Power converter transformer for suppressing conduction EMI and power supply having its transformer
In accordance with the present invention, a power converter transformer for suppressing conduction EMI (ElectroMagnetic Interference) includes a primary winding positioned at a primary side; a secondary winding positioned at a second side and coupled with the primary winding; a parasitic capacitor connected between one end of the primary winding and one end of the secondary winding; a switching unit connected to the other end of the primary winding; a Y-capacitor connected between the switching unit and a ground terminal; an auxiliary winding positioned at the secondary side and coupled with the secondary winding; and an auxiliary capacitor connected between the one end of the primary winding and the auxiliary winding.
1. A power converter transformer for suppressing conduction EMI (ElectroMagnetic Interference) comprising:
a primary winding positioned at a primary side;
a secondary winding positioned at a second side and coupled with the primary winding;
a parasitic capacitor connected between one end of the primary winding and one end of the secondary winding;
a switching unit connected to the other end of the primary winding;
a Y-capacitor connected between the switching unit and a ground terminal;
an auxiliary winding positioned at the secondary side and coupled with the secondary winding; and
an auxiliary capacitor connected between the one end of the primary winding and the auxiliary winding.
2. The power converter transformer for suppressing the conduction EMI of claim 1 , wherein the primary winding, the secondary winding, and the auxiliary winding include polarities respectively and the auxiliary winding includes a polarity opposite to a polarity of the secondary winding.
3. The power converter transformer for suppressing the conduction EMI of claim 1 , wherein the switching unit is a transistor.
4. A power supply comprising:
an AC input power source;
an input choke connected to the AC input power source;
a rectifier connected to the input choke;
a PFC (Power Factor Correction) unit connected to the rectifier;
a power converter transformer connected to the PFC unit; and
a rectification unit connected to the power converter transformer, wherein the power converter transformer includes:
a primary winding positioned at a primary side;
a secondary winding positioned at a second side and coupled with the primary winding;
a parasitic capacitor connected between one end of the primary winding and one end of the secondary winding;
a switching unit connected to the other end of the primary winding;
a Y-capacitor connected between the switching unit and a ground terminal;
an auxiliary winding positioned at the secondary side and coupled with the secondary winding; and
an auxiliary capacitor connected between the one end of the primary winding and the auxiliary winding.
5. The power supply of claim 4 , wherein the primary winding, the secondary winding, and the auxiliary winding include polarities respectively and the auxiliary winding includes a polarity opposite to a polarity of the secondary winding.
6. The power supply of claim 4 , wherein the switching unit is a transistor.
7. The power supply of claim 4 , wherein the rectification unit includes a diode or a synchronous rectifier.