Patent ID: RE44136

Claim:
A method of converting power from a source at a source voltage for delivery to a load at a load voltage, where the source voltage may vary between a high line voltage and a low line voltage in a normal operating range, comprising: providing DC-DC voltage transformation and isolation in a first power conversion stage, the first stage having a CA input for receiving power from the source and a CA output; providing power regulation in a second power conversion stage having a PR input for receiving power from the CA output of the first stage, regulation circuitry, and a PR output for delivering power to the load, the regulation circuitry being adapted to maintain the load voltage within a regulation range while the PR input voltage remains within a normal operating range; providing a hold-up circuit having a charge path and a discharge path for connection to a hold-up capacitance, the discharge path providing a low impedance connection between the hold-up capacitance and the PR input for supplying power to the regulation circuitry, the charge path providing a charge current to charge the hold-up capacitance; configuring the hold-up circuit to charge the hold-up capacitance when a first predetermined condition is satisfied and to provide power to the PR input when a second predetermined condition is satisfied.