Transformer

 What is Transformer?

• A transformer is a static electrical machine which is used to change the voltage level of the AC power supply.
• It can increase(step up) or decrease(step down) the level of voltage.
• It accomplishes this by electromagnetic induction.
• It does so without any change of the supply frequency.

Working Principle of Transformer

"The transformer works on the basic principle of electromagnetic induction and mutual induction between two coils/windings which are magnetically connected"

• Before going to the theory and laws, we will know the main function what it does.
• There are usually two coils primary coil and secondary coil on the transformer core if we give a power supply across the primary coil at any specific voltage level then the secondary coil will provide the same power with another different voltage level.  

 

Theory Explanation

• Suppose you have a coil or winding which is supplied by an alternating electrical power source. 
• Then the alternating current will passes through the coil and it will create a changing(Amplitude & Direction) or alternating magnetic flux that surrounds the coil. 
• Now if another winding is brought close to this winding some portion of this alternating flux will touch or link the second winding.
• Hence there will be an EMF or voltage induced in the second winding as per Faraday's law of electromagnetic induction.
• If you close the circuit of this second winding the an alternating current will flow through it. This is the basic working principle of a transformer.