Rectifiers convert one type of voltage called alternating current (AC) to another voltage called direct current (DC). AC current contains electric flow that can reverse direction, while DC current flows in one constant direction.
Rectifiers can take the form of diodes, two-terminal electronic components that transfer electric current in one direction. Rectifier diodes enable electric current to pass in one direction and block electric current attempting to flow in the reverse direction.
Voltage regulators typically use alternators, which convert mechanical energy into electrical energy in the form of AC current. Regulators disconnect from the generator when it stops producing energy, which prevents the battery from discharging energy back into the generator. The voltage regulator rectifier automatically performs this function, which eliminates the requirement for a specific relay, thereby simplifying the design of the voltage regulator.