Commutation in DC Machines
In DC machines, commutation is the process of reversing current. Both stationary brushes and the commutator are involved. Commutation is the process of changing the direction of a DC motor’s current before it is applied to the coils. Commutation in DC generators transforms the AC produced in the armature winding into DC.
The electrical switch that rotates and reverses the current flowing from the rotor to the external circuit is called a commutator. It is a split rotary ring , made of copper, with one segment attached to either end of the armature coil. Spring-loaded brushes that come into contact with the rotating commutator supply electricity to the armature coils and the commutator’s segments. For optimal transformation of current , there should be a constant moving contact between the brushes and commutator segments.
Commutator – Definition, Construction, Working, Uses
A commutator is an essential component in electric motors, generators, and dynamometers. Its primary function is to reverse the direction of current flow in the windings of the machine. This ensures continuous rotation in one direction in motors and converts alternating current (AC) to direct current (DC) in generators.
As the armature rotates within the magnetic field, the commutator segments periodically change their connection to the brushes. This reverses the current flowing through the armature coils, maintaining continuous rotation in one direction in motors. In generators, the commutator converts the alternating current induced in the armature coils into direct current.
In this article, we will learn in detail about commutators, their function, types and limitations. We will also compare commutators with slip rings.
Table of Content
- What is a Commutator?
- Commutator and Slip Rings
- Working Principle of Commutator
- Properties of a Commutator
- Applications of Commutator