Phone: 86-29-88685333
Mobile: 86-13620067891
E-mail: fks@fks-coils.com
Add：C2 Building, Western Cloud Valley, Fengxi New Town, Xixian New Area, Xi'an City, Shaanxi Province, China
Mobile: 86-13620067891
E-mail: fks@fks-coils.com
Add：C2 Building, Western Cloud Valley, Fengxi New Town, Xixian New Area, Xi'an City, Shaanxi Province, China
How to reduce EMC interference in transformer design? - FKS
Time: 2024-05-21 Source: Author:
1.FKS often collects the noise of the distributed capacitance by adding a shielded copper foil or winding between the primary stage and shunt it to other places through the primary ground.
The thickness of the shielded copper foil is usually 0.1mm, in order to meet the insulation requirements, the backbonded copper foil is generally used, one end of the welded enamelled wire is primarily grounded, the other end does not overlap, and the total number of turns is 0.9. The shielding winding is relatively simple, the wire diameter is mostly 0.2~0.3mm, and it can be wrapped around a layer, one end is primary grounded, and the other end is cut and buried in the online package.
2. Add copper foil around the transformer. Its main purpose is to reduce radiation. The normal operation is to wrap a circle of copper foil around the outside of the wire package and connect it to the secondary ground. The ones with stricter EMI requirements are cross copper foils, and the overlapping parts are welded together for grounding.
However, the peripheral copper foil must consider the primary and secondary insulation issues, so the width of the copper foil needs to be set appropriately to avoid poor voltage resistance. In addition, in order to facilitate the transformer process operation, the peripheral copper foil is mostly self-adhesive copper foil, and the thickness is mostly between 0.05~0.1mm.
3. The primary winding is placed in the innermost layer of the transformer, and all outer windings can shield this layer. This method mainly considers the unstable voltage generated by the drain of the MOS tube, which affects the primary coil.
4. Reduce leakage inductance as much as possible and reduce the peak current of MOS switch tubes, thereby reducing EMI interference.
5. The primary auxiliary winding is grounded, and the other end is grounded through a small capacitor. This method is similar to the principle of shielding between the primary and secondary, but the primary auxiliary winding is generally outside the secondary, and the effect is not as obvious as the shielding between the primary and secondary.
The thickness of the shielded copper foil is usually 0.1mm, in order to meet the insulation requirements, the backbonded copper foil is generally used, one end of the welded enamelled wire is primarily grounded, the other end does not overlap, and the total number of turns is 0.9. The shielding winding is relatively simple, the wire diameter is mostly 0.2~0.3mm, and it can be wrapped around a layer, one end is primary grounded, and the other end is cut and buried in the online package.
2. Add copper foil around the transformer. Its main purpose is to reduce radiation. The normal operation is to wrap a circle of copper foil around the outside of the wire package and connect it to the secondary ground. The ones with stricter EMI requirements are cross copper foils, and the overlapping parts are welded together for grounding.
However, the peripheral copper foil must consider the primary and secondary insulation issues, so the width of the copper foil needs to be set appropriately to avoid poor voltage resistance. In addition, in order to facilitate the transformer process operation, the peripheral copper foil is mostly self-adhesive copper foil, and the thickness is mostly between 0.05~0.1mm.
3. The primary winding is placed in the innermost layer of the transformer, and all outer windings can shield this layer. This method mainly considers the unstable voltage generated by the drain of the MOS tube, which affects the primary coil.
4. Reduce leakage inductance as much as possible and reduce the peak current of MOS switch tubes, thereby reducing EMI interference.
5. The primary auxiliary winding is grounded, and the other end is grounded through a small capacitor. This method is similar to the principle of shielding between the primary and secondary, but the primary auxiliary winding is generally outside the secondary, and the effect is not as obvious as the shielding between the primary and secondary.
