Bridge Rectifier is made of four diodes connected in a bridge circuit. It is housed in a plastic moulded box. This bridge rectifier converts alternating current (AC) into direct current (DC). It provides the same output polarity for either input polarity. All electronic devices require direct current, so bridge rectifiers are used inside the power supplies of almost all electronic equipment. For an easy understanding of the internal circuitry, the circuit diagram is printed on the box.