Patent ID: 7710748

Claim:
An alternating current to direct current (AC/DC) converter comprising: an AC/DC conversion stage having: an input filter that receives an AC input voltage; an input rectification circuit that is coupled to the input filter, wherein the input rectification circuit further comprises: a diode bridge that is coupled to the input filter; and an negative temperature coefficient (NTC) thermister that is coupled to the diode bridge; a transformer having a first winding and a second winding, wherein each of the first and second winding are coupled to the input rectification circuit; a boost diode that is coupled to the first winding of the transformer; and a bulk capacitor that is coupled to the boost diode, wherein the bulk capacitor is configured to store a range of DC voltages that are substantially proportional to the input AC voltage; and a DC/DC conversion stage; a pre-regulator buck converter stage that is coupled to the AC/DC conversion stage; an output isolation transformer stage that is coupled to the pre-regulator buck converter stage; a controller that receives feedback from an output of the AC/DC converter so as to control the pre-regulator buck converter stage.