摘要 |
PROBLEM TO BE SOLVED: To provide a power controller for high-frequency dielectric heating that is not affected by types of magnetrons, characteristic variations in magnetrons, and power-supply voltage fluctuations or the like. SOLUTION: It is composed so as to detect an input current and input voltage of an inverter circuit 10 that converts an AC power-supply voltage 20 to high-frequency power while executing a rectifier 31 and high-frequency-switching the AC power-supply voltage. The detected current and detected voltage are rectified so as to calculate input-current waveform information 90 and input-voltage waveform information 94. Either the input-current waveform information or the input-voltage waveform information which is larger than the other is selected so as to convert a switching-frequency control signal 92, mixed with power control information 91, to a driving signal of semiconductor switching elements 3, 4 of the inverter circuit. COPYRIGHT: (C)2008,JPO&INPIT |