A transformer is a device used in the power transmission of electric energy. The transmission current is AC. It is commonly used to increase or decrease the supply voltage without a change in the frequency of AC between circuits. The transformer works on basic principles of electromagnetic induction and mutual induction.
Working principles of transformer
- A transformer operates on the principle of mutual inductance, between (and sometimes more) inductively coupled coils. It consists of two winding in proximity.
- The two winding are coupled by magnetic induction. (There is no conductive connection between the winding).
- One of the windings call primary is energized by a sinusoidal voltage.
- The second winding, called secondary feeds the load.
- The alternating current in the primary winding steps up an alternating flux in the core.
- The secondary winding is linked by most of this flux and EMFs.
- Energy is transformed from the primary circuit to the secondary circuit through the medium of the magnetic field.
In brief, a transformer is a device that:
(a) transfer electric power from one circuit to another, (b) it does so without change of frequency; and (c) it accomplishes this by electromagnetic induction (or mutual inductance)