| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply unit capable of minimizing possibility of rush current, without increasing the cost or extending an area necessary for layout. SOLUTION: A full-wave rectification circuit 1, connected to an external AC power 100 via a resistive element 8, charges a capacitate element 3 for smoothing. A main-circuit power supply is achieved in an output end 11, which is provided to a three-phase inverter 10, acting as an eternal load. A rectifying circuit 2 is also connected to the external AC power, and it charge a capacitate element 4 for smoothing, which has smaller capacity than that of the capacitive element 3 for smoothing. A non-insulated power circuit 6 lowers the voltage at both ends of the capacitive element 4 for smoothing. Control power is achieved in an output end 12, which functions as an operating power for a control circuit 7. The control circuit 7 outputs a control 14, and the opening/ closing of a switch 9 connected in parallel to the resistive element 8 is controlled, based on the signal. |
