| 摘要 |
PURPOSE:To suppress an irregularity in minimum power consumption of an induction heating cooker by forming a waveform of a part regarding setting of ON pulse width of driving a switching element of an output of a PWM circuit to a minimum value in a square waveform. CONSTITUTION:A PWM circuit 111 has a RC charger/discharger 108, a reference voltage setter 109, and a comparator 110. A minimum ON pulse width for driving a switching element 113 of an inverter 114 is irrespective of charging/ discharging time constants of the charger/discharger 108. Even if the output voltage of the setter 109 is irregular, the waveform of a part regarding the minimum ON pulse width of the output voltage of the charger/discharger 108 is formed in a square waveform. Accordingly, the period of the output of the charger/discharger 108 to be judged as the output voltage or less of the setter 109 in the comparator 110 becomes constant. Thus, the irregularity in the minimum power consumption of an induction heating cooker can be suppressed. |
