Transformer

The transformer comprises a primary side coil and a secondary side coil, the primary side coil and the secondary side coil are mutually insulated and magnetically coupled, and the primary side coil extends from a first starting end to a first ending end in the spiral direction from inside to outside and comprises a plurality of winding sections which are connected end to end. The primary side coil has at least two line widths, and the secondary side coil has one line width. According to the transformer disclosed by the embodiment of the invention, the primary side coil of the transformer has at least two coils, the secondary side coil has one line width, and the matching of the primary side coil and the secondary side coil can effectively enhance the magnetism gathering capability of the coils, improve the coupling coefficient of the primary side and the secondary side, enhance mutual inductance and improve the voltage induction capability of the secondary side coil.