A full-wave rectifier converts alternating current (AC) to direct current (DC). This diode bridge circuit is one implementation of a full-wave rectifier. During positive half of the AC wave only two of the four diodes allow the current to pass through a resistor. During negative half-wave the other two diodes allow the current to pass through the resistor. The diodes are arranged such that the current through the resistor is unidirectional.
EveryCircuit current animation clearly shows the two alternating paths that conduct current during positive and negative half-waves. A picture is worth a thousand words. EveryCircuit animation is worth a thousand pictures
