What is Commutator : Construction and Its Applications

The commutator can be defined as is an electrical rotating switch in a particular type of generators as well as motors. This is mainly used to overturn the direction of current among the external circuit & rotor. It comprises a cylinder with numerous metal contact segments lying on the revolving armature of the machine. The brushes or electrical contacts are made with a carbon press material next to the commutator, designing sliding contact by consecutive segments of the commutator while it revolves. The armature windings are allied to the segments of the commutator.

The applications of commutators include DC (direct current) machines like DC generators, numerous DC motors, as well as universal motors. In a DC motor, the commutator provides electric current to the windings. By changing the direction of current within the revolving windings every half turn, a torque (steady revolving force) will be produced.

Commutator Construction and Working

The construction and working of a commutator are, a commutator can be built with a set of contact bars that are set toward the revolving shaft of a DC machine, and allied to the armature windings. When the shaft turns, the commutator will reverse the current flow within a winding. For a particular armature winding, once the shaft has completed the one-half turn, then the winding will be connected so that current supplies through it in the reverse of the first direction.

In a DC motor, the armature current causes the set magnetic field to use a rotating force, otherwise a torque over the winding for making it revolve. In a DC generator, the mechanical torque can be applied in the direction of the shaft to maintain the armature winding motion via the stationary magnetic field, stimulating a current within the winding. In these two cases, Sometimes, the commutators will reverse the direction of current flow throughout the winding so that the flow of current within the circuit which is external to the machine maintains in only one direction.