Sanyo Electric Co., Ltd.

Tokyo Sanyo Electric Co.

Shin-ichi Kasahara

Hiroshi Okumura

Masayuki Morishima

Yoshihisa Tazima

An induction heating coil and a self-excited inverter are connected to a ripple voltage source. The self-excited inverter comprises a transistor as a switching element and the transistor is rendered conductive responsive to a drive voltage applied for each cycle of the ripple voltage source, whereby the self-excited inverter is started at each cycle of the ripple voltage source. The self-excited inverter stops the oscillation when the voltage of the ripple voltage source becomes lower than a predetermined value. During the non-oscillation period of the intermittent oscillation, the oscillation output of the self-excited inverter is detected. If and when the oscillation output is detected at that time, the oscillation of the inverter is stopped. Furthermore, the pulses of the attenuating oscillation of the self-excited inverter during the oscillation rest period are counted. If and when the count value of the counter is smaller than a predetermined value, the oscillation of the self-excited inverter is started, whereas if and when the count value of the counter exceeds the predetermined value, the oscillation stop state is continued.

Induction heating cooking apparatus

An induction heating coil and a self-excited inverter are connected to a ripple voltage source. The self-excited inverter comprises a transistor as a switching element and the transistor is rendered conductive responsive to a drive voltage applied for each cycle of the ripple voltage source, whereby the self-excited inverter is started at each cycle of the ripple voltage source. The self-excited inverter stops the oscillation when the voltage of the ripple voltage source becomes lower than a predetermined value. During the non-oscillation period of the intermittent oscillation, the oscillation output of the self-excited inverter is detected. If and when the oscillation output is detected at that time, the oscillation of the inverter is stopped. Furthermore, the pulses of the attenuating oscillation of the self-excited inverter during the oscillation rest period are counted. If and when the count value of the counter is smaller than a predetermined value, the oscillation of the self-excited inverter is started, whereas if and when the count value of the counter exceeds the predetermined value, the oscillaton stop state is continued.

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Ashikaga, Japan

Shin-ichi Kasahara