| 摘要 |
PURPOSE:To prevent unstabile control of a switching element even upon reduction of power supply voltage for a predrive circuit. CONSTITUTION:Transistors Tr1-Tr6 constituting an inverter 32 are turned OFF forcibly though a predrive circuit 38. When the power supply for the predrive circuit 38 though a DC/DC converter 46 is interrupted, a DC voltage appearing at an inverter 32 is passed through a DC/DC converter and fed, as a power supply voltage, to the predrive circuit 52. Consequently, even if the power supply for the predrive circuit 38 through the DC/DC converter 46 is interrupted, unstable control of the transistors Tr1-Tr6 is prevented thus preventing runaway due to noise. A contactor SW4 may be provided on the output side of the inverter 32. |
