Patent ID: 6198177
Filing Date: 2001-03-06
Classification: H02J,H02M

Abstract:
A power supply, comprising:a transformer having a main power winding with a first leakage inductance, a backup power winding with a second leakage inductance, and a secondary winding;a primary power stage coupled to said main power winding;a backup power stage coupled to said backup power winding and having a backup battery, one of said primary and backup power stages acting as a current fed source and including an inductor with an inductance greater than one of said first or second leakage inductances to which said current fed source is coupled; andan AC power stage, coupled to said secondary winding, that provides a source of AC voltage, said power supply operable in:a normal mode of operation in which said primary power stage supplies power to said secondary winding and further supplies power to said backup power winding to allow said backup power stage to charge said backup battery, anda backup mode of operation in which said backup power stage transfers power from said backup battery to said secondary winding via said backup power winding.