Patent ID: 7151678

Claim:
A power system comprising: power conversion apparatus comprising: a first input for receiving an alternating current (AC) signal; a second input for receiving a direct current (DC) signal; a first number of power supply circuits each comprising: an AC conversion circuit for generating an output signal based on the AC signal; a revert circuit coupled to the AC conversion circuit for generating the output signal based on the DC signal, the revert circuit comprising a switch and a battery charger, wherein the switch and the battery charger of all of the revert circuits are coupled in common at the second input; and at least one output for providing the output signal; and load apparatus operatively coupled to the power conversion apparatus to receive the output signal and comprising at least one load circuit, wherein each battery charger is configured with a corresponding predetermined capacity that causes at least a portion of the DC signal to be provided by the battery chargers and, thereby, at least a portion of the output signal to be generated using the battery chargers upon failure of at least one AC conversion circuit.