Question

Write a short note on:

1. Armature coil

2. Brushes

3. Commutator

4. Direct current

Answer 1

Fig: Construction of Dynamo or generator

A generator or a Dynamo is a device that converts mechanical energy into electrical energy. The generator was originally designed by Nikola Tesla.

Principle:-

It works on the principle of Electromagnetic induction.

Construction:

The main component of Dynamo

1). Armature coil: - Armature coil consists of a large number of turns of insulated copper wire wounded over a soft iron core. The armature is rotated in a strong uniform magnetic field provided by a powerful permanent magnet NS. The axis of rotation is perpendicular to the field.

2). Brushes: - Brushes are the part of the commutator, the brushes must conduct electricity as the keep contact with the rotating armature. The first brushes were actual wire "brushes" made of small wires.

3). Commutator:- Commutator reverses the current at the exact instant when the armature coil crosses the magnetic field neutral axis. This is necessary to maintain a unidirectional torque. Thus, the commutator converts the direct current into alternating current.

4). Direct current:- Dynamo is an electrical generator that creates direct current using a commutator.