Patent ID: 8754545

Claim:
A power supply comprising: an input port to receive a source of input power, the input port having a first terminal and a second terminal; an output port to provide output power, the output port having a first terminal and a second terminal; a switching power supply having an input coupled to the input port to receive input power and an output coupled to the output port to provide output power; a selected circuit node having a potential, wherein, when input power is provided to the input port, the potential difference between the first terminal of the input port and the selected circuit node has the same polarity as the potential difference between the first and second terminals of the input port, but is less in magnitude; and a circuit combination of a coupling circuit and an energy storage device, a first terminal of the circuit combination being coupled to the first terminal of the input port, and a second terminal of the circuit combination being coupled to the selected circuit node, the circuit combination being configured to couple energy from the energy storage device to the input of the switching power supply when input power is not provided at the input port.