| 摘要 |
PURPOSE:To relax the time change rate of a voltage between the collector and emitter of an IGBT at the time of turning on the IGBT and to reduce a collector loss at the time of transition and a steady state. CONSTITUTION:A serial-parallel connection constituted by connecting a serial connection between a constant voltage diode ZD1 and a resistor R1 in parallel with a resistor R2 having a resistance value larger than that of the resistor R2 is inserted between a forward bias DC power supply having voltage Ef and a transistor(TR) element Tc1 in a photocoupler and an IGBT gate voltage formed in the gate of the IGBT 1 by the voltage Ef impressed through a gate resistor R3 and the parallel-serial connection and used as an envelope voltage of two kinds of component voltages having final voltage values different from respective time constants is used as a required gate voltage VG. |
