Abstract: A first hollow control shaft is rotatable within a housing between actuating and restoring positions with intermediate ON-OFF positions therebetween. A first insulating actuator is rotatable within the housing to operate at least a pair of normally open contacts. A second insulating actuator is slidable along a predetermined path and normally biased to operate normally closed contacts and engageable with the first actuator by a lost motion connection which permits the second actuator to move in a limited range with respect to the rotational movement of the control shaft. The normally closed contacts are placed in a trigger circuit of an induction heating apparatus and the normally open contacts placed in a power supply circuit of the apparatus, the former being operated to disable the trigger circuit prior to energization or de-energization of the power supply circuit. A second control shaft is journaled through the first control shaft. A pinion gear is mounted on the second shaft.