Alternator Components (Typical Example)
(1) Brush holder. (2) Rear frame. (3) Rotor. (4) Stator. (5) Drive end frame. (6) Fan assembly. (7) Slip rings. (8) Rectifier.
The alternator has three phase, full-wave, rectified output. It is a brush type alternator.
The alternator is an electrical and mechanical component driven by a belt from engine rotation. It is used to charge the storage battery during engine operation. The alternator is cooled by a fan that is a part of the alternator. The fan pulls air through holes in the back of the alternator. The air exits the front of the alternator, cooling it in the process.
The alternator converts mechanical and magnetic energy to alternating current (AC) and voltage. This process is done by rotating a direct current (DC) electromagnetic field (rotor) inside a three phase stator. The alternating current and voltage (generated by the stator) are changed to direct current by a three phase, full wave rectifier system using six silicone rectifier diodes. The alternator also has a diode trio which is an assembly made up of three exciter diodes. The diode trio rectifies field current needed to start the charging process. Direct current flows to the alternator output terminal.
A solid state regulator is installed in the back of the alternator. Two brushes conduct current, through two slip rings, to the field coil on the rotor.
There is also a capacitor mounted in the back of the alternator. The capacitor protects the rectifier from high voltages. It also suppresses radio noise.