A dynamo is an electrical generator that creates direct current using a commutator. Simply put, a device that makes direct current electric power using electromagnetism. It is basically a DC generator, i.e. an electrical machine which converts mechanical power into direct current electrical power. Dynamos were the first electrical generators that were used to deliver power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the alternating-current alternator, the electric motor, and the rotary converter.
Working of Dynamo
Above is an image of simple dynamo with a coil made from conducting wire which is placed between the North and the South poles of two permanent magnets. No voltage is induced when the coil is stationary. As the coil rotates, there is a change in the magnetic field which induces a voltage within the coil.
In the first half of the rotation, the left side of the coil moves from the North pole of the left magnet. In the second half of the rotation, the coil moves from the South pole of the right magnet. During these rotations, there are two polarities that is possible: positive and negative. The change between these polarities is known as alternating voltage.
Difference between Dynamo and Generator
|Dynamo is the precursor of modern day electric generators.
Direct current is produced by the dynamo.
|Generators are used for producing electric current.|
|Commutators are used for converting alternating current into direct current.||Solid state electronic AC to DC are used for the conversion.|