| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable high speed power control while stabilizing the induction heating operation of a voltage resonance type inverter and preventing loss/damage of a switching element caused by resonance frequency change during operation. <P>SOLUTION: A resonance voltage detection circuit 601 divides the resonance voltage of an LC parallel resonance circuit, which includes an excitation coil 101 and resonance capacitor Cres, into resistances R71 and R72, and inputs them into a comparator CMP 71. A timing control signal is generated by comparing the divided voltage values of the resonance voltage and a GND (grounding) level so that the CMP 71 can generate an output signal with the timing in which the voltages of both ends of the switching element Q1 are Vce=0. The timing control signal is input to the control part 207. <P>COPYRIGHT: (C)2012,JPO&INPIT |
