UNINTERRUPTIVE POWER SUPPLY AND ITS FEED SWITCHING METHOD

PROBLEM TO BE SOLVED: To reduce the consumption of a storage battery power supply and lessen the frequency of charging of the storage battery power supply by a maintainer. SOLUTION: In the case that the AC voltage input through an inputting section 210 is higher than 95 V, the AC voltage input through the inputting section 210 is outputted as it is. In the case that the AC voltage input through the inputting section 210 is higher than 92 V and at most 95 V, the AC voltage input through the inputting section 210 is outputted through a rectifier circuit 220 and an inverter circuit 250. In the case that the AC voltage input through the inputting section 210 is at most 92 V, voltage accumulated in a storage battery circuit 230 is outputted through the inverter circuit 250.