Transformers

Transformers are electrical devices which transfer electrical energy between two or more circuits without changing the frequency through the use of the principle of electromagnetic induction. The energy transfer usually takes place with a change of voltage and current. Transformers either increases or decreases AC voltage. A varying current in one coil of the transformer produces a varying magnetic field, which in turn induces a varying electromotive force (emf) or “voltage” in a second coil. Power can be transferred between the two coils through the magnetic field, without a metallic connection between the two circuits. Transformers are used to meet a wide variety of needs. A wide range of transformer designs is encountered in electronic and electric power applications. Transformers range in size from RF transformers less than a cubic centimeter in volume to units interconnecting the power grid weighing hundreds of tons. No matter what the shape or size, a transformers purpose remains the same: transforming electrical power from one type to another.