Patent ID: 6852959
Filing Date: 2005-02-08
Classification: H05B

Abstract:
1. A driving circuit of a DC microwave oven having an inverting unit for converting a DC voltage of a DC power supply into an AC voltage by driving pulses, a high voltage transformer for transforming the AC voltage applied by the driving of the inverting unit and supplying the transformed AC voltage to a magnetron, and a pulse driving unit for generating the driving pulses, said driving circuit comprising: an excessive current detecting unit for detecting a current supplied from the DC power supply to the inverting unit, and for outputting an excessive current detecting signal to the pulse driving unit to cut off the generation of the driving pulses of the pulse driving unit when the detected current corresponds to an excessive current; and an excessive current maintaining unit for continuously maintaining the excessive current detecting signal when the excessive current detecting signal is outputted by the excessive current detecting unit; wherein the excessive current maintaining unit includes a feedback transistor turned on by an input of a feedback control signal outputted from the pulse driving unit, and a diode connected between the feedback transistor and the comparison part for continuously outputting to the comparison part a feedback signal higher than a reference signal in correspondence with turn-on of the feedback transistor, the pulse driving unit outputting the feedback control signal in response to outputting of the comparison result signal comprising the excessive current detecting signal by the comparison part.