A generator is commonly responsible for producing power or electric current. These generators are like power plants. They employ the same mechanism as an electric power plant to generate the current. The physical mechanism behind the working of generators is that they convert mechanical energy into electrical energy for supplying electric current to the premises. The working principle of DC generators is that they provide direct current during the power generation process by energy conversion. This article explains how DC generators work and what principles they work on.

Generators

Generators are the setups used to produce power by converting energy from one form to another. Generators are usually of two basic types, based on the nature of power or the current they generate. On such a basis, the two types of generators are: 

• AC generator
• DC generator

DC Generator 

A DC generator produces a direct current by converting energy by doing work. Direct current from a DC generator is produced by continuous rotation of the armature present in the generator. The DC generators play a role in car engines, charging batteries, and the electrolytic systems where the diffusion of dissociated ions comes into play.

Working Principle of a DC generators

A DC generator employs two physical principles stated by Faraday and Flemming. They determine how DC generators work. The two working principles of DC generators are:

• Faraday’s law of electromagnetic induction
• Flemming’s right-hand rule for determining the direction of induced current

Faraday’s Law

Faraday’s law applies to the concept of electromagnetism, which involves the interaction of electrically charged molecules or atoms. The law is used to determine the behaviour of a magnetic field with an electrical network for producing an electromotive force (EMF) due to their interaction. Thus, the law involves three main components. They are:

• Electric field
• Magnetic field
• Electromotive force

The law states that when a conductor is positioned in a continuously altering magnetic field, it produces an electromotive force as a result.

Fleming’s Rule

In general, Fleming’s right-hand rule applies to the power generators. The law is used to determine the direction or how the electric current flows in the coils of a generator when the magnetic field is changing. The law involves three essential components. They are:

• Conductor 
• Magnetic field
• Induced current  

According to Flemming’s right-hand rule, on holding the thumb, index, and middle finger of the right hand in a direction when they are perpendicular to each other: 

• The thumb shows how the conductor is moving.
• The index finger represents how the magnetic field moves.
• The middle finger shows how the induced or freshly generated current moves.

The Working Mechanism of the DC Generator 

• The DC generators produce a direct current of electricity by feeding it with fuel. 
• The DC generator consumes the fuel and burns it, producing mechanical action of rotation of the armature core or rotor. 
• In turn, the mechanical action produces a change in the magnetic field of the coil, producing a direct electric current as electrical energy. 
• This electrical energy can be used to operate electronic items. 
• The fuels used to spark mechanical energy are of various types. 
• The fuels include gas, steam, water, etc.
• DC motors work in the reverse manner of a DC generator. 
• A DC motor fluctuates the amplitude of the current as required. Thus, theoretically, a DC generator can be used as a DC motor by inter-reversing the working process.
• All the DC transformers’ parts work to convert the electrical energy into mechanical energy to do mechanical work. 

Parts of a DC Generator 

A DC generator has several parts that work together to generate a direct current. The parts of the DC generator include the following:

• Commutator
• Brushes 
• Armature core
• Armature winding
• Field winding
• Pole
• Yoke

Commutator 

• The commutator has an important role in ensuring that the current produced is direct current, not alternating.
• They are split ring commutators made of copper materials that are insulated from each other.
• The current direction is reversed when the armature completes a half-circle of rotation—this reversing of current results in alternating currents (AC).
• The armature connection is also reversed when split rings are used while the current reverses. 
• Thus, it maintains a steady direct current (DC) production that is unidirectional.

Brushes 

• The brushes make sure that the commutator remains connected with the external circuit.

Armature core or rotor

• It does the mechanical work by consistently rotating in the generator as a rotor.
• These cylindrical components are laminated to decrease the eddy current loss in the DC generator.
• It has divisions or slots for winding the armature wire connections.

Armature winding

• The insulated copper wires are wound in the armature slots as series to parallel for maximum current.

Field winding

• These are copper wires wound around the poles connected to the external circuit.
• It is wound in series.
• They form alternate North and South poles on energising.

Pole

• The poles are attached to the yoke.
• They are connected by pole shoes, which ensures a uniform flux distribution.

Yoke

• It is the outermost part of a DC machine.
• It is made up of conducting materials such as steel and iron.
• They carry the induced current to the external circuit.

Conclusion 

The generators are responsible for converting the mechanical energy carried out within the generator into electrical energy. The generators are of two types based on the nature of the current they produce. The two types are DC generators and AC generators. DC generators give off direct current, whereas an AC generator gives off alternating current. The DC generators are employed in car engine batteries, charging batteries, etc. The basic working principles of DC generators are Faraday’s law and Flemming’s right-hand rule. These rules determine how DC generators work.