GATE DRIVE CIRCUIT OF SWITCHING ELEMENT

PROBLEM TO BE SOLVED: To provide an insulated gate drive circuit of a switching element where unnecessary vibration due to input capacity is prevented and drive loss accompanying a high frequency can be reduced in the gate drive circuit of the switching element having a MOS gate structure. SOLUTION: A converter drive first circuit 14a includes a DC voltage supply Vcc1 outputting prescribed DC voltage, a transformer T1 having primary winding W1 and secondary wiring W2a and secondary wiring W2b, which are magnetically coupled to primary winding, a full bridge circuit 28 which periodically switches polarity of DC voltage applied to primary winding of the transformer T1 based on a prescribed control signal, a resonance prevention clamping circuit 30a having diodes D5 to D7 connected to secondary winding W2a, an auxiliary power supply part 34a receiving power flowing from the resonance prevention clamping circuit and secondary winding W2b, and a power recovery route forming part 32a forming a power recovery route for returning power accumulated in the auxiliary power supply part to secondary winding W2b. COPYRIGHT: (C)2009,JPO&INPIT