Patent ID: 8755973

Claim:
A vehicular power supply system comprising: a main motor for driving a vehicle; a main machine drive circuit for driving the main motor; a steering assist motor for assisting a steering operation of the vehicle; a steering assist drive circuit for driving the steering assist motor; a brake actuator for braking the vehicle; a brake drive circuit for driving the brake actuator; a battery for supplying power to the main machine drive circuit, the steering assist drive circuit and the brake drive circuit; a main machine switching circuit provided between the battery and the main machine drive circuit and capable of shutting off power supply from the battery to the main machine drive circuit; and an auxiliary machine switching circuit provided between the battery and both of the steering assist drive circuit and the brake drive circuit and in parallel to the main machine drive circuit relative to the battery, the auxiliary machine switching circuit being capable of shutting off power supply from the battery to the steering assist drive circuit and the brake drive circuit, wherein the battery outputs a voltage higher than a voltage, which is required to drive the steering assist motor and the brake actuator, and wherein the auxiliary machine switching circuit includes a switch, a first fuse and a second fuse, the switch being capable of switching between conduction and non-conduction, the first fuse being connected in series between the switch and the steering assist drive circuit, and the second fuse being connected in series between the switch and the brake drive circuit.