Patent ID: 9490636
Filing Date: 2016-11-08
CPC Classification: H02J

Claim Text:
1. A power supply circuit which supplies power to a load from a main power source or an auxiliary power source, the power supply circuit comprising: an energy storage unit that stores power that is supplied from the auxiliary power source; a hybrid selection unit that elects one of the main power source and the auxiliary power source and supplies power to the load from the selected one; a first voltage comparing unit that compares a voltage of the main power source and a voltage of the auxiliary power source; a power source control unit that controls the auxiliary power source in accordance with a comparison result of the voltage comparing unit, and supplies a voltage higher than the voltage of the main power source by a predetermined voltage to the load from the auxiliary power source through the hybrid selection unit; a reference voltage unit that holds a minimum voltage that is necessary for the load; and another voltage comparing unit that compares a power source voltage selected by the hybrid selection unit with the voltage of the reference voltage unit, wherein: the power source control unit suspends supply of power from the auxiliary power source during a period when the first voltage comparing unit determines that the voltage of the auxiliary power source is higher than the voltage of the main power source by a predetermined voltage or more and the another voltage comparing unit determines that the selected power source voltage is higher than the voltage of the reference voltage unit.