Investigation of new contact systems for miniature high-frequency switches
Variation in transitional resistance of electric contacts as function of design, materials, current, and switching frequency - switching elements erosion
ELECTRIC CONTACT↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Power conditioning - inversion, conversion, and regulation
Switching element requirements for spacecraft electric power conversion, inversion, and regulation
SWITCHING ELEMENT↗
Ferromagnetic-fluid logic devices
Logic element switches flows of low pressure process control fluid in fluidics assemblies. Device operates both electrically and fluidically and is controlled by passing permanent magnet or electromagnet over elements, thus providing proximity switching functions.
Makowski, M. J.↗
Parallel-Access Alinement Network Using Barrel Switches
Practical version of parallel-access alinement network utilizes two barrel switches for interfacing N parallel memory modules with N parallel processing elements. Switches are interconnected where 17 memory ports (MP's) are connected to 17 processor ports (PP's). Network uses two electronic barrel switches to direct data flow in parallel data-processing system. Each switch can shift a multibit parallel input a predetermined number of places to left or right, end off, or end around in one clock-pulse.
Barnes, George H.↗
System-state and operating condition sensitive control method and apparatus for electric power delivery systems
This invention provides a method and apparatus for determining a precise switching sequence for the power switching elements of electric power delivery systems of the on-off switching type and which enables extremely fast transient response, precise regulation and highly stable operation. The control utilizes the values of the power delivery system power handling network components, a desired output characteristic, a system timing parameter, and the externally imposed operating conditions to determine where steady state operations should be in order to yield desired output characteristics for the given system specifications. The actual state of the power delivery system is continuously monitored and compared to a state-space boundary which is derived from the desired equilibrium condition, and from the information obtained from this comparison, the system is moved to the desired equilibrium condition in one cycle of switching control. Since the controller continuously monitors the power delivery system's externally imposed operating conditions, a change in the conditions is immediately sensed and a new equilibrium condition is determined and achieved, again in a single cycle of switching control.
Burns, III, William Wesley↗
High voltage DC switchgear development for multi-kW space power system: Aerospace technology development of three types of solid state power controllers for 200-1100VDC with current ratings of 25, 50, and 80 amperes with one type utilizing an electromechanical device
Three types of solid state power controllers (SSPC's) for high voltage, high power DC system applications were developed. The first type utilizes a SCR power switch. The second type employes an electromechanical power switch element with solid state commutation. The third type utilizes a transistor power switch. Significant accomplishments include high operating efficiencies, fault clearing, high/low temperature performance and vacuum operation.
Billings, W. W.↗
Frequency shifting with a solid-state switching capacitor
Frequency shifting, commonly used in electronic signal processing, is applied in tuning, automatic frequency control, antenna element switching, phase shifting, etc. Frequency shifting can be accomplished economically and reliably with simple circuit comprising conventional resistor and solid-state switching device which can be equivalent to two capacitors, depending on switching state.
Mattauch, R. J.↗
New Generation Power System for Space Applications
The Deep Space Avionics (DSA) Project is developing a new generation of power system building blocks. Using application specific integrated circuits (ASICs) and power switching modules a scalable power system can be constructed for use on multiple deep space missions including future missions to Mars, comets, Jupiter and its moons. The key developments of the DSA power system effort are five power ASICs and a mod ule for power switching. These components enable a modular and scalab le design approach, which can result in a wide variety of power syste m architectures to meet diverse mission requirements and environments . Each component is radiation hardened to one megarad) total dose. The power switching module can be used for power distribution to regular spacecraft loads, to propulsion valves and actuation of pyrotechnic devices. The number of switching elements per load, pyrotechnic firin gs and valve drivers can be scaled depending on mission needs. Teleme try data is available from the switch module via an I2C data bus. The DSA power system components enable power management and distribution for a variety of power buses and power system architectures employing different types of energy storage and power sources. This paper will describe each power ASIC#s key performance characteristics as well a s recent prototype test results. The power switching module test results will be discussed and will demonstrate its versatility as a multip urpose switch. Finally, the combination of these components will illu strate some of the possible power system architectures achievable fro m small single string systems to large fully redundant systems.
power switching↗
High-voltage, full-floating 10-MHz square-wave generator with phase control
Wherein a fast (50 ns) rise-time high-frequency square-wave generator capable of switching between arbitrary voltages of high potential difference (1000 V or more) is described utilizing solid-state circuitry of low power consumption. Power field effect transistors are used as the active switching element, which afford compact size and simplified circuit construction. With the addition of monostable multivibrators, high-voltage square-wave pulse trains of controllable phase are produced. The generator should find application in a wide variety of situations where fast switching between high voltages is required, such as in time-of-flight, coincidence, and beams-modulation experiments.
Bernius, Mark T.↗
Low level commutation using mos fet transistors
Metal oxide silicon field effect transistors /MOS FET/ as switching elements for low level commutator
METAL OXIDE SEMICONDUCTOR /MOS/↗
Molecules and memory.
Molecules and memory, discussing role of RNA as switching element in memory processes
NEURON TRANSMISSION↗
Build tunnel-diode pulse generators.
Pulse generators using tunnel diodes as output switching elements driven by on-off current sources
Garrahan, N. M.↗
An unorthodox transformer for free-running parallel inverters
Free-running parallel inverters limitations by critical characteristics of networks, transformers and switching elements
Schwarz, F. C.↗
The thermionic diode as a high-temperature switch
Cs vapor thermionic diodes with low temperature dual mode characteristics applicable as switching elements in DC to AC power conditioner
Luebbers, S. S.↗
A series-resonant silicon-controlled-rectifier power processor for ion thrusters
A program to develop a power processing system for ion thrusters is presented. Basic operation of the silicon controlled rectifier series inverter circuitry is examined. The approach for synthesizing such circuits into a system which limits the electrical stress levels on the power source, semiconductor switching elements, and the ion thruster load is described. Experimental results are presented for a 2.5-kW breadboard system designed to operate a 20-cm ion thruster.
Shumaker, H. A.↗
Southwest Research Institute assistance to NASA in biomedical areas of the technology utilization program
The problem statements presented relate mostly to research on prosthetic equipment and means of attaching biomedical and electronic devices to the human body. A patent application for a reliable switching element in a patient assist control units is also described.
Source record↗
Logic-controlled solid-state switchgear for 270 volt dc.
A feasibility study to design and demonstrate solid-state switchgear composed of circuit breakers and a power transfer switch is described. The switchgear operates on a nominal 270 Vdc circuit and controls power to a load up to 15 A. One circuit breaker may be interconnected to a second to form a power transfer switch. Breaker or switch on-off and transfer functions can be remotely controlled. Automatic overload trip-out is provided through an ultimate current trip and an I squared t trip for transient overcurrents lower than the ultimate current trip level. A number of reclosures with variable time delay between trip-out and reclosure are programmed and controlled by integrated analog and COSMOS logic circuits. A commutation circuit that creates minimal transient disturbances to either source or load was developed to interrupt current flow through the main SCR switching element.-
Waddington, D.↗
Logic-controlled solid state switchgear for 270 volts dc
A feasibility study to design and demonstrate solid state switchgear in the form of circuit breakers and a power transfer switch is described. The switchgear operates on a nominal 270 V dc circuit and controls power to a load of up to 15 amperes. One circuit breaker may be interconnected to a second breaker to form a power transfer switch. On-off and transfer functions of the breakers or the transfer switch are remotely controlled. A number of reclosures with variable time delay between tripout and reclosure are programmed and controlled by integrated analog and COSMOS logic circuits. A unique commutation circuit, that generates only minimal transient disturbance to either source or load, was developed to interrupt current flow through the main SCR switching element. Laboratory tests demonstrated performance of the solid state circuit breakers over specified voltage and temperature ranges.
Sundberg, G. R.↗