The alternator is composed of a rotor assembly, a stator assembly and two end-frame assemblies, one at the drive end of the alternator and one at the slip ring end.

The rotor assembly is composed of a field coil made of many turns off wire wound over and iron core which is contained between two iron segments with interlacing fingers. These fingers serve as magnetic poles. This assembly is press mounted on a steel shaft which turns in pre-lubricated anti-friction bearings. Two slip rings are mounted on one end of the shaft.

Each and of the field coil winding is connected to one of the slip rings. A brush rides on each slip ring. These brushes conduct battery current to the rotor winding to create the magneticfield required for current generation. This is necessary because the rotor is made of a metal alloy that does not retain residual magnetism and is therefore not self exciting.

ALTERNATOR COMPONENTS

The stator assembly is composed of a laminated iron frame and three sets of winding wound into slots in the frame. The manner in which these windings are wound and connected makes the alternator 3 phase unit. Constant voltage can be maintained since each of the three winding reaches its maximum voltage output at a different time. Three voltage impulses are induced for every turn of the rotor with this arrangement it whereas 1 voltage impulse would be induced if a single winding was used. One end of all three windings are connected together while the other end of each winding is connected to a pair of diodes, one positive and one negative.

When assembled, a very small air gap is present between the rotor poles and the stator to keep the magnetic field lines of force as strong as possible. As the rotor spins, the alternate north and south poles of the rotor fingers pass each loop in the stator winding inducing an alternate amperage and voltage in the winding. This alternating current is then rectified by the diodes.

The slip ring end-frame contains 6 diodes, which are electrical rectifying devices. The diodes, three negative and three positive, act as one way valves formatting current to pass freely in one direction but not in the other. By their combined action, the alternating current generated is rectified to direct current.