UNINTERRUPTIBLE POWER SUPPLY

This uninterruptible power supply includes a switch that is turned off while an AC power supply is normal and turned on during power failure, a converter that converts AC power supplied from the AC power supply into DC power to supply resultant DC power to a DC link portion while the AC power supply is normal, and that supplies DC power supplied from a battery through the switch to the DC link portion during power failure, an inverter that converts DC power from the DC link portion into AC power to supply resultant AC power to a load, and a chopper circuit that allows DC power from the DC link portion to be stored in the battery while the AC power supply is normal.