| 摘要 |
PURPOSE:To obtain a precise temperature by providing a means for induction heating, a material detecting circuit for judging the material of a heated substance, and a circuit for detecting a heating temperature, and controlling an electric power supplied to the heating means based on a judgment signal and a temperature detecting signal. CONSTITUTION:A material detecting circuit 15 sends a judgment signal corresponding to the material of a pan 12 to a turns switching circuit 16 and an analog switch 17 based on the current value detected from a current detector 14. When the judgment signal corresponds to Al, Cu pans, the circuit 16 turns a switch 18 to c-a to put heating coils 8a, 8b in series, and also connects capacitors 9a, 9b to reduce the capacity. When the judgment signal corresponds to Fe, SUS pans, the contact is changed to c-b, and only the coil 8a is used to increase the capacity of the capacitor. A temperature detecting circuit 19 measures the temperature of the pan by a temperature sensor 20 provided on the plate 11 back surface, and outputs to the inverse input terminal of a comparator 21. The voltage Vb of the comparator 21 is regulated by the state of a switch 17. Hence, by selecting resistances 23, 24, a desired temperature control holding property can be realized. |
