Transductor

A transductor (not to be confused with a transducer) is type of magnetic amplifier used in power systems for compensating reactive power. It consists of an iron-cored inductor with two windings - a main winding through which an alternating current flows from the power system, and a secondary control winding which carries a small direct current. By varying the direct current, the iron core of the transductor can be arranged to saturate at different levels and thus vary the amount of reactive power absorbed.

Transductors were widely used before the advent of solid-state electronics but today have been largely replaced by power electronic devices such as the Static VAR compensator and STATCOM.