The entire electrical system of a car depends on the electricity generated by the generator. The principle of a generator is that a changing magnetic field inside a coil will cause an electric current through the wires of the coil. So, by revolving a magnet inside a coil, you create an electric current.
In a car generator, the magnetic field is not created by magnets, but by a separate set of coils on the rotor. This means there are two coil systems: one in the rotor, creating the magnetic field, and one on the housing (the stator), creating the electric current.
The rotor depends on current to create the magnetic field, but as the rotor rotates, it's impossible to connect it directly to wires. That's why carbon brushes, sliding over two separated rings on the rotor, which are connected to the ends of the coils, deliver the current.
As the rotor rotates the magnetic poles, so does the current, generated in the stator. That's why these generators are called alternators. A bridge of diodes reroutes the currents to create a direct current, needed to charge the battery.
The voltage of a generator depends on the rotor speed and the strength of the magnetic field. The voltage could go up to as much as 140 Volts if there wouldn't be some sort of regulation. That's why every generator is equipped with a voltage regulator, which decreases the current through the rotor to decrease the magnetic field, thus reducing the generated voltage within its range.
Most common failures in generators are worn carbon brushes, broken or short-circuited wires in the coils or a broken voltage regulator, often resulting in broken light bulbs or "boiled" batteries. Voltage regulators or carbon brushes can sometimes be replaced, though it isn't advisable as the coils and the collector may have suffered. Replacement of the generator by a quality Nipparts generator is the reliable way to go.
Many factors determine the quality of a generator, from the quality of the bearings, the length and spring force of the carbon brushes and the smoothness of the collector, to the balance of the rotor and the quality of the copper wiring and the wire coating, which prevents short-circuiting. Nipparts generators are the result of decades of experience with development of generators. That's why Nipparts generators are always manufactured to OE quality standards.
Nipparts offers a wide range of OE quality generators for Japanese and Korean car brands. Check our catalogue for all our references.
- High quality bearings
- Produced to OE tolerances
- Produced to OE quality standards
- High value for money ratio