Quick Reference

An electrical or electronic device in which a variation in the current in one circuit controls the current in a second circuit. These devices are used in an enormous number of different applications in which electrical control is required. The simplest is the electromechanical relay in which the first circuit energizes an electromagnet, which operates a switch in a second circuit. The thyratron gas-filled relay found many uses in the past but has now been largely replaced by the thyristor solid-state relay.

Subjects: Physics.

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