Question

What is the turns ratio of a transformer?

Answer 1

The turns ratio of a transformer refers to the ratio of the number of turns of wire in the primary winding to the number of turns in the secondary winding. It is a fundamental parameter that determines how voltage and current are transformed between the primary and secondary sides of a transformer.

Mathematically, the turns ratio (N) is given by:


=

primary

secondary
N=
N
secondary
    ​

N
primary
    ​

    ​


Where:


primary
N
primary
    ​

 is the number of turns in the primary winding.

secondary
N
secondary
    ​

 is the number of turns in the secondary winding.

The turns ratio directly affects the voltage and current transformation in the transformer. In an ideal transformer (one without losses), the turns ratio determines the ratio of primary voltage to secondary voltage and the inverse ratio of secondary current to primary current. This relationship is described by the following equations:


primary

secondary
=

V
secondary
    ​

V
primary
    ​

    ​

=N


primary

secondary
=
1

I
secondary
    ​

I
primary
    ​

    ​

=
N
1
    ​


In practical transformers, due to losses and non-ideal behavior, the actual voltage and current transformation may deviate slightly from the ideal ratios.

The turns ratio is a crucial parameter in designing and understanding transformers, as it enables engineers to control the voltage and current levels in electrical systems while maintaining power conservation based on the principle of energy transfer.