A.c generators
Cars use a type of a.c. generator, called an An electrical generator which produces alternating current, an ac generator., to keep the battery charged and to run the electrical system while the engine is working.
The a.c. generator
The diagram shows a simple a.c. generator.
As one side of the coil moves up through the An area around a magnetic material or the moving electric charge through which the force of magnetism acts., a current is The production of a potential difference (voltage) when a conductor, such as a wire, is moved through a magnetic field or exposed to a varying magnetic field. If the conductor is part of an electric circuit, an induced current will flow. in one direction.
As the rotation continues and that side of the coil moves down, the induced current reverses direction.
This means that the generator produces a current that is constantly changing.
This is alternating current or a.c.
The size of the induced voltage, and hence induced current, can be increased by:
- increasing the speed of rotation of the coil;
- increasing the strength of the magnetic field by using a stronger magnet;
- increasing the number of turns on the coil.
In Northern Ireland, large scale a.c. generators are used to produce electricity, like the ones at Ballylumford and Kilroot in Co. Antrim, which is then transmitted across country to consumers.
The coil of these generators rotates 50 times a second and that is why our mains supply is 50 Hz a.c.