What is a car alternator?
The alternator provides the electricity needed to operate a vehicle. When starting the car the battery it is the one that provides the necessary energy, after which the alternator comes into action. It charges the battery continuously, providing the necessary voltage for all electrical and electronic components of the car.
The alternator is actually a electric current generator. Its rotor is driven by the car engine through a drive belt.
By rotating the rotor, which is actually a magnet, inside the stator, a alternative induced voltage. The alternating voltage is transformed into direct voltage and stabilized by means of diodes and voltage regulator.
The constituent elements of the alternator
- Voltage regulator
- Manifold rings
- Diode rectifier bridge
- Rear fan
- Front fan
The alternator is a compact equipment, with small dimensions and relatively simple composition. Modern cars, which incorporate many electronic systems, require a fairly large amount of energy, so alternators must produce up to 2 kW / h.
The alternator housing is usually made of aluminum and has the role of housing the other pieces inside. Through it, the alternator is mounted inside the engine compartment.
Another role of the housing is to protect the sensitive elements inside from the penetration of water and dust that could cause less or more damage.
The stator is a metal body consisting of several thin sheets, over which are wound several turns of copper. This piece has the role of taking over the electric current produced by the movement of the magnets over the copper network. As the name suggests, the stator is an immovable part.
The rotor is moving part of the alternator, placed on a shaft inside the stator. It has the role of producing a magnetic field by spinning. On the rotor there is a rotor winding of copper wire and two apparent magnets, which generate a magnetic field.
The power supply is made with the help of some collector rings, the contact being ensured through a two graphite brushes.
Alternator voltage regulator
The voltage regulator of the alternator has the role of providing power with a constant voltage, regardless of engine speed. By means of this part the intensity of the magnetic field of the rotor is regulated, which leads to the production of an electric current with a regular voltage of about 14.2 V.
The voltage regulator is mounted on the alternator housing, which also has the role of cooling the part.
Car axle rectifier
The rectifier bridge contains 6 diodes integrated in an aluminum radiator. For each phase of the alternator, 2 diodes are used to transform the alternating current into electric current.
Also the rectifier bridge with more diodes has the role of blocking the flow of current from the battery to the alternator, if the alternator voltage drops below the battery voltage. The rectifier bridge is integrated in the alternator housing at the rear.
In addition to these main components, there is another bearing in the composition of the alternator which ensures the smooth and effortless rotation of the rotor, two fans in the front and rear for additional cooling of the assembly and a pulley on the outer end of the rotor, which connects the motor and alternator through the accessory belt.
Signals transmitted by a faulty alternator
An alternator that no longer works properly can lead to other defects, the repair of which can be much more expensive than checking and repairing the alternator.
In the following, we present to you the symptoms of an alternator that no longer works in the parameters.
If the alternator no longer works properly, you will notice that the car's lights (headlights, taillights, turn signals, on-board lights, etc.) will be dimmed from normal and the power windows will open heavily.
Rubber smells would make strange noises
If the alternator bearings have failed (seized, broken, worn, etc.), the rotor can no longer sustain the rotational movement imposed by the motor and then the drive belt begins to slip and friction occurs. By this friction, it also heats up gives off a "burning" smell.
Also, if you hear strange noises, the drive belt is worn or loose.