Results 261 to 270 of about 157,516 (285)

Surge protectors for current transformers

Electrical Engineering, 1936
Surge protection and open-circuit protection of current transformers may be obtained by the application of shunts in which the material known as ``thyrite,'' and which has a negative resistance characteristic, is used. The surge protector is connected across the current transformer primary, and the open-circuit protector across the secondary.
G. Camilli, L. V. Bewley
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Magnetooptical current transformer 1: Principles

Applied Optics, 1980
The principles of measuring currents in high-voltage lines by magnetooptical means are described. Particular attention is payed to using an optical fiber both as a transmission line and a measuring sensor. The influence of birefringence on the measuring signal is discussed.
A, Papp, H, Harms
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Magnetooptical current transformer 3: Measurements

Applied Optics, 1980
A laboratory setup of a magnetooptical current transformer was established. A ingle-mode fiber acts as both a measuring sensor and a transmission line. The overall measurement accuracy at room temperature within a primary current range 50-1200 A is better than 0.24%, the SNR at 1000 A is 85 dB.
H, Harms, A, Papp
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Current-transformer testing

Journal of the Institution of Electrical Engineers, 1934
A method of testing current transformers by comparison with standard current transformers is described. The apparatus has three ranges. The most sensitive range is capable of measuring ratio differences up to 5 parts in 10000 with an accuracy of approximately 1 part in 1000000, and phase angles up to 2.5 minutes with an accuracy of approximately 0.01 ...
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Current european transformations

Innovation: The European Journal of Social Science Research, 1992
Abstract Part of the difficulty in theorizing the current processes of transformation in contemporary Europe lies with the fact that Europe has always been more of an idea rather than a geographical or political entity. On the face of this, this articles suggests some general guidelines for collecting and classifying information about the many and ...
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Current transformer calibration

1988
The practical application of the current comparator to current transformer calibration is accomplished with a configuration that has been called the compensated current comparator. The principal feature of this configuration is a winding located inside the main magnetic shield which has the same number of turns as one of the ratio windings located ...
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Methods for Testing Current Transformers

Transactions of the American Institute of Electrical Engineers, 1924
In the sale of electric power especially in large amounts at high voltages, current transformers are universally used to operate the meters from the readings of which the bills are made out. While the secondary currents of such transformers reproduce fairly faithifully on a smaller scale the conditions of current strength and phase existing in their ...
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Harmonics in transformer magnetizing currents

Proceedings of the American Institute of Electrical Engineers, 1915
The purpose of this paper is to show in a concise manner the cause and effects of higher harmonic currents in magnetizing currents of transformers. A hypothetical case is analyzed to show the cause of the harmonics; then the schemes of connecting transformers that are commonly used for polyphase transformation are taken up and the effects of the ...
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Reviewing current transformers and current transducers

2007 Electrical Insulation Conference and Electrical Manufacturing Expo, 2007
The purpose of this paper is to provide a tutorial review of three types of current transducers that are used in instruments and power. The three current transducers that will be discussed are; (1) the ac current transducer; (2) the dc current saturable reactor; and (3) the Hall effect generator with the rugged solid iron core.
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Current transformers near high-current busses

Electrical Engineering, 1951
WHEN CURRENT TRANSFORMERS are applied in the vicinity of busses carrying large currents, the transformer accuracy may be very seriously affected. This is particularly true on systems which normally carry over 2,000 amperes and may carry 10 or 20 times this current during faults.
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