| 摘要 |
PURPOSE:To reduce input regardless of the kind of cookers so as to enable driving with minimum power by detecting the current of a resonance condensor only during operation of a semi-conductor switching element, and controlling a charging current using a control circuit. CONSTITUTION:A cooker 9 is heated via a resonance circuit comprising a semiconductor element 8 the operation of which is controlled by a control circuit 11, and a resonance condensor 7 and the like. The current of the resonance condensor 7 is detected only during operation of the switching element 8 and is output to the comparing circuit 15 of the control circuit 11, and, when the value exceeds a reference value, the excess value is output to a duty cycle setting circuit so that the control mode is switched to control of a duty cycle by which operation of the switching element 8 is repeatedly on and off for a predetermined period of time. Thereby input power is reduced and so driving with minimum power is enabled regardless of the kind of cookers, and noise level is reduced. |
