Patent ID: 8482939

Claim:
A power supply, comprising: a source of input supply voltage; a transformer coupled to a load for energizing said load; a switching, power Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) having a source terminal coupled to said transformer and having a drain terminal coupled to said source of input supply voltage for producing a ramping current that stores magnetic energy in said transformer and for developing a voltage at said source terminal of said MOSFET that is coupled to a gate terminal of said MOSFET via said transformer by an auto-transformer action in a regenerative feedback manner, during a first portion of a switching cycle of said MOSFET, when said MOSFET is conductive; and a current sampling resistor coupled in a current path of said ramping current for developing a ramping, degenerative voltage in said resistor to reduce the conductivity of said MOSFET in accordance with said resistor voltage until a turn off threshold voltage of said MOSFET is reached, such that when said turn off threshold voltage of said MOSFET is reached, said source terminal voltage changes in a degenerative feedback manner until said MOSFET becomes non-conductive at an end of said cycle first portion, said MOSFET remaining non-conductive until an oscillatory resonant voltage produced from the stored magnetic energy renders said MOSFET conductive again, at an end of a following, second portion of said switching cycle.