17-10-2017, 03:39 PM
A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. A variable current in a coil of the transformer produces a variable magnetic field, which in turn induces a voltage in a second coil. The power can be transferred between the two coils through the magnetic field, without a metallic connection between the two circuits. Faraday's law of induction discovered in 1831 described this effect. Transformers are used to increase or decrease alternating voltages in electrical power applications.
Since the invention of the first constant potential transformer in 1885, transformers have become essential for the transmission, distribution and utilization of the electric power of alternating current. A wide range of transformer designs are found in electrical and electronic power applications. Transformers range in size from RF transformers of less than one cubic centimeter in volume to units that interconnect the power grid that weighs hundreds of tons.