What is a Generator
Generator is a device which is used for converting mechanical energy into an electrical energy its working is based on Faraday’s law of electromagnetic induction, e.m.f is produced according to Faraday’s law, the law states that whenever a conductor is placed in a varying magnetic field an e.m.f will be induced in the conductor, and the e.m.f will cause a current flow to the conductor which will take place if the circuit is closed
Introduction to DC generator
There are two types of generator which are AC and DC generator a generator always converts mechanical power into electrical power. In an AC generator, it produces alternating current while in DC it produces direct current
A simple generator can be converted into a direct current generator by doing this
- Current must be made to move in one direction
- The current must be conducted from the rotating loop of the wire
Components of DC generator
Rotor
It is the rotating device in the generator it consists of a single loop of wire made to rotate in a magnetic field. Mostly the rotor consists of several coils of wire wound on an armature
Armature
The armature is a cylinder which is made up of laminated iron and it is mounted on the axle, the axle is mounted in the external part of the generator. To make the rotor spin torque is applied to the axle.
Coil
Mostly the coil will be copper wire which is wounded to the armature, each end of the coil is either connected to two slip rings or it will be connected to two opposite bars of split ring commutator
Stator
It is the fixed part of the generator that supplies the magnetic field in which the coil rotates and it may consist of two permanent magnets with opposite poles which are shaped to fit around the rotor, the magnetic field may be provided by two electromagnets alternatively
Brushes
The brushes will maintain contact with the coil by the help of slip rings or the split ring commutator. And the electric current will be conducted from the coil to an external circuit
Field electromagnets
The electromagnet has many turns of a copper wire coil wound on a soft iron core, the electromagnets are mounted in a way that the opposite poles face each other and wrap around the rotor
Uses of DC generator
Many DC generators are AC driven in a combination called motor generator sets and thus we could change the alternating current into direct current
- It can be used in factories that do electroplating
- It is used in factories which produce aluminum, chlorine and other industrial material needs a large amount of DC current
- It is used in locomotives and ships driven by a diesel-electric motor
- It is used in series arc lightning
Why does a DC generator is replaced by an AC generator
It is because the commutators of the Dc generator is complex and it is very costly and due to that a lot of DC generator is replaced by a modified AC generator and it is very economical
The AC generator modification is done by adding rectifiers which will change the current flow to only one direction