What Is DC Generator | Construction of DC Generator | Working Principle of DC Generator | Types of DC Generator



Hello friends, in today’s article we will talk about the construction of a DC generator and its type and its working principle and its use. The primary electromagnetic generator was invented by Michael Faraday, a British scientist, in 1831. This is a machine used to generate electrical energy.

The main function of this machine is to convert mechanical energy into electrical energy. Mechanical energy is available to us in many ways such as hand cranks, internal combustion engines, water turbines, gas, and steam turbines.

The reverse of the generator can be done by an electric motor. The generator powers all the electrical power grids. The main function of a motor is to convert electrical energy into mechanical.

What is a DC Generator?

The DC generator works to convert direct current to electric current. The energy change process uses the principle of electromotive force induced by energy.

When any conductor intercepts a magnetic flux, it generates an induced electromotive force based on the principle of electromagnetic induction according to Faraday’s law. This electromotive force can cause a current to flow when the conductor circuit is not opened.

Also Read: Best Pole Changing Method Of Speed Control Of Induction Motor

Construction of DC Generator:

The DC generator can also be used as a DC motor without any modification work in its construction. So in general DC motor can also be used as a DC generator. The construction of a 4-pole DC generator uses the parts shown below.

#1. Stator.
#2. Rotor or Armature Core.
#3. Armature Windings.
#4. Yoke.
#5. Poles.
#6. Pole Shoe.
#7. Commutator.
#8. Brushes.

4 Pole DC Generator

#1. Stator:

The stator is a part of the importance of a DC generator whose main function is to provide magnetic fields where the coil spins. Inside is a stationary magnet. Where two of them are facing opposite poles. This magnet is located to fit in the field of the rotor.

#2. Rotor or Armature Core:

The rotor or Armature Core is another important part of the DC generator. It consists of slotted iron laminations with slots that are stacked to shape the cylindrical armature core.

Armature Core

Generally, these laminations are used to reduce the damage caused by eddy currents.

#3. Armature Windings:

Armor core slots are mainly used to hold the armor windings. This is in the form of a closed circuit winding, and it is connected in series with a parallel to increase the sum of the currents produced.

Also Read: Difference Between AC And DC Generator | AC Vs DC Generator

#4. Yoke:

The exterior of a DC generator is a yoke, and it is made of cast iron otherwise steel. It provides the mechanical strength required to carry the magnetic flux provided by the poles.

#5. Poles:

This is mainly used to grip the field windings. Typically, these windings are wound on poles, and they are connected in series otherwise parallel by armature windings. Besides, the poles will not be welded to the joint by the welding method using a screw.

Pole Core & Pole Shoes

#6. Pole Shoe:

Pole shoes are mainly used to propagate magnetic flux otherwise used to prevent field coils from falling.

#7. Commutator:

The function of the commutator is similar to that of a rectifier which is used as a rectifier in converting AC voltage to DC voltage. Which is crossed by an armature brush.


Which is made from a segment of copper, and each copper segment is protected from each other with the help of mica sheets. It is located on the shaft of the machine.

#8. Brushes:

Electrical connections can be ensured between the commuter as well as the external load circuit with the help of a brush.

Working Principle of DC Generator:

The working principle of a DC generator depends on Faraday’s law of electromagnetic induction. When a conductor is located in an unstable magnetic field, an electromotive force is induced inside the conductor.

The intensity of the induced e.m.f can be measured by the equation of the electromotive force of the generator.

If the conductor is present in the closed lane, the current that is induced will flow into the lane. In this generator, the field coil will generate an electromagnetic field as well as the armature conductor will be rotated in the field.

Therefore, an electromagnetic induced electromotive force (e.m.f) will be generated in the armature conductor. The path of the induced flow will be offered by Fleming’s right-hand rule.

Types of DC Generators:

The DC generator can be divided into two main parts one is Separately excited and the other is Self-excited.

1.Separately excited: In this type of field the coils are excited from an independent external DC source.


The field coils are excited from the current produced by the generator itself in this generator. The initial Emf generation is due to residual magnetism in the field poles. The generated emf causes the current coil to flow into the field coil. Thus strengthening the flow of the field and thereby increasing the Emf Generation. Self-propelled DC generators can be further divided into three types

(A) Series wound – field winding in series with the armature winding.
(B) Shunt-wound – field winding parallel to the armature winding.
(C) Compound wound – a combination of series and shunt winding.

Uses of DC Generator:

  • This type of generator is used for booster and for electroplating.
  • Self-excited DC generators or shunt DC generators are used for general lighting with the help of power as well as regulators. It can be used for battery lighting.
  • Compound DC generators are used to supply power to DC welding machines.
  • Over compound, DC generators are used to compensate for voltage drop in feeders.


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