Question

What is a commutator?

THE COMMUTATOR of an electric motor is the means by which an appropriate reversal of current may be achieved. In the case of a single loop a suitable commutator would consist of two half cylinders of brass, insulated from each other and mounted on the same shaft as the loop.

Current may be supplied to the half cylinders by means of carbon brushes and if the half cylinders are connected in turn to the ends of the loop then, as shown below, the current in the loop will be reversed in such manner that the rotation of the loop will be continuous.