Patent ID: 7723866

Claim:
A power backup system connected to at least one regular power supply system to generate an action to switch the power supply system in the event of abnormal output power occurring to the regular power supply system to maintain power supply, the power backup system comprising: a temporary power supply system which includes a power conversion unit and a backup power source that are connected to each other; and a power source switch unit which has a voltage judgment circuit, a power supply switch controlled by the voltage judgment circuit and a voltage output end, the power source switch unit being connected to the regular power supply system and the temporary power supply system at the same time, the power supply switch having one end connecting to the regular power supply system in regular conditions, the voltage judgment circuit being connected to the power supply switch to get a voltage output from the regular power supply system and delivering output through the voltage output end, the voltage judgment circuit detecting an abnormal voltage output from the regular power supply system and generating a switch signal to control one end of the power supply switch to switch to the temporary power supply system to supply power to the voltage output end; wherein the backup power source of the temporary power supply system includes a DC/DC converter, a charge circuit, an energy storage element, and a switch to receive the switch signal and switch a connecting position, the charge circuit being connected to the DC/DC converter which receives DC power and getting the DC power to charge the energy storage element, the switch having one end connected to the DC/DC converter in the regular conditions and triggered by the switch signal to switch to the energy storage element and another end connected to the power conversion unit at a rear end.