is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature. Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually the term refers to small rotating machines driven by automotive and other internal combustion engines. An alternator that uses a permanent magnet for its magnetic field is called a magneto. Alternators in power stations driven by steam turbines are called turbo-alternators.
Conclusion An alternator is such a machine which converts mechanical energy from a prime mover to AC electric power at specific voltage and current. It is also known as synchronous generator.
Uses of Alternator
The power for electrical system of modern vehicles produces from alternator. In previous days, DC generators or dynamos were used for this purpose but after development of alternator, the DC dynamos are replaced by more robust and light weight alternator. Although the electrical system of motor vehicles generally requires direct current but still an alternator along withdiode rectifier instead of a DC generator is better choice as the complicated commutation is absent here. This special type of generator which is used in vehicle is known as automotive alternator. Another use of alternator is in diesel electric locomotive. Actually the engine of this locomotive is nothing but an alternator driven by diesel engine. The alternating current produced by this generator is converted to DC by integrated silicon diode rectifiers to feed all the DC traction motors. And these dc traction motors drive the wheel of the locomotive.
Types of Alternator
Alternators or synchronous generators can be classified in may ways depending upon their application and design. According to application these machines are classified as-
- Automotive type – used in modern automobile.
- Diesel-electric locomotive type – used in diesel electric multiple unit.
- Marine type – used in marine.
- Brush less type – used in electrical power generation plant as main source of power.
- Radio alternators – used for low brand radio frequency transmission
HOW Does it work ?