| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an appropriate control method of an induction heating power source which supplies a desired induction heating power to a heating object on a heating coil, by connecting a series resonance circuit consisting of the heating coil and a capacitor to an output end of a power conversion circuit and controlling the power conversion circuit. <P>SOLUTION: A monitoring circuit 22 calculates and leads out a value, corresponding to a switching loss value per unit time at the turning off of IGBT to form a power conversion circuit 2 and monitors whether this value exceeds a permissible value of the IGBT; and when it exceeds the permissible value, outputs a power set value that restricts the power instruction value instructed from the outside by a power instruction limiting circuit 21 and, with this power set value, makes the induction heating power source operate; thereby, the current outputted from the power conversion circuit 2 is reduced, and as a result, operation of the induction heating power source can be continued, while monitoring the increase of switching loss of the IGBT. <P>COPYRIGHT: (C)2010,JPO&INPIT |
