ELECTROMAGNETIC INDUCTION HEATING COOKER

摘要

PURPOSE:To control input power by the phase difference between an inverter output voltage and a heating coil current and prevent the float of a metal vessel. CONSTITUTION:The AC voltage from a commercial power source 9 is rectified and smoothed by a smoothing circuit 8 to supply a DC voltage to a high frequency inverter circuit 4. The high frequency inverter circuit 4 is driven by an inverter driving circuit 7 and a high frequency power is sent to a heating coil 2 to generate a high frequency alternating magnetic field. An eddy current is generated in a metal vessel 1 by this high frequency alternating magnetic field, and the metal vessel 1 is heated by this eddy current. The current running in the heating coil 2 is detected by a current sensor 13 and inputted to a driving frequency detecting circuit 10, whereby the driving frequency of the high frequency invertor circuit 4 is detected and inputted to a main control part 12. The main control part 12 controls the high frequency inverter circuit 4 according to the detected driving frequency to prevent the levitation of the metal vessel 1 containing material to be heated.