Exciter for induction heating apparatus

Claim 1

Induction heating apparatus comprising: a central magnetic pole, a plurality of peripheral magnetic poles positioned equidistant from the central magnetic pole, a yoke for positionally disposing the central magnetic pole and the peripheral magnetic poles, a cover plate supported by the peripheral magnetic poles, a heated element supported by the cover plate, a central excitation winding wound about the central magnetic poles, a plurality of peripheral excitation windings wound about the peripheral magnetic poles, a first excitation circuit comprising the central excitation winding, means connecting the peripheral excitation windings to form a second excitation circuit. means for energizing the first excitation circuit with a first excitation circuit and for energizing the second excitation circuit with a second excitation current having a difference in phase with respect to the first excitation current of 70°-110° to generate an electromagnetic force perpendicular to the cover plate so that no turning force is applied to the heated element and so that vertical vibration is prevented while at the same time generating eddy currents in the heated element from alternating magnetic fluxes to heat the heated element.