Patent ID: 8405254

Claim:
A power supply system, comprising: a first power supply circuit including: a power relay provided between a power supply and a load circuit; a control section that supplies a drive voltage to the power relay upon reception of a power-on command from an external device; a mode selecting switch that turns on/off a connection between the control section and the power supply, wherein the mode selecting switch is turned on for setting the first power supply circuit as a master mode; a power supply input terminal that receives the drive voltage for driving the power relay from an independent power supply circuit separated from the power supply; and a power supply output terminal that outputs the drive voltage to the independent power supply circuit; and a second power supply circuit including; a power relay provided between a power supply and a load circuit; a control section that supplies a drive voltage to the power relay upon reception of a power-on command from an external device; a mode selecting switch that turns on/off a connection between the control section and the power supply; and a power supply input terminal that receives the drive voltage for driving the power relay from the independent power supply circuit, wherein the mode selecting switch of the second power supply circuit is turned off for setting the second power supply circuit as a slave mode; and wherein the power supply output terminal of the first power supply circuit is electrically connected to the power supply input terminal of the second power supply circuit.