Internal Circuitry

The alternator has a 12-pole rotor and six (four-cylinder engine) or 12 (V6 engine) zener diodes(1) for rectification.

An excitation diode is connected to each of the three stator windings (2).
The stator windings form three phases and are star- connected (3).

The six (four-cylinder engine) or twelve (V6 engine) rectifier diodes are connected in the form of an a.c. bridge circuit, i.e. three (4-cylinder) or six (V6) diodes are connected for normal polarity (anode to terminal) and three or six for reversed polarity (anode to ground).

According to the polarity, the diode holder is either insulated from ground or connected directly to ground.

The excitation winding (4) is mounted in the rotor, which has claw-type poles.

Each alternate claw serves as north pole and south pole.

The ends of the excitation winding are connected to slip- rings through which the excitation current is supplied.