BACKUP POWER SUPPLY DEVICE, POWER SUPPLY SYSTEM, COMPUTER SYSTEM, COMPUTER SYSTEM POWER SUPPLY CONTROL METHOD, AND POWER SUPPLY CONTROL PROGRAM

摘要

PROBLEM TO BE SOLVED: To keep a computer device supplied with a DC voltage when a backup power supply device is actuated.SOLUTION: A backup power supply device backs up an ordinary power supply device including a first conversion circuit which converts a first AC voltage to a first DC voltage and a second conversion circuit which is connected via a diode to the first conversion circuit to convert the first DC voltage to a second DC voltage. The backup power supply device includes: a first detection circuit, connected to the output of the first conversion circuit, which outputs a first detection signal when the first DC voltage is lower than a first predetermined value; a third conversion circuit which converts a second AC voltage to a third DC voltage; a battery which is charged with the third DC voltage; and a first switch circuit which connects either one of the battery output and the third conversion circuit output to the input of the second conversion circuit on the basis of output of the first detection signal.