The deterioration of contacts during the switching of low voltage /up to 220 V/ dc and ac currents
Wear of electric contacts during switching of low voltage direct and alternating currents
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Wear of electric contacts during switching of low voltage direct and alternating currents
Flux switching in multipath ferrimagnetic core materials - computational analyses for unloaded core, loaded core, core-diode-transistor binary counter, and loaded three-leg core
Improvements for low current detector components - high megohm resistors, electrometer tubes, solid state devices, modulators, electron multipliers, insulators, and high impedance switching devices
Switching properties of partially set square-loop ferrite core, noting flux level influence, measurement techniques, etc
Statistical model of switching time jitter for tunnel diode threshold-crossing detector
Linear power amplification with switching techniques, using pulse width modulation
Nondissipatively regulated variable frequency DC TO DC converter with variable on time and variable off time
Computer-implemented minimization techniques used to determine realizability of N-variable switching function with single threshold-element device
Low noise transistor switch design capable of switching 1A and meeting military current probe EMI specifications
Single-ended step-up regulator-chopper power supply /employing conventional chopper circuitry/ combines the advantages of the chopper and switching regulator circuits. Schematic of the power supply incorporating the step-up regulator is shown.
Isolated, multiple output voltage dc-to-dc converter provides power for television transmitter used in space vehicles. The isolation is accomplished by using a single-end switching transformer circuit. The converter is completely solid state.
Transistor-driven temperature-stable amplifier with logarithmic operating characteristics permits presentation of the entire range of the reactor without range switching. This circuit is capable of monitoring ion chamber currents over spans of 8 or 9 decades and is used in nuclear reactor instrumentation. Application is found in materials under ultrahigh vacuum.
Circuit technique uses a signal diode as a series current-pass element. Technique is applied to the design of a biased amplifier circuit and a nanosecond-pulse stretcher circuit.
Input radio frequency circuit for switching type absolute temperature measuring radiometer for noise sources
An extensive investigation of irradiate-anneal (IRAN) screening against total dose radiation effects was carried out as part of a program to harden the Mariner Jupiter/Saturn 1977 (MJS'77) spacecraft to survive the Jupiter radiation belts. The method consists of irradiating semiconductor devices with Cobalt-60 to a suitable total dose under representative bias conditions and of separating the parts in the undesired tail of the distribution from the bulk of the parts by means of a predetermined acceptance limit. The acceptable devices are then restored close to their preirradiation condition by annealing them at an elevated temperature. IRAN was used when lot screen methods were impracticable due to lack of time, and when members of a lot showed a diversity of radiation response. The feasibility of the technique was determined by testing of a number of types of linear bipolar integrated circuits, analog switches, n-channel JFETS and bipolar transistors. Based on the results of these experiments a number of device types were selected for IRAN of flight parts in the MJS'77 spacecraft systems. The part types, screening doses, acceptance criteria, number of parts tested and rejected as well as the program steps are detailed.
Circuit controls switching of bidirectional motor with dynamic braking.
The objective of the NASA Communications Division is to provide operational communications in support of NASA projects and mission activities. Nascom is a generic term referring collectively to a global system of circuits and switching and terminal facilities established and operated by NASA to provide longhaul operational communications support for all NASA projects. Aspects of network evolution are discussed, taking into account the integrated Nascom network. A description is presented of the present Nascom network, giving attention to the Spaceflight Tracking and Data Network (STDN), the Deep Space Network (DSN), the voice network, and the Teletypewriter (TTY) Network. Concepts and techniques for the 1980's are also considered. It is pointed out that the Nascom Network will extend the Tracking and Data Relay Satellite System (TDRSS) forward- and return-link services to users of the TDRSS by providing ground-to-ground data communications links between the NASA Ground Terminal at White Sands, New Mexico, and major user spacecraft control centers and data capture/data processing facilities.
A regio-regular poly(3-hexylthiophene) (RRP3HT) thin-film transistor having a split-gate architecture has been fabricated on a doped silicon/silicon nitride substrate and characterized. RRP3HT is a semiconducting polymer that has a carrier mobility and on/off ratio when used in a field effect transistor (FET) configuration. This commercially available polymer is very soluble in common organic solvents and is easily processed to form uniform thin films. The most important polymer-based device fabricated and studied is the FET, since it forms the building block in logic circuits and switches for active matrix (light-emitting-diode) (LED) displays, smart cards, and radio frequency identification (RFID) cards.