The generator is driven by a crankshaft and V-belt, with the rotor rotating at approximately twice the engine shaft speed by an excitation winding located within the rigidly mounted stator winding.
With the help of carbon brushes and slip rings, the excitation current flows through the excitation winding. In this case, an electromagnetic field is formed. The position of the electromagnetic field constantly changes in relation to the stator winding in accordance with the rotation of the rotor. Due to this, a three-phase current is generated in the stator winding. But since the battery can only be charged with direct current, the three-phase current is converted into direct current by a rectifier mounted on the diode board. The voltage regulator changes the charging current by switching the excitation current on and off in accordance with the state of discharge of the battery. At the same time, the regulator maintains a constant operating voltage of about 12 volts, regardless of the rotation speed.
Safety precautions when working on an alternator
When working on the alternator, pay attention to the points given below the instructions. Complete disassembly and repair of the alternator should be carried out in a specialized auto repair shop.
If an additional battery is connected (for example, to facilitate engine starting), be sure to ensure that the same poles of the batteries are connected to each other.
When connecting the charger, connect the wires of the latter to the corresponding terminals of the battery. During charging, disconnect the wire from the flexible partition between the body and the engine and the positive wire from the battery terminals.
Do not allow the engine to run without a battery.
Never short-circuit the terminals on the alternator and the regulator.
Never reverse the polarity of the alternator.
Article text obtained from the website mercedesman.ru