| 摘要 |
PURPOSE:To prevent a power device for a control circuit from being shortcircuited by inserting a smoothing capacitor and a diode into the input part of the power device. CONSTITUTION:A diode 9 limits energy-suppliable objects by the discharge of a smoothing capacitor 10 for a control circuit power source only to the power device 2 for a control circuit, and only charging is feasible from a battery 1 and a main-circuit smoothing capacitor 6. Accordingly, the terminal voltage of the smoothing capacitor 10 for a control circuit power source i.e., the input voltage of the power device 2 for a control circuit is not influenced in the voltage-lowering direction, when the terminal voltage of the battery lowers temporarily by drawing energy out from the battery rapidly during motor driving operation, or concerning to a pulsating flow of high-frequency voltage flowing reversely from an inverter circuit 5. Consequently, continuity of the operation of a control circuit 3 is protected, and it becomes possible to evade dangerous states such as a short circuit of the power source, etc. |
