Electrical connector

An electrical connector (10) includes plural pairs of mating terminals (24), plural pairs of foot terminals (26), and a number of circuit board component units. The circuit board component unit includes an upper inner circuit board (141), a lower inner circuit board (142), and a number of electronic components mounted onto the upper and lower inner circuit board (141,142). The electronic components include a number of transformers (15), each transformer (15) including a drum type core (161), a primary winding wire (171), and a secondary winding wire (172) wound around the drum type core (161). The primary winding wire (171) of one transformer (15) and the primary winding wire (171) of an adjacent transformer (15) or the secondary winding wire (172) of the one transformer (15) and the secondary winding wire (172) of the adjacent transformer (15) are disposed adjacent to each other to prevent electric discharge.