1 - front part
2 - drive bearing
3 - plate
4 - segment key
5 - rotor
6 - rear ball bearing
7 - stator
8 - diode board
9 - carbon brushes
10 - voltage regulator
11 - terminal elements
12 - Noise suppression capacitor
AUDI 80/90 are equipped with an alternator. Depending on the model, a generator with a capacity of 65 A to 90 A can be installed.
The generator rotates from the crankshaft via a V-belt. At the same time, the anchor with the excitation coil rotates inside the stator coil with double the engine speed.
The excitation current flows through the excitation winding via carbon brushes and slip rings, creating a magnetic field.
The position of the magnetic field relative to the stator winding constantly changes along with the rotation of the anchor. Thus, an alternating current is induced in the stator winding.
But since the battery can only be charged with direct current, the alternating current is converted to direct current by a rectifier on the diode board. The voltage regulator changes the magnitude of the charging current, turning the excitation current on and off depending on the state of charge of the battery. At the same time, the regulator maintains the voltage of the on-board network constant at about 14 V, regardless of the number of revolutions.
Caution: Unlike a DC generator, it is prohibited to operate an AC generator without a battery. That is, the battery must not be removed when the engine is running.