| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an induction heating device capable of controlling a switching frequency so as not to be set not larger than a resonance frequency of a resonance circuit. <P>SOLUTION: 1 is an A.C. power source; 2 is a D.C. rectifier circuit rectifying A.C. power from the A.C. power source 1 to D.C. input power; 3 is an induction heating coil; 4a and 4b are switching elements; 5 is an input voltage detection means; 6 is an input current detection means; 7 is a resonance capacitor; 8 is an induction heating control circuit; and 9 is a signal input means for operating the induction heating control circuit 8 by arbitrary power. The induction heating control circuit 8 detects that the change of input power with respect to the switching frequency becomes moderate, and switches the switching elements 4a and 4b at a frequency higher than the resonance frequency f0, whereby the operation of the resonance circuit 10 comprising the induction heating coil 3 and the resonance capacitor 7 becomes inductive, and the switching element 4a can be prevented from failing. <P>COPYRIGHT: (C)2008,JPO&INPIT |
