CONTROLLED H.F. INDUCTION HEATING APPARATUS

摘要

A controlled H.F. induction heating apparatus useful as a cooking device. The apparatus comprises a heating unit which includes at least one heater coil, a static power converter connected between the heating unit and an a.c. power source for converting the supplied alternating current into a high-frequency current to cause the heater coil to produce a commutating magnetic field. The converter includes a switching circuit for commutating the high-frequency current at a frequency equal to a frequency with which the switching circuit is triggered. A control circuit, including a start control circuit, is provided for triggering the switching circuit at a predetermined frequency during an incipient stage of operation of the induction heating apparatus and thereafter for shifting the triggering frequency of the switching circuit to a predetermined normal level.