| 摘要 |
PURPOSE:To prevent an abrupt and excessive rush current from flowing into a large-capacity capacitor, for example, when a power switch is turned ON by providing a relief means which turns ON a switching element slower than the switch is turned ON. CONSTITUTION:A DC power source l is connected to an inverter 6 which controls a motor 7 through a relay switch 2 and a fuse 8. The large-capacity capacitor 3 is connected in parallel to the inverter 6 and DC power source 1, and a power MOSFET 4 is connected in series to the large-capacity capacitor 3. A capacitor 14 is connected to the gate of the power MOSFET 4. A capacitor 14 is charged through a resistance 11 (1st resistor) and its charging voltage is determined by the capacitor 14, the ratio of voltage division by resistances 11 and 15, and the voltage of the power source 1. The resistances 11 and 15 and the capacitor 14 constitute the relief means which turns ON the power MOSFET slowly. Consequently, the abrupt and excessive rush current is prevented from flowing into the large-capacity capacitor, for example, when the power switch is turned ON. |
