Transformer

Voltage generated at the power station, voltage level required for efficient transmission and consumers voltage requirement varies. As per the requirement voltage level has to maintained. For this transformer is employed. A transformer can change voltage level without changing the power.

So, a transformer is an electrical machine which converts a high level ac voltage into low level ac voltage and vice-versa.

Types of transformer:-

(i)  Step-down transformer
(ii) Step-up transformer.

Step-down transformer

The transformer which converts high ac voltage level to low ac voltage level is called a step-down transformer.

Number of turns in primary winding is more than number of turns in secondary winding.

Np > Ns

Input voltage at primary terminal is higher than output voltage at secondary terminal.

Vp > Vs

Current flowing in primary winding is less than current flowing in secondary winding.

Ip < Is

Step-down Transformer

Step-up transformer

The transformer which converts low ac voltage level to high ac voltage level is called a step up transformer.

Number of turns in primary winding is less than number of turns in secondary winding.

Np < Ns

Input voltage at primary terminal is less than output voltage at secondary terminal.

Vp < Vs

Current flowing in primary winding is more than current flowing in secondary winding.

Ip > Is

Step-up Transformer