A d.c. chopper circuit using triacs.

A simple type of d.c. chopper circuit with triacs is presented. The circuit is analyzed and the design criteria for the reliable operation of the circuit are evolved. Certain circuit modifications are suggested and their effects are discussed.
The triac (RCA manual 1971, GE SCR manual 1972) is basically a controlled bidirectional switch and can be used to replace the combination of a thyristor and an inverse-parallel connected diode used in chopper circuits. In an earlier work the concept of forced commutation in triac circuits (Revankar and Trasi 1975 a) is evolved and the necessary conditions are derived. Use of triacs in chopper circuits (Revankar and Trasi 1975 b) is investigated and a simple chopper circuit with a commutating L-C circuit directly across the main triac is presented. In this paper a triac chopper circuit, where the commutating circuit appears directly across the load circuit, is discussed. [ABSTRACT FROM AUTHOR]