Electrical connector having transformer with winding wires of different diameters

An electrical connector comprising:

• an insulative housing;
• and
• an inserting module positioned in the insulative housing and including a transformer, the transformer comprising:
• a toroidal magnetic core having a central opening;
• and
• a first and second wire groups each including plural wires, each wire having a central portion, a first end, and an opposite second end, the central portions of each wire group wound around the magnetic core through the central opening;
• wherein
• the first and second wire groups joint to function as a primary winding and a secondary winding of the transformer, and a wire diameter of each of the plural wires of the secondary winding is greater than a wire diameter of each of the plural wires of the primary winding.