I. Alternator. 4. Pulley. 5. Fan. 6. Front holder (bracket). 7. Drive bearing. V. Rotor. 9. Rear bearing. 10. Washer. 11. Diode board. 12. Rear holder. 13. Voltage regulator. 14. Capacitor to suppress electrical interference.
Automobile "Mercedes" equipped with a three-phase alternator. The generator is driven by the crankshaft via a fan belt, with the generator rotor rotating with the generator winding inside the stationary stator winding at approximately twice the speed (rpm).
Electric voltage is applied to the generator winding through carbon brushes and current collectors, resulting in a magnetic field. The position of the magnetic field is constantly changing in relation to the stator windings due to the rotation of the rotor. This, in turn, leads to the appearance of a three-phase current in the stator winding.
Since the battery can only be charged with direct current, the three-phase current is converted into direct current using a rectifier assembled on the diode board. The voltage regulator converts the charging current by switching the generator current on and off depending on the battery charging conditions. At the same time, the voltage regulator maintains a constant generator voltage level (approx. 14 V) regardless of engine speed.
Caution: The three-phase alternator must never be run without a battery. Never run the engine without the battery.