An uninterruptible power supply which is down-sized and lightened is provided. A utility line 1 is connected with a switch 8 and the switch 8 is connected with a rectifying circuit 2 and DC power from the rectifying circuit 2 inputs to a first inverter 3-1 and charges a battery 6 by a charger 7 connected...http://www.google.es/patents/US5384792?utm_source=gb-gplus-sharePatente US5384792 - Uninterruptible power supply
