Patent ID: 7256675

Claim:
An energy transfer apparatus for reducing a conductivity electromagnetic interference for a power supply, connected to an input voltage for outputting an output voltage, comprising: a core; an input winding, wound around the core; an output winding, wound around the core, the output winding capacitively coupled to the input winding; a supply voltage, coupled to a controller for providing an operating voltage; a shielding winding, wound around the core, the shielding winding electrically coupled to the input winding and capacitively coupled to the output winding, and an electric potential produced by a capacitive coupling between the shielding winding and the output winding for reducing a potential difference between the input winding and the output winding for stabilizing an electric potential between an input-grounding terminal and an output-grounding terminal of the energy transfer apparatus to reduce the conductivity electromagnetic interference; and an auxiliary winding, wound around the core, the auxiliary winding electrically coupled to the shielding winding and the input winding and further capacitively coupled to the output winding; wherein the input winding receives the input voltage for outputting the output voltage through the core and the output winding, and outputting the supply voltage through the shielding winding and the auxiliary winding, the output voltage and the supply voltage are produced in proportional to the input voltage respectively.