An electrical commutator is a rotating switch that periodically switches the direction of current flowing between the rotor and the external circuit.
The DC generator's commutator transforms AC into pulsing DC. The commutator guarantees that the generator's current always flows in a single direction. The generator and the load are electrically connected via the brushes, which travel on the commutator.
DC devices like DC motors and generators use commutators. The commutators function as a mechanical rectifiers in a DC generator, converting the alternating current from the windings to direct current in the external load circuit. The commutator in a DC motor switches the direction of the current to deliver electricity to the windings.