| 摘要 |
PROBLEM TO BE SOLVED: To unify a voltage source and to reduce power consumption in a gate drive circuit using a charging voltage charged to a capacitance between the gate and emitter of an IGBT(insulated gate bipolar transistor) for a gate voltage and driving the IGBT. SOLUTION: In this gate drive circuit, the capacitance 20 is charged in a forward direction by a charging circuit composed by serially connecting a capacitor 25 charged by a voltage source 26, the capacitance 20 and a MOSFET 27 to be a switch, the charging voltage of the capacitance 20 is discharged by a discharging circuit composed by serially connecting the capacitance 20, a first diode 22 and a MOSFET 24 to be the switch and the capacitance 20 is charged in an opposite direction by an inductance component present in the discharging circuit. Thereafter, the charging voltage in the opposite direction is used again for charging the capacitance 20 in the forward direction together with the charging voltage of the capacitor 25. |
