There are many tapes used on transformers, which can be determined according to the needs of the designer, mainly using insulating tape, Mara tape, and copper foil tape. Let's talk about the role of transformer outsourcing shielding copper foil.
In the transformer, copper foil is used as a shielding layer, that is, after the primary coil is wound, a layer of copper foil is wrapped and then the secondary coil is wound. Leading the copper foil out of a head to ground can play a shielding role.
The role of self-adhesive copper foil in transformers
Many high-frequency transformers are wound with a self-adhesive copper foil. This is to prevent external high-frequency interference signals from entering the machine. Therefore, there is an electrostatic shielding layer between the primary and secondary of the transformer (a very thin layer). The copper foil that cannot be short-circuited is generally connected to the steel support of the transformer) and connected to the bottom wire of the machine.
In addition, the presence of the conductive copper foil tape shielding layer greatly reduces the distributed capacitance between the primary and secondary coils, and can reduce the transmission of high-frequency stray interference signals. Because the equivalent capacitance is connected in series after isolation, the capacitance between primary and secondary will naturally become smaller. And the high frequency components can be discharged directly through the capacitance to ground.