Patent ID: 7321174

Claim:
An apparatus to maximize power system holdup time during loss of input power, the apparatus comprising: an energy storage module configured to deliver energy to an output stage of a first power supply, the output stage delivering energy to a bus; a power loss module configured to detect loss of power transmitting capability from an input stage of the first power supply to the output stage of the first power supply; a set-point reduction module configured to reduce an output voltage of the first power supply in response to the power loss module detecting loss of power transmitting capability, wherein reducing the output voltage of the first power supply comprises changing a set point of the first power supply, the set point used by the first power supply to maintain the output voltage of the first power supply at a level proportionate to the set point; and an isolation module configured to prevent energy flow from the energy storage module to the bus when the output voltage of the first power supply is lower than a voltage on the bus sustained by a second power supply.