| 摘要 |
PROBLEM TO BE SOLVED: To improve the efficiency and reliability of a backup power supply device for feeding power from a battery when an AC power supply fails. SOLUTION: A backup power supply device includes a power factor improvement circuit 2 for improving a power factor by switching control and for supplying an output DC voltage to a single or a plurality of DC-DC converters 51-5n, a battery 3, and a converter 4 for backup for supplying an output DC voltage to the DC-DC converters 51-5n from the battery 3 when the AC power supply 1 fails. The converter 4 for backup is started or set to a normal operating state according to the power failure detection signal of the AC power supply 1, and the output DC voltage is set to a lower value than the output DC voltage of the power factor improvement circuit 2. |
