IMPROPER LOAD PROTECTION FOR INDUCTION HEATING APPLIANCE

摘要

An induction heating apparatus comprising a d.c. power source, a static power inverter for producing a high-frequency oscillating current and an induction heating unit including a plurality of heater coils jointly connected to the inverter for producing a commutating magnetic field around each of the heater coils is provided with protective circuits for disabling one or more or all of the heater coils from being energized from the inverter in the event an improper load is applied to at least one of the heater coils. The induction heating apparatus is typically used as a cooking appliance and the improper load which may be applied to each of the heater coils includes a cooking pan, pot or kettle of a non-magnetic material such as aluminum and a rejectable magnetic load such as a kitchen knife, spoon or fork.