Patent ID: 8213190

Claim:
A single-stage isolated high power factor AC/DC converter with a leakage inductor energy recovery function, comprising: a buck-boost circuit, for step-down or step-up a power supply and comprising an input inductor, a first capacitor, and a first rectifier, wherein the input inductor is serially connected to the first capacitor, and the first rectifier is connected to the serially connected input inductor and first capacitor in parallel; an input capacitor, one end of which is electrically connected to the input inductor, and an other end of which is electrically connected to a ground; a transformer, comprising a primary side and a secondary side, for transforming the stepped-down or stepped-up power supply, wherein one end of the primary side is electrically connected to the first rectifier and the first capacitor and an other end of the primary side is electrically connected to the ground; a switch, one end of which is electrically connected to the input inductor and the first capacitor, and an other end of which is electrically connected to the ground, wherein when the switch is cut off, the buck-boost circuit provides an energy recovery path to return energy stored in a leakage inductor of the transformer to the input capacitor; and an output circuit, electrically connected to the secondary side of the transformer, for outputting the power supply transformed by the transformer.