, and their role in breakdown, for different electrode geometries (different macroscopic field enhancements).

High-Voltage Characterization for the Prototype Induction Cells

NASA Astrophysics Data System (ADS)

Huacen, Wang; Kaizhi, Zhang; Long, Wen; Qinggui, Lai; Linwen, Zhang; Jianjun, Deng

2002-12-01

Two linear induction prototype cells expected to work at 250kV, 3kA,with accelerating voltage flattop (±1%) ⩾ 70ns, have been tested to determine their high-voltage characteristics. Each cell is composed of a ferrite core immersed in oil, a gap with curved stainless steel electrodes, a solenoid magnet, and a insulator. The experiments were carried out with full-scale cells. The high voltage pulses were applied to two cells using a 100ns, 12Ω pulse Blumlein. The tests were performed at various high-voltage levels ranging from -250kV to -350kV. No breakdown was observed during the test at vacuum level (7-10) ṡ10-4 Pa. The cell schematic, the experimental set up, and the measured voltage waveforms are presented in this paper.

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.

Low-voltage organic transistors on plastic comprising high-dielectric constant gate insulators

PubMed

Dimitrakopoulos; Purushothaman; Kymissis; Callegari; Shaw

1999-02-05

The gate bias dependence of the field-effect mobility in pentacene-based insulated gate field-effect transistors (IGFETs) was interpreted on the basis of the interaction of charge carriers with localized trap levels in the band gap. This understanding was used to design and fabricate IGFETs with mobility of more than 0.3 square centimeter per volt per second and current modulation of 10(5), with the use of amorphous metal oxide gate insulators. These values were obtained at operating voltage ranges as low as 5 volts, which are much smaller than previously reported results. An all-room-temperature fabrication process sequence was used, which enabled the demonstration of high-performance organic IGFETs on transparent plastic substrates, at low operating voltages for organic devices.

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...-Voltage Distribution § 75.807 Installation of high-voltage transmission cables. [Statutory Provisions] All underground high-voltage transmission cables shall be installed only in regularly inspected air courses and...

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.

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.

Low voltage operation of GaN vertical nanowire MOSFET

NASA Astrophysics Data System (ADS)

Son, Dong-Hyeok; Jo, Young-Woo; Seo, Jae Hwa; Won, Chul-Ho; Im, Ki-Sik; Lee, Yong Soo; Jang, Hwan Soo; Kim, Dae-Hyun; Kang, In Man; Lee, Jung-Hee

2018-07-01

GaN gate-all-around (GAA) vertical nanowire MOSFET (VNWMOSFET) with channel length of 300 nm and diameter of 120 nm, the narrowest GaN-based vertical nanowire transistor ever achieved from the top-down approach, was fabricated by utilizing anisotropic side-wall wet etching in TMAH solution and photoresist etch-back process. The VNWMOSFET exhibited output characteristics with very low saturation drain voltage of less than 0.5 V, which is hardly observed from the wide bandgap-based devices. Simulation results indicated that the narrow diameter of the VNWMOSFET with relatively short channel length is responsible for the low voltage operation. The VNWMOSFET also demonstrated normally-off mode with threshold voltage (VTH) of 0.7 V, extremely low leakage current of ∼10-14 A, low drain-induced barrier lowering (DIBL) of 125 mV/V, and subthreshold swing (SS) of 66-122 mV/decade. The GaN GAA VNWMOSFET with narrow channel diameter investigated in this work would be promising for new low voltage logic application. He has been a Professor with the School of Electrical Engineering and Computer Science, Kyungpook National University, Daegu, Korea, since 1993

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... § 75.810 High-voltage trailing cables; splices. [Statutory Provisions] In the case of high-voltage cables used as trailing cables, temporary splices shall not be used and all permanent splices shall be...

Harmonic voltage excess problem test and analysis in UHV and EHV grid particular operation mode

NASA Astrophysics Data System (ADS)

Lv, Zhenhua; Shi, Mingming; Fei, Juntao

2018-02-01

The test and analysis of the power quality of some 1000kV UHV transmission lines and 500kV EHV transmission lines is carried out. It is found that there is harmonic voltage excess problems when the power supply of the UHV and EHV voltage line is single-ended or single-loop, the problem basically disappeared after the operation mode change, different operating conditions, the harmonic current has not been greatly affected, indicating that the harmonic voltage changes mainly caused by the system harmonic impedance. With the analysis of MATLAB Simulink system model, it can be seen that there are specific harmonic voltage excess in the system under the specific operating mode, which results in serious distortion of the specific harmonic voltage. Since such phenomena are found in 500kV and 1000kV systems, it is suggested that the test evaluation work should be done under the typical mode of operation in 500kV, 1000kV Planning and construction process to prevent the occurrence of serious distortion and the regional harmonic current monitoring and suppression work should be done.

Boeing's High Voltage Solar Tile Test Results

NASA Astrophysics Data System (ADS)

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

2002-10-01

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.

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.

Low-voltage organic strain sensor on plastic using polymer/high- K inorganic hybrid gate dielectrics

NASA Astrophysics Data System (ADS)

Jung, Soyoun; Ji, Taeksoo; Varadan, Vijay K.

2007-12-01

In this paper, gate-induced pentacene semiconductor strain sensors based on hybrid-gate dielectrics using poly-vinylphenol (PVP) and high-K inorganic, Ta IIO 5 are fabricated on flexible substrates, polyethylene naphthalate (PEN). The Ta IIO 5 gate dielectric layer is combined with a thin PVP layer to obtain very smooth and hydrophobic surfaces which improve the molecular structures of pentacene films. The PVP-Ta IIO 5 hybrid-gate dielectric films exhibit a high dielectric capacitance and low leakage current. The sensors adopting thin film transistor (TFT)-like structures show a significantly reduced operating voltage (~6V), and good device characteristics with a field-effect mobility of 1.89 cm2/V•s, a threshold voltage of -0.5 V, and an on/off ratio of 10 3. The strain sensor, one of the practical applications in large-area organic electronics, was characterized with different bending radii of 50, 40, 30, and 20 mm. The sensor output signals were significantly improved with low-operating voltages.

30 CFR 75.811 - High-voltage underground equipment; grounding.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-voltage equipment supplying power to such equipment receiving power from resistance grounded systems shall... 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...

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.

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.

High-voltage subnanosecond dielectric breakdown

NASA Astrophysics Data System (ADS)

Mankowski, John Jerome

Current interests in ultrawideband radar sources are in the microwave regime, which correspond to voltage pulse risetimes less than a nanosecond. Some new sources, including the Phillips Laboratory Hindenberg series of hydrogen gas switched pulsers use hydrogen at hundreds of atmospheres of pressure in the switch. Unfortunately, the published data of electrical breakdown of gas and liquid media at these time lengths are relatively scarce. A study was conducted on the electrical breakdown properties of liquid and gas dielectrics at subnanosecond and nanoseconds. Two separate voltage sources with pulse risetimes less than 400 ps were developed. Diagnostic probes were designed and tested for their capability of detecting high voltage pulses at these fast risetimes. A thorough investigation into E-field strengths of liquid and gas dielectrics at breakdown times ranging from 0.4 to 5 ns was performed. The voltage polarity dependence on breakdown strength is observed. Streak camera images of streamer formation were taken. The effect of ultraviolet radiation, incident upon the gap, on statistical lag time was determined.

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.

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.

PV source based high voltage gain current fed converter

NASA Astrophysics Data System (ADS)

Saha, Soumya; Poddar, Sahityika; Chimonyo, Kudzai B.; Arunkumar, G.; Elangovan, D.

2017-11-01

This work involves designing and simulation of a PV source based high voltage gain, current fed converter. It deals with an isolated DC-DC converter which utilizes boost converter topology. The proposed converter is capable of high voltage gain and above all have very high efficiency levels as proved by the simulation results. The project intends to produce an output of 800 V dc from a 48 V dc input. The simulation results obtained from PSIM application interface were used to analyze the performance of the proposed converter. Transformer used in the circuit steps up the voltage as well as to provide electrical isolation between the low voltage and high voltage side. Since the converter involves high switching frequency of 100 kHz, ultrafast recovery diodes are employed in the circuitry. The major application of the project is for future modeling of solar powered electric hybrid cars.

Review of adult electrical burn injury outcomes worldwide: An analysis of low- voltage versus high-voltage electrical injury

PubMed Central

Shih, Jessica G; Shahrokhi, Shahriar; Jeschke, Marc G

2016-01-01

Objective To review low-voltage versus high-voltage electrical burn complications in adults, and to identify novel areas that are not recognized to improve outcomes. Methods An extensive literature search on electrical burn injuries was performed using OVID Medline, PubMed and EMBASE databases from 1946–2015. Studies relating to outcomes of electrical injury in the adult population (≥18 years of age) were included in the study. Results Forty-one single-institution publications with a total of 5485 electrical injury patients were identified and included in the present study. 18.0% of these patients were low-voltage injuries (LVI), 38.3% high-voltage injuries (HVI) and 43.7% with voltage not otherwise specified (NOS). Forty-four percent of studies did not characterize outcomes according to low versus high-voltage injuries. Reported outcomes include surgical, medical, post-traumatic, and other (long-term/psychological/rehabilitative), all of which report greater incidence rates in HVI compared to LVI. Only two studies report on psychological outcomes such as post-traumatic stress disorder. Mortality from electrical injuries are 2.6% in LVI, 5.2% in HVI and 3.7% in NOS. Coroner’s reports reveal a ratio of 2.4:1 for deaths caused by low-voltage injury compared to high voltage-injury. Conclusions High-voltage injuries lead to greater morbidity and mortality than low-voltage injuries. However, the results of the coroner’s reports suggest that immediate mortality from low-voltage injury may be underestimated. Furthermore, based on the data of this analysis we conclude that the majority of studies report electrical injury outcomes, however, the majority of them do not analyze complications by low versus high voltage and often lack long-term psychological and rehabilitation outcomes post-electrical injury indicating that a variety of central aspects are not being evaluated or assessed. PMID:27359191

30 CFR 77.804 - High-voltage trailing cables; minimum design requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage trailing cables; minimum design... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.804 High-voltage trailing cables; minimum design requirements. (a) High-voltage trailing cables used in resistance grounded systems shall be...

30 CFR 77.804 - High-voltage trailing cables; minimum design requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-voltage trailing cables; minimum design... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.804 High-voltage trailing cables; minimum design requirements. (a) High-voltage trailing cables used in resistance grounded systems shall be...

30 CFR 77.804 - High-voltage trailing cables; minimum design requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-voltage trailing cables; minimum design... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.804 High-voltage trailing cables; minimum design requirements. (a) High-voltage trailing cables used in resistance grounded systems shall be...

30 CFR 77.804 - High-voltage trailing cables; minimum design requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-voltage trailing cables; minimum design... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.804 High-voltage trailing cables; minimum design requirements. (a) High-voltage trailing cables used in resistance grounded systems shall be...

Polymer/metal oxide hybrid dielectrics for low voltage field-effect transistors with solution-processed, high-mobility semiconductors

NASA Astrophysics Data System (ADS)

Held, Martin; Schießl, Stefan P.; Miehler, Dominik; Gannott, Florentina; Zaumseil, Jana

2015-08-01

Transistors for future flexible organic light-emitting diode (OLED) display backplanes should operate at low voltages and be able to sustain high currents over long times without degradation. Hence, high capacitance dielectrics with low surface trap densities are required that are compatible with solution-processable high-mobility semiconductors. Here, we combine poly(methyl methacrylate) (PMMA) and atomic layer deposition hafnium oxide (HfOx) into a bilayer hybrid dielectric for field-effect transistors with a donor-acceptor polymer (DPPT-TT) or single-walled carbon nanotubes (SWNTs) as the semiconductor and demonstrate substantially improved device performances for both. The ultra-thin PMMA layer ensures a low density of trap states at the semiconductor-dielectric interface while the metal oxide layer provides high capacitance, low gate leakage and superior barrier properties. Transistors with these thin (≤70 nm), high capacitance (100-300 nF/cm2) hybrid dielectrics enable low operating voltages (<5 V), balanced charge carrier mobilities and low threshold voltages. Moreover, the hybrid layers substantially improve the bias stress stability of the transistors compared to those with pure PMMA and HfOx dielectrics.

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.

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.

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.

A high-voltage supply used on miniaturized RLG

NASA Astrophysics Data System (ADS)

Miao, Zhifei; Fan, Mingming; Wang, Yuepeng; Yin, Yan; Wang, Dongmei

2016-01-01

A high voltage power supply used in laser gyro is proposed in this paper. The power supply which uses a single DC 15v input and fly-back topology is adopted in the main circuit. The output of the power supply achieve high to 3.3kv voltage in order to light the RLG. The PFM control method is adopted to realize the rapid switching between the high voltage state and the maintain state. The resonant chip L6565 is used to achieve the zero voltage switching(ZVS), so the consumption is reduced and the power efficiency is improved more than 80%. A special circuit is presented in the control portion to ensure symmetry of the two RLG's arms current. The measured current accuracy is higher than 5‰ and the current symmetry of the two RLG's arms up to 99.2%.

30 CFR 75.802 - Protection of high-voltage circuits extending underground.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Protection of high-voltage circuits extending...-Voltage Distribution § 75.802 Protection of high-voltage circuits extending underground. (a) Except as provided in paragraph (b) of this section, high-voltage circuits extending underground and supplying...

30 CFR 75.802 - Protection of high-voltage circuits extending underground.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Protection of high-voltage circuits extending...-Voltage Distribution § 75.802 Protection of high-voltage circuits extending underground. (a) Except as provided in paragraph (b) of this section, high-voltage circuits extending underground and supplying...

30 CFR 75.802 - Protection of high-voltage circuits extending underground.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Protection of high-voltage circuits extending...-Voltage Distribution § 75.802 Protection of high-voltage circuits extending underground. (a) Except as provided in paragraph (b) of this section, high-voltage circuits extending underground and supplying...

Determination of threshold and maximum operating electric stresses for selected high voltage insulations. Task 2: Investigation of oil-filled paper insulated cables

NASA Astrophysics Data System (ADS)

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

1983-06-01

Threshold voltage of oil-impregnated paper insulated cables are investigaed. Experimental work was done on model cables specially manufactured for this project. The cables were impregnated with mineral and with synthetic oils. Standard impulse breakdown voltage tests and impulse voltage breakdown tests with dc prestressing were performed at room temperature and at 1000C. The most important result is the finding of very high level of threshold voltage stress for oil-impregnated paper insulated cables. This threshold voltage is approximately 1.5 times higher than the threshold voltage or crosslinked polyethylene insulated cables.

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.

Oxidatively stable fluorinated sulfone electrolytes for high voltage high energy lithium-ion batteries

DOE PAGES

Su, Chi -Cheung; He, Meinan; Redfern, Paul C.; ...

2017-03-16

New fluorinated sulfones were synthesized and evaluated in high voltage lithium-ion batteries using LiNi 0.5Mn 1.5O 4 (LNMO) cathode. Fluorinated sulfones with an α-trifluoromethyl group exhibit enhanced oxidation stability, reduced viscosity and superior separator wettability as compared to their non-fluorinated counterparts. Finally, the improved performance in high voltage cells makes it a promising high voltage electrolyte for 5-V lithium-ion chemistry.

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

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

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

Safety aspects for public access defibrillation using automated external defibrillators near high-voltage power lines.

PubMed

Schlimp, C J; Breiteneder, M; Lederer, W

2004-05-01

Automated external defibrillators (AEDs) must combine easy operability and high-quality diagnosis even under unfavorable conditions. This study determined the influence of electromagnetic interference caused by high-voltage power lines with 16.7-Hz alternating current on the quality of AEDs' rhythm analysis. Two AEDs frequently used in Austria were tested near high-voltage power lines (15 kV or 110 kV, alternating current with 16.7 Hz). The defibrillation electrodes were attached either to a proband with true sinus rhythm or to a resuscitation dummy with generated sinus rhythm, ventricular fibrillation, ventricular tachycardia or asystole. Electromagnetic interference was much more prominent in a human's than in a dummy's electrocardiogram and depended on the position of the electrodes and cables in relation to the power line. Near high-voltage power lines the AEDs showed a significant operational fault. One AED interpreted the interference as a motion artifact, even when underlying rhythms were clearly detectable. The other AED interpreted 16.7-Hz oscillation as ventricular fibrillation with consequent shock advice when no underlying rhythm was detected. The tested AEDs neither filter nor recognize a technical interference of 16.7 Hz caused by 15-kV power lines above railway tracks or 110-kV overland power lines, as run by railway companies in Austria, Germany, Norway, Sweden and Switzerland. These failures in AEDs' algorithms for rhythm analysis may cause substantial harm to patients undergoing public access defibrillation. The proper function of AEDs needs to be reconsidered to guarantee patients' safety near high-voltage power lines.

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.

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.

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.

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.

21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Diagnostic x-ray high voltage generator. 892.1700... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1700 Diagnostic x-ray high voltage generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended to...

21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Diagnostic x-ray high voltage generator. 892.1700... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1700 Diagnostic x-ray high voltage generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended to...

21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic x-ray high voltage generator. 892.1700... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1700 Diagnostic x-ray high voltage generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended to...

21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Diagnostic x-ray high voltage generator. 892.1700... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1700 Diagnostic x-ray high voltage generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended to...

21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Diagnostic x-ray high voltage generator. 892.1700... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1700 Diagnostic x-ray high voltage generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended to...

Measurement of high-voltage and radiation-damage limitations to advanced solar array performance

NASA Technical Reports Server (NTRS)

Guidice, D. A.; Severance, P. S.; Keinhardt, K. C.

1991-01-01

A description is given of the reconfigured Photovoltaic Array Space Power (PASP) Plus experiment: its objectives, solar-array complement, and diagnostic sensors. Results from a successful spaceflight will lead to a better understanding of high-voltage and radiation-damage limitations in the operation of new-technology solar arrays.

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.

Modular High Voltage Power Supply

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

Newell, Matthew R.

The goal of this project is to develop a modular high voltage power supply that will meet the needs of safeguards applications and provide a modular plug and play supply for use with standard electronic racks.

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.

A compact 100 kV high voltage glycol capacitor.

PubMed

Wang, Langning; Liu, Jinliang; Feng, Jiahuai

2015-01-01

A high voltage capacitor is described in this paper. The capacitor uses glycerol as energy storage medium, has a large capacitance close to 1 nF, can hold off voltages of up to 100 kV for μs charging time. Allowing for low inductance, the capacitor electrode is designed as coaxial structure, which is different from the common structure of the ceramic capacitor. With a steady capacitance at different frequencies and a high hold-off voltage of up to 100 kV, the glycol capacitor design provides a potential substitute for the ceramic capacitors in pulse-forming network modulator to generate high voltage pulses with a width longer than 100 ns.

30 CFR 77.704-2 - Repairs to energized 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 high-voltage lines. 77.704... UNDERGROUND COAL MINES Grounding § 77.704-2 Repairs to energized high-voltage lines. An energized high-voltage... repairs will be performed on power circuits with a phase-to-phase nominal voltage no greater than 15,000...

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

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

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 AD8000more » 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.« less

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

A low-voltage sense amplifier with two-stage operational amplifier clamping for flash memory

NASA Astrophysics Data System (ADS)

Guo, Jiarong

2017-04-01

A low-voltage sense amplifier with reference current generator utilizing two-stage operational amplifier clamp structure for flash memory is presented in this paper, capable of operating with minimum supply voltage at 1 V. A new reference current generation circuit composed of a reference cell and a two-stage operational amplifier clamping the drain pole of the reference cell is used to generate the reference current, which avoids the threshold limitation caused by current mirror transistor in the traditional sense amplifier. A novel reference voltage generation circuit using dummy bit-line structure without pull-down current is also adopted, which not only improves the sense window enhancing read precision but also saves power consumption. The sense amplifier was implemented in a flash realized in 90 nm flash technology. Experimental results show the access time is 14.7 ns with power supply of 1.2 V and slow corner at 125 °C. Project supported by the National Natural Science Fundation of China (No. 61376028).

A quick response four decade logarithmic high-voltage stepping supply

NASA Technical Reports Server (NTRS)

Doong, H.

1978-01-01

An improved high-voltage stepping supply, for space instrumentation is described where low power consumption and fast settling time between steps are required. The high-voltage stepping supply, utilizing an average power of 750 milliwatts, delivers a pair of mirror images with 64 level logarithmic outputs. It covers a four decade range of + or - 2500 to + or - 0.29 volts having an output stability of + or - 0.5 percent or + or - 20 millivolts for all line load and temperature variations. The supply provides a typical step setting time of 1 millisecond with 100 microseconds for the lower two decades. The versatile design features of the high-voltage stepping supply provides a quick response staircase generator as described or a fixed voltage with the option to change levels as required over large dynamic ranges without circuit modifications. The concept can be implemented up to + or - 5000 volts. With these design features, the high-voltage stepping supply should find numerous applications where charged particle detection, electro-optical systems, and high voltage scientific instruments are used.

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.

Polymer/metal oxide hybrid dielectrics for low voltage field-effect transistors with solution-processed, high-mobility semiconductors

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

Held, Martin; Schießl, Stefan P.; Gannott, Florentina

Transistors for future flexible organic light-emitting diode (OLED) display backplanes should operate at low voltages and be able to sustain high currents over long times without degradation. Hence, high capacitance dielectrics with low surface trap densities are required that are compatible with solution-processable high-mobility semiconductors. Here, we combine poly(methyl methacrylate) (PMMA) and atomic layer deposition hafnium oxide (HfO{sub x}) into a bilayer hybrid dielectric for field-effect transistors with a donor-acceptor polymer (DPPT-TT) or single-walled carbon nanotubes (SWNTs) as the semiconductor and demonstrate substantially improved device performances for both. The ultra-thin PMMA layer ensures a low density of trap states atmore » the semiconductor-dielectric interface while the metal oxide layer provides high capacitance, low gate leakage and superior barrier properties. Transistors with these thin (≤70 nm), high capacitance (100–300 nF/cm{sup 2}) hybrid dielectrics enable low operating voltages (<5 V), balanced charge carrier mobilities and low threshold voltages. Moreover, the hybrid layers substantially improve the bias stress stability of the transistors compared to those with pure PMMA and HfO{sub x} dielectrics.« less

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.

Characteristics of Partial Discharge and Ozone Generation for Twisted-pair of Enameled Wires under High-repetitive Impulse Voltage Application

NASA Astrophysics Data System (ADS)

Kanazawa, Seiji; Enokizono, Masato; Shibakita, Toshihide; Umehara, Eiji; Toshimitsu, Jun; Ninomiya, Shinji; Taniguchi, Hideki; Abe, Yukari

In recent years, inverter drive machines such as a hybrid vehicle and an electric vehicle are operated under high voltage pulse with high repetition rate. In this case, inverter surge is generated and affected the machine operation. Especially, the enameled wire of a motor is deteriorated due to the partial discharge (PD) and finally breakdown of the wire will occur. In order to investigate a PD on a resistant enameled wire, characteristics of PD in the twisted pair sample under bipolar repetitive impulse voltages are investigated experimentally. The relationship between the applied voltage and discharge current was measured at PD inception and extinction, and we estimated the repetitive PD inception and extinction voltages experimentally. The corresponding optical emission of the discharge was also observed by using an ICCD camera. Furthermore, ozone concentration due to the discharge was measured during the life-time test of the resistant enameled wires from a working environmental point of view.

30 CFR 18.53 - High-voltage longwall mining systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage motor...-interrupting devices must be designed and installed to prevent automatic reclosure. (d) Transformers with high... “open” position; (iv) When located in an explosion-proof enclosure, the device must be designed and...

30 CFR 18.53 - High-voltage longwall mining systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage motor...-interrupting devices must be designed and installed to prevent automatic reclosure. (d) Transformers with high... “open” position; (iv) When located in an explosion-proof enclosure, the device must be designed and...

30 CFR 18.53 - High-voltage longwall mining systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage motor...-interrupting devices must be designed and installed to prevent automatic reclosure. (d) Transformers with high... “open” position; (iv) When located in an explosion-proof enclosure, the device must be designed and...

30 CFR 18.53 - High-voltage longwall mining systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage motor...-interrupting devices must be designed and installed to prevent automatic reclosure. (d) Transformers with high... “open” position; (iv) When located in an explosion-proof enclosure, the device must be designed and...

30 CFR 18.53 - High-voltage longwall mining systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage motor...-interrupting devices must be designed and installed to prevent automatic reclosure. (d) Transformers with high... “open” position; (iv) When located in an explosion-proof enclosure, the device must be designed and...

Development of a High-speed Electromagnetic Repulsion Mechanism for High-voltage Vacuum Circuit Breakers

NASA Astrophysics Data System (ADS)

Tsukima, Mitsuru; Takeuchi, Toshie; Koyama, Kenichi; Yoshiyasu, Hajimu

This paper presents a design and testing of a new high-speed electromagnetic driving mechanism for a high-voltage vacuum circuit breaker (VCB). This mechanism is based on a high-speed electromagnetic repulsion and a permanent magnet spring (PMS). This PMS is introduced instead of the conventional disk spring due to its low spring energy and more suitable force characteristics for VCB application. The PMS has been optimally designed by the 3d non-linear finite-elements magnetic field analysis and investigated its internal friction and eddy-current effect. Furthermore, we calculated the dynamic of this mechanism coupling with the electromagnetic field and circuit analysis, in order to satisfy the operating characteristics—contact velocity, response time and so on, required for the high-speed VCB. A prototype VCB, which was built based on the above analysis shows sufficient operating performance. Finally, the short circuit interruption tests were carried out with this prototype breaker, and we have been able to verify its satisfying performance.

30 CFR 75.705 - Work on high-voltage lines; deenergizing and grounding.

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; deenergizing and... Work on high-voltage lines; deenergizing and grounding. [Statutory Provisions] High-voltage lines, both..., except that repairs may be permitted, in the case of energized surface high-voltage lines, if such...

A 32 kb 9T near-threshold SRAM with enhanced read ability at ultra-low voltage operation

NASA Astrophysics Data System (ADS)

Kim, Tony Tae-Hyoung; Lee, Zhao Chuan; Do, Anh Tuan

2018-01-01

Ultra-low voltage SRAMs are highly sought-after in energy-limited systems such as battery-powered and self-harvested SoCs. However, ultra-low voltage operation diminishes SRAM read bitline (RBL) sensing margin significantly. This paper tackles this issue by presenting a novel 9T cell with data-independent RBL leakage in combination with an RBL boosting technique for enhancing the sensing margin. The proposed technique automatically tracks process, temperature and voltage (PVT) variations for robust sensing margin enhancement. A test chip fabricated in 65 nm CMOS technology shows that the proposed scheme significantly enlarges the sensing margin compared to the conventional bitline sensing scheme. It also achieves the minimum operating voltage of 0.18 V and the minimum energy consumption of 0.92 J/access at 0.4 V. He received 2016 International Low Power Design Contest Award from ISLPED, a best paper award at 2014 and 2011 ISOCC, 2008 AMD/CICC Student Scholarship Award, 2008 Departmental Research Fellowship from Univ. of Minnesota, 2008 DAC/ISSCC Student Design Contest Award, 2008, 2001, and 1999 Samsung Humantec Thesis Award and, 2005 ETRI Journal Paper of the Year Award. He is an author/co-author of +100 journal and conference papers and has 17 US and Korean patents registered. His current research interests include low power and high performance digital, mixed- mode, and memory circuit design, ultra-low voltage circuits and systems design, variation and aging tolerant circuits and systems, and circuit techniques for 3D ICs. He serves as an associate editor of IEEE Transactions on VLSI Systems. He is an IEEE senior member and the Chair of IEEE Solid-State Circuits Society Singapore Chapter. He has served numerous conferences as a committee member.

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.

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. © The Royal Society of Chemistry 2011

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+%.

Voltage controlled current source

DOEpatents

Casne, Gregory M.

1992-01-01

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

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.

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

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

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

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.

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.

High-Capacity Cathode Material with High Voltage for Li-Ion Batteries

DOE PAGES

Shi, Ji -Lei; Xiao, Dong -Dong; Ge, Mingyuan; ...

2018-01-15

Electrochemical energy storage devices with a high energy density are an important technology in modern society, especially for electric vehicles. The most effective approach to improve the energy density of batteries is to search for high-capacity electrode materials. According to the concept of energy quality, a high-voltage battery delivers a highly useful energy, thus providing a new insight to improve energy density. Based on this concept, a novel and successful strategy to increase the energy density and energy quality by increasing the discharge voltage of cathode materials and preserving high capacity is proposed. The proposal is realized in high-capacity Li-richmore » cathode materials. The average discharge voltage is increased from 3.5 to 3.8 V by increasing the nickel content and applying a simple after-treatment, and the specific energy is improved from 912 to 1033 Wh kg-1. The current work provides an insightful universal principle for developing, designing, and screening electrode materials for high energy density and energy quality.« less

High-Capacity Cathode Material with High Voltage for Li-Ion Batteries

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

Shi, Ji -Lei; Xiao, Dong -Dong; Ge, Mingyuan

Electrochemical energy storage devices with a high energy density are an important technology in modern society, especially for electric vehicles. The most effective approach to improve the energy density of batteries is to search for high-capacity electrode materials. According to the concept of energy quality, a high-voltage battery delivers a highly useful energy, thus providing a new insight to improve energy density. Based on this concept, a novel and successful strategy to increase the energy density and energy quality by increasing the discharge voltage of cathode materials and preserving high capacity is proposed. The proposal is realized in high-capacity Li-richmore » cathode materials. The average discharge voltage is increased from 3.5 to 3.8 V by increasing the nickel content and applying a simple after-treatment, and the specific energy is improved from 912 to 1033 Wh kg-1. The current work provides an insightful universal principle for developing, designing, and screening electrode materials for high energy density and energy quality.« less

High voltage system: Plasma interaction summary

NASA Technical Reports Server (NTRS)

Stevens, N. John

1986-01-01

The possible interactions that could exist between a high voltage system and the space plasma environment are reviewed. A solar array is used as an example of such a system. The emphasis in this review is on the discrepancies that exist in this technology in both flight and ground experiment data. It has been found that, in ground testing, there are facility effects, cell size effects and area scaling uncertainties. For space applications there are area scaling and discharge concerns for an array as well as the influence of the large space structures on the collection process. There are still considerable uncertainties in the high voltage-space plasma interaction technology even after several years of effort.

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.

High voltage holding in the negative ion sources with cesium deposition

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

Belchenko, Yu.; Abdrashitov, G.; Ivanov, A.

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.

Planar multijunction high voltage solar cells

NASA Technical Reports Server (NTRS)

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.

Voltage-Load Sensitivity Matrix Based Demand Response for Voltage Control in High Solar Penetration Distribution Feeders

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

Zhu, Xiangqi; Wang, Jiyu; Mulcahy, David

This paper presents a voltage-load sensitivity matrix (VLSM) based voltage control method to deploy demand response resources for controlling voltage in high solar penetration distribution feeders. The IEEE 123-bus system in OpenDSS is used for testing the performance of the preliminary VLSM-based voltage control approach. A load disaggregation process is applied to disaggregate the total load profile at the feeder head to each load nodes along the feeder so that loads are modeled at residential house level. Measured solar generation profiles are used in the simulation to model the impact of solar power on distribution feeder voltage profiles. Different casemore » studies involving various PV penetration levels and installation locations have been performed. Simulation results show that the VLSM algorithm performance meets the voltage control requirements and is an effective voltage control strategy.« less

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.

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.

High-temperature, gas-filled ceramic rectifiers, thyratrons, and voltage-reference tubes

NASA Technical Reports Server (NTRS)

Baum, E. A.

1969-01-01

Thyratron, capable of being operated as a rectifier and a voltage-reference tube, was constructed and tested for 1000 hours at temperatures to 800 degrees C. With current levels at 15 amps and peak voltages of 2000 volts and frequencies at 6000 cps, tube efficiency was greater than 97 percent.

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.

Multiloop Rapid-Rise/Rapid Fall High-Voltage Power Supply

NASA Technical Reports Server (NTRS)

Bearden, Douglas

2007-01-01

A proposed multiloop power supply would generate a potential as high as 1.25 kV with rise and fall times <100 s. This power supply would, moreover, be programmable to generate output potentials from 20 to 1,250 V and would be capable of supplying a current of at least 300 A at 1,250 V. This power supply is intended to be a means of electronic shuttering of a microchannel plate that would be used to intensify the output of a charge-coupled-device imager to obtain exposure times as short as 1 ms. The basic design of this power supply could also be adapted to other applications in which high voltages and high slew rates are needed. At the time of reporting the information for this article, there was no commercially available power supply capable of satisfying the stated combination of voltage, rise-time, and fall-time requirements. The power supply would include a preregulator that would be used to program a voltage 1/30 of the desired output voltage. By means of a circuit that would include a pulse-width modulator (PWM), two voltage doublers, and a transformer having two primary and two secondary windings, the preregulator output voltage would be amplified by a factor of 30. A resistor would limit the current by controlling a drive voltage applied to field-effect transistors (FETs) during turn-on of the PWM. Two feedback loops would be used to regulate the high output voltage. A pulse transformer would be used to turn on four FETs to short-circuit output capacitors when the outputs of the PWM were disabled. Application of a 0-to-5-V square to a PWM shut-down pin would cause a 20-to-1,250-V square wave to appear at the output.

A Double-Pole High Voltage High Current Switch

DTIC Science & Technology

2005-12-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited A DOUBLE- POLE HIGH...December 2005 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE: A Double- Pole High Voltage High Current Switch 6. AUTHOR(S...to divert heavy charged particles, e.g. Cu+. 15. NUMBER OF PAGES 68 14. SUBJECT TERMS Double- Pole , Pulse Forming Inductive Network, PFIN

Software control program for 25 kW breadboard testing. [spacecraft power supplies; high voltage batteries

NASA Technical Reports Server (NTRS)

Pajak, J. A.

1981-01-01

A data acquisition software program developed to operate in conjunction with the automated control system of the 25 kW PM Electric Power System Breadboard Test facility is described. The proram provides limited interactive control of the breadboard test while acquiring data and monitoring parameters, allowing unattended continuous operation. The breadboard test facility has two positions for operating separate configurations. The main variable in each test setup is the high voltage Ni-Cd battery.

Recycling potential for low voltage and high voltage high rupturing capacity fuse links.

PubMed

Psomopoulos, Constantinos S; Barkas, Dimitrios A; Kaminaris, Stavros D; Ioannidis, George C; Karagiannopoulos, Panagiotis

2017-12-01

Low voltage and high voltage high-rupturing-capacity fuse links are used in LV and HV installations respectively, protecting mainly the LV and HV electricity distribution and transportation networks. The Waste Electrical and Electronic Equipment Directive (2002/96/EC) for "Waste of electrical and electronic equipment" is the main related legislation and as it concerns electrical and electronic equipment, it includes electric fuses. Although, the fuse links consist of recyclable materials, only small scale actions have been implemented for their recycling around Europe. This work presents the possibilities for material recovery from this specialized industrial waste for which there are only limited volume data. Furthermore, in order to present the huge possibilities and environmental benefits, it presents the potential for recycling of HRC fuses used by the Public Power Corporation of Greece, which is the major consumer for the country, but one of the smallest ones in Europe and globally, emphasizing in this way in the issue. According to the obtained results, fuse recycling could contribute to the effort for minimize the impacts on the environment through materials recovery and reduction of the wastes' volume disposed of in landfills. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Phosphorus Enrichment as a New Composition in the Solid Electrolyte Interphase of High-Voltage Cathodes and Its Effects on Battery Cycling

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

Yan, Pengfei; Zheng, Jianming; Kuppan, Saravanan

2015-11-10

Immersion of a solid into liquid often leads to the modification of both the structure and chemistry of surface of the solid, which subsequently affects the chemical and physical properties of the system. For the case of the rechargeable lithium ion battery, such a surface modification is termed as solid electrolyte interphase (SEI) layer, which has been perceived to play critical role for the stable operation of the batteries. However, the structure and chemical composition of SEI layer and its spatial distribution and dependence on the battery operating condition remain unclear. By using aberration corrected scanning transmission electron microscopy coupledmore » with ultra-high sensitive energy dispersive x-ray spectroscopy, we probed the structure and chemistry of SEI layer on several high voltage cathodes. We show that layer-structured cathodes, when cycled at a high cut off voltage, can form a P-rich SEI layer on their surface, which is a direct evidence of Li-salt (LiPF6) decomposition. Our systematical investigations indicate such cathode/Li-salt side reaction shows strong dependence on structure of the cathode materials, operating voltage and temperature, indicating the feasibility of SEI engineering. These findings provide us valuable insights into the complex interface between the high-voltage cathode and the electrolyte.« less

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... Repairs to energized surface high-voltage lines. An energized high-voltage surface line may be repaired... on power circuits with a phase-to-phase nominal voltage no greater than 15,000 volts; (3) Such...

High Voltage Test-Stand Research Done on ICRF Antenna Elements of the High-Harmonic Fast-Wave System of NSTX

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

Perkins, R. J.; Ahn, J.W.; Bortolon, A.

The twelve-strap high-harmonic fast-wave (HHFW) antenna on NSTX has exhibited a high-voltage standoff around 25 kV during previous experimental campaigns; this standoff needs to be improved for increased power coupling. During the recent NSTX-U upgrade period, a test-stand was set up with two antenna straps along with Faraday screens for testing purposes. Using a diagnostic suite consisting of a fast camera, a residual gas analyzer, a pressure gage, high-voltage probes, and an infrared camera, several interesting discoveries were made, leading to possible improvements of the antenna RF voltage operation level. First, arcing was observed outside the Faraday shields towards themore » low-voltage ("grounded") end of the straps (faraday shield box ends); this arcing was successfully eliminated by installing an additional grounding point between the Faraday shield box and the vessel wall. Second, considerable outgassing was observed during the RF pulse and the amount of outgassing was found to decrease with increasing RF power, possibly indicative of multipacting. Finally, infrared camera measurements of heating on the Faraday shield assembly suggest that the return currents on the Faraday shield box are highly localized at the box sides and possibly account for the pressure increase observed. Computations of these RF currents using Microwave Studio show qualitative agreement with the heated regions. New grounding points between the antenna box and the vessel have been implemented in NSTX-U, where future tests will be done to determine if the high-voltage standoff has improved. Further antenna improvements will be sought through future experiments on the test stand.« less

Planar LTCC transformers for high voltage flyback converters.

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

Schofield, Daryl; Schare, Joshua M.; Glass, Sarah Jill

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 demonstratedmore » 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.« less

[Design of a high-voltage insulation testing system of X-ray high frequency generators].

PubMed

Huang, Yong; Mo, Guo-Ming; Wang, Yan; Wang, Hong-Zhi; Yu, Jie-Ying; Dai, Shu-Guang

2007-09-01

In this paper, we analyze the transformer of X-ray high-voltage high-frequency generators and, have designed and implemented a high-voltage insulation testing system for its oil tank using full-bridge series resonant soft switching PFM DC-DC converter.

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.

Experimental Study of Arcing on High-Voltage Solar Arrays

NASA Technical Reports Server (NTRS)

Vayner, Boris; Galofaro, Joel; Ferguson, Dale

2003-01-01

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 suggests that such modifications can be done in the following directions: 1) To insulate conductor-dielectric junction from a plasma environment (wrapthrough interconnects); 2) To change a coverglass geometry (overhang); 3) To increase a coverglass thickness; 4) 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 a 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 stimulates the LEO operational temperature. The experimental setup is described below.

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.

Electro-optic voltage sensor for sensing voltage in an E-field

DOEpatents

Woods, Gregory K.; Renak, Todd W.

1999-01-01

A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

Low-voltage operating flexible ferroelectric organic field-effect transistor nonvolatile memory with a vertical phase separation P(VDF-TrFE-CTFE)/PS dielectric

NASA Astrophysics Data System (ADS)

Xu, Meili; Xiang, Lanyi; Xu, Ting; Wang, Wei; Xie, Wenfa; Zhou, Dayu

2017-10-01

Future flexible electronic systems require memory devices combining low-power operation and mechanical bendability. However, high programming/erasing voltages, which are universally needed to switch the storage states in previously reported ferroelectric organic field-effect transistor (Fe-OFET) nonvolatile memories (NVMs), severely prevent their practical applications. In this work, we develop a route to achieve a low-voltage operating flexible Fe-OFET NVM. Utilizing vertical phase separation, an ultrathin self-organized poly(styrene) (PS) buffering layer covers the surface of the ferroelectric polymer layer by one-step spin-coating from their blending solution. The ferroelectric polymer with a low coercive field contributes to low-voltage operation in the Fe-OFET NVM. The polymer PS contributes to the improvement of mobility, attributing to screening the charge scattering and decreasing the surface roughness. As a result, a high performance flexible Fe-OFET NVM is achieved at the low P/E voltages of ±10 V, with a mobility larger than 0.2 cm2 V-1 s-1, a reliable P/E endurance over 150 cycles, stable data storage retention capability over 104 s, and excellent mechanical bending durability with a slight performance degradation after 1000 repetitive tensile bending cycles at a curvature radius of 5.5 mm.

Sequential circuit design for radiation hardened multiple voltage integrated circuits

DOEpatents

Clark, Lawrence T [Phoenix, AZ; McIver, III, John K.

2009-11-24

The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

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.

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.

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

Investigation of high voltage spacecraft system interactions with plasma environments

NASA Technical Reports Server (NTRS)

Stevens, N. J.; Berkopec, F. D.; Purvis, C. K.; Grier, N.; Staskus, J. V.

1978-01-01

An experimental investigation was undertaken for insulator and conductor test surfaces biased up to + or - 1kV in a simulated low earth orbit charged particle environment. It was found that these interactions are controlled by the insulator surfaces surrounding the biased conductors. For positive applied voltages the electron current collection can be enhanced by the insulators. For negative applied voltages the insulator surface confines the voltage to the conductor region. Understanding these interactions and the technology to control their impact on system operation is essential to the design of solar cell arrays for ion drive propulsion applications that use direct drive power processing.

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.

Evaluation of the Fretting Resistance of the High Voltage Insulation on the ITER Magnet Feeder Busbars

NASA Astrophysics Data System (ADS)

Clayton, N.; Crouchen, M.; Evans, D.; Gung, C.-Y.; Su, M.; Devred, A.; Piccin, R.

2017-12-01

The high voltage (HV) insulation on the ITER magnet feeder superconducting busbars and current leads will be prepared from S-glass fabric, pre-impregnated with an epoxy resin, which is interleaved with polyimide film and wrapped onto the components and cured during feeder manufacture. The insulation architecture consists of nine half-lapped layers of glass/Kapton, which is then enveloped in a ground-screen, and two further half-lapped layers of glass pre-preg for mechanical protection. The integrity of the HV insulation is critical in order to inhibit electrical arcs within the feeders. The insulation over the entire length of the HV components (bus bar, current leads and joints) must provide a level of voltage isolation of 30 kV. In operation, the insulation on ITER busbars will be subjected to high mechanical loads, arising from Lorentz forces, and in addition will be subjected to fretting erosion against stainless steel clamps, as the pulsed nature of some magnets results in longitudinal movement of the busbar. This work was aimed at assessing the wear on, and the changes in, the electrical properties of the insulation when subjected to typical ITER operating conditions. High voltage tests demonstrated that the electrical isolation of the insulation was intact after the fretting test.

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.

Manufacture and mechanical characterisation of high voltage insulation for superconducting busbars - (Part 1) Materials selection and development

NASA Astrophysics Data System (ADS)

Clayton, N.; Crouchen, M.; Devred, A.; Evans, D.; Gung, C.-Y.; Lathwell, I.

2017-04-01

It is planned that the high voltage electrical insulation on the ITER feeder busbars will consist of interleaved layers of epoxy resin pre-impregnated glass tapes ('pre-preg') and polyimide. In addition to its electrical insulation function, the busbar insulation must have adequate mechanical properties to sustain the loads imposed on it during ITER magnet operation. This paper reports an investigation into suitable materials to manufacture the high voltage insulation for the ITER superconducting busbars and pipework. An R&D programme was undertaken in order to identify suitable pre-preg and polyimide materials from a range of suppliers. Pre-preg materials were obtained from 3 suppliers and used with Kapton HN, to make mouldings using the desired insulation architecture. Two main processing routes for pre-pregs have been investigated, namely vacuum bag processing (out of autoclave processing) and processing using a material with a high coefficient of thermal expansion (silicone rubber), to apply the compaction pressure on the insulation. Insulation should have adequate mechanical properties to cope with the stresses induced by the operating environment and a low void content necessary in a high voltage application. The quality of the mouldings was assessed by mechanical testing at 77 K and by the measurement of the void content.

High voltage breakdown phenomena in RF window, electron gun and RF cavities in 250 kW CW C band Klystron and their preventive measures

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

Lamba, O.S.; Badola, Richa; Baloda, Suman

The paper describes voltage break down phenomenon and preventive measures in components of 250 KW CW, C band Klystron under development at CEERI Pilani. The Klystron operates at a beam voltage of 50 kV and delivers 250 kW RF power at 5 GHz frequency. The Klystron consists of several key components and regions, which are subject to high electrical stress. The most important regions of electrical breakdown are electron gun, the RF ceramic window and output cavity gap area. In the critical components voltage breakdown considered at design stage by proper gap and other techniques. All these problems discussed, asmore » well as solution to alleviate this problem. The electron gun consists basically of cathode, BFE and anode. The cathode is operated at a voltage of 50 kV. In order to maintain the voltage standoff between cathode and anode a high voltage alumina seal and RF window have been designed developed and successfully used in the tube. (author)« less

High-temperature performance of MoS2 thin-film transistors: Direct current and pulse current-voltage characteristics

NASA Astrophysics Data System (ADS)

Jiang, C.; Rumyantsev, S. L.; Samnakay, R.; Shur, M. S.; Balandin, A. A.

2015-02-01

We report on fabrication of MoS2 thin-film transistors (TFTs) and experimental investigations of their high-temperature current-voltage characteristics. The measurements show that MoS2 devices remain functional to temperatures of at least as high as 500 K. The temperature increase results in decreased threshold voltage and mobility. The comparison of the direct current (DC) and pulse measurements shows that the direct current sub-linear and super-linear output characteristics of MoS2 thin-films devices result from the Joule heating and the interplay of the threshold voltage and mobility temperature dependences. At temperatures above 450 K, a kink in the drain current occurs at zero gate voltage irrespective of the threshold voltage value. This intriguing phenomenon, referred to as a "memory step," was attributed to the slow relaxation processes in thin films similar to those in graphene and electron glasses. The fabricated MoS2 thin-film transistors demonstrated stable operation after two months of aging. The obtained results suggest new applications for MoS2 thin-film transistors in extreme-temperature electronics and sensors.

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

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.

The Architecture Design of Detection and Calibration System for High-voltage Electrical Equipment

NASA Astrophysics Data System (ADS)

Ma, Y.; Lin, Y.; Yang, Y.; Gu, Ch; Yang, F.; Zou, L. D.

2018-01-01

With the construction of Material Quality Inspection Center of Shandong electric power company, Electric Power Research Institute takes on more jobs on quality analysis and laboratory calibration for high-voltage electrical equipment, and informationization construction becomes urgent. In the paper we design a consolidated system, which implements the electronic management and online automation process for material sampling, test apparatus detection and field test. In the three jobs we use QR code scanning, online Word editing and electronic signature. These techniques simplify the complex process of warehouse management and testing report transferring, and largely reduce the manual procedure. The construction of the standardized detection information platform realizes the integrated management of high-voltage electrical equipment from their networking, running to periodic detection. According to system operation evaluation, the speed of transferring report is doubled, and querying data is also easier and faster.

A cross flow-through pedicle free latissimus dorsi flap for high voltage electrical burns.

PubMed

Gencel, Eyuphan; Eser, Cengiz; Kesiktas, Erol; Tabakan, Ibrahim; Yavuz, Metin

2016-06-01

The management of a high voltage electrical injury and lower limb salvage remains a challenging task for plastic surgeons. Reconstruction with flaps is often the only alternative to limb amputation. The purpose of this study was to present a cross flow-through pedicle free latissimus dorsi muscle flap for the salvage of severely traumatized lower limbs perfused by one remaining vessel (a single vessel lower limb) in high voltage electrical injuries. In this retrospective study, between 2000 and 2014, six men underwent cross-leg free Latissimus dorsi muscle flap operations for limb salvage. They had soft tissue lower leg defects due to high voltage electrical injuries. Their medical records were retrospectively reviewed. All had only one artery that perfused the leg. Free pedicled thoracodorsal artery latissimus dorsi flaps were harvested and connected to the contralateral posterior tibial artery. All defects were successfully covered. No flap loss or major amputation occurred during follow-up (mean; 5.9 years). A computerized tomography angiogram showed intact vessel continuity in the recipient vascular system. The patients were able to walk without any apparatus or assistance after long term follow-up. We recommend that the cross flow-through pedicle free muscle flap should be considered as a salvage procedure for single vessel lower extremities resulting from high voltage electrical burns. Extremity perfusion was not compromised by this procedure. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

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.

[4,4‧-bi(1,3,2-dioxathiolane)] 2,2‧-dioxide: A novel cathode additive for high-voltage performance in lithium ion batteries

NASA Astrophysics Data System (ADS)

Lee, Sang Hyun; Yoon, Sukeun; Hwang, Eui-Hyung; Kwon, Young-Gil; Lee, Young-Gi; Cho, Kuk Young

2018-02-01

High-voltage operation of lithium-ion batteries (LIBs) is a facile approach to obtaining high specific energy density, especially for LiNi0·5Mn0·3Co0·2O2 (NMC532) cathodes currently used in mid- and large-sized energy storage devices. However, high-voltage charging (>4.3 V) is accompanied by a rapid capacity fade over long cycles due to severe continuous electrolyte decomposition and instability at the cathode surface. In this study, the sulfite-based compound, [4,4‧-bi(1,3,2-dioxathiolane)] 2,2‧-dioxide (BDTD) is introduced as a novel electrolyte additive to enhance electrochemical performances of alumina-coated NMC532 cathodes cycled in the voltage range of 3.0-4.6 V. X-ray photoelectron spectroscopy (XPS) and AC impedance of cells reveal that BDTD preferentially oxidizes prior to the electrolyte solvents and forms stable film layers on to the cathode surface, preventing increased impedance caused by repeated electrolyte solvent decomposition in high-voltage operation. The cycling performance of the Li/NMC532 half-cell using an electrolyte of 1.0 M LiPF6 in ethylene carbonate/ethyl methyl carbonate (3/7, in volume) can be improved by adding a small amount of BDTD into the electrolyte. BDTD enables the usage of sulfite-type additives for cathodes in high-voltage operation.

Copper wire theft and high voltage electrical burns.

PubMed

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.

MOSFET-based high voltage short pulse generator for ultrasonic transducer excitation

NASA Astrophysics Data System (ADS)

Hidayat, Darmawan; Setianto, Syafei, Nendi Suhendi; Wibawa, Bambang Mukti

2018-02-01

This paper presents the generation of a high-voltage short pulse for the excitation of high frequency ultrasonic transducers. This is highly required in the purpose of various ultrasonic-based evaluations, particularly when high resolution measurement is necessary. A high voltage (+760 V) DC voltage source was pulsated by an ultrafast switching MOSFET which was driven by a pulse generator circuit consisting of an astable multivibrator, a one-shot multivibrator with Schmitt trigger input and a high current MOSFET driver. The generated pulses excited a 200-kHz and a 1-MHz ultrasonic transducers and tested in the transmission mode propagation to evaluate the performances of the generated pulse. The test results showed the generator were able to produce negative spike pulses up to -760 V voltage with the shortest time-width of 107.1 nanosecond. The transmission-received ultrasonic waves show frequency oscillation at 200 and 961 kHz and their amplitudes varied with the voltage of excitation pulse. These results conclude that the developed pulse generator is applicable to excite transducer for the generation of high frequency ultrasonic waves.

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

Reliability and Characterization of High Voltage Power Capacitors

DTIC Science & Technology

2014-03-01

Cable The HVPS cable is a specialized coaxial cable that utilizes a high voltage bayonet connector. The cable itself has a voltage rating in excess...the( LabVIEW(program( GPIB( CABLE ( HVPS( HVPS( COAXIAL ( CABLE ( BNC( COAXIAL ( CABLE ( BNC( COAXIAL ( CABLE ( CAPACITOR(‘C’(DATA( CAPACITOR(‘A’(DATA( Circuit...16   F.   CABLES AND CONNECTORS ...................................................................16

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.

Solid-Body Fuse Developed for High- Voltage Space Power Missions

NASA Technical Reports Server (NTRS)

Dolce, James L.; Baez, Anastacio N.

2001-01-01

AEM Incorporated has completed the development, under a NASA Glenn Research Center contract, of a solid-body fuse for high-voltage power systems of satellites and spacecraft systems. High-reliability fuses presently defined by MIL-PRF-23419 do not meet the increased voltage and amperage requirements for the next generation of spacecraft. Solid-body fuses exhibit electrical and mechanical attributes that enable these fuses to perform reliably in the vacuum and high-vibration and -shock environments typically present in spacecraft applications. The construction and screening techniques for solid-body fuses described by MIL-PRF-23419/12 offer an excellent roadmap for the development of high-voltage solid-body fuses.

Electro-optic voltage sensor for sensing voltage in an E-field

DOEpatents

Woods, G.K.; Renak, T.W.

1999-04-06

A miniature electro-optic voltage sensor system capable of accurate operation at high voltages is disclosed. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam`s polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured. 18 figs.

High-voltage positive electrode materials for lithium-ion batteries

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

Li, Wangda; Song, Bohang; Manthiram, Arumugam

The ever-growing demand for advanced rechargeable lithium-ion batteries in portable electronics and electric vehicles has spurred intensive research efforts over the past decade. The key to sustaining the progress in Li-ion batteries lies in the quest for safe, low-cost positive electrode (cathode) materials with desirable energy and power capabilities. One approach to boost the energy and power densities of batteries is to increase the output voltage while maintaining a high capacity, fast charge–discharge rate, and long service life. Here, this review gives an account of the various emerging high-voltage positive electrode materials that have the potential to satisfy these requirementsmore » either in the short or long term, including nickel-rich layered oxides, lithium-rich layered oxides, high-voltage spinel oxides, and high-voltage polyanionic compounds. The key barriers and the corresponding strategies for the practical viability of these cathode materials are discussed along with the optimization of electrolytes and other cell components, with a particular emphasis on recent advances in the literature. Finally, a concise perspective with respect to plausible strategies for future developments in the field is also provided.« less

High-voltage positive electrode materials for lithium-ion batteries

DOE PAGES

Li, Wangda; Song, Bohang; Manthiram, Arumugam

2017-04-25

The ever-growing demand for advanced rechargeable lithium-ion batteries in portable electronics and electric vehicles has spurred intensive research efforts over the past decade. The key to sustaining the progress in Li-ion batteries lies in the quest for safe, low-cost positive electrode (cathode) materials with desirable energy and power capabilities. One approach to boost the energy and power densities of batteries is to increase the output voltage while maintaining a high capacity, fast charge–discharge rate, and long service life. Here, this review gives an account of the various emerging high-voltage positive electrode materials that have the potential to satisfy these requirementsmore » either in the short or long term, including nickel-rich layered oxides, lithium-rich layered oxides, high-voltage spinel oxides, and high-voltage polyanionic compounds. The key barriers and the corresponding strategies for the practical viability of these cathode materials are discussed along with the optimization of electrolytes and other cell components, with a particular emphasis on recent advances in the literature. Finally, a concise perspective with respect to plausible strategies for future developments in the field is also provided.« less

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

30 CFR 77.704 - Work on high-voltage lines; deenergizing and grounding.

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; deenergizing and... OF UNDERGROUND COAL MINES Grounding § 77.704 Work on high-voltage lines; deenergizing and grounding. High-voltage lines shall be deenergized and grounded before work is performed on them, except that...

Low-Voltage Continuous Electrospinning Patterning.

PubMed

Li, Xia; Li, Zhaoying; Wang, Liyun; Ma, Guokun; Meng, Fanlong; Pritchard, Robyn H; Gill, Elisabeth L; Liu, Ye; Huang, Yan Yan Shery

2016-11-30

Electrospinning is a versatile technique for the construction of microfibrous and nanofibrous structures with considerable potential in applications ranging from textile manufacturing to tissue engineering scaffolds. In the simplest form, electrospinning uses a high voltage of tens of thousands volts to draw out ultrafine polymer fibers over a large distance. However, the high voltage limits the flexible combination of material selection, deposition substrate, and control of patterns. Prior studies show that by performing electrospinning with a well-defined "near-field" condition, the operation voltage can be decreased to the kilovolt range, and further enable more precise patterning of fibril structures on a planar surface. In this work, by using solution dependent "initiators", we demonstrate a further lowering of voltage with an ultralow voltage continuous electrospinning patterning (LEP) technique, which reduces the applied voltage threshold to as low as 50 V, simultaneously permitting direct fiber patterning. The versatility of LEP is shown using a wide range of combination of polymer and solvent systems for thermoplastics and biopolymers. Novel functionalities are also incorporated when a low voltage mode is used in place of a high voltage mode, such as direct printing of living bacteria; the construction of suspended single fibers and membrane networks. The LEP technique reported here should open up new avenues in the patterning of bioelements and free-form nano- to microscale fibrous structures.

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.

An operational amplifier B1404UD1A-1 in the patch-clamp current-to-voltage converter.

PubMed

Korzun, A M; Rozinov, S V; Abashin, G I

1997-01-01

The applicability of the home-made operational amplifier B1404UD1A-1 in a patch-clamp current-to-voltage converter was analyzed. Its parameters (background noise, input bias current, and gain-bandwidth product) were estimated. Schematic solutions and practical recommendations for the use of this amplifier in a current-to-voltage converter were given. Based on the background noise and frequency parameters of the converter, we found that this device can be used for measuring ion channel currents with a high sensitivity and within a broad frequency range (0.055 pA, to 1 kHz; 0.4 pA, to 10 kHz). An example of the converter application in experiments is given.

Programmable Multiple-Ramped-Voltage Power Supply

NASA Technical Reports Server (NTRS)

Ajello, Joseph M.; Howell, S. K.

1993-01-01

Ramp waveforms range up to 2,000 V. Laboratory high-voltage power-supply system puts out variety of stable voltages programmed to remain fixed with respect to ground or float with respect to ramp waveform. Measures voltages it produces with high resolution; automatically calibrates, zeroes, and configures itself; and produces variety of input/output signals for use with other instruments. Developed for use with ultraviolet spectrometer. Also applicable to control of electron guns in general and to operation of such diverse equipment used in measuring scattering cross sections of subatomic particles and in industrial electron-beam welders.

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.

High voltage and high specific capacity dual intercalating electrode Li-ion batteries

NASA Technical Reports Server (NTRS)

Blanco, Mario (Inventor); West, William C. (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.

A method for encapsulating high voltage power transformers

NASA Astrophysics Data System (ADS)

Sanchez, Robert O.

Voltage breakdowns become a major concern in reducing the size of high-voltage power converter transformers. Even the smallest of voids can provide a path for corona discharge which can cause a dielectric breakdown leading to a transformer failure. A method of encapsulating small high voltage transformers has been developed. The method virtually eliminates voids in the impregnation material, provides an exceptional dielectric between windings and provides a mechanically rugged package. The encapsulation material is a carboxyl terminated butadiene nitril (CTBN) modified mica filled epoxy. The method requires heat/vacuum to impregnate the coil and heat/pressure to cure the encapsulant. The transformer package utilizes a diallyl phthalate (DAP) contact assembly in which a coated core/coil assembly is mounted and soldered. This assembly is then loaded into an RTV mold and the encapsulation process begins.

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.

Stable, fast and high-energy-density LiCoO2 cathode at high operation voltage enabled by glassy B2O3 modification

NASA Astrophysics Data System (ADS)

Zhou, Aijun; Wang, Weihang; Liu, Qin; Wang, Yi; Yao, Xu; Qing, Fangzhu; Li, Enzhu; Yang, Tingting; Zhang, Long; Li, Jingze

2017-09-01

In this work, commercial LiCoO2 is modified with a glassy B2O3 by solution mixing with H3BO3 followed by post-calcination in order to enhance its high-voltage electrochemical performance. The glassy B2O3 coating/additive is believed to serve as an effective physiochemical buffer and protection between LiCoO2 and liquid electrolyte, which can suppress the high-voltage induced electrolyte decomposition and active material dissolution. During the early cycling and due to the electrochemical force, the as-coated B2O3 glasses which have 3D open frameworks tend to accommodate some mobile Li+ and form a more chemically-resistant and ion-conductive lithium boron oxide (LBO) interphase as a major component of the solid electrolyte interphase (SEI), which consequently enables much easier Li+ diffusion/transfer at the solid-liquid interfaces upon further cycling. Due to the synergetic effects of B2O3 coating/modification, the high-voltage capacity and energy density of the B2O3-modified LiCoO2 cathode are promisingly improved by 35% and 30% after 100 cycles at 1 C within 3.0-4.5 V vs. Li/Li+. Meanwhile, the high-rate performance of the B2O3-modified electrode is even more greatly improved, showing a capacity of 105 mAh g-1 at 10 C while the bare electrode has dropped to no more than 30 mAh g-1 under this rate condition.

Wearable Solid-State Supercapacitors Operating at High Working Voltage with a Flexible Nanocomposite Electrode.

PubMed

Li, Xiaoyan; Wang, Jun; Zhao, Yaping; Ge, Fengyan; Komarneni, Sridhar; Cai, Zaisheng

2016-10-05

The proposed approach for fabricating ultralight self-sustained electrodes facilitates the structural integration of highly flexible carbon nanofibers, amino-modified multiwalled carbon nanotubes (AM-MWNT), and MnO 2 nanoflakes for potential use in wearable supercapacitors. Because of the higher orientation of AM-MWNT and the sublimation of terephthalic acid (PTA) in the carbonization process, freestanding electrodes could be realized with high porosity and flexibility and could possess remarkable electrochemical properties without using polymer substrates. Wearable symmetric solid-state supercapacitors were further assembled using a LiCl/PVA gel electrolyte, which exhibit a maximum energy density of 44.57 Wh/kg (at a power density of 337.1 W/kg) and a power density of 13330 W/kg (at an energy density of 19.64 Wh/kg) with a working voltage as high as 1.8 V. Due to the combination of several favorable traits such as flexibility, high energy density, and excellent electrochemical cyclability, the presently developed wearable supercapacitors with wide potential windows are expected to be useful for new kinds of portable electric devices.

An Inexpensive Source of High Voltage

NASA Astrophysics Data System (ADS)

Saraiva, Carlos

2012-04-01

As a physics teacher I like recycling old apparatus and using them for demonstrations in my classes.1-4 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 can use a car ignition coil as a high voltage source. Such a coil can be obtained from an old car found in a car salvage yard and used to power cathode ray tubes and discharge tubes to observe the spectra. It can also be used as a source of ignition to simulate explosive combustion that occurs in car engines, rockets, etc. You can also buy these coils in shops that sell car accessories and they are cheaper than induction coils. In Fig. 1 you can see a coil that I used.

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.

Micalastic high-voltage insulation: Design features and experience

NASA Astrophysics Data System (ADS)

Wichmann, A.

1981-12-01

High-quality mica, carefully selected epoxy resins and a well-matched vacuum/pressure impregnation process determine the characteristics of the MICALASTIC insulation for large turbine-generators. Logical development and process manufacturing quality control have led to an insulation system of high quality and operating reliability. The first winding of a turbine-generator being impregnated and cured under vacuum with solvent-free synthetic resin in 1958 was designed for 10.5 kV rated voltage. Ever since, Siemens AG and Kraftwerk Union AG have used this type of insulation for all direct-cooled windings and also for an increasing number of indirect-cooled windings. At present, 240 turbine-generators with a total of more than 115,000 MVA output have been built. Since 1960, this insulation system has been registered for Siemens AG under the trade name MICALASTIC. The stator windings of the largest, single-shaft generators to date, rated 1560 MVA, 27 kV, has been built with MICALASTIC insulation.

Fuel Cell/Electrochemical Cell Voltage Monitor

NASA Technical Reports Server (NTRS)

Vasquez, Arturo

2012-01-01

A concept has been developed for a new fuel cell individual-cell-voltage monitor that can be directly connected to a multi-cell fuel cell stack for direct substack power provisioning. It can also provide voltage isolation for applications in high-voltage fuel cell stacks. The technology consists of basic modules, each with an 8- to 16-cell input electrical measurement connection port. For each basic module, a power input connection would be provided for direct connection to a sub-stack of fuel cells in series within the larger stack. This power connection would allow for module power to be available in the range of 9-15 volts DC. The relatively low voltage differences that the module would encounter from the input electrical measurement connection port, coupled with the fact that the module's operating power is supplied by the same substack voltage input (and so will be at similar voltage), provides for elimination of high-commonmode voltage issues within each module. Within each module, there would be options for analog-to-digital conversion and data transfer schemes. Each module would also include a data-output/communication port. Each of these ports would be required to be either non-electrical (e.g., optically isolated) or electrically isolated. This is necessary to account for the fact that the plurality of modules attached to the stack will normally be at a range of voltages approaching the full range of the fuel cell stack operating voltages. A communications/ data bus could interface with the several basic modules. Options have been identified for command inputs from the spacecraft vehicle controller, and for output-status/data feeds to the vehicle.

Optimization of power systems with voltage security constraints

NASA Astrophysics Data System (ADS)

Rosehart, William Daniel

As open access market principles are applied to power systems, significant changes in their operation and control are occurring. In the new marketplace, power systems are operating under higher loading conditions as market influences demand greater attention to operating cost versus stability margins. Since stability continues to be a basic requirement in the operation of any power system, new tools are being considered to analyze the effect of stability on the operating cost of the system, so that system stability can be incorporated into the costs of operating the system. In this thesis, new optimal power flow (OPF) formulations are proposed based on multi-objective methodologies to optimize active and reactive power dispatch while maximizing voltage security in power systems. The effects of minimizing operating costs, minimizing reactive power generation and/or maximizing voltage stability margins are analyzed. Results obtained using the proposed Voltage Stability Constrained OPF formulations are compared and analyzed to suggest possible ways of costing voltage security in power systems. When considering voltage stability margins the importance of system modeling becomes critical, since it has been demonstrated, based on bifurcation analysis, that modeling can have a significant effect of the behavior of power systems, especially at high loading levels. Therefore, this thesis also examines the effects of detailed generator models and several exponential load models. Furthermore, because of its influence on voltage stability, a Static Var Compensator model is also incorporated into the optimization problems.

Laser guiding of Tesla coil high voltage discharges.

PubMed

Henriksson, Markus; Daigle, Jean-Francois; Théberge, Francis; Châteauneuf, Marc; Dubois, Jacques

2012-06-04

We have investigated the guiding and triggering of discharges from a Tesla coil type 280 kHz AC high voltage source using filaments created by a femtosecond Terawatt laser pulse. Without the laser the discharges were maximum 30 cm long. With the laser straight, guided discharges up to 110 cm length were detected. The discharge length was limited by the voltage amplitude of the Tesla coil.

Flexible low-voltage organic transistors with high thermal stability at 250 °C.

PubMed

Yokota, Tomoyuki; Kuribara, Kazunori; Tokuhara, Takeyoshi; Zschieschang, Ute; Klauk, Hagen; Takimiya, Kazuo; Sadamitsu, Yuji; Hamada, Masahiro; Sekitani, Tsuyoshi; Someya, Takao

2013-07-19

Low-operating-voltage flexible organic thin-film transistors with high thermal stability using DPh-DNTT and SAM gate dielectrics are reported. The mobility of the transistors are decreased by 23% after heating to 250 °C for 30 min. Furthermore, flexible organic pseudo-CMOS inverter circuits, which are functional after heating to 200 °C, are demonstrated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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 NaPF 6 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 atmore » moderate power. The conductivity of NaPF 6 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

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)

Voltage balanced multilevel voltage source converter system

DOEpatents

Peng, Fang Zheng; Lai, Jih-Sheng

1997-01-01

A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.

Voltage balanced multilevel voltage source converter system

DOEpatents

Peng, F.Z.; Lai, J.S.

1997-07-01

Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.

The effect of applied control strategy on the current-voltage correlation of a solid oxide fuel cell stack during dynamic operation

NASA Astrophysics Data System (ADS)

Szmyd, Janusz S.; Komatsu, Yosuke; Brus, Grzegorz; Ghigliazza, Francesco; Kimijima, Shinji; Ściążko, Anna

2014-09-01

This paper discusses the transient characteristics of the planar type SOFC cell stack, of which the standard output is 300 W. The transient response of the voltage to the manipulation of an electric current was investigated. The effects of the response and of the operating condition determined by the operating temperature of the stack were studied by mapping a current-voltage (I-V) correlation. The current-based fuel control (CBFC) was adopted for keeping the fuel utilization factor at constant while the value of the electric current was ramped at the constant rate. The present experimental study shows that the transient characteristics of the cell voltage are determined by primarily the operating temperature caused by the manipulation of the current. Particularly, the slope of the I-V curve and the overshoot found on the voltage was remarkably influenced by the operating temperature. The different values of the fuel utilization factor influence the height of the settled voltages. The CBFC has significance in determining the slope of the I-V characteristic, but the different values ofthe fuel utilization factor does not affect the slope as the operating temperature does. The CBFC essentially does not alter the amplitude of the overshoot on the voltage response, since this is dominated by the operating temperature and its change is caused by manipulating the current.

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.

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.

Vacuum-processed polyethylene as a dielectric for low operating voltage organic field effect transistors

PubMed Central

Kanbur, Yasin; Irimia-Vladu, Mihai; Głowacki, Eric D.; Voss, Gundula; Baumgartner, Melanie; Schwabegger, Günther; Leonat, Lucia; Ullah, Mujeeb; Sarica, Hizir; Erten-Ela, Sule; Schwödiauer, Reinhard; Sitter, Helmut; Küçükyavuz, Zuhal; Bauer, Siegfried; Sariciftci, Niyazi Serdar

2012-01-01

We report on the fabrication and performance of vacuum-processed organic field effect transistors utilizing evaporated low-density polyethylene (LD-PE) as a dielectric layer. With C60 as the organic semiconductor, we demonstrate low operating voltage transistors with field effect mobilities in excess of 4 cm2/Vs. Devices with pentacene showed a mobility of 0.16 cm2/Vs. Devices using tyrian Purple as semiconductor show low-voltage ambipolar operation with equal electron and hole mobilities of ∼0.3 cm2/Vs. These devices demonstrate low hysteresis and operational stability over at least several months. Grazing-angle infrared spectroscopy of evaporated thin films shows that the structure of the polyethylene is similar to solution-cast films. We report also on the morphological and dielectric properties of these films. Our experiments demonstrate that polyethylene is a stable dielectric supporting both hole and electron channels. PMID:23483783

Experimental investigation of SDBD plasma actuator driven by AC high voltage with a superimposed positive pulse bias voltage

NASA Astrophysics Data System (ADS)

Qi, Xiao-Hua; Yan, Hui-Jie; Yang, Liang; Hua, Yue; Ren, Chun-Sheng

2017-08-01

In this work, a driven voltage consisting of AC high voltage with a superimposed positive pulse bias voltage ("AC+ Positive pulse bias" voltage) is adopted to study the performance of a surface dielectric barrier discharge plasma actuator under atmospheric conditions. To compare the performance of the actuator driven by single-AC voltage and "AC+ Positive pulse bias" voltage, the actuator-induced thrust force and power consumption are measured as a function of the applied AC voltage, and the measured results indicate that the thrust force can be promoted significantly after superimposing the positive pulse bias voltage. The physical mechanism behind the thrust force changes is analyzed by measuring the optical properties, electrical characteristics, and surface potential distribution. Experimental results indicate that the glow-like discharge in the AC voltage half-cycle, next to the cycle where a bias voltage pulse has been applied, is enhanced after applying the positive pulse bias voltage, and this perhaps is the main reason for the thrust force increase. Moreover, surface potential measurement results reveal that the spatial electric field formed by the surface charge accumulation after positive pulse discharge can significantly affect the applied external electric field, and this perhaps can be responsible for the experimental phenomenon that the decrease of thrust force is delayed by pulse bias voltage action after the filament discharge occurs in the glow-like discharge region. The schlieren images further verify that the actuator-induced airflow velocity increases with the positive pulse voltage.

Low-voltage operation of Si-based ferroelectric field effect transistors using organic ferroelectrics, poly(vinylidene fluoride-trifluoroethylene), as a gate dielectric

NASA Astrophysics Data System (ADS)

Miyata, Yusuke; Yoshimura, Takeshi; Ashida, Atsushi; Fujimura, Norifumi

2016-04-01

Si-based metal-ferroelectric-semiconductor (MFS) capacitors have been fabricated using poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as a ferroelectric gate. The pinhole-free P(VDF-TrFE) thin films with high resistivity were able to be prepared by spin-coating directly onto hydrogen-terminated Si. The capacitance-voltage (C-V) characteristics of the ferroelectric gate field effect transistor (FeFET) using this MFS structure clearly show butterfly-shaped hysteresis originating from the ferroelectricity, indicating carrier modulation on the Si surface at gate voltages below 2 V. The drain current-gate voltage (I D-V G) characteristics also show counterclockwise hysteresis at gate voltages below 5 V. This is the first report on the low-voltage operation of a Si-based FeFET using P(VDF-TrFE) as a gate dielectric. This organic gate FeFET without any insulator layer at the ferroelectric/Si interface should be one of the promising devices for overcoming the critical issues of the FeFET, such as depolarization field and a decrease in the gate voltage.

The interaction of spacecraft high voltage power systems with the space plasma environment

NASA Technical Reports Server (NTRS)

Domitz, S.; Grier, N. T.

1974-01-01

The development of spacecraft with electrical loads that require high voltage power is discussed. The high voltage solar array has been considered for supplying d.c. power directly to high voltage loads such as ion thrusters and communication tubes without intermediate power processing. Space power stations for transferring solar power to earth are being studied in the 40 kilovolt, multikilowatt regime. Analytical and experimental studies have determined that with the advent of high voltage power, new problems will arise through the interaction of the high voltage surfaces with the charged particle environment of space. The interactive environment has been identified and duplicated to some extent in simulation facilities at NASA-Lewis Research Center and at several contractor locations.

Development and application of network virtual instrument for emission spectrum of pulsed high-voltage direct current discharge

NASA Astrophysics Data System (ADS)

Gong, X.; Wu, Q.

2017-12-01

Network virtual instrument (VI) is a new development direction in current automated test. Based on LabVIEW, the software and hardware system of VI used for emission spectrum of pulsed high-voltage direct current (DC) discharge is developed and applied to investigate pulsed high-voltage DC discharge of nitrogen. By doing so, various functions are realized including real time collection of emission spectrum of nitrogen, monitoring operation state of instruments and real time analysis and processing of data. By using shared variables and DataSocket technology in LabVIEW, the network VI system based on field VI is established. The system can acquire the emission spectrum of nitrogen in the test site, monitor operation states of field instruments, realize real time face-to-face interchange of two sites, and analyze data in the far-end from the network terminal. By employing the network VI system, the staff in the two sites acquired the same emission spectrum of nitrogen and conducted the real time communication. By comparing with the previous results, it can be seen that the experimental data obtained by using the system are highly precise. This implies that the system shows reliable network stability and safety and satisfies the requirements for studying the emission spectrum of pulsed high-voltage discharge in high-precision fields or network terminals. The proposed architecture system is described and the target group gets the useful enlightenment in many fields including engineering remote users, specifically in control- and automation-related tasks.

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

Self-aligned photolithography for the fabrication of fully transparent high-voltage devices

NASA Astrophysics Data System (ADS)

Zhang, Yonghui; Mei, Zengxia; Huo, Wenxing; Wang, Tao; Liang, Huili; Du, Xiaolong

2018-05-01

High-voltage devices, working in the range of hundreds of volts, are indispensable elements in the driving or readout circuits for various kinds of displays, integrated microelectromechanical systems and x-ray imaging sensors. However, the device performances are found hardly uniform or repeatable due to the misalignment issue, which are extremely common for offset drain high-voltage devices. To resolve this issue, this article reports a set of self-aligned photolithography technology for the fabrication of high-voltage devices. High-performance fully-transparent high-voltage thin film transistors, diodes and logic inverters are successfully fabricated with this technology. Unlike other self-aligned routes, opaque masks are introduced on the backside of the transparent substrate to facilitate proximity exposure method. The photolithography process is simulated and analyzed with technology computer aided design simulation to explain the working principle of the proximity exposure method. The substrate thickness is found to be vital for the implementation of this technology based on both simulation and experimental results. The electrical performance of high-voltage devices is dependent on the offset length, which can be delicately modulated by changing the exposure dose. The presented self-aligned photolithography technology is proved to be feasible in high-voltage circuits, demonstrating its huge potential in practical industrial applications.

Recent Developments in High Voltage Research in the United Kingdom

NASA Astrophysics Data System (ADS)

Haddad, A. Manu

This paper gives an overview of research activities in the area of high voltage engineering in UK universities. It summarises the main activities of all active high voltage research groups. Furthermore, current research drivers and funding sources for research in the area are described, and the main initiatives to safeguard the health of the discipline are presented.

High-conductance low-voltage organic thin film transistor with locally rearranged poly(3-hexylthiophene) domain by current annealing on plastic substrate

NASA Astrophysics Data System (ADS)

Pei, Zingway; Tsai, Hsing-Wang; Lai, Hsin-Cheng

2016-02-01

The organic material based thin film transistors (TFTs) are attractive for flexible optoelectronics applications due to the ability of lager area fabrication by solution and low temperature process on plastic substrate. Recently, the research of organic TFT focus on low operation voltage and high output current to achieve a low power organic logic circuit for optoelectronic device,such as e-paper or OLED displayer. To obtain low voltage and high output current, high gate capacitance and high channel mobility are key factors. The well-arranged polymer chain by a high temperature postannealing, leading enhancement conductivity of polymer film was a general method. However, the thermal annealing applying heat for all device on the substrate and may not applicable to plastic substrate. Therefore, in this work, the low operation voltage and high output current of polymer TFTs was demonstrated by locally electrical bias annealing. The poly(styrene-comethyl methacrylate) (PS-r-PMMA) with ultra-thin thickness is used as gate dielectric that the thickness is controlled by thermal treatment after spin coated on organic electrode. In electrical bias-annealing process, the PS-r- PMMA is acted a heating layer. After electrical bias-annealing, the polymer TFTs obtain high channel mobility at low voltage that lead high output current by a locally annealing of P3HT film. In the future, the locally electrical biasannealing method could be applied on plastic substrate for flexible optoelectronic application.

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.

High-frequency graphene voltage amplifier.

PubMed

Han, Shu-Jen; Jenkins, Keith A; Valdes Garcia, Alberto; Franklin, Aaron D; Bol, Ageeth A; Haensch, Wilfried

2011-09-14

While graphene transistors have proven capable of delivering gigahertz-range cutoff frequencies, applying the devices to RF circuits has been largely hindered by the lack of current saturation in the zero band gap graphene. Herein, the first high-frequency voltage amplifier is demonstrated using large-area chemical vapor deposition grown graphene. The graphene field-effect transistor (GFET) has a 6-finger gate design with gate length of 500 nm. The graphene common-source amplifier exhibits ∼5 dB low frequency gain with the 3 dB bandwidth greater than 6 GHz. This first AC voltage gain demonstration of a GFET is attributed to the clear current saturation in the device, which is enabled by an ultrathin gate dielectric (4 nm HfO(2)) of the embedded gate structures. The device also shows extrinsic transconductance of 1.2 mS/μm at 1 V drain bias, the highest for graphene FETs using large-scale graphene reported to date.

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

First test of a high voltage feedthrough for liquid Argon TPCs connected to a 300 kV power supply

NASA Astrophysics Data System (ADS)

Cantini, C.; Gendotti, A.; Molina Bueno, L.; Murphy, S.; Radics, B.; Regenfus, C.; Rigaut, Y.-A.; Rubbia, A.; Sergiampietri, F.; Viant, T.; Wu, S.

2017-03-01

Voltages above a hundred kilo-volt will be required to generate the drift field of future very large liquid Argon Time Projection Chambers. One of the most delicate component is the feedthrough whose role is to safely deliver the very high voltage to the cathode through the thick insulating walls of the cryostat without compromising the purity of the argon inside. This requires a feedthrough that is typically meters long and carefully designed to be vacuum tight and have small heat input. Furthermore, all materials should be carefully chosen to allow operation in cryogenic conditions. In addition, electric fields in liquid argon should be kept below a threshold to reduce risks of discharges. The combination of all above requirements represents significant challenges from the design and manufacturing perspective. In this paper, we report on the successful operation of a feedthrough satisfying all the above requirements. The details of the feedthrough design and its manufacturing steps are provided. Very high voltages up to unprecedented voltages of -300 kV could be applied during long periods repeatedly. A source of instability was observed, which was specific to the setup configuration which was used for the test and not due to the feedthrough itself.

An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers.

PubMed

Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

2013-07-01

Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class.

Electrochemical capacitance voltage measurements in highly doped silicon and silicon-germanium alloys

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

Sermage, B.; Essa, Z.; Taleb, N.

2016-04-21

The electrochemical capacitance voltage technique has been used on highly boron doped SiGe and Si layers. Although the boron concentration is constant over the space charge depth, the 1/C{sup 2} versus voltage curves are not linear. They indeed present a negative curvature. This can be explained by the existence of deep acceptors which ionise under a high electric field (large inverse voltage) and not at a low inverse voltage. The measured doping concentration in the electrochemical capacitance voltage increases strongly as the inverse voltage increases. Thanks to a comparison with the boron concentration measured by secondary ions mass spectrometry, wemore » show that the relevant doping concentrations in device layers are obtained for small inverse voltage in agreement with the existence of deep acceptors. At the large inverse voltage, the measured doping can be more than twice larger than the boron concentration measured with a secondary ion mass spectroscopy.« less

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.

High-voltage crowbar circuit with cascade-triggered series ignitrons

DOEpatents

Baker, William R. [Orinda, CA

1980-11-04

A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors.

High-voltage crowbar circuit with cascade-triggered series ignitrons

DOEpatents

Baker, W.R.

A series string of ignitrons for switching a large current at high voltage to ground is discussed. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors.

High-voltage crowbar circuit with cascade-triggered series ignitrons

DOEpatents

Baker, W.R.

1980-11-04

A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors. 1 fig.

Assessment of High-Voltage Photovoltaic Technologies for the Design of a Direct Drive Hall Effect Thruster Solar Array

NASA Technical Reports Server (NTRS)

Mikellides, I. G.; Jongeward, G. A.; Schneider, T.; Carruth, M. R.; Peterson, T.; Kerslake, T. W.; Snyder, D.; Ferguson, D.; Hoskins, A.

2004-01-01

A three-year program to develop a Direct Drive Hall-Effect Thruster system (D2HET) begun in 2001 as part of the NASA Advanced Cross-Enterprise Technology Development initiative. The system, which is expected to reduce significantly the power processing, complexity, weight, and cost over conventional low-voltage systems, will employ solar arrays that operate at voltages higher than (or equal to) 300 V. The lessons learned from the development of the technology also promise to become a stepping-stone for the production of the next generation of power systems employing high voltage solar arrays. This paper summarizes the results from experiments conducted mainly at the NASA Marshal Space Flight Center with two main solar array technologies. The experiments focused on electron collection and arcing studies, when the solar cells operated at high voltages. The tests utilized small coupons representative of each solar array technology. A hollow cathode was used to emulate parts of the induced environment on the solar arrays, mostly the low-energy charge-exchange plasma (1012-1013 m-3 and 0.5-1 eV). Results and conclusions from modeling of electron collection are also summarized. The observations from the total effort are used to propose a preliminary, new solar array design for 2 kW and 30-40 kW class, deep space missions that may employ a single or a cluster of Hall- Effect thrusters.

High Voltage Hybrid Electric Propulsion - Multilayered Functional Insulation System (MFIS) NASA-GRC

NASA Technical Reports Server (NTRS)

Lizcano, M.

2017-01-01

High power transmission cables pose a key challenge in future Hybrid Electric Propulsion Aircraft. The challenge arises in developing safe transmission lines that can withstand the unique environment found in aircraft while providing megawatts of power. High voltage AC, variable frequency cables do not currently exist and present particular electrical insulation challenges since electrical arcing and high heating are more prevalent at higher voltages and frequencies. Identifying and developing materials that maintain their dielectric properties at high voltage and frequencies is crucial.

The eGo grid model: An open source approach towards a model of German high and extra-high voltage power grids

NASA Astrophysics Data System (ADS)

Mueller, Ulf Philipp; Wienholt, Lukas; Kleinhans, David; Cussmann, Ilka; Bunke, Wolf-Dieter; Pleßmann, Guido; Wendiggensen, Jochen

2018-02-01

There are several power grid modelling approaches suitable for simulations in the field of power grid planning. The restrictive policies of grid operators, regulators and research institutes concerning their original data and models lead to an increased interest in open source approaches of grid models based on open data. By including all voltage levels between 60 kV (high voltage) and 380kV (extra high voltage), we dissolve the common distinction between transmission and distribution grid in energy system models and utilize a single, integrated model instead. An open data set for primarily Germany, which can be used for non-linear, linear and linear-optimal power flow methods, was developed. This data set consists of an electrically parameterised grid topology as well as allocated generation and demand characteristics for present and future scenarios at high spatial and temporal resolution. The usability of the grid model was demonstrated by the performance of exemplary power flow optimizations. Based on a marginal cost driven power plant dispatch, being subject to grid restrictions, congested power lines were identified. Continuous validation of the model is nescessary in order to reliably model storage and grid expansion in progressing research.

SDVSRM - a new SSRM based technique featuring dynamically adjusted, scanner synchronized sample voltages for measurement of actively operated devices.

PubMed

Doering, Stefan; Wachowiak, Andre; Roetz, Hagen; Eckl, Stefan; Mikolajick, Thomas

2018-06-01

Scanning spreading resistance microscopy (SSRM) with its high spatial resolution and high dynamic signal range is a powerful tool for two-dimensional characterization of semiconductor dopant areas. However, the application of the method is limited to devices in equilibrium condition, as the investigation of actively operated devices would imply potential differences within the device, whereas SSRM relies on a constant voltage difference between sample surface and probe tip. Furthermore, the standard preparation includes short circuiting of all device components, limiting applications to devices in equilibrium condition. In this work scanning dynamic voltage spreading resistance microscopy (SDVSRM), a new SSRM based two pass atomic force microscopy (AFM) technique is introduced, overcoming these limitations. Instead of short circuiting the samples during preparation, wire bond devices are used allowing for active control of the individual device components. SDVSRM consists of two passes. In the first pass the local sample surface voltage dependent on the dc biases applied to the components of the actively driven device is measured as in scanning voltage microscopy (SVM). The local spreading resistance is measured within the second pass, in which the afore obtained local surface voltage is used to dynamically adjust the terminal voltages of the device under test. This is done in a way that the local potential difference across the nano-electrical contact matches the software set SSRM measurement voltage, and at the same time, the internal voltage differences within the device under test are maintained. In this work the proof of the concept could be demonstrated by obtaining spreading resistance data of an actively driven photodiode test device. SDVSRM adds a higher level of flexibility in general to SSRM, as occurring differences in cross section surface voltage are taken into account. These differences are immanent for actively driven devices, but can also be

High voltage pulse ignition of mercury discharge hollow cathodes

NASA Technical Reports Server (NTRS)

Wintucky, E. G.

1973-01-01

A high voltage pulse generated by a capacitor discharge into a step-up transformer has been demonstrated capable of consistently igniting hollow cathode mercury discharges at propellant flows and heater power levels much below those required by conventional cathode starting. Results are presented for 3.2-mm diameter enclosed and open keeper cathodes. Starting characteristics are shown to depend on keeper voltage, mercury flow rate, heater power, keeper orifice size, emissive materials, and electrode to which the pulse is applied. This starting technique has been used to start a cathode over 10,000 times without any degradation of starting capability. The starting reliability, propellant and power savings offered by the high voltage pulse start should favorably impact performance of electron bombardment thrusters in missions requiring many on-off duty cycles.

Experiments with high-voltage insulators in the presence of tritium

NASA Astrophysics Data System (ADS)

Grisham, L. R.; Falter, H.; Causey, R.; Chrisman, W.; Stevenson, T.; Wright, K.

1991-02-01

During the final deuterium-tritium phases of the TFTR and JET tokamaks half of the neutral injectors will be used to produce tritium neutral beams to maintain an equal mix of deuterium and tritium in the core plasma, and such requirements may also occur in future devices. This will require that the voltage hold off capabilities of the high voltage insulators in the accelerators be unimpaired by any charge buildups associated with the beta decay of adsorbed layers. We report tests in which we measured the drain currents under high dc voltage of TFTR and JET accelerator insulators while they were successively exposed to vacuum, deuterium and tritium. There did not appear to be any substantial reduction in hold-off capability with tritium, although at some voltages there was a small increase in the leakage current. We also compared the breakdown properties of a plastic tubing filled with deuterium and then tritium at varying pressures, since such tubing has been considered as a high-voltage break in the gas feed system for TFTR, and the presence of large numbers of electron-ion pairs might lead to enhanced Paschen breakdown. We found no significant differences in the behavior for the geometry used.

29 CFR 1926.1410 - Power line safety (all voltages)-equipment operations closer than the Table A zone.

Code of Federal Regulations, 2011 CFR

2011-07-01

... accessories) to a complete stop; wind conditions; degree of sway in the power line; lighting conditions, and... 29 Labor 8 2011-07-01 2011-07-01 false Power line safety (all voltages)-equipment operations... FOR CONSTRUCTION Cranes and Derricks in Construction § 1926.1410 Power line safety (all voltages...

30 CFR 75.154 - Repair of energized surface high voltage lines; qualified person.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Repair of energized surface high voltage lines... Certified Persons § 75.154 Repair of energized surface high voltage lines; qualified person. An individual... high voltage lines only if he has had at least 2 years experience in electrical maintenance, and at...

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.

Controlled phase stability of highly Na-active triclinic structure in nanoscale high-voltage Na2-2xCo1+xP2O7 cathode for Na-ion batteries

NASA Astrophysics Data System (ADS)

Song, Hee Jo; Kim, Jae-Chan; Dar, Mushtaq Ahmad; Kim, Dong-Wan

2018-02-01

With the increasing demand for high energy density in energy-storage systems, a high-voltage cathode is essential in rechargeable Li-ion and Na-ion batteries. The operating voltage of a triclinic-polymorph Na2CoP2O7, also known as the rose form, is above 4.0 V (vs. Na/Na+), which is relatively high compared to that of other cathode materials. Thus, it can be employed as a potential high-voltage cathode material in Na-ion batteries. However, it is difficult to synthesize a pure rose phase because of its low phase stability, thus limiting its use in high-voltage applications. Herein, compositional-engineered, rose-phase Na2-2xCo1+xP2O7/C (x = 0, 0.1 and 0.2) nanopowder are prepared using a wet-chemical method. The Na2-2xCo1+xP2O7/C cathode shows high electrochemical reactivity with Na ions at 4.0 V, delivering high capacity and high energy density.

30 CFR 77.104 - Repair of energized surface high-voltage lines; qualified person.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Repair of energized surface high-voltage lines... high-voltage lines; qualified person. An individual is a qualified person within the meaning of § 77.704 of this part for the purpose of repairing energized surface high-voltage lines only if he has had...

Experimental simulation of space plasma interactions with high voltage solar arrays

NASA Technical Reports Server (NTRS)

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

1981-01-01

Operating high voltage solar arrays in the space environment can result in anomalously large currents being collected through small insulation defects. Tests of simulated defects have been conducted in a 45-cm vacuum chamber with plasma densities of 100,000 to 1,000,000/cu cm. Plasmas were generated using an argon hollow cathode. The solar array elements were simulated by placing a thin sheet of polyimide (Kapton) insulation with a small hole in it over a conductor. Parameters tested were: hole size, adhesive, surface roughening, sample temperature, insulator thickness, insulator area. These results are discussed along with some preliminary empirical correlations.

FAST TRACK COMMUNICATION High mobility and low operating voltage ZnGaO and ZnGaLiO transistors with spin-coated Al2O3 as gate dielectric

NASA Astrophysics Data System (ADS)

Xia, D. X.; Xu, J. B.

2010-11-01

Spin-coated alumina serving as a gate dielectric in thin film transistors shows interesting dielectric properties for low-voltage applications, despite a moderate capacitance. With Ga singly doped and Ga, Li co-doped ZnO as the active channel layers, typical mobilities of 4.7 cm2 V-1 s-1 and 2.1 cm2 V-1 s-1 are achieved, respectively. At a given gate bias, the operation current is much smaller than the previously reported values in low-voltage thin film transistors, primarily relying on the giant-capacitive dielectric. The reported devices combine advantages of high mobility, low power consumption, low cost and ease of fabrication. In addition to the transparent nature of both the dielectric and semiconducting active channels, the superior electrical properties of the devices may provide a new avenue for future transparent electronics.

An Underappreciated Radiation Hazard from High Voltage Electrodes in Vacuum.

PubMed

West, Adam D; Lasner, Zack; DeMille, David; West, Elizabeth P; Panda, Cristian D; Doyle, John M; Gabrielse, Gerald; Kryskow, Adam; Mitchell, Corinne

2017-01-01

The use of high voltage (HV) electrodes in vacuum is commonplace in physics laboratories. In such systems, it has long been known that electron emission from an HV cathode can lead to bremsstrahlung x rays; indeed, this is the basic principle behind the operation of standard x-ray sources. However, in laboratory setups where x-ray production is not the goal and no electron source is deliberately introduced, field-emitted electrons accelerated by HV can produce x rays as an unintended hazardous byproduct. Both the level of hazard and the safe operating regimes for HV vacuum electrode systems are not widely appreciated, at least in university laboratories. A reinforced awareness of the radiation hazards associated with vacuum HV setups would be beneficial. The authors present a case study of a HV vacuum electrode device operated in a university atomic physics laboratory. They describe the characterization of the observed x-ray radiation, its relation to the observed leakage current in the device, the steps taken to contain and mitigate the radiation hazard, and suggested safety guidelines.

Adjustable, High Voltage Pulse Generator with Isolated Output for Plasma Processing

NASA Astrophysics Data System (ADS)

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

2015-09-01

Eagle Harbor Technologies (EHT), Inc. has developed a high voltage pulse generator with isolated output for etch, sputtering, and ion implantation applications within the materials science and semiconductor processing communities. The output parameters are independently user adjustable: output voltage (0 - 2.5 kV), pulse repetition frequency (0 - 100 kHz), and duty cycle (0 - 100%). The pulser can drive loads down to 200 Ω. Higher voltage pulsers have also been tested. The isolated output allows the pulse generator to be connected to loads that need to be biased. These pulser generators take advantage modern silicon carbide (SiC) MOSFETs. These new solid-state switches decrease the switching and conduction losses while allowing for higher switching frequency capabilities. This pulse generator has applications for RF plasma heating; inductive and arc plasma sources; magnetron driving; and generation of arbitrary pulses at high voltage, high current, and high pulse repetition frequency. This work was supported in part by a DOE SBIR.

Design and Testing of 100 mK High-voltage Electrodes for AEgIS

NASA Astrophysics Data System (ADS)

Derking, J. H.; Liberadzka, J.; Koettig, T.; Bremer, J.

The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) experiment at CERN has as main goal to perform the first direct measurement of the Earth's gravitational acceleration on antihydrogen atoms within 1% precision. To reach this precision, the antihydrogen should be cooled down to about 100 mK to reduce its random vertical velocity. This is obtained by mounting a Penning trap consisting of multiple high-voltage electrodes on the mixing chamber of a dilution refrigerator with cooling capacity of 100 μW at 50 mK. A design of the high-voltage electrodes is made and experimentally tested at operating conditions. The high-voltage electrodes are made of sapphire with four gold sputtered electrode sectors on it. The electrodes have a width of 40 mm, a height of 18 mm and a thickness of 5.8 mm and for performance testing are mountedto the mixing chamber of a dilution refrigerator with a 250 μm thick indium foil sandwiched inbetween the two to increase the thermal contact. A static heat load of 120 nW applied to the top surface of the electrode results in a maximum measured temperature of 100 mK while the mixing chamber is kept at a constant temperature of 50 mK. The measured totalthermal resistivity lies in the range of 210-260 cm2 K4 W-1, which is much higher than expected from literature. Further research needs to be done to investigate this.

Electro-optical voltage sensor head

DOEpatents

Woods, Gregory K.

1998-01-01

A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

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

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

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

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 propertiesmore » 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.« less

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.

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.

Low voltage-driven oxide phototransistors with fast recovery, high signal-to-noise ratio, and high responsivity fabricated via a simple defect-generating process

PubMed Central

Yun, Myeong Gu; Kim, Ye Kyun; Ahn, Cheol Hyoun; Cho, Sung Woon; Kang, Won Jun; Cho, Hyung Koun; Kim, Yong-Hoon

2016-01-01

We have demonstrated that photo-thin film transistors (photo-TFTs) fabricated via a simple defect-generating process could achieve fast recovery, a high signal to noise (S/N) ratio, and high sensitivity. The photo-TFTs are inverted-staggered bottom-gate type indium-gallium-zinc-oxide (IGZO) TFTs fabricated using atomic layer deposition (ALD)-derived Al2O3 gate insulators. The surfaces of the Al2O3 gate insulators are damaged by ion bombardment during the deposition of the IGZO channel layers by sputtering and the damage results in the hysteresis behavior of the photo-TFTs. The hysteresis loops broaden as the deposition power density increases. This implies that we can easily control the amount of the interface trap sites and/or trap sites in the gate insulator near the interface. The photo-TFTs with large hysteresis-related defects have high S/N ratio and fast recovery in spite of the low operation voltages including a drain voltage of 1 V, positive gate bias pulse voltage of 3 V, and gate voltage pulse width of 3 V (0 to 3 V). In addition, through the hysteresis-related defect-generating process, we have achieved a high responsivity since the bulk defects that can be photo-excited and eject electrons also increase with increasing deposition power density. PMID:27553518

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…

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.

High-voltage zones within the pulmonary vein antra: Major determinants of acute pulmonary vein reconnections after atrial fibrillation ablation.

PubMed