| 摘要 |
A power control unit for high-frequency dielectric heating not affected by variations in the types or the characteristics of magnetrons, power supply voltage fluctuation, etc., is provided. The unit has an input current detection section 71, 72 for detecting input current of an inverter circuit 10 for rectifying 31 AC power supply voltage 20, performing high frequency switching, and converting into high frequency power, mixes input current waveform information 90 of the input current detection section and power control information 91 for controlling so that output of the input current detection section becomes a predetermined value in a mix circuit 81, outputs ON voltage information 92, makes a comparison between the ON voltage information and a sawtooth wave from a sawtooth wave generation circuit 83 in a PWM comparator 82, performs pulse width modulation, and outputs a drive signal for controlling turning on/off of a switching transistor 39 of an inverter circuit. |
