Results 211 to 220 of about 966,415 (249)

Some recent developments in impulse-voltage testing

Electrical Engineering, 1940
Impulse-voltage testing of electrical apparatus and circuits is a steadily growing practice and constant attention is therefore being given to improvements in testing methods. Accordingly, as progress is made it is necessary to describe recent changes.
C. M. Foust, N. Rohats
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Measurement of High-Voltage Impulses

2013
For conventional measurement of lightning, switching, chopped and oscillating impulse voltages, measuring systems with high-voltage dividers up to several megavolts have been employed for decades. They are classified as resistive, capacitive and resistive-capacitive voltage dividers.
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Electroluminescence in polyethylene terephthalate (PET) (impulse voltage)

Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1981, 1981
Electroluminescence was observed in PET when an impulse voltage was applied. The electroluminescence depended on the electrode material of the cathode and showed only a weak temperature dependence and a superlinear dependence on the electric field. The spectrum of the electroluminescence was identical with that of the photoluminescence originating from
Kenzo Kojima, Yoshiaki Takai, Masayuki Ieda   +2 more
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Polypropylene foil response to voltage impulses

2018 19th International Scientific Conference on Electric Power Engineering (EPE), 2018
Electrical insulating materials used in the electric power engineering are exposed to various overvoltage phenomena during operation. Effects of voltage impulses with various front time on the breakdown voltage of the biaxially oriented polypropylene foil were studied.
Bystrik Dolnik, Lukas Kruzelak
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Measuring transmission-line impulse voltages

Electrical Engineering, 1954
THREE companion papers describe impulse tests performed on the experimental transmission lines of the American Gas and Electric Company.1–3 When these tests were being planned, it was necessary to select voltage dividers capable of reducing the high-surge voltages to a level suitable for measurement by a cathode-ray oscillograph. Selecting dividers for
S. B. Griscom, B. L. Lloyd, A. R. Hileman   +2 more
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Low Voltage Impulse Circuits

Physics, 1933
Three different types of low voltage circuits suitable for supplying impulse voltages in oscillographic work are discussed. These circuits use Thyratrons as the connecting and timing switches in place of the spark gaps ordinarily employed in transient investigations. Charged condensers are used as the source of voltage.
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Effects of impulse surge voltages on alternators

2001 IEEE Porto Power Tech Proceedings (Cat. No.01EX502), 2002
We consider the impulse surge voltages acting on alternators running in the block with the elevating transformer. The alternators' insulation is not stable, particularly when the block alternators are placed in more severe conditions because the surge voltage waves coming from the line and through the step-up transformer have a direct effect on them ...
T. Otmane-Cherif, R. Chaibi, N.A. Mufidzada   +2 more
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The effects of impulse voltages on transformer windings

Journal of the Institution of Electrical Engineers, 1937
The effects of the application of impulse voltages of varied wave-shapes to transformers are analysed theoretically and experimentally. Single and multiple transients have been considered, and oscillographic tests have been made on model transformers of different winding characteristics, and on both single-phase and 3-phase transformers.
T.E. Allibone, D.B. McKenzie, F.R. Perry
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Peak-voltage measurements of standard impulse voltage waves

Proceedings of the IEE Part C: Monographs, 1956
The frequency spectrum of a 1/50 microsec impulse wave is obtained by the use of the Fourier transform. The corresponding frequency spectrum of the output from a simple capacitance potential divider, suitable for use up to 300 kV, is calculated from the input frequency spectrum for a 1/50 microsec wave and the frequency response of the divider ...
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The measurement of the magnitude of impulse voltages using voltage comparators

Journal of Physics E: Scientific Instruments, 1971
A digital peak voltmeter is described which determines the unknown voltage by comparing it with each of 100 known constant voltages in turn. Each constant voltage exceeds its predecessor by a fixed amount. Despite the large number of reference voltages employed, only ten comparators are used.
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