Patent attributes
A transformer is to be electrically connected to a circuit board. The transformer has a bobbin, a copper sheet assembly and a coil assembly. The bobbin has two side plates and a winding core on which a primary winding, a secondary winding and a magnetic core assembly are mounted. The copper sheet assembly as the primary or the secondary winding has multiple copper sheets. Each copper sheet is an inverted U-shape with two legs, and is mounted on a groove defined on the winding core. Engaging structures formed on the copper sheets and the grooves steadily hold the copper sheet assembly on the winding core to prevent the copper sheets from shifting to incorrect positions. A conducting board below the bobbin connects the copper sheets in sequence. Since the loops formed by the copper sheets and the electrical connector are more nearly concentric, leakage inductance of the transformer will reduce.
