In this video we will logically understand the operation and construction of a commercial DC motor. The working of a DC motor is well D with the help of animation. Construction details of DC Motor, Shunt & Series motor, concept of back EMF are also explained in this video.
The DC motor is a machine that transforms electric energy into mechanical energy in form of rotation. Its movement is produced by the physical behavior of electromagnetism. DC motors have inductors inside, which produce the magnetic field used to generate movement.
The stator is a permanent magnet and provides a constant magnetic field. The armature, which is the rotating part, is a simple coil.The armature is connected to a DC power source through a pair of commutator rings. When the current flows through the coil an electromagnetic force is induced on it according to the Lorentz law, so the coil will start to rotate.
You will notice that as the coil rotates, the commutator rings connect with the power source of opposite polarity.As a result, on the left side of the coil the electricity will always flow ‘away ‘and on the right side , electricity will always flow ‘towards ‘. This ensures that the torque action is also in the same direction throughout the motion, so the coil will continue rotating.