ALTERNATOR (A.C. GENERATOR)
In DC Generator. the conductors are rotated in a stationary magnetic field and current flows in the same direction. But in A.C. generator, the magnetic field is rotating and the conductors remain stationary. The current flows first on one direction and then in other alternately.
As shown in Figure, a rotating bar magnet furnishes the moving field which cut the U-shaped conductor. As at when the north pole passes the upper leg of the conductor, the current flows in one direction. As at (B), when the south pole passes the upper leg of the conductor, the direction of the magnetic lines of force is reversed and the current flows in reverse direction in the conductor. Thus, the magnet is revolving continuously, the direction of lines of force is also changing continuously, the current alternate in direction-alternating current flows. The strength of the current depends upon the following factors:
- Strength of the magnetic field.
- Speed of the magnetic field with which it revolves.
- No. of conductors.
|AC Generator Or Alternator Line diagram.|
Instead of a simple bar magnet, two or more pole pieces, having field winding, are assembled on a shaft. When the current flows in the winding, a strong magnetic field is created and the pointed ends of the pole pieces become alternately north and south poles. The two ends of the conductors are connected to the two slip rings fixed on the shaft. The brushes make continuous sliding contact with the slip rings, by which the current is taken out to an external circuit for power transmission and distribution.
|AC Generator Or Alternator|
CONSTRUCTION OF A.C. GENERATOR
Watch the animation video below to know how an AC Generator Or Alternator Works?
Applications Or Uses of AC Generator
- Used in automobiles.
- Power generation system of windmills.
- Power generation system of Hydro-electric power plants.
- Construction projects.
- Oil and gas mining areas.
- Rail and marine transportation.