Transformer

A transformer is an electrical device that transfers energy from one circuit to another by magnetic coupling, without requiring relative motion between its parts. A transformer comprises two or more coupled windings, and, in most cases, a magnetic core to concentrate magnetic flux. A changing voltage applied to one winding creates a time-varying magnetic flux in the core, which induces a voltage in the other windings.

The transformer is one of the simplest of electrical devices, yet transformer designs and materials continue to be improved.

Transformers come in a range of sizes from a thumbnail-sized coupling transformer hidden inside a stage microphone to huge gigawatt units used to interconnect large portions of national power grids. All operate with the same basic principles and with many similarities in their parts.

Audio frequency transformers were used by the earliest experimenters in the development of the telephone. While new technologies have made some transformers in electronics n implications obsolete, transformers are still found in many electronic devices.

Transformers are essential for high voltage power transmission, which makes long distance transmission .economically practical. This advantage was the principal factor in the selection of alternating current power transmission in the "War of Currents" in the late 1880s.

ВАРІАНТ II