Patent ID: 8723363

Claim:
An uninterrupted power supply apparatus, comprising: a rectifying unit, having a positive output terminal and a negative output terminal, which outputs a positive half-cycle of voltage potential and a negative half-cycle of voltage potential respectively; a backup battery, having a positive terminal and a negative terminal, for outputting a backup voltage; a first boost unit, coupled to the positive output terminal of the rectifying unit and the positive terminal of the backup battery, for receiving the positive half-cycle of voltage potential or the backup voltage and outputting a first voltage; a second boost unit, coupled to the negative output terminal of the rectifying unit and the negative terminal of the backup battery, for receiving the negative half-cycle of voltage potential or the backup voltage and outputting a second voltage; a charge circuit, coupled to the rectifying unit, the backup battery, the first boost unit, and the second boost unit, for controlling the second boost unit to either store a first charging power or charge the backup battery by applying the first charging power alternatively and successively and for controlling the first boost unit to either store a second charging power or charge the backup battery by applying the second charging power alternatively and successively; and a current shunt unit, coupled to the first boost unit and the second boost unit, for receiving the first voltage and the second voltage and outputting an AC output voltage.