Lamp power regulator

摘要

An effective voltage across a load such a lamp (L) is squared by means of a field effect transistor (FET) to produce an output voltage which varies in proportion to the power through the load (L). A trigger phase of a thyristor (TRC) connected between an A.C. power source (PS) and the load (L) is automatically varied in such a manner that the output voltage and thereby the power through the lamp (L) are regulated to a desired value.