ELECTROMAGNETIC INDUCTION HEATING APPARATUS

摘要

In an electromagnetic induction heating apparatus according to the present invention, a cooking kettle made of a nonmagnetic metal, which has a conventionally been incapable of magnetic induction heating, is provided with a heating coil which applies an alternating field with a high-frequency level of 50 kHz or more, preferably with a frequency level of 100 kHz or more. An inverter circuit for supplying the heating coil with a high-frequency current operates in response to an output signal from a detector which automatically detects the kind of metallic material of the cooking kettle. As the high-frequency magnetic field is applied, a skin effect is produced within the metallic material of the vessel, so that the impedance for the magnetic field of the vessel is substantially fixed without regard to the wall thickness of the vessel.