POWER SUPPLY DEVICE FOR VEHICLE, AND VEHICLE EQUIPPED WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a power supply device for precharging a parallel capacitor by utilizing an element for connecting a traveling battery to a vehicle side load without providing a dedicated semiconductor switching element for precharging the parallel capacitor.SOLUTION: The power supply device for a vehicle includes: a traveling battery 1 for enabling the vehicle to travel; an output switch 2 for connecting the battery 1 to a vehicle side load 20; and a control circuit 3 for controlling the output switch 2. The output switch 2 is a semiconductor switching element 11 capable of controlling ON resistance. In the power supply device, the ON resistance of the semiconductor switching element 11 is controlled by the control circuit 3 so that the ON resistance in a state of precharging the parallel capacitor 23 of the vehicle side load 20 is set larger than the ON resistance in an electrically-conducted state. After the parallel capacitor 23 of the vehicle side load 20 is precharged, the vehicle side load 20 is supplied with power from the traveling battery 1 with the semiconductor switching element 11 being brought into the electrically-conducted state in which the ON resistance of the semiconductor switching element 11 is smaller than the precharge state.