The generator is driven by a crankshaft and a V-belt. In this case, the rotor rotates at approximately twice the speed of the motor shaft with the help of an excitation winding located inside a rigidly installed stator winding.
With the help of carbon brushes and slip rings, the excitation current flows through the excitation winding. This creates an electromagnetic field. The position of the electromagnetic field is constantly changing with respect 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 to direct current using 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 degree of discharge of the battery. At the same time, the regulator maintains a constant operating voltage of about 12 volts, regardless of the speed.
Safety precautions when working on an alternator
When working on the alternator, pay attention to the points below. Complete disassembly and repair of the alternator should be carried out in a specialized car workshop.
If an optional battery is connected (e.g. to make starting the engine easier), be sure to pay attention to the fact 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 let the engine run without the battery.
Never short-circuit the terminals on the alternator and on the regulator.
Never reverse the polarity of an alternator.