Patent ID: 8817495

Claim:
An ultralow no-load conduction loss DC converter, comprising: a DC power source comprising a positive terminal and a negative terminal; and a transformer comprising a first winding, a second winding and a third winding, the first winding provided on a primary side of the transformer and the second winding and the third winding provided on a secondary side of the transformer, said first winding having one end thereof electrically connected to the positive terminal of said DC power source and an opposite end thereof electrically connected to a first MOSFET, said first MOSFET being electrically connected to said PWM controller, said PWM controller having the function of entering one of a burst mode, a pulse skipping mode and an off-time modulation mode at low load; and a drive control unit and a rectifier unit configured to output an output voltage, which are electrically connected with each other, the drive control unit being electrically connected with a second MOSFET, said second MOSFET, said drive control unit and said rectifier unit constituting a combination circuit electrically coupled between one end of said second winding and one end of said third winding, and said second MOSFET is directly electrically coupled between said second winding and said third winding, said second MOSFET comprising therein a body diode, said second winding and said second MOSFET forming a combination circuit electrically connected to a load; wherein said output voltage is less than a predetermined voltage to turn off said drive control unit and further turn off said second MOSFET when said DC converter is operated in the no-load condition.