Patent ID: 7646182

Claim:
A power supply apparatus including an input terminal and an output terminal, the power supply apparatus boosting an output of a direct-current power supply connected to the input terminal and supplying a predetermined direct-current output to a load connected to the output terminal, the power supply apparatus comprising: a booster circuit that includes a first booster circuit and a second booster circuit each including an input capacitor, a reactor, a diode, a switch element, and an output capacitor, in which the reactors of the first booster circuit and the second booster circuit are magnetically coupled, terminals of a pair of input capacitors formed by connecting the input capacitor of the first booster circuit and the input capacitor of the second booster circuit in series are set as an input terminal, terminals of a pair of output capacitors formed by connecting the output capacitor of the first booster circuit and the output capacitor of the second booster circuit in series are set as an output terminal, and a connection terminal of the output capacitors is set as an-intermediate voltage terminal; a control circuit that controls the booster circuit; and a voltage measuring unit that measures either one of terminal voltages of each of the input capacitors and each of the output capacitors of the first booster circuit and the second booster circuit and terminal voltages of the pair of the input capacitors and the pair of the output capacitors in either one of a direct manner and an indirect manner, wherein the control circuit performs an on/off control of each of the switch elements of the first booster circuit and the second booster circuit simultaneously based on a result of measurement of the voltage measuring unit.