Equivalent circuit for a field effect transistor established for computer simulation
Equivalent circuit for the field effect transistor made up of circuit elements can be simulated by existing computer programs.
Ming, L. J.↗
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Results for “equivalent circuit”
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Noise and equivalent circuit of double injection.
Silicon double injection diode, discussing HF noise measurement, Nyquist noise equivalent circuit for double injection process and source of LF noise
Bilger, H. R.↗
Noise equivalent circuit of a semiconductor laser diode
A small-signal model of a semiconductor laser is extended to include the effects of intrinsic noise by adding current and voltage noise sources. The current noise source represents the shot noise of carrier recombination, while the voltage noise source represents the random process of simulated emission. The usefulness of the noise equivalent circuit is demonstrated by calculating the modulation and noise characteristics of a current-driven diode as a function of bias current and frequency.
Harder, C.↗
Analysis and modeling of a family of two-transistor parallel inverters
A family of five static dc-to-square-wave inverters, each employing a square-loop magnetic core in conjunction with two switching transistors, is analyzed using piecewise-linear models for the nonlinear characteristics of the transistors, diodes, and saturable-core devices. Four of the inverters are analyzed in detail for the first time. These analyses show that, by proper choice of a frame of reference, each of the five quite differently appearing inverter circuits can be described by a common equivalent circuit. This equivalent circuit consists of a five-segment nonlinear resistor, a nonlinear saturable reactor, and a linear capacitor. Thus, by proper interpretation and identification of the parameters in the different circuits, the results of a detailed solution for one of the inverter circuits provide similar information and insight into the local and global behavior of each inverter in the family.
Lee, F. C. Y.↗
Comparison of NASCAP modelling results with lumped circuit analysis
Engineering design tools that can be used to predict the development of absolute and differential potentials by realistic spacecraft under geomagnetic substorm conditions are described. Two types of analyses are in use: (1) the NASCAP code, which computes quasistatic charging of geometrically complex objects with multiple surface materials in three dimensions; (2) lumped element equivalent circuit models that are used for analyses of particular spacecraft. The equivalent circuit models require very little computation time, however, they cannot account for effects, such as the formation of potential barriers, that are inherently multidimensional. Steady state potentials of structure and insulation are compared with those resulting from the equivalent circuit model.
Stang, D. B.↗
Adaptability of FET models to computer-aided circuit design Final report
Equivalent circuit and modified and approximate models for metal oxide semiconductor-field effect transistor devices, and adaptability to computerized circuit design
Birznieks, U.↗
A study of microwave downcoverters operating in the K sub u band
A computer program for parametric amplifier design is developed with special emphasis on practical design considerations for microwave integrated circuit degenerate amplifiers. Precision measurement techniques are developed to obtain a more realistic varactor equivalent circuit. The existing theory of a parametric amplifier is modified to include the equivalent circuit, and microwave properties, such as loss characteristics and circuit discontinuities are investigated.
Fellers, R. G.↗
Ignitor plug erosion and arc initiation processes in a one-millipound pulsed plasma thruster
The results are presented of a one-millipound pulsed plasma ignition system study. The preliminary data indicate that inductively coupling the ignition plug cathode to the thruster cathode is more beneficial to ignitor plug longevity than resistive coupling. These benefits arise from the ability of the coupling conductor to control the build-up of a carbonaceous deposit on the plug face. The deposit build-up is a strong function of the peak coupling current experienced during thruster operation. The relationship between the ignitor plug discharge and thruster discharge is shown to be very complex with equivalent circuit elements which are dynamic in nature. A preliminary representation of this equivalent circuit is developed.
Aston, G.↗
Relationships among classes of self-oscillating transistor parallel inverters
A procedure is developed for classifying dc-to-square-wave two-transistor parallel inverters used in power conditioning applications. The inverters are reduced to equivalent RLC networks and are then grouped with other inverters with the same basic equivalent circuit. Distinction between inverter classes is based on the topology characteristics of the equivalent circuits. Information about one class can then be extended to another class using the basic oscillation theory and the concept of duality. Oscillograms from test circuits confirm the validity of the procedure adopted.
Wilson, T. G.↗
Pyrotechnic hazards classification and evaluation program. Electrostatic vulnerability of the E8 and XM15/XM165 clusters, phase 2
An investigation into the electrostatic phenomena associated with the manufacturing and handling of explosives is discussed. The testing includes measurement of the severity of the primary charge generation mechanism, triboelectric effects between dissimilar surfaces; refinement of equivalent circuits of the XM15/XM165 and E8 fuse trains; evaluation of the electrostatic spark discharge characteristics predicted by an equivalent circuit analysis; and determination of the spark ignition sensitivity of materials, components, junctions, and subassemblies which compose the XM15/XM165 and E8 units. Special studies were also performed. These special tests included ignition sensitivity of the complete XM15 fuse train when subjected to discharges through its entire length, measurement of electrostatic potentials which occur during the E8 foaming operation during fabrication, and investigation of the inadvertent functioning of an XM15 cluster during manufacturing. The test results are discussed and related to the effectiveness of suggested modification to reduce the electrostatic ignition sensitivity.
Source record↗
Mathematical Characterization of Battery Models
The purpose of this document is to demonstrate the use of the Extended Kalman Filter as a tool for battery state estimation and the estimation of battery state of charge. The mathematical details based on the equivalent circuit model are presented followed by an electrochemical engineering model. A simplified first-order model is used to demonstrate the procedure followed by second and third-order models. Next a simplified electrochemistry model is presented along with observer development. State observability is calculated for the simpler equivalent circuit models and the simplified electrochemistry model. An outline of the battery model parameter identification method is presented, and model performance based on experimental and flight data is demonstrated.
Battery↗
Factors in the design of spacecraft utilizing multiple electric thrusters
An analysis has been performed which describes the electrical interactions between simultaneously operating ion thrusters and between the ion thrusters and a spacecraft bus. The problem is reduced to a relatively simple equivalent circuit including all leakage paths. The influence of the various circuits elements on a spacecraft potential is studied. A thruster grounding scheme is introduced which is designed to minimize the electrical interactions and includes protection for both thrusters and spacecraft from possible damage due to neutralizer failure. The paper includes the results of various experiments which have been conducted to quantitatively define the elements of the equivalent circuit.
Fitzgerald, D. J.↗
Program on application of communications satellites to educational development. Wideband CW microwave amplification using Gunn effect devices
Application of Gunn effect to coaxial and microstrip circuits and development of equivalent circuits
Sene, A.↗
Theoretical expression for the noise equivalent power of pyroelectric detectors.
Equivalent circuit for pyroelectric materials used in obtaining noise equivalent power for detection of electromagnetic radiation and heat transfer measurement
NOISE INTENSITY↗
Magnetogasdynamic compression of a coaxial plasma accelerator flow for micrometeoroid simulation.
A new configuration of a coaxial plasma accelerator with self-energized magnetic compressor coil attached is described. It is shown that the circuit may be treated theoretically by analyzing an equivalent circuit mesh. The results obtained from the theoretical analysis are shown to compare favorably with the results measured experimentally. Using this accelerator configuration, glass beads of 125-micron diameter were accelerated to velocities as high as 11 km/sec, while 700-micron-diam glass beads were accelerated to velocities as high as 5 km/sec. The velocities are within the hypervelocity regime of meteroids.
Igenbergs, E. B.↗
Magnetogasdynamic compression of a coaxial plasma accelerator flow for micrometeoroid simulation
A new configuration of a coaxial plasma accelerator with self-energized magnetic compressor coil attached is described. It is shown that the circuit may be treated theoretically by analyzing an equivalent circuit mesh. The results obtained from the theoretical analysis compare favorably with the results measured experimentally. Using this accelerator configuration, glass beads of 125 micron diameter were accelerated to velocities as high as 11 kilometers per second, while 700 micron diameter glass beads were accelerated to velocities as high as 5 kilometers per second. The velocities are within the hypervelocity regime of meteoroids.
Igenbergs, E. B.↗
Frequency method for determining the parameters of the electromagnetic brakes and slip-type couplings with solid magnetic circuits
The equivalent representation of brakes and coupling by lumped circuits is investigated. Analytical equations are derived for relating the indices of the transients to the parameters of the equivalent circuits for arbitrary rotor speed. A computer algorithm is given for the calculations.
Guseynov, F. G.↗
Fabrication of multijunction high voltage concentrator solar cells by integrated circuit technology
Standard integrated circuit technology has been developed for the design and fabrication of planar multijunction (PMJ) solar cell chips. Each 1 cm x 1 cm solar chip consisted of six n(+)/p, back contacted, internally series interconnected unit cells. These high open circuit voltage solar cells were fabricated on 2 ohm-cm, p-type 75 microns thick, silicon substrates. A five photomask level process employing contact photolithography was used to pattern for boron diffusions, phorphorus diffusions, and contact metallization. Fabricated devices demonstrated an open circuit voltage of 3.6 volts and a short circuit current of 90 mA at 80 AMl suns. An equivalent circuit model of the planar multi-junction solar cell was developed.
Valco, G. J.↗