Safety circuit for induction heated hotplates - has bimetallic switches protecting circuitry and utensil bearing surfaces

摘要

The induction heated hot plate safety circuit (100) is used esp., for limiting the max. obtained temp. for the cooking utensils and for the semiconductor switching components. The oscillator thyristors and diodes are mounted on a heat sink, and a radiator. The bridge rectifier supplying the oscillator land induction heating coil are mounted to one side of the insulating plate supporting the cooking utensil. The supply to the oscillator is made via a triac or similar switch whose gate bias is controlled by two bimetallic switches, one in close contact with the radiator and one with the utensils plate.