18 Feb 2017
Electromagnetic Induction implies that when a conductor is placed in an area of varying magnetic field, current is induced in the conductor. A DC Dynamo Motor works on this principle of electromagnetic induction- a dynamo motor consists of a rectangular coil/wire which moves in a magnetic field thus inducing current in the coil/wire. In the case of this application, the armature is the rectangular coil and when the armature rotates, it cuts the lines of magnetic force only to produce a current in the field coil.
To sum it up, a basic dynamo motor contains a rectangular coil, made from many turns of an insulated copper wire, the armature coil. This armature coil can be rotated at a high speed between the poles of a field coil, to produce current. With each end of the armature coil connected through two copper half rings, it also consists of two carbon brushes which tend to pass against these ‘split rings of a commutator’. The passing of these brushes against the two half rings, one by one, taps out the current produced in the armature coil.