An unorthodox transformer for free-running parallel inverters
Free-running parallel inverters limitations by critical characteristics of networks, transformers and switching elements
Schwarz, F. C.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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A microscopic test of inverted nuclear coexistence
Inverted coexistence possibility of spherical and deformed states in Si 28 and S 32 nuclei
Braley, R. C.↗
The influence of a circuit parameter on the harmonics of a PWM dc-to-sinusoidal inverter
DC-to-sinusoidal inverter employing PWM waveform, analyzing circuit parameters effect on harmonic content
Babaa, I. M. H.↗
HCl, HF, and DF partially inverted CW chemical lasers
CW chemical lasers operation from partially inverted transitions of HCl, HF and DF molecules in subsonic flow
Cool, T. A.↗
Performance evaluation of Brayton space power system 400-hertz inverters
Performance evaluation of Brayton space power system 400-hertz inverters
Birchenough, A. G.↗
Static inverters which sum a plurality of waves Patent
Describing static inverter with single or multiple phase output
Anderson, D. L.↗
High-resolution inverted Lamb-dip spectroscopy on SF6
Sulfur hexafluoride absorption lines observation by inverted Lamb dip high resolution spectroscopy, using heterodyne methods
Goldberg, M. W.↗
Series commutation for variable frequency thyristor inverters
Variable voltage and frequency thyristor inverter, describing series commutation power stage
Wawzonek, J. J.↗
Substrate-emitter monolithic inverted transistor structure for low-power high- current-gain applications
Substrate emitter monolithic inverted transistor structure for low-power high-current gain application
Cress, S. B.↗
Practical considerations for Abel inverting of photographic data with application to the analysis of a 15-kW wall-stabilized arc-light source
Temperature profiles were measured for agron atmospheric pressure by using absolute line and continuum intensity and were compared with stark width and shift measurements. A detailed analysis of the engineering aspects of setting up for Abel inverting deta photographically is presented. The merits of using photographic detection and of using continuum radiation for temperature profile analysis are discussed. The importance of empirically determining the optical depth is emphasized by discrepancies between measured (two-path) and calculated estimates.
Snow, W. L.↗
Design and material selection for inverter transformer cores
Report is announced which studied magnetic properties of candidate materials for use in spacecraft transformers, static inverters, converters, and transformer-rectifier power supplies. Included are material characteristics for available alloy compositions in tabular form, including: trade names, saturated flux density, dc coercive force, loop squareness, material density, and watts per pound at 3 KHz.
Mclyman, W. T.↗
Motor starting a Brayton cycle power conversion system using a static inverter
The power conversion module of a 2- to 15-kWe Brayton engine was motor started using a three-phase, 400-hertz static inverter as the power source. Motor-static tests were conducted for initial gas loop pressures of 10, 14, and 17 N/sq cm (15, 20, and 25 psia) over a range of initial turbine inlet temperatures from 366 to 550 K (200 to 530 F). The data are presented to show the effects of temperature and pressure on the motor-start characteristics of the rotating unit. Electrical characteristics during motoring are also discussed.
Curreri, J. S.↗
Molecular solid-state inverter-converter system
A modular approach for aerospace electrical systems has been developed, using lightweight high efficiency pulse width modulation techniques. With the modular approach, a required system is obtained by paralleling modules. The modular system includes the inverters and converters, a paralleling system, and an automatic control and fault-sensing protection system with a visual annunciator. The output is 150 V dc, or a low distortion three phase sine wave at 120 V, 400 Hz. Input power is unregulated 56 V dc. Each module is rated 2.5 kW or 3.6 kVA at 0.7 power factor.
Birchenough, A. G.↗
Control and protection system for paralleled modular static inverter-converter systems
A control and protection system was developed for use with a paralleled 2.5-kWe-per-module static inverter-converter system. The control and protection system senses internal and external fault parameters such as voltage, frequency, current, and paralleling current unbalance. A logic system controls contactors to isolate defective power conditioners or loads. The system sequences contactor operation to automatically control parallel operation, startup, and fault isolation. Transient overload protection and fault checking sequences are included. The operation and performance of a control and protection system, with detailed circuit descriptions, are presented.
Birchenough, A. G.↗
Coaxial inverted geometry transistor having buried emitter
The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed.
Hruby, R. J.↗
Magnetic materials selection for static inverter and converter transformers
A program to study magnetic materials is described for use in spacecraft transformers used in static inverters, converters, and transformer-rectifier supplies. Different magnetic alloys best suited for high-frequency and high-efficiency applications were comparatively investigated together with an investigation of each alloy's inherent characteristics. The materials evaluated were the magnetic alloys: (1) 50% Ni, 50% Fe; (2) 79% Ni, 17% Fe, 4% Mo; (3) 48% Ni, 52% Fe; (4) 78% Ni, 17% Fe, 5% Mo; and (5) 3% Si, 97% Fe. Investigations led to the design of a transformer with a very low residual flux. Tests were performed to determine the dc and ac magnetic properties at 2400 Hz using square-wave excitation. These tests were performed on uncut cores, which were then cut for comparison of the gapped and ungapped magnetic properties. When the data of many transformers in many configurations were compiled the optimum transformer was found to be that with the lowest residual flux and a small amount of air gap in the magnetic material. The data obtained from these tests are described, and the potential uses for the materials are discussed.
Mclyman, W. T.↗
A buoyant tornado-probe concept incorporating an inverted lifting device
Addition of an inverted lifting device to a simple balloon probe is shown to make possible low-altitude entry to tornado cores with easier launch conditions than for the simple balloon probe. Balloon-lifter combinations are particularly suitable for penetration of tornadoes with average to strong circulation, but tornadoes of less than average circulation which are inaccessible to simple balloon probes become accessible. The increased launch radius which is needed for access to tornadoes over a wide range of circulation results in entry times of about 3 minutes. For a simple balloon probe the uninflated balloon must be first dropped on, or near, the track of the tornado from a safe distance. The increase in typical launch radius from about 0.75 kilometer to slightly over 1.0 kilometer with a balloon-lifter combination suggests that a direct air launch may be feasible.
Grant, F. C.↗