摘要 |
The present invention provides a power-supply device, which can continuously supply a voltage from a power supply to a load even if a breakdown of a circuit is generated. The power-supply device includes a booster circuit, a normally-closed bypass relay, a CPU, and a switching circuit. A first switch of the switching circuit is turned on by a switching signal from the CPU, and a second switch is turned on by a boosting request signal from a boosting request signal generator. In the case that one of or both the switching signal and the boosting request signal are not input to the switching circuit 14, because a coil of a bypass relay is not energized, a contact turns on, and a voltage is supplied from a DC power supply to the load through the contact. When both the switching signal and the boosting request signal are input to the switching circuit, the coil is energized to turn off the contact, and a voltage supply path to the load is switched from the side of the bypass relay to the side of the booster circuit.
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