- A generator can be modified to an a.c generator by replacing its commutators with two (separate) slip rings. The two slip rings rotate in tandem with the armature.
- Carbon brushes connect the armature to the external circuit. The armature is initially at the vertical position. No magnetic flux is cut and hence no induced current exists.
- When the armature rotates, the change in magnetic flux increases and the induced current increases until its maximum value at the horizontal position.
- The direction of the induced current can be determined from Fleming’s Right-Hand Rule.
- As the armature continues on its rotation, the change in magnetic flux decreases until, at the vertical position, no induced current exists.
- Subsequently, upon reaching the horizontal position again, the induced current is maximum, but the direction of the induced current flowing through the external circuit is reversed.
- The direction of the induced current (which flows through the external circuit) keeps changing depending on the orientation of the armature. This induced current is also known as alternating current.
- The current is positive (+) in one direction and negative in the other (-). The smooth rings play a critical role in the generation of alternating current.