# transformer

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transformer
/trans fawr"meuhr/, n.
1. a person or thing that transforms.
2. Elect. an electric device consisting essentially of two or more windings wound on the same core, which by electromagnetic induction transforms electric energy from one set of one or more circuits to another set of one or more circuits such that the frequency of the energy remains unchanged while the voltage and current usually change.
[1595-1605; TRANSFORM + -ER1]

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Device that transfers electric energy from one alternating-current circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping down) the voltage.

Uses for transformers include reducing the line voltage to operate low-voltage devices (doorbells or toy electric trains) and raising the voltage from electric generators so that electric power can be transmitted over long distances. Transformers act through electromagnetic induction; current in the primary coil induces current in the secondary coil. The secondary voltage is calculated by multiplying the primary voltage by the ratio of the number of turns in the secondary coil to that in the primary.

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device that transfers electric energy from one alternating-current circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping down) the voltage (volt). Transformers are employed for widely varying purposes; e.g., to reduce the voltage of conventional power circuits to operate low-voltage devices, such as doorbells and toy electric trains, and to raise the voltage from electric generators so that electric power can be transmitted over long distances.

Transformers change voltage through electromagnetic induction; (induction, electromagnetic) i.e., as the magnetic lines of force (flux lines) build up and collapse with the changes in current passing through the primary coil, current is induced in another coil, called the secondary. The secondary voltage is calculated by multiplying the primary voltage by the ratio of the number of turns in the secondary coil to the number of turns in the primary coil, a quantity called the turns ratio.

Air-core transformers are designed to transfer radio-frequency currents—i.e., the currents used for radio transmission; they consist of two or more coils wound around a solid insulating substance or on an insulating coil form. Iron-core transformers serve analogous functions in the audio-frequency range.

Impedance-matching transformers are used to match the impedance of a source and that of its load, for most efficient transfer of energy. Isolation transformers are usually employed for reasons of safety to isolate a piece of equipment from the source of power.

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Universalium. 2010.

### Look at other dictionaries:

• transformer — [ trɑ̃sfɔrme ] v. tr. <conjug. : 1> • v. 1295; lat. transformare « former (formare) au delà (trans) » I ♦ 1 ♦ Faire passer d une forme à une autre, donner un autre aspect, d autres caractères formels à. ⇒ changer, modifier , renouveler.… …   Encyclopédie Universelle

• Transformer — Trans*form er, n. 1. One who, or that which, transforms. Specif. (Elec.), an apparatus for producing from a given electrical current another current of different voltage. [1913 Webster] 2. (1990 s) a toy consisting of a figure or representation… …   The Collaborative International Dictionary of English

• Transformer — (homonymie) Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom …   Wikipédia en Français

• Transformer — bezeichnet: Transformator in der englischen Sprache eine Spielzeug Actionfigur, siehe Transformers ein Überkopf Fahrgeschäft, siehe Top Star Tour Transformer (Album) ein Album von Lou Reed Siehe auch: Transformers (Begriffsklärung)… …   Deutsch Wikipedia

• transformer — UK US /trænsˈfɔːmər/ noun [C] ► a piece of electrical equipment that changes the force of an electrical current: »an electric/electrical/power transformer …   Financial and business terms

• transformer — transformer. См. трансформер. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

• transformer — (n.) device to reduce electrical currents, 1883, from Fr. transformateur (1882); see TRANSFORM (Cf. transform) …   Etymology dictionary

• transformer —  Transformer  Трансформатор   Статическое (не имеющее подвижных частей) электромагнитное устройство, предназначенное для преобразования посредством электромагнитной индукции системы переменного тока одного напряжения в систему переменного тока… …   Толковый англо-русский словарь по нанотехнологии. - М.

• transformer — Transformer, Transformare, Transfigurare …   Thresor de la langue françoyse

• transformer — Transformer. v. a. Metamorphoser, Changer une personne ou une chose en une autre forme. La femme de Lot fut transformée en une statuë de sel. On lit dans Homere que Circé transforma les compagnons d Ulysse en bestes …   Dictionnaire de l'Académie française

• transformer — ► NOUN ▪ a device for changing the voltage of an alternating current by electromagnetic induction …   English terms dictionary