Working Principle and Types of Transformers

Working Principle of Transformer

A transformer’s operation is straightforward. It works on the principle that mutual induction allows the transfer of electrical energy across circuits using two or more coils.

  • Transfers electric power from one circuit to another.
  • Transfers electricity without any change in frequency.
  • Uses the electromagnetic induction method to transfer electricity.
  • Links the two electrical circuits with mutual induction.

Components of a Transformer

A transformer’s primary components are as follows:


The core of the transformer functions as a support for the winding. It also provides a low resistance channel for the flow of magnetic flux. To decrease energy losses, a core consists of a laminated soft iron core. Furthermore, parameters such as operational voltage, current, and power determine the core composition. A point to note is that the core diameter is related to the amount of copper lost and inversely proportional to the amount of iron lost. (For more information, read the FAQs)

The Winding

Windings are the copper wires that coil around the transformer core. The high conductivity of copper minimizes the loss of energy because of the principle: “when the conductivity increases, resistance to current flow decreases”. Furthermore, the high ductility of copper, which allows for the metal to be moulded into thin wires, is a desirable trait as well.

  • Primary Winding: These are the set of coils that obtain supply current.
  • Secondary winding: These are the set of coils that release the current output.


Transformers require insulation to separate windings as well as prevent short circuits. Therefore, insulating agents have an impact on a transformer’s durability and stability. A transformer employs the following materials as an insulating medium:

  • Oil
  • Tape
  • Wood-based lamination

Types of Transformers: Based on Design

The arrangement of the main and secondary coils around the laminated steel core varies across transformer types. This gives rise to two types of transformers based on their design:

Core Transformers



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