| 摘要 |
PURPOSE: To suppress as much as possible an interference of communication to use an electric wave of an ISM band, even though a magnetron is made to be actuated on both phases of a commercial alternate electric source. CONSTITUTION: A rectification circuit 2 for full-wave rectification of this AC electric power is connected with the commercial alternate electric power source 1, and an inverter circuit 3 is connected between output terminals of this rectification circuit 2. A magnetron 6 is connected with the inverter circuit 3 via a high-frequency transformer 4 and a high voltage rectification circuit 5. Further, a zero cross detecting circuit 9 is connected with the commercial alternate electric power source 1. A pulse signal of 'H' level is outputted on a counter circuit 10 by the zero cross detecting circuit 9 if a zero cross of the commercial alternate power source 1 is detected. The pulse signals are counted by the counter circuit 10, and 'H', 'L' signals are outputted to a stop circuit 7a of an inverter control circuit 7 at a rate of 18 pulses L/2 pulses H by the counter circuit 10.
|
