Transformers

The transformer is a device that transfers electrical energy from one circuit to another circuit through the medium of magnetic field and without change in the frequency. The electrical circuit which receives energy from the supply mains is called primary winding and the other circuit which delivers electric energy to the load is called the secondary winding.

This device is a electromagnetic energy conversion device. The electrical energy present in the primary winding is changed into magnetic energy and this magnetic energy is again converted back to electrical energy in  secondary circuit. The two circuits primary and secondary are magnetically coupled. Energy is transfered by this magnetic coupling between two cicuits  and no mechanical device is utilized therefore efficiency of transformers is as high as 98%.

Step Up Transformers: If the secondary windings has more number of turns then primary winding then the secondary voltage is higher then the primary voltage and the transformer is called as step up transformer.

Step Down Transformers: If the number of turns in the secondary side is less than the primary side then the voltage in secondary side is  lower then the primary voltage and the transformer is called as step down transformer.

There is  a third kind of transformer where number of windings in primary is equal to the number of windings in secondary these transformers are used for isolation purpose.