Lenzie’s Law The magnetic effect surrounding the conductor in which a current is induced opposes the movement of the conductor through which the inducing current is flowing.

Commutators By rotating a coil in a magnetic field an alternating current is produced fig 10c.

To obtain direct current flow from a generator a circuit using a commutator and brushes must be used. fig 10d illustrates a basic armature with commutator and brushes fitted.

The commutator is the moving output surface which is in contact with the brushes.

As the armature revolves the commutator contacts are designed to ensure that brush A always carries current from the commutator to the charging circuit.

Fig 10f

Direct Current Generators are always fitted with Commutators and brushes