Transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. The main components are a primary coil, a secondary coil and an iron core (magnetic core). The main functions are: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer), etc. It can be divided into: power transformer and special transformer (electric furnace transformer, rectifier transformer, power frequency test transformer, voltage regulator, mining transformer, audio transformer, intermediate frequency transformer, high frequency transformer, impact transformer, instrument transformer, electronic transformer , Reactors, transformers, etc.).