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  • Other Sources  (760)
  • ELECTRONICS AND ELECTRICAL ENGINEERING  (760)
  • 1975-1979  (760)
  • 1
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    Inflight lightning characteristics measurement system (1979)
    In:  CASI
    Details
    Publication Date: 2005-04-28
    Description: A research data-gathering system being developed for inflight measurement of direct and nearby lightning strike characteristics is described. Wideband analog recorders used to record the lightning scenario are supplemented with high-sample-rate digital transient recorders with augmented memory capacity for increased time resolution of specific times of interest. The endless-loop data storage technique employed by the transient recorders circumvents problems associated with oscilloscopic techniques and allows unattended operation. System integrity and immunity from induced effects is accomplished by fiber-optics signal-transmission links, shielded system enclosures, and the use of a dynamotor for power system isolation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Florida Inst. of Technol. FAA-Florida Inst. of Technol. Workshop on Grounding and Lightning Technol.; p 105-111
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  • 2
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    Waveguide arc study (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: Research on waveguide arcs is presented as well as an evaluation on an arc detector. Ways of improving the radio frequency arc generation include methods of generating RF arcs inside the resonator. Dc nitrogen arcs were used to study a spectroradiometer. The spectral strucutres obtained provide a general sketch of spectral distribution and their relative magnitude. The upgrading of a transmitter test light and the simulation of an LED array are reported.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Deep Space Network; p 196-203
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  • 3
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    A transmission line phase stabilizer (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: To meet the phase stability requirements of certain experiments performed with the Deep Space Network, transmission lines carrying reference signals must be stabilized to reduce changes in their electrical length due to mechanical movement or changes in ambient temperature. A transmission line phase stabilizer being developed at JPL to perform this function is described.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Deep Space Network; p 67-71
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  • 4
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    Induced electric currents in the Alaska oil pipeline measured by gradient, fluxgate, and SQUID magnetometers (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: The field gradient method for observing the electric currents in the Alaska pipeline provided consistent values for both the fluxgate and SQUID method of observation. These currents were linearly related to the regularly measured electric and magnetic field changes. Determinations of pipeline current were consistent with values obtained by a direct connection, current shunt technique at a pipeline site about 9.6 km away. The gradient method has the distinct advantage of portability and buried- pipe capability. Field gradients due to the pipe magnetization, geological features, or ionospheric source currents do not seem to contribute a measurable error to such pipe current determination. The SQUID gradiometer is inherently sensitive enough to detect very small currents in a linear conductor at 10 meters, or conversely, to detect small currents of one amphere or more at relatively great distances. It is fairly straightforward to achieve imbalance less than one part in ten thousand, and with extreme care, one part in one million or better.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 182-192
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  • 5
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    Prediction of solar induced currents and effects on power transmission systems in central Canada (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: The auroral-electrojet zone covers three quarters of Manitoba and consequently, solar storms strongly affect transmission lines. Harmonics are generated at transformers due to the saturation of their cores by induced currents, and the level of harmonics produced may cause malfunction of control relays, and yield unacceptable distortions in normal ac waveforms. The expected effects of long ac transmission systems were studied with emphasis on a 500 kv line to be built from Winnipeg to Minneapolis-St. Paul. Spectral analysis of induced current records from Manitoba Hydro's LaVerendrye station and magnetograms from IMS stations in Manitoba were used along with results of Campbell's work on the Alaskan pipeline induction problem (1978) in order to predict periodic and surge currents. It is concluded that the surge currents will produce significant levels of harmonics and corresponding operating problems during magnetic storms.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 162-171
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  • 6
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    Harmonics of 60 Hz in power systems caused by geomagnetic disturbances (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: Simultaneous VLF/ULF observations carried out near Winnipeg, Manitoba show that geomagnetic disturbances control the behavior of harmonics of 60 Hz man-made electric power. The harmonics of 60 Hz detected by the VLF receiver are at multiples of 180 Hz, indicating that they originated from a 3 phase ac power system. Under geomagnetically quiet conditions, only odd harmonics of 70 Hz were detected. In disturbed conditions, both odd and even harmonics were excited. The strength of each harmonic changed concurrently with geomagnetic pulsation (ULF) activity. These findings seem to indicate that a portion of telluric currents shunted into the power line system through the neutrals of the Y-connected transformers give rise to a dc bias to the transformer core materials and that it distorts their hysteresis loops, activating harmonics of 60 Hz power. A mathematical proof is given that a hysteresis loop having a point of symmetry generates odd harmonics only, whereas loops lacking in point-symmetry generally give rise to both odd and even harmonics. A general formula was obtained to calculate the strength of each harmonic based on the shape of the hysteresis loop.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 172-181
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  • 7
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    The problem of solar induced currents (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: The production of surface electric fields by geomagnetic variations is discussed with reference to magnetotelluric theory; and evidence is presented to show that the severity of solar-induced currents (SIC) at Cornerbrook, Newfoundland is due to channeling of currents induced in the sea through a region adjacent to the power line. An 'isolated loop' approximation is proposed for calculating the quasi-dc currents produced in the power system by the surface electric fields. Identification of the processes causing the geomagnetic perturbations responsible for SIC would be aided by investigation of the local time dependence of SIC occurrence. Such knowledge could potentially be used to provide several hours warning of SIC.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 149-161
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  • 8
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    Magnetic storm effects in electric power systems and prediction needs (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: Geomagnetic field fluctuations produce spurious currents in electric power systems. These currents enter and exit through points remote from each other. The fundamental period of these currents is on the order of several minutes which is quasi-dc compared to the normal 60 Hz or 50 Hz power system frequency. Nearly all of the power systems problems caused by the geomagnetically induced currents result from the half-cycle saturation of power transformers due to simultaneous ac and dc excitation. The effects produced in power systems are presented, current research activity is discussed, and magnetic storm prediction needs of the power industry are listed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 137-148
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  • 9
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    Heat pipe cooled power magnetics (1979)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: A high frequency, high power, low specific weight (0.57 kg/kW) transformer developed for space use was redesigned with heat pipe cooling allowing both a reduction in weight and a lower internal temperature rise. The specific weight of the heat pipe cooled transformer was reduced to 0.4 kg/kW and the highest winding temperature rise was reduced from 40 C to 20 C in spite of 10 watts additional loss. The design loss/weight tradeoff was 18 W/kg. Additionally, allowing the same 40 C winding temperature rise as in the original design, the KVA rating is increased to 4.2 KVA, demonstrating a specific weight of 0.28 kg/kW with the internal loss increased by 50W. This space environment tested heat pipe cooled design performed as well electrically as the original conventional design, thus demonstrating the advantages of heat pipes integrated into a high power, high voltage magnetic. Another heat pipe cooled magnetic, a 3.7 kW, 20A input filter inductor was designed, developed, built, tested, and described. The heat pipe cooled magnetics are designed to be Earth operated in any orientation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: TRW-33572-6001-RU-00 , NASA-CR-159659
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  • 10
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    Multilayer self-structured bubble memories (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Research work on multilayer self-structured bubble memories is at an early stage. The coupling of bubbles to stripes is investigated theoretically and experimentally and shown to be adequate for propagation. Propagation of stripes is demonstrated both by current access and field access techniques. These propagation techniques are of prime interest because they can eliminate most photographic features from the storage area. Multilayer films offer great promise for higher-capacity higher-density memories in which most of the photolithography has been eliminated and the minimum feature size of much of the remaining has been increased. Furthermore, stripe propagation can be carried out with current access, providing a significant reduction in packaging cost and power consumption over field access devices.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 11
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    LaF3 insulators for MIS structures (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Thin films of LaF3 deposited on Si or GaAs substrates have been observed to form blocking contacts with very high capacitances. This results in comparatively hysteresis-free and sharp C-V (capacitance-voltage) characteristics for MIS structures. Such structures have been used to study the interface states of GaAs with increased resolution and to construct improved photocapacitive infrared detectors.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters; 34; June 1
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  • 12
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    Shot-noise in resistive-diode mixers and the attenuator noise model (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The representation of a pumped exponential diode, operating as a mixer, by an equivalent lossy network, is reexamined. It is shown that the model is correct provided the network has ports for all sideband frequencies at which (real) power flow can occur between the diode and its embedding. The temperature of the equivalent network is eta/2 times the physical temperature of the diode. The model is valid only if the series resistance and nonlinear capacitance of the diode are negligible. Expressions are derived for the input and output noise temperature and the noise-temperature ratio of ideal mixers. Some common beliefs concerning noise-figure and noise-temperature ratio are shown to be incorrect.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Microwave Theory and Techniques; MTT-27; Feb. 197
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  • 13
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    A matrix solution for the simulation of magnetic fields with ideal current loops (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: A matrix formulation is presented for describing axisymmetric magnetic field data with ideal current loops. A computer program written in APL is used to invert the matrix and hence to solve for the coil strengths which are used to represent the field data. Examples are given of the coil representation for (1) measured magnetic data, (2) refocusing fields, and (3) PPM focusing fields.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Oct. 197
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  • 14
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    Thermionic cathode life-test studies (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: A NASA-Lewis Research Center program for life testing commercial, high-current-density thermionic cathodes has been in progress since 1971. The purpose of the program is to develop long-life power microwave tubes for space communications. Four commercial-type cathodes are being evaluated in this investigation. They are the 'Tungstate', 'S' type, 'B' type, and 'M' type cathodes, all of which are capable of delivering 1 A/ sq cm or more of emission current at an operating temperature in the range of 1000-1100 C. The life test vehicles used in these studies are similar in construction to that of a high-power microwave tube and employ a high-convergence electron-gun structure; in contrast to earlier studies that used close-space diodes. These guns were designed for operation at 2 A/sq cm of cathode loading. The 'Tungstate' cathodes failed at 700 h or less and the 'S' cathode exhibited a lifetime of about 20,000 h. One 'B' cathode has failed after 27,000 h, the remaining units continuing to operate after up to 30,000 h. Only limited data are now available for the 'M' cathode, because only one has been operated for as long as 19,000 h. However, the preliminary results indicate the emission current from the 'M' cathode is more stable than the 'B' cathode and that it can be operated at a true temperature approximately 100 C lower than for the 'B' cathode.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Oct. 197
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  • 15
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    Analysis of the interaction of an electron beam with a solar cell. III - The effect of spacial variations of the number density of recombination centers on SEM measurements (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: By means of an exactly soluble model the short circuit current generated by a scanning electron microscope in a P-N junction has been determined in cases where the trap density is inhomogeneous. The diffusion length for minority carriers becomes then dependent on the spacial coordinates. It is shown that in this case the dependence of the Isc on characteristic parameters as cell thickness, distance of the beam excitation spot from ohmic contacts, etc., becomes very intricate. This fact precludes the determination of the local diffusion length in the usual manner. Although the model is somewhat simplified in order to make it amenable to exact solutions, it is nevertheless realistic enough to lead to the conclusion that SEM measurements of bulk transport parameters in inhomogeneous semiconductor material are impractical since they may lead to serious errors in the interpretation of the data by customary means.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Solid-State Electronics; 22; Sept
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  • 16
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    Analytical prediction and experimental verification of TWT and depressed collector performance using multidimensional computer programs (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Oct. 197
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  • 17
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    90- to 93-percent efficient collector for operation of a dual-mode traveling-wave tube in the linear region (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: An axisymmetric multistage depressed collector was evaluated in conjunction with a dual-mode TWT. Collector performance optimizations for the TWT operation in the linear range were stressed. Measured collector efficiencies in excess of 90 percent led to dramatic improvements in TWT overall efficiency.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Oct. 197
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  • 18
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    Efficiency enhancement of coupled-cavity TWT's through cavity resonance tapering (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The paper examines efficiency enhancement of coupled-cavity traveling-wave tube (TWT) through cavity resonance tapering. Beam-wave resynchronization through circuit velocity reduction is used for TWT efficiency enhancement, with circuit velocity reduction in coupled cavity TWT's accomplished through period tapering. However, the amount of the latter is limited by the stability considerations, so that beyond a critical value of velocity reduction, the tube may be subject to zero drive oscillations originating in the velocity taper region. The coupled-cavity resonance tapering allows the velocity reduction to continue beyond the limit of stable period tapering, and it is accomplished by a gradual reduction in the cavity resonance frequency, with the period and the circuit bandwidth unchanged. The advantages of cavity resonance tapering vs period tapering are discussed, and test data are presented with the results of large-signal computer calculations. It is shown that cavity resonance tapering can produce efficiencies as period tapering without incurring the same risk of lower band-edge oscillations.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Oct. 197
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  • 19
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    Two-dimensional representations of axisymmetric fields for computer calculations (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: An accurate representation of axisymmetric fields has been devised by extending the method of ideal current loops to off-axis fields. It is assumed that the data to be simulated are available through measurements or through a solution of a boundary value problem. The method provides an algebraic expression for the fields throughout a two-dimensional region of interest and eliminates the need for the axial expansion formula in approximating off-axis fields. The use of Gaussian and other functions as alternatives to the coil function is proposed. Examples of the technique in simulating a periodic permanent magnet (PPM) focusing field are presented and compared with a Fourier analysis of the problem.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Nov. 197
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  • 20
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    Annual Conference on Nuclear and Space Radiation Effects, 16th, Santa Cruz, Calif., July 17-20, 1979, Proceedings (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Papers are presented on the following topics: radiation effects in bipolar microcircuits; basic radiation mechanisms in materials and devices; energy deposition and dosimetry; and system responses from SGEMP, IEMP, and EMP. Also considered are basic processes in SGEMP and IEMP, radiation effects in MOS microcircuits, and space radiation effects and spacecraft charging.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 21
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    Noise and loss in balanced and subharmonically pumped mixers. I - Theory. II - Application (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The theory of noise and frequency conversion for two-diode balanced and subharmonically pumped mixers is presented. The analysis is based on the equivalent circuit of the Schottky diode, having nonlinear capacitance, series resistance, and shot and thermal noise. Expressions for the conversion loss, noise temperature, and input and output impedances are determined in a form suitable for numerical analysis. In Part II, the application of the theory to practical mixers is demonstrated, and the properties of some two-diode mixers are examined. The subharmonically pumped mixer is found to be much more strongly affected by the loop inductance than the balanced mixer, and the ideal two-diode mixer using exponential diodes has a multiport noise-equivalent network (attenuator) similar to that of the ideal single-diode mixer. It is concluded that the theory can be extended to mixers with more than two diodes and will be useful for their design and analysis, provided a suitable nonlinear analysis is available to determine the diode waveforms.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 22
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    Extension of a theorem used in the investigation of P-N junctions with the scanning electron microscope to arbitrary geometries and arbitrarily inhomogeneous material (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters; 35; Sept. 1
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  • 23
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    A note on photocurrents in extrinsic semiconductors (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The advent of the concept of holes and careful determination of mobilities have made it possible to realize that the potential difference between the contacts of an irradiated semiconductor in the absence of current flow is due to the difference in mobility of electrons and holes. In this paper, a preliminary analysis shows that charge neutrality and zero-current condition are compatible. This situation is clarified and it is found that the equation for the electric field E in the absence of current is not absolutely correct even under low-level injection conditions. In particular, it is shown that fairly large currents can be generated by suitable light sources, currents which are entirely due to the disparity between electron and hole mobilities.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Solid-State Electronics; 22; Mar. 197
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  • 24
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    Comments on measuring the overall and the depressed collector efficiency in TWT's and klystron amplifiers (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Kosmahl and Ramins (1977), who reported results achieved with broadband, high-performance TWT's, augmented with multistage depressed collectors for higher overall efficiency, have pointed out the necessity for accurately measuring and correctly defining the various power terms involved. In view of the now wide-spread use of depressed collectors and reported results, the definitions of tube and collector efficiency are restated and comments are provided on the sensitivity of these terms to various sources of experimental and definitional errors in order to permit a uniform evaluation of collector performance.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Feb. 197
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  • 25
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    On the determination of diffusion lengths by means of angle-lapped p-n junctions (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: A standard procedure for determining the minority carrier diffusion length by means of SEM consists of scanning an angle-lapped surface of a p-n junction and measuring the resulting short circuit current as a function of beam position. The present paper points out that the usual expression linking the short circuit current induced by the electron beam to the angle between the semiconductor surface and the junction plane is incorrect. The correct expression is discussed and it is noted that, for angles less than 10 deg, the new and the old expression are practically indistinguishable.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Solid-State Electronics; 22; Jan. 197
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  • 26
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    Space Shuttle communications RF switch matrix (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The Shuttle Orbiter communications equipment includes phase modulation (PM) and frequency modulation (FM) channels. The PM section has the capability of routing high levels of energy (175 W) from any one of four transmitters to any one of four antennas, mutually exclusive. The FM channel uses a maximum of 15-W power routed from either of two transmitters to one of two antennas, mutually exclusive. The paper describes the design and the theory of a logic-controlled RF switch matrix devised for the purposes cited. Both PM and FM channels are computer-controlled with manual overrides. The logic interface is realized with CMOS logic for low power consumption and high noise immunity. The interior of the switch matrix is maintained at a pressure of 15 psi (90% nitrogen, 10% helium) by an electron beam-welded encapsulation. The computational results confirm the viability of the RF switch matrix concept.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Microwave Journal; 22; Jan. 197
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  • 27
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    Comment on the mechanism of operation of the impregnated tungsten cathode (1979)
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    Publication Date: 2011-08-17
    Description: Recent life-test measurements, over 20,000-30,000 h, on impregnated tungsten cathodes in tubes employing an open-type electron-gun structure, show emission current degradation with time. This is in contrast to those recently published by Rittner on B-type cathodes, run in close-spaced diodes, taken some years ago. These more recent life-test results are consistent with the model suggested by Forman and disputed by Rittner that the barium coverage on an impregnated cathode is less than a monolayer for most of its life and decreases with time.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics; 50; Mar. 197
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  • 28
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    Internal stress and degradation in short-wavelength AlGaAs double-heterojunction devices (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Aging tests of incoherently operated zinc-doped double-heterojunction (DH) lasers designed for short-wavelength (0.71-0.72 micron) operation show that the introduction of buffer layers between the substrate and the DH structure leads to a drastic reduction in gradual degradation. This is attributed to a decrease in lattice mismatch stress.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electronics Letters; 15; June 7
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  • 29
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    Radiation hardened PMOS process with ion implanted threshold adjust (1979)
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    Publication Date: 2011-08-17
    Description: By including specific process modifications the effect of ion implantation on radiation hardness can be minimized and radiation hard ion implanted MOS circuits can be fabricated. The experimental procedure followed was to examine key processing steps (with respect to radiation hardness) on ion-implanted individual PMOS transistors. The individual transistors were evaluated by continuously monitoring the threshold voltage as the transistors were being irradiated. By comparing runs it was possible to deduce what is considered a radiation hard ion implanted process. Tests with a complex LSI PMOS IC processor chip containing over 2000 transistors and resistors were also conducted
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  • 30
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    Internal noise of a phase-locked receiver with a loop-controlled synthesizer (1979)
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    Publication Date: 2011-08-17
    Description: A local oscillator design that uses a digitally programmed frequency synthesizer instead of an analog VCO was proposed. The integral of the synthesizer input, the digital phase, is a convenient measure of integrated Doppler. The internal noise of such a receiver was examined. At high carrier margin, the local oscillator phase noise equals that of the Block IV receiver, about 2 deg rms at S-band, whereas the digital phase noise is about 0.5 deg rms.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Deep Space Network; p 41-50
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  • 31
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    Gyrotron: A high-frequency microwave amplifier (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A proposed microwave amplifier mechanism for future generations of millimeter high power uplinks to spacecraft and planetary radar transmitters is introduced. Basic electron-electromagnetic field interaction theory for RF power gain is explained. The starting point for general analytical methods leading to detailed design results is presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Deep Space Network; p 8-12
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  • 32
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    Automatic filament warm-up controller (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: As part of the unattended operations objective of the Deep Space Network deep space stations, this filament controller serves as a step between manual operation of the station and complete computer control. Formerly, the operator was required to devote five to fifteen minutes of his time just to properly warm up the filaments on the klystrons of the high power transmitters. The filament controller reduces the operator's duty to a one-step command and is future-compatible with various forms of computer control.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Deep Space Network; p 132-133
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  • 33
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    Development program on a cold cathode electron gun (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A prototype electron gun with a field emitter cathode capable of producing 95 mA in a 1/4 mm diameter beam at 12 kV was produced. Achievement of this goal required supporting studies in cathode fabrication, cathode performance, gun design, cathode mounting and gun fabrication. A series of empirical investigations advanced fabrication technology: More stable emitters were produced and multiple cone failure caused by chain reaction discharges were reduced. The cathode is capable of producing well over 95 mA, but a substantial collector development effort was required to demonstrate emission levels in the 100 mA region. Space charge problems made these levels difficult to achieve. Recommendations are made for future process and materials investigation. Electron gun designs were modeled and tested. A pair of two-electrode gun structures were fabricated and tested; one gun was delivered to NASA. Cathodes were pretested up to 100 mA at SRI and delivered to NASA for test in the gun structure.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-159570 , SRI-5413
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  • 34
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    The 2.2 GHz Surface Acoustic Wave (SAW) oscillator development Ku-band frequency source development (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Two 2.2 GHz SAW oscillators using aluminum nitride on sapphire (AlN/Al2O3) delay lines were fabricated. The oscillators were electronically temperature compensated and characterized. One of the oscillators was used as the frequency reference for the Ku band source; the second oscillator is available for continued evaluation. A 15 GHz frequency source was designed and fabricated. The 15 GHz source consists of a Ku band FET oscillator which is phase locked to the frequency multiplied (X7) output of the 2.2 GHz SAW reference source. The Ku band source was built using microstrip circuit designs, which are hybrid compatible. Two wafer runs of 2.2 GHz TED devices were fabricated and evaluated. The devices were mounted on microstrip test substrates and evaluated as 15 GHz divide by 7 circuits. The device evaluation indicated that in their present form the TED is not a practical circuit element.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-160080
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  • 35
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    Standard Transistor Array (STAR). Volume 2, addendum 1: SIMLOG/TESTGN user's guide (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A brief introduction to the SIMLOG/TESTGN system of programs is given. Detailed instructions on how to use the system are also included. SIMLOG is a logic simulation program. TESTGN is a test pattern generation program.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-161295
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  • 36
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    Standard Transistor Array (STAR). Volume 2: Test pattern generation (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Testing of large scale integrated logic circuits is considered from the point-of-view of automatic test pattern generation. A logic simulator based approach for automatic test pattern generation is taken and is described. The logic model and the timing model used in the simulator are also described. Two methods are presented for generating test patterns from the output of the simulator. Recommendations for future study are also presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-161294
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  • 37
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    Standard Transistor Array (STAR). Volume 1, addendum 2: CAPSTAR programmer's guide (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Instructions are given for updating and maintaining the cell arrangement program for the standard transistor array (CAPSTAR).
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-161292
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  • 38
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    Standard Transistor Array (STAR). Volume 1, addendum 1: CAPSTAR user's guide (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The cell placement techniques developed for use with the standard transistor array were incorporated in the cell arrangement program for STAR (CAPSTAR). Instructions for use of this program are given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-161291
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  • 39
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    Standard Transistor Array (STAR). Volume 1: Placement technique (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A large scale integration (LSI) technology, the standard transistor array uses a prefabricated understructure of transistors and a comprehensive library of digital logic cells to allow efficient fabrication of semicustom digital LSI circuits. The cell placement technique for this technology involves formation of a one dimensional cell layout and "folding" of the one dimensional placement onto the chip. It was found that, by use of various folding methods, high quality chip layouts can be achieved. Methods developed to measure of the "goodness" of the generated placements include efficient means for estimating channel usage requirements and for via counting. The placement and rating techniques were incorporated into a placement program (CAPSTAR). By means of repetitive use of the folding methods and simple placement improvement strategies, this program provides near optimum placements in a reasonable amount of time. The program was tested on several typical LSI circuits to provide performance comparisons both with respect to input parameters and with respect to the performance of other placement techniques. The results of this testing indicate that near optimum placements can be achieved by use of the procedures incurring severe time penalties.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-161289
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  • 40
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    The MSFC complementary metal oxide semiconductor (including multilevel interconnect metallization) process handbook (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The fabrication techniques for creation of complementary metal oxide semiconductor integrated circuits at George C. Marshall Space Flight Center are described. Examples of C-MOS integrated circuits manufactured at MSFC are presented with functional descriptions of each. Typical electrical characteristics of both p-channel metal oxide semiconductor and n-channel metal oxide semiconductor discrete devices under given conditions are provided. Procedures design, mask making, packaging, and testing are included.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-78188 , M-262
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  • 41
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    Thermally grown oxide and diffusions for automatic processing of integrated circuits (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A totally automated facility for semiconductor oxidation and diffusion was developed using a state-of-the-art diffusion furnace and high temperature grown oxides. Major innovations include: (1) a process controller specifically for semiconductor processing; (2) an automatic loading system to accept wafers from an air track, insert them into a quartz carrier and then place the carrier on a paddle for insertion into the furnace; (3) automatic unloading of the wafers back onto the air track, and (4) boron diffusion using diborane with plus or minus 5 percent uniformity. Processes demonstrated include Wet and dry oxidation for general use and for gate oxide, boron diffusion, phosphorous diffusion, and sintering.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-78247
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  • 42
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    Interleaving device (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: An interleaving device for processing energy signals between various logic devices has a first number of spaced energy carrying layer mateials. Each of the first layer materials has a number of juxtaposed conduits passing energy signals through which are passed. Each of the conduits has a longitudinal axis substantially parallel to a diagonal of each of the first layers. A second group of energy carrying materials is arranged between adjacent ones of the spaced first layer materials. Each of the second layer materials has a number of juxtaposed conduits through which the energy signals are also passed. Each of the conduits in the second layer has a longitudinal axis substantially parallel to a diagonal of each of the second layer materials and substantially perpendicular to the axes of the conduits of the first layer materials.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 43
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    A 4-W 56-dB gain microstrip amplifier at 15 GHz utilizing GaAs FET's and IMPATT diodes (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Performance results and design considerations are presented for an all solid-state Ku-band power amplifier which is feasible for use in PM communication systems for airborne or spacecraft transmitter applications. A six-stage GaAs FET preamplifier and a driver and balanced power amplifier utilizing GaAs IMPATT diodes operating in the injection locked oscillator mode are discussed. For high power and efficiency Schottky-Read IMPATT's with low-high-low doping profiles are employed. For improved reliability the IMPATT's incorporate a TiW barrier metallization to retard degradation of the IMPATT's. Results of accelerated life testing of the IMPATT devices are also presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 44
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    Prediction of field-time-dependent gate-oxide breakdown in MOS devices (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: The model for field-time-dependent breakdown in the gate oxide of MOS devices is extended and verified with experimental data. The model permits accelerated tests at high fields which can be used to predict gate-oxide breakdowns at much longer times at normal operating fields.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Solid-State Electronics; 22; Nov. 197
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  • 45
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    Space applications of superconductivity - High field magnets (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: The paper discusses developments in superconducting magnets and their applications in space technology. Superconducting magnets are characterized by high fields (to 15T and higher) and high current densities combined with low mass and small size. The superconducting materials and coil design are being improved and new high-strength composites are being used for magnet structural components. Such problems as maintaining low cooling temperatures (near 4 K) for long periods of time and degradation of existing high-field superconductors at low strain levels can be remedied by research and engineering. Some of the proposed space applications of superconducting magnets include: cosmic ray analysis with magnetic spectrometers, energy storage and conversion, energy generation by magnetohydrodynamic and thermonuclear fusion techniques, and propulsion. Several operational superconducting magnet systems are detailed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Cryogenics; 19; Dec. 197
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  • 46
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    Distributed effect in GaAs MESFET (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: In order to obtain higher output power, the width of a single cell MESFET must be large. When it becomes too large the distributed effect along the width direction tends to limit the output power. It is found that the distributed effect is important when the gate width not less than 150 microns and that the gain decreases with gate width. Also found is that spurious oscillations occur due to line resonances at much higher frequencies than can be accounted for by the instability factor in the discrete device model.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Solid-State Electronics; 22; Dec. 197
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  • 47
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    Cosmic ray-induced soft errors in static MOS memory cells (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Previous analytical models were extended to predict cosmic ray-induced soft error rates in static MOS memory devices. The effect is due to ionization and can be introduced by high energy, heavy ion components of the galactic environment. The results indicate that the sensitivity of memory cells is directly related to the density of the particular MOS technology which determines the node capacitance values. Hence, CMOS is less sensitive than e.g., PMOS. In addition, static MOS memory cells are less sensitive than dynamic ones due to differences in the mechanisms of storing bits. The flip-flop of a static cell is inherently stable against cosmic ray-induced bit flips. Predicted error rates on a CMOS RAM and a PMOS shift register are in general agreement with previous spacecraft flight data.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 48
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    Simulation of cosmic-ray induced soft errors and latchup in integrated-circuit computer memories (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Soft errors have been induced in solid-state static RAM's by iron nuclei from the Lawrence Berkeley Laboratory (LBL) Bevalac, in experiments designed to prove the ability of iron-group cosmic rays to generate such errors. Subsequently, various delidded device types were tested in beams of argon and krypton ions from the LBL 88-inch Cyclotron, at energies near 2 MeV/nucleon. The latter tests showed that some devices are essentially immune to bit error while others are quite susceptible. Good agreement was obtained with model predictions in cases where the latter exist. Latchup, whose cause is attributed to individual heavy ions, was also observed in some device types.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 49
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    Modelling switching-time effects in high-frequency power conditioning networks (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Power transistor networks which switch large currents in highly inductive environments are beginning to find application in the hundred kilohertz switching frequency range. Recent developments in the fabrication of metal-oxide-semiconductor field-effect transistors in the power device category have enhanced the movement toward higher switching frequencies. Models for switching devices and of the circuits in which they are imbedded are required to properly characterize the mechanisms responsible for turning on and turning off effects. Easily interpreted results in the form of oscilloscope-like plots assist in understanding the effects of parametric studies using topology oriented computer-aided analysis methods.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: ESA SPACECAD 1979: Computer-Aided Design of Electron. for Space Appl.; p 325-337
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  • 50
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    An investigation of thermal resistance in single- and multiple-cell GaAs MESFETs (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Thermal resistances among FETs of a variable number of gates in parallel are compared. Although the thermal resistance per cell for multiple cells is higher, the total thermal resistance is still low because all the cells are parallel to one another. This implies that the multiple-cell structure is capable of dissipating more power than the single-cell structure and therefore of being used as a power FET.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: International Journal of Electronics; 47; Aug. 197
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  • 51
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    High power thyristors with 5 kV blocking voltage. Volume 1: Development of high-voltage-thyristors (4.5 kV) with good dynamic properties (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Using neutron irradiated silicon with considerably lower spread in resistivity as compared to conventionally doped silicon it was possible to produce power thyristors with breakdown voltages between 3.5 kV and 5.5 kV. The thyristor pellets have a diameter of 50 mm. Maximum average on-state currents of 600 to 800 A can be reached with these elements. The dynamic properties of the thryistors could be improved to allow standard applications up to maximum repetitive voltages of 4.5 kV.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-75449 , BMFT-FB-T-77-22
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  • 52
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    Equivalent statistical bandwidths of conventional low-pass filters (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Values of the equivalent statistical bandwidths of Butterworth up to ten poles and Chebyshev up to eight poles low-pass filters for six different passband ripple levels have been computed and tabulated along with the corresponding noise bandwidths. The results obtained can be used for estimating the mean-square error resulting from power spectrum measurements employed in the sensitivity analysis of microwave radiometer systems.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Communications; COM-27; Oct. 197
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  • 53
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    Magnetic suspension system for an Annular Momentum Control Device (AMCD) (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A technique to control a rim suspended in a magnetic field was developed. A complete system was developed, incorporating a support structure, magnetic actuators, a rim drive mechanism, an emergency fail-safe system, servo control system, and control electronics. Open loop and closed loop response of the system at zero speed and at 500 revolutions per minute (r/min) of the rim was obtained and analyzed. The rim was then dynamically balanced and a rim speed of 725 r/min was achieved. An analog simulation of the hardware was developed and tested with the actual control electronics connected to the analog computer. The system under development is stable at rim speeds below 700 r/min. Test results indicate that the rim under test is not rigid. The rim has a warp and a number of binding modes which prevented achievement of higher speeds. Further development efforts are required to achieve higher rim speeds.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-159255
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  • 54
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    Numerical simulation of dynamics of brushless dc motors for aerospace and other applications. Volume 2: User's guide to computer EMA model (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A description and user's guide of the computer program developed to simulate the dynamics of an electromechanical actuator for aerospace applications are presented. The effects of the stator phase currents on the permanent magnets of the rotor are examined. The voltage and current waveforms present in the power conditioner network during the motoring, regenerative braking, and plugging modes of operation are presented and discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-160356
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  • 55
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    Numerical simulation of dynamics of brushless dc motors for aerospace and other applications. Volume 1: Model development and applications, part B (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A mathematical model was developed and computerized simulations were obtained for a brushless dc motor. Experimentally obtained oscillograms of the machine phase currents are presented and the corresponding current and voltage waveforms for various modes of operation of the motor are presented and discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-160355
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  • 56
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    Method for analyzing radiation sensitivity of integrated circuits (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: A method for analyzing the radiation sensitivity of an integrated circuit is described to determine the components. The application of a narrow radiation beam to portions of the circuit is considered. The circuit is operated under normal bias conditions during the application of radiation in a dosage that is likely to cause malfunction of at least some transistors, while the circuit is monitored for failure of the irradiated transistor. When a radiation sensitive transistor is found, then the radiation beam is further narrowed and, using a fresh integrated circuit, a very narrow beam is applied to different parts of the transistor, such as its junctions, to locate the points of greatest sensitivity.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 57
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    Performance of 22.4-kW nonlaminated-frame dc series motor with chopper controller (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Performance data obtained through experimental testing of a 22.4 kW traction motor using two types of excitation are presented. Ripple free dc from a motor-generator set for baseline data and pulse width modulated dc as supplied by a battery pack and chopper controller were used for excitation. For the same average values of input voltage and current, the motor power output was independent of the type of excitation. However, at the same speeds, the motor efficiency at low power output (corresponding to low duty cycle of the controller) was 5 to 10 percentage points lower on chopped dc than on ripple free dc. The chopped dc locked-rotor torque was approximately 1 to 3 percent greater than the ripple free dc torque for the same average current.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-79252 , DOE/NASA/1044-79/4 , E-163
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  • 58
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    Shuttle GPS R/PA configuration and specification study (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Changes in the technical specifications for a global positioning system (GPS) receiving system dedicated to space shuttle use are presented. Various hardware functions including acquisition, tracking, and measurement are emphasized. The anti-jam performance of the baseline GPS systems are evaluated. Other topics addressed include: the impact on R/PA design of the use of ground based transmitters; problems involved with the use of single channel tests sets; utility of various R/PA antenna interconnections topologies; the choice of the averaging interval for delta range measurements; and the use of interferometry techniques for the computation of orbiter attitude were undertaken.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-160396 , TR-1080-1779
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  • 59
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    An introduction to the BANNING design automation system for shuttle microelectronic hardware development (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The BANNING MOS design system is presented. It complements rather than supplant the normal design activities associated with the design and fabrication of low-power digital electronic equipment. BANNING is user-oriented and requires no programming experience to use effectively. It provides the user a simulation capability to aid in his circuit design and it eliminates most of the manual operations involved in the layout and artwork generation of integrated circuits. An example of its operation is given and some additional background reading is provided.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-80831 , MSC-06779
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  • 60
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    Contamination control in hybrid microcircuit modules (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The influence of chemical and particulate contamination upon the reliability and service life of hybrid microelectronic systems is documented. Several coating systems used include the parylene and Dow Corning silicone (DC90-711). These passivating coatings have potential for decreasing the degradation caused by particulate contaminants in hybrid systems as well as the possible deleterious effect of trapping chemical contaminants which have long term degrading influences upon the performance of the system. The reliability of a representative hybrid microcircuit is enhanced by the coating process.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-161778
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  • 61
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    Analysis of a parallel-arrayed power regulating system (1979)
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    Publication Date: 2019-06-27
    Description: A power regulation system incorporating n-parallel power supplies employing PWM switching regulators is studied. Analysis of individual unit operation and coupled-system parameter sensitivity is considered from an operations viewpoint. A detailed example is included to illustrate parallel system operation for 18 such units powered by solar-cell banks.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Industrial Electronics and Control Instrumentation; IECI-26; Aug. 197
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  • 62
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    III-V alloy heterostructure high speed avalanche photodiodes (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Heterostructure avalanche photodiodes have been successfully fabricated in several III-V alloy systems: GaAlAs/GaAs, GaAlSb/GaAlSb, and InGaAsP/InP. These diodes cover optical wavelengths from 0.4 to 1.8 micron. Early stages of development show very encouraging results. High speed response of less than 35 ps and high quantum efficiency more than 95 percent have been obtained. The dark currents and the excess avalanche noise are also dicussed. A direct comparison of GaAlSb, GaAlAsSb, and In GaAsP avalanche photodiodes is given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Journal of Quantum Electronics; QE-15; July 197
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  • 63
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    Transport of majority and minority carriers in 2-micron-diameter Pt-GaAs Schottky barriers (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: An experimental study of small area (2-micron diameter) Pt-GaAs Schottky barrier diodes has been made, by using a wafer chip with a matrix of these diodes lying within approximately a minority carrier diffusion length of one another. Using one diode as collector and another as emitter, transistor measurements indicated that the dominant contribution to the current is the majority-carrier thermionic field emission current for large forward-bias voltage of the emitter junction (V-EB no less than about 0.4 V), whereas the smaller forward-bias (V-EB no greater than about 0.4 V) recombination in the space-charge region was most important. The minority carrier injection ratio is measurable only for large forward-bias voltages, decreasing from about 0.02 to 0.00001 as VEB increases from 0.5 to 1.0 V. The minority carrier diffusion length was measured to be about 1.3 microns. These results are of considerable significance for the understanding and optimization of the performance of these devices as classical detectors and mixers.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; Mar. 197
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    Heavily doped transparent-emitter regions in junction solar cells, diodes, and transistors (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: The paper presents an analytical treatment of transparent-emitter devices, particularly solar cells, that is more complete than previously available treatments. The proposed approach includes the effects of bandgap narrowing, Fermi-Dirac statistics, built-in field due to impurity profile, and a finite surface recombination velocity at the emitter surface. It is demonstrated that the transparent-emitter model can predict experimental values of Voc observed on n(plus)-p thin diffused junction silicon solar cells made on low-resistivity (0.1 ohm-cm) substrates. A test is included for the self-consistent validity of the transparent-emitter model. This test compares the calculated transit time of minority carriers across the emitter with the Auger-impact minority-carrier lifetime within the emitter region.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices; ED-26; June 197
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    Power combining in an array of microwave power rectifiers (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: This work analyzes the resultant efficiency degradation when identical rectifiers operate at different RF power levels as caused by the power beam taper. Both a closed-form analytical circuit model and a detailed computer-simulation model are used to obtain the output dc load line of the rectifier. The efficiency degradation is nearly identical with series and parallel combining, and the closed-form analytical model provides results which are similar to the detailed computer-simulation model.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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    On the Performance of the Martin Digital Filter for High- and Low-pass Applications (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: A nonrecursive numerical filter is described in which the weighting sequence is optimized by minimizing the excursion from the ideal rectangular filter in a least squares sense over the entire domain of normalized frequency. Additional corrections to the weights in order to reduce overshoot oscillations (Gibbs phenomenon) and to insure unity gain at zero frequency for the low pass filter are incorporated. The filter is characterized by a zero phase shift for all frequencies (due to a symmetric weighting sequence), a finite memory and stability, and it may readily be transformed to a high pass filter. Equations for the filter weights and the frequency response function are presented, and applications to high and low pass filtering are examined. A discussion of optimization of high pass filter parameters for a rather stringent response requirement is given in an application to the removal of aircraft low frequency oscillations superimposed on remotely sensed ocean surface profiles. Several frequency response functions are displayed, both in normalized frequency space and in period space. A comparison of the performance of the Martin filter with some other commonly used low pass digital filters is provided in an application to oceanographic data.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-80593
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    A user oriented computer program for the analysis of microwave mixers, and a study of the effects of the series inductance and diode capacitance on the performance of some simple mixers (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: A user oriented computer program for analyzing microwave and millimeter wave mixers with a single Schottky barrier diode of known I-V and C-V characteristics is described. The program first performs a nonlinear analysis to determine the diode conductance and capacitance waveforms produced by the local oscillator. A small signal linear analysis is then used to find the conversion loss, port impedances, and input noise temperature of the mixer. Thermal noise from the series resistance of the diode and shot noise from the periodically pumped current in the diode conductance are considered. The effects of the series inductance and diode capacitance on the performance of some simple mixer circuits using a conventional Schottky diode, a Schottky diode in which there is no capacitance variation, and a Mott diode are studied. It is shown that the parametric effects of the voltage dependent capacitance of a conventional Schottky diode may be either detrimental or beneficial depending on the diode and circuit parameters.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-80324
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    Space shuttle active-pogo-suppressor control design using linear quadratic regulator techniques (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: Two methods of active pogo suppression (stabilization) for the space shuttle vehicle were studied analytically. The basis for both approaches was the linear quadratic regulator, state space technique. The first approach minimized root-mean-square pump inlet pressure by using either fullstate feedback, partial-state feedback, or output feedback with a Kalman filter. The second approach increased the modal damping associated with the critical structural modes by using either full-state feedback or reconstructed state feedback. A number of implementable controls were found by both approaches. The designs were analyzed with respect to sensitivity, complexity, and controller energy requirements, as well as controller performance. Practical controllers resulting from the two design approaches tended to use pressure and flow as feedback variables for the minimum-rms method and structural accelerations or velocities for the modal control method. Both approaches are suitable for the design of active pogo-suppression controllers.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TP-1217 , E-9578
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    Preliminary study, analysis and design for a power switch for digital engine actuators (1979)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: Innovative control configurations using high temperature switches to operate actuator driving solenoids were studied. The impact on engine control system life cycle costs and reliability of electronic control and (ECU) heat dissipation due to power conditioning and interface drivers were addressed. Various power supply and actuation schemes were investigated, including optical signal transmission and electronics on the actuator, engine driven alternator, and inside the ECU. The use of a switching shunt power conditioner results in the most significant decrease in heat dissipation within the ECU. No overall control system reliability improvement is projected by the use of remote high temperature switches for solenoid drivers.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-159559 , NAS 1.26:159559 , PWA-5643-6
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    Design of high-perveance confined-flow guns for periodic-permanent-magnet-focused tubes (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: An approach to the design of high perveance, low compression guns is described in which confinement is used to stabilize the beam for subsequent periodic-permanent-magnet focusing. The computed results for two cases are presented. A magnetic boundary value problem was solved for the scalar potential from which the axial magnetic field was computed. A solution was found by iterating between Poisson's equation and the electron trajectory calculations. Magnetic field values were varied in magnitude until a laminar beam with minimum scalloping was produced.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TP-1485 , E-9729
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    A dc model for power switching transistors suitable for computer-aided design and analysis (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: A model for bipolar junction power switching transistors whose parameters can be readily obtained by the circuit design engineer, and which can be conveniently incorporated into standard computer-based circuit analysis programs is presented. This formulation results from measurements which may be made with standard laboratory equipment. Measurement procedures, as well as a comparison between actual and computed results, are presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-158764
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    Efficiency enhancement of octave-bandwidth traveling wave tubes by use of multistage depressed collectors (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Small, three- and five-stage depressed collectors were evaluated in conjunction with a 4.8- to 9.6-GHz TWT of 325- to 675-W power output and a beam of 0.5 microperv. The multistage depressed collector (MDC) performed well even though its design had been optimized for a TWT of identical design but considerably less output power. Despite large, fixed losses significant efficiency enhancement was demonstrated with both the three- and five-stage depressed collectors. At saturated rf power output, the improvement in the overall efficiency ranged from a factor of 2.5 to 3.0 for the three-stage collector and a factor of 3.0 to 3.5 for the five-stage collector. At saturation three-stage collector efficiencies of 77 to 80 percent and five-stage collector efficiencies of 81 to 84 percent were obtained across the frequency band. An overall efficiency of 37.0 to 44.3 percent across the frequency band of 4.8 to 9.6 GHz was demonstrated with the use of harmonic injection. For operation below saturation, even larger relative improvements in the overall TWT efficiency were demonstrated. Collector performance was relatively insensitive to the degree of regulation of the collector power supply.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TP-1416 , E-9749
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    Switching transients in high-frequency high-power converters using power MOSFET's (1979)
    In:  Other Sources
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    Publication Date: 2019-07-13
    Description: The use of MOSFETs in a high-frequency high-power dc-to-dc converter is investigated. Consideration is given to the phenomena associated with the paralleling of MOSFETs and to the effect of stray circuit inductances on the converter circuit performance. Analytical relationships between various time constants during the turning-on and turning-off intervals are derived which provide estimates of plateau and peak levels during these intervals.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: PESC ''79; Jun 18, 1979 - Jun 22, 1979; San Diego, CA
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    Ku-band field-effect power transistors (1979)
    In:  CASI
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    Publication Date: 2019-07-13
    Description: A single stage amplifier was developed using an 8 gate, 1200 micrometer width device to give a gain of 3.3 + or - 0.1 dB over the 14.4 to 15.4 GHz band with an output power of 0.48 W and 15% minimum efficiency with 0.255 W of input power. With two 8 gate devices combined and matched on the device carrier, using a lumped element format, a gain of 3 dB was attained over the 14.5 to 15.5 GHz band with a maximum efficiency of 9.9% for an output power of 0.8 W.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-160010 , PRRL-79-CR-39
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    TWT design requirements for 30/20 GHz digital communications' satellite (1979)
    In:  CASI
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    Publication Date: 2019-07-13
    Description: The rapid growth of communication traffic (voice, data, and video) requires the development of additional frequency bands before the 1990's. The frequencies currently in use for satellite communications at 6/4 GHz are crowded and demands for 14/12 GHz systems are increasing. Projections are that these bands will be filled to capacity by the late 1980's. The next higher frequency band allocated for satellite communications is at 30/20 GHz. For interrelated reasons of efficiency, power level, and system reliability criteria, a candidate for the downlink amplifier in a 30/20 GHz communications' satellite is a dual mode traveling wave tube (TWT) equipped with a highly efficient depressed collector. A summary is given of the analyses which determine the TWT design requirements. The overall efficiency of such a tube is then inferred from a parametric study and from experimental data on multistaged depressed collectors. The expected TWT efficiency at 4 dB below output saturation is 24 percent in the high mode and 22 percent in the low mode.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-79119 , E-9952 , Aerospace Sci. Meeting; Jan 15, 1979 - Jan 17, 1979; New Orleans, LA; United States
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    Proceedings of the distribution automation and control working group. Volume 1: Executive summary (1979)
    In:  CASI
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    Publication Date: 2019-07-13
    Description: The meeting was sponsored by the Department of Energy, Division of Electric Energy Systems. Its purpose was to bring together some members of the electric utility community so that they might reach a common understanding on: (1) key issues and uncertainties to be resolved, (2) the existing state of the art, and (3) specific requirements for further RD&D in the area of DAC. The statements and recommendations formulated by the group on various topics are presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-158642 , JPL-PUB-79-35-VOL-1 , Nov 20, 1978 - Nov 22, 1978; Baltimore, MD; United States
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    Input filter design for switching regulators (1979)
    In:  Other Sources
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    Publication Date: 2019-07-13
    Description: A small signal average model is derived to study analytically the complex interaction among input filter, output filter and control loop, which frequently causes degradation of switch regulator performance. Analytically based design guidelines are formulated, and key design parameters are identified. It is shown that minimization of the forward transfer characteristics and the output impedance of the input filter at filter resonance are key to designing an input filter for a switching regulator with given output filter parameters and specified line and load conditions.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NAECON 1979; May 15, 1979 - May 17, 1979; Dayton, OH
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    Direct observation of voltage barriers in ZnO varistors (1979)
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    Publication Date: 2019-06-27
    Description: Voltage barriers in a ZnO varistor have been imaged by voltage-contrast scanning electron microscopy. They are due to grain boundaries and are capable of supporting voltage differences of up to about 4 V.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters; 34; June 1
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    A structure for digital notch filters (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Narrow-band digital notch filters have their poles near the unit circle. As the sampling rate is increased, the poles move towards Z = +1. Implementing such filters requires long registers to overcome the sensitivity and roundoff errors. A filter structure based on digital incremental computers is proposed which has low sensitivity and round-off errors, and simple hardware implementation. The filter structure can be directly used on differentially pulse-code modulated signals. Hardware multipliers are not required as the poles approach z = +1, and excellent results can be obtained using multipliers with very short word lengths, or with small size read-only memories.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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    Support of lightning analysis and testing on the Solid Rocket Booster (SRB) vehicle (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-161313 , AMRC-R-196
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    Modeling of switching regulator power stages with and without zero-inductor-current dwell time (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: State-space techniques are employed to derive accurate models for the three basic switching converter power stages: buck, boost, and buck/boost operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without dwell time as a special case of the discontinuous-current mode when the dwell time vanishes. Abrupt changes of system behavior, including a reduction of the system order when the dwell time appears, are shown both analytically and experimentally. Merits resulting from the present modeling technique in comparison with existing modeling techniques are illustrated.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Industrial Electronics and Control Instrumentation; IECI-26; Aug. 197
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    Velocity overshoot effect on a short-gate microwave MESFET (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: The device parameters of short-gate GaAs and InP FETs have been found to be dependent on the nonequilibrium velocity overshoot phenomenon. Both saturation velocity and critical field are found to be larger for shorter gates. The v-E characteristics of Pucel et al. (1975) are modified. The cutoff frequency and other parameters for GaAs, InP, and Si are given as a function of gate length and bias. The cutoff frequency of InP MESFETs with a doping density of 10 to the 17th per cu cm is only 20% higher than those of equivalent GaAs MESFETs at 300 K. Comparison with other work is also presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: International Journal of Electronics; 47; July 197
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  • 83
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    Solid-state X-band Combiner Study (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: The feasibility of developing solid-state amplifiers at 4 and 10 GHz for application in spacecraft altimeters was studied. Bipolar-transistor, field-effect-transistor, and Impatt-diode amplifier designs based on 1980 solid-state technology are investigated. Several output power levels of the pulsed, low-duty-factor amplifiers are considered at each frequency. Proposed transistor and diode amplifier designs are illustrated in block diagrams. Projections of size, weight, and primary power requirements are given for each design.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-162432
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    Numerical simulation of dynamics of brushless dc motors for aerospace and other applications. Volume 1: Model development and applications, part A (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: The development, fabrication and evaluation of a prototype electromechanical actuator (EMA) is discussed. Application of the EMA as a motor for control surfaces in aerospace flight is examined. A mathematical model of the EMA is developed for design optimization. Nonlinearities which complicate the mathematical model are discussed. The dynamics of the EMA from the underlying physical principles are determined and a discussion of similating the control logic by means of equivalent boolean expressions is presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-160349
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    The potential of carbon fiber induced shock hazards in household toasters (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: The average exposure to carbon fibers which produced a short and potential shock hazard in a household toaster was determined. Toasters are normally in the off state. They are used for brief periods during the day and have timed cycles during which power is applied. The possibility of a short occurring from the heating element to the case was investigated to find the exposure levels at which a potential shock hazard could appear. The short produced was tested to determine its importance.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-159147
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    Digital PSK to BiO-L demodulator for 2 sup nx(bit rate) carrier (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: A phase shift key (PSK) to BiO-L demodulator which uses standard digital integrated circuits is discussed. The demodulator produces NRZ-L, bit clock, and BiO-L outputs from digital PSK input signals for which the carrier is a 2 to the Nth multiple of the bit rate. Various bit and carrier rates which are accommodated by changing various component values within the demodulator are described. The use of the unit for sinusoidal inputs as well as digital inputs is discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-80159
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    State-of-the-art performance of GaAlAs/GaAs avalanche photodiodes (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Ga(0.15)Al(0.85)As/GaAs avalanche photodiodes have been successfully fabricated. The performance of these detectors is characterized by a rise time of less than 35 ps, an external quantum efficiency with an antireflection coating of 95% at 0.53 microns, and a microwave optical gain of 42 dB. The dark current density is in the low range (10 to the minus A/sq cm) at one-half the breakdown voltages, and rises to 0.0001 A/sq cm at 42 dB optical gain.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters; 35; July 15
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    Development and fabrication of low ON resistance high current vertical VMOS power FETs (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The design of a VMOS Power FET exhibiting low ON resistance, high current as well as high breakdown voltage and fast switching speeds is described. The design which is based on a 1st-order device model, features a novel polysilicon-gate structure and fieldplated groove termination to achieve high packing density and high breakdown voltage, respectively. One test chip, named VNTKI, can block 180 V at an ON resistence of 2.5 ohm. A 150 mil x 200 mil (.19 sq cm) experimental chip has demonstrated a breakdown voltage of 200v, an ON resistance of 0.12 ohm, a switching time of less than 100 ns, and a pulse drain - current of 50 A with 10 V gate drive.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-159646
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    On the minimization of spherical aberration in spherical reflector antennas (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: An expression for the phase error in the aperture plane of a spherical reflector was developed. The nature of this phase error over the aperture plane is discussed, and, to illustrate the usage of the expression, examples are given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-80140
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    Optically isolated logarithmic nanoammeter capable of floating to 5 kilovolts (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: A logarithmic current-measuring instrument was developed to measure plasma coupling currents at a common mode voltage of 5 kilovolts. Positive or negative currents can be measured from 10 to the -9th power to .001 ampere direct current. Optical isolation is used to control input switching and to provide data referenced to ground potential. Analog meter readouts as well as zero to five volt outputs are provided for peripheral data collection. Six independent channels are provided. Three measure positive currents, and three measure negative currents. Although designed for vacuum operation, it can be used equally well in air to measure low currents at high common mode voltages.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TP-1527 , E-9934
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    Silicon-gate CMOS/SOS processing (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: Major silicon-gate CMOS/SOS processes are described. Sapphire substrate preparation is also discussed, as well as the following process variations: (1) the double epi process; and (2) ion implantation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-150319
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    Analytical core loss calculations for magnetic materials used in high frequency high power converter applications (1979)
    In:  CASI
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    Publication Date: 2019-06-27
    Description: The basic magnetic properties under various operating conditions encountered in the state-of-the-art DC-AC/DC converters are examined. Using a novel core excitation circuit, the basic B-H and loss characteristics of various core materials may be observed as a function of circuit configuration, frequency of operation, input voltage, and pulse-width modulation conditions. From this empirical data, a mathematical loss characteristics equation is developed to analytically predict the specific core loss of several magnetic materials under various waveform excitation conditions.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-79234 , E-9993
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    Advanced risk assessment of the effects of graphite fibers on electronic and electric equipment, phase 1 (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A model was developed to generate quantitative estimates of the risk associated with the release of graphite fibers during fires involving commercial aircraft constructed with graphite fiber composite materials. The model was used to estimate the risk associated with accidents at several U.S. airports. These results were then combined to provide an estimate of the total risk to the nation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-159027
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    Dipole and quadrupole synthesis of electric potential fields (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A general technique for expanding an unknown potential field in terms of a linear summation of weighted dipole or quadrupole fields is described. Computational methods were developed for the iterative addition of dipole fields. Various solution potentials were compared inside the boundary with a more precise calculation of the potential to derive optimal schemes for locating the singularities of the dipole fields. Then, the problem of determining solutions to Laplace's equation on an unbounded domain as constrained by pertinent electron trajectory data was considered.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-158850
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  • 95
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    Efficiency enhancement of dual-mode traveling wave tubes at saturation and in the linear range by use of spent-beam refocusing and multistage depressed collectors (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An axisymmetric, multistage depressed collector of fixed geometric design was evaluated in conjunction with an octave-bandwidth, dual-mode TWT. The TWT was operated over a wide range of conditions to simulate different applications. The collector was operated in three-, four-, and five-stage configurations, and its performance was optimized (within the constraint of fixed geometric design) over the range of TWT operating conditions covered. For operation of the dual-mode TWT at and near saturation, the collectors increased the TWT overall efficiency by a factor of 2 1/2 to 3 1/2. Collector performance was relatively constant for both the high and low TWT modes and for operation of the TWT across an octave bandwidth. For operation of the TWT in the linear, low-distortion range, collector efficiencies of 90 percent and greater were obtained, leading to a five- to twelvefold increase in the TWT overall efficiency for the range of operating conditions covered and reasonably high (greater than 25 percent) overall efficiencies well below saturation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TP-1486 , E-9912
    Format: application/pdf
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  • 96
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    Microwave dichroic plate (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A dichroic plate for microwave energy includes an array of interlaced crossed slots or dipole elements. Each of the elements includes first and second crossed arms that are at approximately right angles to each other and aligned with X and Y axes. The elements are arranged so that the centers thereof are aligned parallel to the X and Y axes to form columns and rows, and the interlacing is such that a line between the centers of all adjacent elements has nonzero, differing components relative to the X and Y axes. In one embodiment, the spacing between adjacent arms of different, adjacent elements is the same along the X and Y axes, while in a second embodiment, the spacing between similarly directed arms of adjacent elements differs from the spacing between oppositely directed arms of adjacent elements.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 97
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    System for automatically switching transformer coupled lines (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A system is presented for automatically controlling transformer coupled alternating current electric lines. The secondary winding of each transformer is provided with a center tap. A switching circuit is connected to the center taps of a pair of secondary windings and includes a switch controller. An impedance is connected between the center taps of the opposite pair of secondary windings. The switching circuit has continuity when the AC lines are continuous and discontinuity with any disconnect of the AC lines. Normally open switching means are provided in at least one AC line. The switch controller automatically opens the switching means when the AC lines become separated.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
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  • 98
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    Performance of a 14.9-kW laminated-frame dc series motor with chopper controller (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Traction motor using two types of excitation: ripple free dc from a motor generator set for baseline data and chopped dc as supplied by a battery and chopper controller was tested. For the same average values of input voltage and current, the power output was independent of the type of excitation. At the same speeds, motor efficiency at low power output (corresponding to low duty cycle of the controller) was 5 to 10 percentage points less on chopped dc than on ripple-free dc. This illustrates that for chopped waveforms, it is incorrect to calculate input power as the product of average voltage and average current. Locked-rotor torque, no load losses, and magnetic saturation data were so determined.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-79177 , DOE/NASA/1044-79/2
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  • 99
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    Electrical Characterization of Hughes HCMP 1853D and RCA CDP1853D N-bit, CMOS, 1-of-8 Decoder Microcircuits (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Electrical characterization tests were performed on two different manufactured types of integrated circuits. The devices were subjected to functional and AC and DC parametric tests at ambient temperatures of -55 C, -20 C, 25 C, 85 C, and 125 C. The data were analyzed and tabulated to show the effect of operating conditions on performance and to indicate parameter deviations among devices in each group. Accuracy was given precedence over test time efficiency where practical, and tests were designed to measure worst case performance.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: HAC-REF-E0963 , FR79-76-870
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  • 100
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    Electrical characterization of standard and radiation-hardened RCA CDP1856D 4-BIT, CMOS, bus buffer/separator (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Tests performed to determine accuracy and efficiency of bus separators used in microprocessors are presented. Functional, AC parametric, and DC parametric tests were performed in a Tektronix S-3260 automated test system. All the devices passed the functional tests and yielded nominal values in the parametric test.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-CR-158725 , FR79-76-871
    Format: application/pdf
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