| 摘要 |
PROBLEM TO BE SOLVED: To provide an uninterruptible power supply device that can continue operating a load even if a transformer fails.SOLUTION: An uninterruptible power supply device 1 includes: a voltage detection circuit 21 for outputting a signal indicating an instantaneous value of an output voltage VO of a transformer 11; a failure detection circuit 30 for bringing a failure detection signal &phgr;D to an "H" level if a pulsating signal is superimposed on the output signal of the voltage detection circuit 21; and a control device 20 for switching from an inverter feed state to a bypass feed state if the failure detection signal &phgr;D is brought to the "H" level. This can prevent the transformer 11 from burning out and continue operating a load 52 even if the transformer 11 fails and a pulsating current appears. |
