A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other. The diode allows an electric current to pass in one direction (called the diode’s forward direction), while blocking it in the opposite direction (the reverse direction). This unidirectional behavior is called rectification, and is used to convert alternating current (ac) to direct current (dc) which is required by the rotor of the Genset alternator