US Patent 8106535 Power conditioner

A reliable power conditioner comprises: a power converting circuit for converting direct-current power obtained from a direct-current power source to alternating-current power of a commercial power system; a charger/discharger circuit for charging the direct-current power obtained from the direct-current power source to an accumulator or discharging the direct-current power stored in the accumulator; a control circuit for controlling the power converting circuit and the charger/discharger circuit; and a power source selecting circuit for selecting at least one of first, second, and third power source circuits and supplying power to the control circuit.