Difference between Armature and Commutator

An electrical device like DC Generator converts the energy from mechanical to electrical. This device includes three essential parts like an armature, magnetic field system, commutator, brush gear, yoke, magnetic frame, pole core, pole shoes, exciting coils/field, windings, armature core, end housings, brushes, shafts & bearings. This article discusses an overview of the difference between armature and commutator.

Difference between Armature and Commutator

The combination of the commutator, ball bearings, winding & brushes is called an armature. It is an essential part where all these parts include here to execute different tasks. It is responsible for the flux generation once the current supply throughout the winding is connected through the field flux.

This flux association generates a reaction that locates some influence on the flux caused. The flux obtained will get decreased or distorted because of the armature reaction. However, the commutator role is dissimilar from the armature because it is utilized for unidirectional energy generation.

Here we are going to discuss the main difference between armature and commutator which includes its definitions and functionalities

What is an Armature?

In electrical machines like motors and generators, the armature is an essential component that holds AC or alternating current. In a machine, it is a stationary part or rotating part. The interaction of armature through the magnetic flux can be attained within the air gap.


As a conductor, an armature works & normally sloping within both the field directions & the direction of torque, motion, or force. The essential components of an armature mainly include the core, the shaft, the commutator, and the winding.


Armature Components. An armature can be designed with a number of components namely the core, the winding, the commutator, & the shaft.

An armature is used for different purposes. The main function of this is to transmit current across the field & produces shaft torque in an active machine or linear machine. The secondary task of this is to generate an electromotive force (EMF).

In this, both the relative movement of the armature & the field can be an electromotive force. When the machine is utilized like a motor, then EMF will oppose the current of an armature & it converts the power from electrical to mechanical in a torque form. Finally, it transmits it throughout the shaft.

Once the mechanism is used as a generator, then the EMF of the armature will drive the current of the armature & the motion is changed to electrical power. In the generator, the generated power will be drawn from the stationary part like the stator.

What is Commutator?

A rotating electrical switch like a commutator has periodically overturned the flow of current among the rotor & the exterior circuit. A commutator includes a set of copper segments that are arranged approximately to the part of the turning machine otherwise the rotor & a set of brushes loaded with spring can be attached to the inactive frame of the DC machine.


In DC machines like DC motors and generators, commutators are used. A commutator provides a current supply to the motor windings. A stable rotary torque can be generated by overturning the direction of current within the rotary windings every half turn.

The commutator in a generator will reverse the flow of current direction through every turn serving as a mechanical rectifier to change the AC from the generator windings to unidirectional DC within the exterior load circuit.

Key Difference between Armature & Commutator

The key difference between armature and commutator is discussed in the following table.



An armature is an essential component in a DC machine. A commutator is a rotating electrical switch
It gets the flow of current from the windings of an armature. It gets the flow of current from the core of an armature.
The core of an armature includes armature windings, brushes & a commutator. It includes some segments


It is designed with silicon (Si) steel It is designed with Mica Insulation through 0.5mm width


It provides current to commutator from the core of the armature It changes AC to DC & vice-versa
It is a set of coils arranged in the core It is a set of segments


The armature is laminated to decrease the losses It is insulated through Mica to decrease the sparking & to execute a level operation


It is responsible for the production of flux It is responsible for the receiving of armature current
It transmits AC (alternating current) to segments The AC is changed into DC with the segments


It produces  non-uniform current It changes either to non-uniform/ uniform  current based on the necessity


It generates flux that communicates through the major field to generate armature reaction Because of the armature reaction, it is capable of receiving the current using the winding of the core.


How does an Armature Rotate in a Motor?

Generally, an electric motor converts the energy from electrical to mechanical. In DC machines, it is a rotary part. A conductor which carries current experiences force once it is located within the magnetic field & the way of force can be provided through the left-hand rule of Fleming.

When the supply is given to the stator, the rotating magnetic field is induced in the motor. This rotating magnetic field exerts a force on the armature (rotor) and the armature rotates. This is sometimes referred to as the armature reaction of a synchronous motor.


The applications of armature include the following.

  • The armature within an electrical system is used to produce power.
  • It may be used like a stator or a rotor.
  • In DC motor applications, it is used to monitor the flow of current

The applications of commutator include the following.

  • In electrical machines, it is a moving part and the main function of this is to reverse the direction of current in between the rotor & the exterior circuit.
  • According to the DC machine, its function will be changed
  • It is used in different AC and DC machines which include motors and generators

Thus, this is all about an overview of the difference between armature and commutator. The major disparity between the armature or rotor windings is how the connection of windings can be done electrically. The connection in the usual DC motor can be done through a commutator & brushes. Here is a question for you, what are the rotor and stator in dc machines?