Transformer

A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.

If a load is connected to the secondary winding, current will flow in this winding, and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (Vs) is in proportion to the primary voltage (Vp) and is given by the ratio of the number of turns in the secondary (Ns) to the number of turns in the primary (Np) as follows:


frac{V_text{s}}{V_{text{p}}} = frac{N_text{s}}{N_text{p}}

By appropriate selection of the ratio of turns, a transformer thus enables an alternating current (AC) voltage to be "stepped up" by making Ns greater than Np, or "stepped down" by making Ns less than Np. The windings are coils wound around a ferromagnetic core, air-core transformers being a notable exception.

Transformers range in size from a thumbnail-sized coupling transformer hidden inside a stage microphone to huge units weighing hundreds of tons used in power stations, or to interconnect portions of power grids. All operate on the same basic principles, although the range of designs is wide. While new technologies have eliminated the need for transformers in some electronic circuits, transformers are still found in nearly all electronic devices designed for household ("mains") voltage. Transformers are essential for high-voltage electric power transmission, which makes long-distance transmission economically practical.

Read more about Transformer:  Basic Principles, Equivalent Circuit, Classification, Types, Applications

Other articles related to "transformer, transformers":

Electrical Machine - Transformer
... A transformer is a static device that converts alternating current from one voltage level to another level (higher or lower), or to the same level, without changing ... A transformer transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils ... primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding ...
Constant Voltage Speaker System - Loudspeaker Connection
... speaker system, each loudspeaker's step-down transformer can be designed for a single power level or it can have multiple taps, one of which is selected to match the desired power level to be applied to the loudspeaker ... Transformers with various taps allow the installer to adjust the sound pressure level up or down at an individual loudspeaker ... power losses, the wires connecting the loudspeaker to the step-down transformer are kept as short as possible ...
Transformer - Applications
... A major application of transformers is to increase voltage before transmitting electrical energy over long distances through wires ... for transmission and back again afterward, transformers enable economical transmission of power over long distances ... Consequently, transformers have shaped the electricity supply industry, permitting generation to be located remotely from points of demand ...
London Drugs Ltd. V. Kuehne & Nagel International Ltd. - Background
... Kuehne Nagel was storing a transformer owned by London Drugs valued at $32,000 ... parties included a limitation of liability clause which limited liability for damage to the transformer to $40 ... Two employees were moving the transformer with a forklift and negligently dropped it ...
Topology (electrical Circuits) - Graph Theory - Mutual Coupling
... no means of explicitly representing mutual inductive couplings, such as occurs in a transformer, and such components may result in a disconnected graph with more than one separate part ... An example would be a transformer earthed on both the primary and secondary side ... The transformer still functions as a transformer with the same voltage ratio but can now no longer be used as an isolation transformer ...

Famous quotes containing the word transformer:

    Man, became man through work, who stepped out of the animal kingdom as transformer of the natural into the artificial, who became therefore the magician, man the creator of social reality, will always stay the great magician, will always be Prometheus bringing fire from heaven to earth, will always be Orpheus enthralling nature with his music. Not until humanity itself dies will art die.
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