The generator is driven by a belt from the crankshaft. The generator, as its name suggests, can only produce alternating current. However, the on-board network requires constant current, because the battery is a source of direct current. Therefore, the generator has a built-in diode rectifier unit that converts alternating current into direct current. Rectifier diodes are very sensitive to voltage peaks.
To ensure that the generator's performance is sufficient even at low engine speeds, the generator's rotation speed is greater than the crankshaft's. This is achieved by installing a belt pulley on the generator shaft that has a smaller diameter than the generator drive belt pulley on the crankshaft shaft. The voltage regulator is mounted on the rear side of the generator.
When working on a generator, certain safety precautions must be observed.
- a) Do not disconnect the battery or voltage regulator while the engine is running. In such cases, voltage peaks are formed, damaging electronic devices.
- b) Do not short-circuit the generator excitation winding terminal or the wire from this terminal to ground (-).
- c) Do not reverse the polarity of the voltage regulator wires.
- d) Do not turn on the voltage regulator if it is shorted to ground (-). Otherwise, it will be damaged.
- d) Do not remove the alternator without first disconnecting the battery completely or at least the negative (ground) terminal. Otherwise, irreparable damage will inevitably occur.
- g) Do not use a test lamp connected to a 110 or 220 V network. It is permissible to use a 12 V test lamp.
- h) Disconnect the cables from the battery when charging it with a charger without removing it from the vehicle. Instead, connect the charger wires, observing the polarity. If the polarity is not observed, the rectifier, voltage regulator, and electronic devices will be damaged.