Patent ID: 6853564

Claim:
An AC to DC power supply having an autoranging front end for receiving high-line and low-line AC voltage inputs, said AC to DC power supply comprising a full wave rectifier circuit for receiving AC voltage at first and second nodes thereof, a third node being coupled to an input capacitor filter including first and second capacitors at an output node, and a fourth node coupled to the series configuration of input capacitors at a return node, said power supply comprising: a switching device having a first and second terminal, a first terminal connected to a node common to said first and second capacitors, and a second terminal connected to a first ac line input, said switching device being in a conduction state at low line AC voltage input and being switched out of conduction for high line AC voltage inputs to provide said auto ranging front end; a linear inductor connected between a first node of said full wave rectifier circuit and said second terminal of said switching device, wherein said linear inductor is switched in series with the input capacitor filter at high line AC voltage inputs in order to reduce current values at harmonic frequencies generated by said AC to DC power supply and increase power factor for said power supply.