The transformer is an electromagnetic device , which is used to either step up or step down the voltage levels by keeping power, frequency and flux as constant.

These are devices used in electrical circuits to change the voltage of electricity flowing in the circuit. Transformers can be used either to increase the voltage (called “stepping up”) or decrease the voltage (“step down”).By the definition you will get the clear idea that transformers are the need of electrical industry, we use it in our home, apartment, building, electrical appliances etc. wherever we want the power supply in huge amount.

Also Read: Induction motor definition and working principles


Classification / Types-

Transformers can be classified on a different basis, like types of construction, types of cooling etc.

(A) On the basis of construction, transformers can be classified into two types as;

           (i) Core type transformer

            (ii) Shell type transformer


(I) Core Type –

In core type transformer, windings are cylindrical former wound, mounted on the core limbs as shown in the figure above. The cylindrical coils have different layers and each layer is insulated from each other. Materials like paper, cloth or mica can be used for insulation. Low voltage windings are placed nearer to the core, as they are easier to insulate.

(Ii) Shell Type Transformer-