GATE DRIVE CIRCUIT FOR SWITCHING ELEMENT

PROBLEM TO BE SOLVED: To constitute a gate drive circuit for driving a main switching element having an MOS gate structure, as an insulating type circuit, which can prevent unnecessary vibration resulting from an input capacity to attain a reduction in a drive loss accompanying higher frequency. SOLUTION: The gate drive circuit includes: a DC power supply Vcc1 for outputting a specified DC voltage; a transformer T1 having a primary winding, a first secondary winding and a second secondary winding to be magnetically connected to the primary winding; an application voltage polarity switching circuit for periodically switching the polarity of the DC voltage to be applied to the primary winding of the transformer T1 based on a specified control signal; a resonance preventive clamp circuit 30a having diodes D5 to D7 to be connected to the first secondary winding; a resonance preventive clamp circuit 30b having diodes D8 to D10 to be connected to the second secondary winding; and suction type power supplies Vcc2a, Vcc2b for each receiving the recovered power flowing from the resonance preventive clamp circuits 30a, 30b. COPYRIGHT: (C)2008,JPO&INPIT