Step Up and Step Down Transformers

In a transformer, the secondary voltage can be more or less than primary voltage. The voltage is dependent on the number of turns in each coil. In an ideal transformer, the relationship between the voltages and the ratio of the turns of the primary and secondary coils is given as below:

Where:

Vs = Secondary voltage

Vp= Primary voltage

Ns = Number of turns in secondary coil

Np = Number of turns in primary coil

From the above equation, if Ns is greater than Np, the Vs is greater than Vp. In this case we have a step-up transformer. If Ns is less than Np, we have a step-down transformer, where the secondary voltage is less than the primary voltage.