Basic Concepts about Transformer

A transformer transfers alternating voltage at one circuit to another circuit without a change in power and frequency. Fig. 1 shows the general configuration. The iron core is made up of laminated thin sheets of silicon steel. Each sheet is 0.35 mm thick insulated on both side by a thin layer of varnish or paper.

  
Here there is two coil. The primary coil has N₁ turns and connected to the source of ac supply. The secondary coil has N₂ turns and supplies power to the load.