| 摘要 |
<p>A microwave oven having a high voltage control circuit which prevents an overheating of a high voltage transformer (HVT). The high voltage control circuit includes a thermostat (TCO) which is turned on or off according to a temperature of the high voltage transformer. The thermostat is disposed between a first fixed terminal (D) of a tap formed at a primary coil of the high voltage transformer and a second fixed terminal (C) connected to a power stage, so as to allow the primary coil to have different numbers of turns. According, where the output of a magnetron of the microwave oven becomes high and the temperature of the high voltage transformer reaches a predetermined temperature, the thermostat is turned off, thus enabling the first and second fixed terminals to be disconnected from each other. Therefore, the number of turns of the primary coil of the high voltage transformer is increased and the voltage supplied to the magnetron is decreased, thus maintaining the decreased output of the magnetron and preventing the overheating of the high voltage transformer. <IMAGE></p> |
