| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve a problem that, in an induction heating device having a plurality of inverters to drive a plurality of heating coils, when the heating coils are controlled with a constant frequency in order to prevent an interference sound due to the difference of respective drive frequencies of the plurality of inverters, there arises a restriction in the power adjustment range depending on a load and controllability of heating output becomes worse. <P>SOLUTION: In the induction heating device, when the plurality of inverters 4, 5 are simultaneously operated, a first maximum power is established and a second maximum power which is set at the time of individual operation of the inverters 4, 5 is established, and at least up to the first maximum power, the drive frequency of the inverters 4, 5 is made constant to operate and the interference sound is prevented. After exceeding the first maximum power and up to the second maximum power, the drive frequencies of semiconductor switches 11, 12, 14, 15 in the inverters 4, 5 are changed to carry out power adjustment, thus, power adjustment range is increased, and controllability of heating output is improved. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
