Transformer - Electrical Machine

8/9/2019 Transformer - Electrical Machine

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TransformerFrom Wikipedia, the free encyclopediaThis article is about the electrical device. For the media and toy franchise, seeTransformers. For other uses,seeTransformer (disambiguation).

Pole-mounteddistribution transformer ith center-tapped secondary inding used to provide!split-phase! po er for residential and light commercial service, hich in "orth #merica is typically rated $%&'% & .*$+*%+

# transformer is an electrical device that transfers energy bet een t o or more circuits through

electromagnetic induction.# varying current in the transformer!s primary inding creates a varyingmagnetic flu in the core and avarying magnetic field impinging on the secondary inding. This varyingmagnetic field at the secondaryinduces a varyingelectromotive force ( F) or voltage in the secondary inding. aking use of Faraday!s/a in con0unction ith highmagnetic permeability core properties, transformers can thus be designed toefficiently change#1 voltages from one voltage level to another ithin po er net orks.

Transformers range in si2e from3F transformers less than a cubic centimetre in volume to unitsinterconnecting the po er grid eighing hundreds of tons. # ide range of transformer designs isencountered in electronic and electric po er applications. 4ince the invention in $556 of the first constant

potential transformer, transformers have become essential for the #1transmission, distribution, andutili2ation of electrical energy.*7+

Contents

$ 8asic principles

o $.$ 9deal transformer

o $.% 3eal transformer

% 8asic transformer parameters and construction

o %.$ ffect of fre:uency
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o %.% nergy losses

o %.7 1ore form and shell form transformers

7 1onstruction

o 7.$ 1ores

o 7.% Windings

o 7.7 1ooling

o 7. 9nsulation drying

o 7.6 8ushings

1lassification parameters

6 Types

; #pplications

< =istory

o iscovery of induction

o


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8y Faraday!s la of induction

. . . ($)*a+

. . . (%)

1ombining ratio of ($) A (%)

Turns ratio . . . (7) here

for step-do n transformers, a B $for step-up transformers, a C $

8y la of 1onservation of nergy, apparent, real and reactive po er are each conserved in the input andoutput

. . . ( )

1ombining (7) A ( ) ith this endnote*b+ yields the ideal transformeridentity

. (6)

8y ?hm!s /a and ideal transformer identity

. . . (;)

#pparent load impedance D!/ (D/ referred to the primary)

. (


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9deal transformer connected ith source P on primary and load impedance D/ on secondary, here & C D/ C.

# varying current in the transformer!s primary inding creates a varying magnetic flu in the core and avarying magnetic field impinging on the secondary inding. This varying magnetic field at the secondaryinduces a varyingelectromotive force ( F) or voltage in the secondary inding. The primary andsecondary indings are rapped around a core of infinitely high magnetic permeability*d+ so that all of themagnetic flu passes through both the primary and secondary indings. With avoltage source connected tothe primary inding and loadimpedance connected to the secondary inding, the transformer currents floin the indicated directions. (4ee alsoPolarity.)

9deal transformer and induction la*e+

#ccording to Faraday!s la of induction, since the same magnetic flu passes through both the primary andsecondary indings in an ideal transformer,*


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8y ?hm!s /a and the ideal transformer identityH

the secondary circuit load impedance can be e pressed as e:. (;)

the apparent load impedancereferred to the primary circuit is derived in e:. (


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4uch flu is termedleakage flux , and results inleakage inductance in series ith the mutually coupledtransformer indings.*$&+ /eakage flu results in energy being alternately stored in and discharged from themagnetic fields ith each cycle of the po er supply. 9t is not directly a po er loss, but results in inferiorvoltage regulation, causing the secondary voltage not to be directly proportional to the primary voltage, particularly under heavy load.*% + Transformers are therefore normally designed to have very lo leakageinductance.

9n some applications increased leakage is desired, and long magnetic paths, air gaps, or magnetic bypassshunts may deliberately be introduced in a transformer design to limit theshort-circuit current it ill supply.*$&+ /eaky transformers may be used to supply loads that e hibitnegative resistance, such aselectric arcs,mercury vapor lamps, andneon signs or for safely handling loads that become periodically short-circuitedsuch aselectric arc elders.*%6+

#ir gaps are also used to keep a transformer from saturating, especially audio-fre:uency transformers incircuits that have a >1 component flo ing in the indings.*%;+

Jno ledge of leakage inductance is also useful hen transformers are operated in parallel. 9t can be sho nthat if the percent impedance*l+ and associated inding leakage reactance-to-resistance (G'3) ratio of t o

transformers ere hypothetically e actly the same, the transformers ould share po er in proportion totheir respective volt-ampere ratings (e.g. 6&& k # unit in parallel ith $,&&& k # unit, the larger unit ouldcarry t ice the current). =o ever, the impedance tolerances of commercial transformers are significant.#lso, the D impedance and G'3 ratio of different capacity transformers tends to vary, corresponding$,&&& k # and 6&& k # units! values being, to illustrate, respectively, D K 6.


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1ore loss and reactance is represented by the follo ing shunt leg impedances of the modelH

1ore or iron lossesH R1

agneti2ing reactanceH X .

R1 and X are collectively termed themagnetizing branch of the model.

1ore losses are caused mostly by hysteresis and eddy current effects in the core and are proportional to ths:uare of the core flu for operation at a given fre:uency.*7$+ The finite permeability core re:uires amagneti2ing current I to maintain mutual flu in the core. agneti2ing current is in phase ith the flu , therelationship bet een the t o being non-linear due to saturation effects. =o ever, all impedances of thee:uivalent circuit sho n are by definition linear and such non-linearity effects are not typically reflected intransformer e:uivalent circuits.*7$+ Withsinusoidal supply, core flu lags the induced F by @&N. Withopen-circuited secondary inding, magneti2ing branch current I & e:uals transformer no-load current.*7&+

The resulting model, though sometimes termed !e act! e:uivalent circuit based onlinearity assumptions,retains a number of appro imations.*7&+ #nalysis may be simplified by assuming that magneti2ing branchimpedance is relatively high and relocating the branch to the left of the primary impedances. This introduerror but allo s combination of primary and referred secondary resistances and reactances by simplesummation as t o series impedances.

Transformer e:uivalent circuit impedance and transformer ratio parameters can be derived from thefollo ing testsHopen-circuit test,*m+ short-circuit test, inding resistance test, and transformer ratio test.

Basic transformer parameters and construction

Po er transformer over-e citation condition caused by decreased fre:uencyE flu (green), iron core!smagnetic characteristics (red) and magneti2ing current (blue).

"ffect of frequency

Transformer universal "#$ equation

9f the flu in the core is purelysinusoidal, the relationship for either inding bet een itsrms volta e E rms of the inding, and the supply fre:uency f , number of turns N , core cross-sectional areaa in m% and peakmagnetic flu density B peak in Wb'm% or T (tesla) is given by the universal F e:uationH*%7+
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1ore lossesysteresis lossesach time the magnetic field is reversed, a small amount of energy is lost due to hysteresis ithin thecore. #ccording to 4teinmet2!s formula, the heat energy due to hysteresis is given by

, and,hysteresis loss is thus given by

here, f is the fre:uency, is the hysteresis coefficient and Qma is the ma imum flu density, theempirical e ponent of hich varies from about $. to $ .5 but is often given as $.; for iron.* &+*$+* %+"ddy current lossesFerromagnetic materials are also goodconductors and a core made from such a material alsoconstitutes a single short-circuited turn throughout its entire length.ddy currents therefore circulateithin the core in a plane normal to the flu , and are responsible for resistive heating of the corematerial. The eddy current loss is a comple function of the s:uare of supply fre:uency and inverses:uare of the material thickness.* &+ ddy current losses can be reduced by making the core of a stackof plates electrically insulated from each other, rather than a solid blockE all transformers operatinlo fre:uencies use laminated or similar cores.

#a netostriction related transformer %umagnetic flu in a ferromagnetic material, such as the core, causes it to physically e pand andcontract slightly ith each cycle of the magnetic field, an effect kno n asmagnetostriction, thefrictional energy of hich produces an audible noise kno n asmains hum or transformer hum.*$$+*7+ This transformer hum is especially ob0ectionable in transformers supplied at po er fre:uencies*o+ andin high-fre:uency flyback transformers associated ith P#/ system 13Ts .

*tray losses/eakage inductance is by itself largely lossless, since energy supplied to its magnetic fields isreturned to the supply ith the ne t half-cycle. =o ever, any leakage flu that intercepts nearbyconductive materials such as the transformer!s support structure ill give rise to eddy currents and bconverted to heat.* + There are also radiative losses due to the oscillating magnetic field but these areusually small.

1ore form M core typeE shell form M shell type#ec%anical vi+ration and audi+le noise transmission9n addition to magnetostriction, the alternating magnetic field causes fluctuating forces bet een the primary and secondary indings. This energy incites vibration transmission in interconnectedmetal ork, thus amplifying audibletransformer hum.* 6+

Core form and s%ell form transformers

1losed-core transformers are constructed in !core form! or !shell form!. When indings surround the core,transformer is core formE hen indings are surrounded by the core, the transformer is shell form. 4hellform design may be more prevalent than core form design for distribution transformer applications due tothe relative ease in stacking the core around inding coils.* ;+ 1ore form design tends to, as a general rule, bemore economical, and therefore more prevalent, than shell form design for high voltage po er transformeapplications at the lo er end of their voltage and po er rating ranges (less than or e:ual to, nominally,
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%7& k or


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/aminating the core greatly reduces eddy-current losses

?ne common design of laminated core is made from interleaved stacks of-shaped steel sheets capped ith9-shaped pieces, leading to its name of ! -9 transformer!.*66+ 4uch a design tends to e hibit more losses, but isvery economical to manufacture. The cut-core or 1-core type is made by inding a steel strip around arectangular form and then bonding the layers together. 9t is then cut in t o, forming t o 1 shapes, and thecore assembled by binding the t o 1 halves together ith a steel strap.*66+ They have the advantage that theflu is al ays oriented parallel to the metal grains, reducing reluctance.# steel core!s remanence means that it retains a static magnetic field hen po er is removed. When po er isthen reapplied, the residual field ill cause a highinrush current until the effect of the remaining magnetismis reduced, usually after a fe cycles of the applied #1 aveform.*6;+ ?vercurrent protection devices such asfuses must be selected to allo this harmless inrush to pass. ?n transformers connected to long, overhead po er transmission lines, induced currents due to geomagnetic disturbances duringsolar storms can causesaturation of the core and operation of transformer protection devices.*6istribution transformers can achieve lo no-load losses by using cores made ith lo -loss high- permeability silicon steel or amorphous (non-crystalline) metal alloy. The higher initial cost of the corematerial is offset over the life of the transformer by its lo er losses at light load.*65+

*olid cores

Po dered iron cores are used in circuits such as s itch-mode po er supplies that operate above mainsfre:uencies and up to a fe tens of kilohert2. These materials combine high magnetic permeability ith high bulk electricalresistivity. For fre:uencies e tending beyond the=F band , cores made from non-conductive magnetic ceramic materials calledferrites are common.*66+ 4ome radio-fre:uency transformersalso have movable cores (sometimes called !slugs!) hich allo ad0ustment of thecoupling coefficient (and band idth) of tuned radio-fre:uency circuits.

Toroidal cores

4mall toroidal core transformer
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Toroidal transformers are built around a ring-shaped core, hich, depending on operating fre:uency, is madfrom a long strip ofsilicon steel or permalloy ound into a coil, po dered iron, orferrite.*6@+ # stripconstruction ensures that thegrain boundaries are optimally aligned, improving the transformer!s efficiency by reducing the core!sreluctance. The closed ring shape eliminates air gaps inherent in the construction of an-9 core.*%6+ The cross-section of the ring is usually s:uare or rectangular, but more e pensive cores ithcircular cross-sections are also available. The primary and secondary coils are often ound concentrically cover the entire surface of the core. This minimi2es the length of ire needed and provides screening tominimi2e the core!s magnetic field from generatingelectromagnetic interference.

Toroidal transformers are more efficient than the cheaper laminated -9 types for a similar po er level.?ther advantages compared to -9 types, include smaller si2e (about half), lo er eight (about half), lessmechanical hum (making them superior in audio amplifiers), lo er e terior magnetic field (about one tenthlo off-load losses (making them more efficient in standby circuits), single-bolt mounting, and greaterchoice of shapes. The main disadvantages are higher cost and limited po er capacity (see1lassification parameters belo ). 8ecause of the lack of a residual gap in the magnetic path, toroidal transformers alsotend to e hibit higher inrush current, compared to laminated -9 types.

Ferrite toroidal cores are used at higher fre:uencies, typically bet een a fe tens of kilohert2 to hundreds of

megahert2, to reduce losses, physical si2e, and eight of inductive components. # dra back of toroidaltransformer construction is the higher labor cost of inding. This is because it is necessary to pass the entilength of a coil inding through the core aperture each time a single turn is added to the coil. #s aconse:uence, toroidal transformers rated more than a fe k # are uncommon. 4mall distributiontransformers may achieve some of the benefits of a toroidal core by splitting it and forcing it open, theninserting a bobbin containing primary and secondary indings.

,ir cores

# physical core is not an absolute re:uisite and a functioning transformer can be produced simply by placithe indings near each other, an arrangement termed an !air-core! transformer. The air hich comprises the

magnetic circuit is essentially lossless, and so an air-core transformer eliminates loss due to hysteresis in core material.*$&+ The leakage inductance is inevitably high, resulting in very poor regulation, and so suchdesigns are unsuitable for use in po er distribution.*$&+ They have ho ever very high band idth, and arefre:uently employed in radio-fre:uency applications,*;&+ for hich a satisfactory coupling coefficient ismaintained by carefully overlapping the primary and secondary indings. They!re also used forresonanttransformers such as Tesla coils here they can achieve reasonably lo loss in spite of the high leakageinductance.

'indin s

Windings are usually arranged concentrically to minimi2e flu leakage.9t has been suggested that Compensation winding bemerged into this article. (>iscuss) Proposed

since arch !"#$%
http://en.wikipedia.org/wiki/Silicon_steelhttp://en.wikipedia.org/wiki/Permalloyhttp://en.wikipedia.org/wiki/Ferrite_(magnet)http://en.wikipedia.org/wiki/Transformer#cite_note-74http://en.wikipedia.org/wiki/Transformer#cite_note-74http://en.wikipedia.org/wiki/Transformer#cite_note-74http://en.wikipedia.org/wiki/Grain_boundaryhttp://en.wikipedia.org/wiki/Grain_boundaryhttp://en.wikipedia.org/wiki/Reluctancehttp://en.wikipedia.org/wiki/Transformer#cite_note-Say.2C_p._485-36http://en.wikipedia.org/wiki/Electromagnetic_interferencehttp://en.wikipedia.org/wiki/Electromagnetic_interferencehttp://en.wikipedia.org/wiki/Transformer#Classification_parametershttp://en.wikipedia.org/wiki/Transformer#Classification_parametershttp://en.wikipedia.org/wiki/Transformer#cite_note-calvert-15http://en.wikipedia.org/wiki/Transformer#cite_note-calvert-15http://en.wikipedia.org/wiki/Transformer#cite_note-calvert-15http://en.wikipedia.org/wiki/Transformer#cite_note-calvert-15http://en.wikipedia.org/wiki/Bandwidth_(signal_processing)http://en.wikipedia.org/wiki/Transformer#cite_note-75http://en.wikipedia.org/wiki/Transformer#cite_note-75http://en.wikipedia.org/wiki/Transformer#cite_note-75http://en.wikipedia.org/wiki/Resonant_inductive_couplinghttp://en.wikipedia.org/wiki/Resonant_inductive_couplinghttp://en.wikipedia.org/wiki/Compensation_windinghttp://en.wikipedia.org/wiki/Compensation_windinghttp://en.wikipedia.org/wiki/Wikipedia:Merginghttp://en.wikipedia.org/wiki/Talk:Transformerhttp://en.wikipedia.org/wiki/Silicon_steelhttp://en.wikipedia.org/wiki/Permalloyhttp://en.wikipedia.org/wiki/Ferrite_(magnet)http://en.wikipedia.org/wiki/Transformer#cite_note-74http://en.wikipedia.org/wiki/Grain_boundaryhttp://en.wikipedia.org/wiki/Reluctancehttp://en.wikipedia.org/wiki/Transformer#cite_note-Say.2C_p._485-36http://en.wikipedia.org/wiki/Electromagnetic_interferencehttp://en.wikipedia.org/wiki/Transformer#Classification_parametershttp://en.wikipedia.org/wiki/Transformer#Classification_parametershttp://en.wikipedia.org/wiki/Transformer#cite_note-calvert-15http://en.wikipedia.org/wiki/Transformer#cite_note-calvert-15http://en.wikipedia.org/wiki/Bandwidth_(signal_processing)http://en.wikipedia.org/wiki/Transformer#cite_note-75http://en.wikipedia.org/wiki/Resonant_inductive_couplinghttp://en.wikipedia.org/wiki/Resonant_inductive_couplinghttp://en.wikipedia.org/wiki/Compensation_windinghttp://en.wikipedia.org/wiki/Wikipedia:Merginghttp://en.wikipedia.org/wiki/Talk:Transformer


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Theconducting material used for the indings depends upon the application, but in all cases the individualturns must be electrically insulated from each other to ensure that the current travels throughout every tur*;$+ For small po er and signal transformers, in hich currents are lo and the potential difference bet eenad0acent turns is small, the coils are often ound from enamelled magnet ire, such as Formvar ire. /arger po er transformers operating at high voltages may be ound ith copper rectangular strip conductorsinsulated by oil-impregnated paper and blocks of pressboard.*;%+

1ut vie through transformer indings. WhiteH insulator. Rreen spiralHRrain oriented silicon steel. 8lackHPrimary inding made ofo ygen-free copper . 3edH 4econdary inding. Top leftH Toroidal transformer.3ightH 1-core, but -core ould be similar. The black indings are made of film. TopH :ually locapacitance bet een all ends of both indings. 4ince most cores are at least moderately conductive theyalso need insulation. 8ottomH /o est capacitance for one end of the secondary inding needed for lo - po er high-voltage transformers. 8ottom leftH 3eduction ofleakage inductance ould lead to increase ofcapacitance.

=igh-fre:uency transformers operating in the tens to hundreds of kilohert2 often have indings made of braided/it2 ire to minimi2e the skin-effect and pro imity effect losses.*;7+ /arge po er transformers usemultiple-stranded conductors as ell, since even at lo po er fre:uencies non-uniform distribution ofcurrent ould other ise e ist in high-current indings.*;%+ ach strand is individually insulated, and thestrands are arranged so that at certain points in the inding, or throughout the hole inding, each portionoccupies different relative positions in the complete conductor. The transposition e:uali2es the currentflo ing in each strand of the conductor, and reduces eddy current losses in the inding itself. The strandedconductor is also more fle ible than a solid conductor of similar si2e, aiding manufacture.*;%+

The indings of signal transformers minimi2e leakage inductance and stray capacitance to improve high-fre:uency response. 1oils are split into sections, and those sections interleaved bet een the sections of theother inding.

Po er-fre:uency transformers may havetaps at intermediate points on the inding, usually on the highervoltage inding side, for voltage ad0ustment. Taps may be manually reconnected, or a manual or automats itch may be provided for changing taps. #utomatic on-loadtap changers are used in electric po ertransmission or distribution, on e:uipment such asarc furnace transformers, or for automatic voltageregulators for sensitive loads. #udio-fre:uency transformers, used for the distribution of audio to publicaddress loudspeakers, have taps to allo ad0ustment of impedance to each speaker. #center-tappedtransformer is often used in the output stage of an audio po eramplifier in a push-pull circuit. odulationtransformers in# transmitters are very similar.

>ry-type transformer inding insulation systems can be either of standard open- ound !dip-and-bake!

construction or of higher :uality designs that include vacuum pressure impregnation ( P9), vacuum pressureencapsulation ( P ), and cast coil encapsulation processes.*; + 9n the P9 process, a combination of heat,vacuum and pressure is used to thoroughly seal, bind, and eliminate entrained air voids in the inding polyester resin insulation coat layer, thus increasing resistance to corona. P indings are similar to P9
http://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Transformer#cite_note-Dixon_.281997.29-76http://en.wikipedia.org/wiki/Enameled_wirehttp://en.wikipedia.org/wiki/Enameled_wirehttp://en.wikipedia.org/wiki/Formvarhttp://en.wikipedia.org/wiki/Formvarhttp://en.wikipedia.org/wiki/Transformerboardhttp://en.wikipedia.org/wiki/Transformerboardhttp://en.wikipedia.org/wiki/Transformer#cite_note-cegb_1982-77http://en.wikipedia.org/wiki/Electrical_steelhttp://en.wikipedia.org/wiki/Oxygen-free_copperhttp://en.wikipedia.org/wiki/Leakage_inductancehttp://en.wikipedia.org/wiki/Litz_wirehttp://en.wikipedia.org/wiki/Transformer#cite_note-dixon-78http://en.wikipedia.org/wiki/Transformer#cite_note-cegb_1982-77http://en.wikipedia.org/wiki/Transformer#cite_note-cegb_1982-77http://en.wikipedia.org/wiki/Tap_(transformer)http://en.wikipedia.org/wiki/Tap_changerhttp://en.wikipedia.org/wiki/Tap_changerhttp://en.wikipedia.org/wiki/Arc_furnacehttp://en.wikipedia.org/wiki/Arc_furnacehttp://en.wikipedia.org/wiki/Center_taphttp://en.wikipedia.org/wiki/Center_taphttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Push-pull_converterhttp://en.wikipedia.org/wiki/Push-pull_converterhttp://en.wikipedia.org/wiki/Amplitude_modulationhttp://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Transformer_types#Cast_resin_transformerhttp://en.wikipedia.org/wiki/Transformer#cite_note-Lane_.282007.29-79http://en.wikipedia.org/wiki/Transformer#cite_note-Lane_.282007.29-79http://en.wikipedia.org/wiki/Transformer#cite_note-Lane_.282007.29-79http://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Transformer#cite_note-Dixon_.281997.29-76http://en.wikipedia.org/wiki/Enameled_wirehttp://en.wikipedia.org/wiki/Formvarhttp://en.wikipedia.org/wiki/Transformerboardhttp://en.wikipedia.org/wiki/Transformer#cite_note-cegb_1982-77http://en.wikipedia.org/wiki/Electrical_steelhttp://en.wikipedia.org/wiki/Oxygen-free_copperhttp://en.wikipedia.org/wiki/Leakage_inductancehttp://en.wikipedia.org/wiki/Litz_wirehttp://en.wikipedia.org/wiki/Transformer#cite_note-dixon-78http://en.wikipedia.org/wiki/Transformer#cite_note-cegb_1982-77http://en.wikipedia.org/wiki/Transformer#cite_note-cegb_1982-77http://en.wikipedia.org/wiki/Tap_(transformer)http://en.wikipedia.org/wiki/Tap_changerhttp://en.wikipedia.org/wiki/Arc_furnacehttp://en.wikipedia.org/wiki/Center_taphttp://en.wikipedia.org/wiki/Center_taphttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Push-pull_converterhttp://en.wikipedia.org/wiki/Amplitude_modulationhttp://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Transformer_types#Cast_resin_transformerhttp://en.wikipedia.org/wiki/Transformer#cite_note-Lane_.282007.29-79


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used to either alarm or de-energi2e the transformer.*6;+ ?il-immersed transformer installations usually includefire protection measures such as alls, oil containment, and fire-suppression sprinkler systems.

Polychlorinated biphenyls have properties that once favored their use as adielectric coolant, thoughconcerns over theirenvironmental persistence led to a idespread ban on their use.*


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Circuit application H 4uch as po er supply, impedance matching, output voltage and current stabili2eor circuit isolation.

+tilization HPulse, po er, distribution, rectifier , arc furnace, amplifier output, etc..

Basic magnetic form H 1ore form, shell form.

Constant,potential transformer descriptor H 4tep-up, step-do n,isolation. -eneral winding configuration H 8y91 vector group O various possible t o- inding combinations

of the phase designations delta, ye or star, and 2ig2ag or interconnected star E*p+ other Oautotransformer , 4cott-T, 2ig2ag grounding transformer inding.*5 +*56+*5;+*5


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Instrument transformer H Potential orcurrent transformer used to accurately and safely representvoltage, current or phase position of high voltage or high po er circuits.*55+

#n electrical substation in elbourne , #ustralia sho ing three of five %%& k O ;; k transformers, eachith a capacity of $6& # *@$+

,pplications

Transformer at the/imestone Renerating 4tation in anitoba , 1anada

Transformers are used to increase voltage before transmitting electrical energy over long distances througires . Wires have resistance hich loses energy through 0oule heating at a rate corresponding to s:uare ofthe current. 8y transforming po er to a higher voltage transformers enable economical transmission of po er and distribution. 1onse:uently, transformers have shaped theelectricity supply industry, permittinggeneration to be located remotely from points ofdemand.*@%+ #ll but a tiny fraction of the orld!s electrical po er has passed through a series of transformers by the time it reaches the consumer.* +

Transformers are also used e tensively inelectronic products to step-do n the supply voltage to a levelsuitable for the lo voltage circuits they contain. The transformer also electrically isolates the end user frocontact ith the supply voltage.

4ignal and audio transformers are used to couple stages of amplifiers and to match devices such asmicrophones andrecord players to the input of amplifiers. #udio transformers allo edtelephone circuits tocarry on at o- ay conversation over a single pair of ires. # balun transformer converts a signal that isreferenced to ground to a signal that has balanced voltages to ground, such as bet een e ternal cables andinternal circuits.

istory

Discovery of induction
http://en.wikipedia.org/wiki/Transformer_types#Instrument_transformerhttp://en.wikipedia.org/wiki/Current_transformerhttp://en.wikipedia.org/wiki/Current_transformerhttp://en.wikipedia.org/wiki/Transformer#cite_note-Knowlton.2C_p._549-550-104http://en.wikipedia.org/wiki/Transformer#cite_note-Knowlton.2C_p._549-550-104http://en.wikipedia.org/wiki/Electrical_substationhttp://en.wikipedia.org/wiki/Electrical_substationhttp://en.wikipedia.org/wiki/Melbournehttp://en.wikipedia.org/wiki/Melbournehttp://en.wikipedia.org/wiki/Melbournehttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/Transformer#cite_note-AEMO_.282012-108http://en.wikipedia.org/wiki/Limestone_Generating_Stationhttp://en.wikipedia.org/wiki/Manitobahttp://en.wikipedia.org/wiki/Manitobahttp://en.wikipedia.org/wiki/Canadahttp://en.wikipedia.org/wiki/Wirehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_power_industryhttp://en.wikipedia.org/wiki/Electrical_loadhttp://en.wikipedia.org/wiki/Electrical_loadhttp://en.wikipedia.org/wiki/Transformer#cite_note-109http://en.wikipedia.org/wiki/Transformer#cite_note-nailen-59http://en.wikipedia.org/wiki/Consumer_electronicshttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Microphonehttp://en.wikipedia.org/wiki/Record_playerhttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Hybrid_coilhttp://en.wikipedia.org/wiki/Hybrid_coilhttp://en.wikipedia.org/wiki/Balunhttp://en.wikipedia.org/wiki/Balunhttp://en.wikipedia.org/wiki/Balunhttp://en.wikipedia.org/wiki/Balanced_linehttp://en.wikipedia.org/wiki/Balanced_linehttp://en.wikipedia.org/wiki/Transformer_types#Instrument_transformerhttp://en.wikipedia.org/wiki/Current_transformerhttp://en.wikipedia.org/wiki/Transformer#cite_note-Knowlton.2C_p._549-550-104http://en.wikipedia.org/wiki/Electrical_substationhttp://en.wikipedia.org/wiki/Melbournehttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/Transformer#cite_note-AEMO_.282012-108http://en.wikipedia.org/wiki/Limestone_Generating_Stationhttp://en.wikipedia.org/wiki/Manitobahttp://en.wikipedia.org/wiki/Canadahttp://en.wikipedia.org/wiki/Wirehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_power_industryhttp://en.wikipedia.org/wiki/Electrical_loadhttp://en.wikipedia.org/wiki/Transformer#cite_note-109http://en.wikipedia.org/wiki/Transformer#cite_note-nailen-59http://en.wikipedia.org/wiki/Consumer_electronicshttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Microphonehttp://en.wikipedia.org/wiki/Record_playerhttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Hybrid_coilhttp://en.wikipedia.org/wiki/Balunhttp://en.wikipedia.org/wiki/Balanced_line


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The first type of transformer to see ide use as theinduction coil, invented by 3ev. "icholas 1allan ofaynooth 1ollege, 9reland in $57;. =e as one of the first researchers to reali2e the more turns thesecondary inding has in relation to the primary inding, the larger the induced secondary F ill be.9nduction coils evolved from scientists! and inventors! efforts to get higher voltages from batteries. 4ince batteries producedirect current (>1) rather than #1, induction coils relied upon vibrating electrical contactsthat regularly interrupted the current in the primary to create the flu changes necessary for induction.8et een the $57&s and the $5


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1ore form, frontE shell form, back. arliest specimens of D8>-designed high-efficiency constant-potentialtransformers manufactured at the Ran2 factory in $556.

The D8> team consisted of J roly Diperno sky, ?ttX 8l thy and iksa >Yri

4tanley!s $55; design for ad0ustable gap open-core induction coils*$& +

Closed&core transformers and parallel po-er distri+ution

9n the autumn of $55 ,J roly Diperno sky, ?ttX 8l thy and iksa >Yri (D8>), three engineers associatedith the Ran2 factory, had determined that open-core devices ere impracticable, as they ere incapable ofreliably regulating voltage.*$&6+ 9n their 0oint $556 patent applications for novel transformers (later calledD8> transformers), they described t o designs ith closed magnetic circuits here copper indings ereeither a) ound around iron ire ring core or b) surrounded by iron ire core.*$&%+ The t o designs ere thefirst application of the t o basic transformer constructions in common use to this day, hich can as a classall be termed as either core form or shell form (or alternatively, core type or shell type), as in a) or b),respectively (see images).* ;+*


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the use of closed cores, Diperno sky had suggested the use of parallel shunt connections, and >Yri had performed the e perimentsE*$$ +

Transformers today are designed on the principles discovered by the three engineers. They also populari2the ord !transformer! to describe a device for altering the F of an electric current,*$$%+*$$6+ although theterm had already been in use by $55%.*$$;+*$$ engineers designed, and the Ran2 factorysupplied electrical e:uipment for, the orld!s first po er station that used #1 generators to po er a parallelconnected common electrical net ork, the steam-po ered 3ome-1erchi po er plant.*$$5+

#lthoughReorge Westinghouse had bought Raulard and Ribbs! patents in $556, thedison lectric /ight1ompany held an option on the S4 rights for the D8> transformers, re:uiring Westinghouse to pursuealternative designs on the same principles. =e assigned toWilliam 4tanley the task of developing a devicefor commercial use in Snited 4tates.*$$@+ 4tanley!s first patented design as for induction coils ith singlecores of soft iron and ad0ustable gaps to regulate the F present in the secondary inding (see image).*$& + This design*$%&+ as first used commercially in the S4 in $55;*$&7+ but Westinghouse as intent on improvingthe 4tanley design to make it (unlike the D8> type) easy and cheap to produce.*$%&+

Westinghouse, 4tanley and associates soon developed an easier to manufacture core, consisting of a stack

thin ! -shaped! iron plates, insulated by thin sheets of paper or other insulating material. Pre ound coppercoils could then be slid into place, and straight iron plates laid in to create a closed magnetic circuit.Westinghouse applied for a patent for the ne lo -cost design in >ecember $55;E it as granted in Iuly$55olivo->obrovolsky developed the first three-phase transformer atthe#llgemeine lektricitZts-Resellschaft (!Reneral lectricity 1ompany!) in Rermany.*$%%+

9n $5@$, "ikola Tesla invented the Tesla coil, an air-cored, dual-tuned resonant transformer for generatingveryhigh voltages at high fre:uency.*$%7+*$% +

*ee also

Energy portal

Electronics portal

1ompensation inding

9nductor

/oad profile

agnetic core

agneti2ation

Paraformer

Polyphase system
http://en.wikipedia.org/wiki/Shunt_(electrical)http://en.wikipedia.org/wiki/Transformer#cite_note-Smil-131http://en.wikipedia.org/wiki/Transformer#cite_note-Smil-131http://en.wikipedia.org/wiki/Transformer#cite_note-Bl.C3.A1thy_HPO-129http://en.wikipedia.org/wiki/Transformer#cite_note-132http://en.wikipedia.org/wiki/Transformer#cite_note-133http://en.wikipedia.org/wiki/Transformer#cite_note-133http://en.wikipedia.org/wiki/Transformer#cite_note-134http://en.wikipedia.org/wiki/Transformer#cite_note-134http://en.wikipedia.org/wiki/Power_stationhttp://en.wikipedia.org/wiki/Power_stationhttp://en.wikipedia.org/wiki/Cerchihttp://en.wikipedia.org/wiki/Transformer#cite_note-135http://en.wikipedia.org/wiki/Transformer#cite_note-135http://en.wikipedia.org/wiki/George_Westinghousehttp://en.wikipedia.org/wiki/George_Westinghousehttp://en.wikipedia.org/wiki/Edison_Electric_Light_Companyhttp://en.wikipedia.org/wiki/Edison_Electric_Light_Companyhttp://en.wikipedia.org/wiki/William_Stanley,_Jr.http://en.wikipedia.org/wiki/Transformer#cite_note-Skrabec-136http://en.wikipedia.org/wiki/Transformer#cite_note-Stanley_adj_gap_ind_coil-121http://en.wikipedia.org/wiki/Transformer#cite_note-Stanley_adj_gap_ind_coil-121http://en.wikipedia.org/wiki/Transformer#cite_note-Coltman_.282002.29-137http://en.wikipedia.org/wiki/Transformer#cite_note-Coltman-120http://en.wikipedia.org/wiki/Transformer#cite_note-Coltman_.282002.29-137http://en.wikipedia.org/wiki/Transformer#cite_note-Smil-131http://en.wikipedia.org/wiki/Transformer#cite_note-138http://en.wikipedia.org/wiki/Mikhail_Dolivo-Dobrovolskyhttp://en.wikipedia.org/wiki/Mikhail_Dolivo-Dobrovolskyhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Allgemeine_Elektricit%C3%A4ts-Gesellschafthttp://en.wikipedia.org/wiki/Transformer#cite_note-139http://en.wikipedia.org/wiki/Nikola_Teslahttp://en.wikipedia.org/wiki/Tesla_coilhttp://en.wikipedia.org/wiki/Tesla_coilhttp://en.wikipedia.org/wiki/High_voltagehttp://en.wikipedia.org/wiki/Transformer#cite_note-PBS-140http://en.wikipedia.org/wiki/Transformer#cite_note-141http://en.wikipedia.org/wiki/Portal:Energyhttp://en.wikipedia.org/wiki/Portal:Electronicshttp://en.wikipedia.org/wiki/Compensation_windinghttp://en.wikipedia.org/wiki/Inductorhttp://en.wikipedia.org/wiki/Load_profilehttp://en.wikipedia.org/wiki/Magnetic_corehttp://en.wikipedia.org/wiki/Magnetizationhttp://en.wikipedia.org/wiki/Paraformerhttp://en.wikipedia.org/wiki/Polyphase_systemhttp://en.wikipedia.org/wiki/Shunt_(electrical)http://en.wikipedia.org/wiki/Transformer#cite_note-Smil-131http://en.wikipedia.org/wiki/Transformer#cite_note-Bl.C3.A1thy_HPO-129http://en.wikipedia.org/wiki/Transformer#cite_note-132http://en.wikipedia.org/wiki/Transformer#cite_note-133http://en.wikipedia.org/wiki/Transformer#cite_note-134http://en.wikipedia.org/wiki/Power_stationhttp://en.wikipedia.org/wiki/Cerchihttp://en.wikipedia.org/wiki/Transformer#cite_note-135http://en.wikipedia.org/wiki/George_Westinghousehttp://en.wikipedia.org/wiki/Edison_Electric_Light_Companyhttp://en.wikipedia.org/wiki/Edison_Electric_Light_Companyhttp://en.wikipedia.org/wiki/William_Stanley,_Jr.http://en.wikipedia.org/wiki/Transformer#cite_note-Skrabec-136http://en.wikipedia.org/wiki/Transformer#cite_note-Stanley_adj_gap_ind_coil-121http://en.wikipedia.org/wiki/Transformer#cite_note-Coltman_.282002.29-137http://en.wikipedia.org/wiki/Transformer#cite_note-Coltman-120http://en.wikipedia.org/wiki/Transformer#cite_note-Coltman_.282002.29-137http://en.wikipedia.org/wiki/Transformer#cite_note-Smil-131http://en.wikipedia.org/wiki/Transformer#cite_note-138http://en.wikipedia.org/wiki/Mikhail_Dolivo-Dobrovolskyhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Allgemeine_Elektricit%C3%A4ts-Gesellschafthttp://en.wikipedia.org/wiki/Transformer#cite_note-139http://en.wikipedia.org/wiki/Nikola_Teslahttp://en.wikipedia.org/wiki/Tesla_coilhttp://en.wikipedia.org/wiki/High_voltagehttp://en.wikipedia.org/wiki/Transformer#cite_note-PBS-140http://en.wikipedia.org/wiki/Transformer#cite_note-141http://en.wikipedia.org/wiki/Portal:Energyhttp://en.wikipedia.org/wiki/Portal:Electronicshttp://en.wikipedia.org/wiki/Compensation_windinghttp://en.wikipedia.org/wiki/Inductorhttp://en.wikipedia.org/wiki/Load_profilehttp://en.wikipedia.org/wiki/Magnetic_corehttp://en.wikipedia.org/wiki/Magnetizationhttp://en.wikipedia.org/wiki/Paraformerhttp://en.wikipedia.org/wiki/Polyphase_system


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For e ample, the delta- ye transformer , by far the most common commercial three-phasetransformer, is kno n as the >yn$$ vector group configuration, >yn$$ denoting > for delta primaryinding, y for ye secondary inding, n for neutral of the ye inding, and $$ for relative phase positionon the clock by hich the secondary inding leads the primary inding, namely, 7&N leading.

$. While the above formal definition, derived from standards such as 9 16elhiH /a mi Publications. p. $&


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9 P 4 T1 (Fall %&$$). [>iscussion of 1lass 9 A 99 Terminology[. 9 P 4 Transformer1ommittee. p. slide ;. 3etrieved %< Ianuary %&$7.

Jno lton, \$%-7 $, fig. $%-@6, p. $&56 # ? et al. (%&$%). [Ioint 1onsultation Paper - Western etropolitan elbourne Transmission

1onnection and 4ubtransmission 1apacity[. p. $$. 3etrieved andarchived Ianuary %&$7. 1heck datevalues inH|accessdate= (help)

=eathcote, p. $ Poyser, #rthur William ($5@%). agnetism and Electricit&: . anual for 1tudents in .d/anced

Classes . /ondon and "e VorkH /ongmans, Rreen, A 1o. p. %56, fig. % 5. [# 8rief =istory of lectromagnetism[. [Ioseph =enry[. 'istinguished embers -aller&0 National .cadem& of 1ciences . #rchived from theoriginal on $7 of >ecember of %&$7. 1heck date values inH|archivedate= (help) [ lectromagnetism[. 1mithsonian Institution .rchi/es .

1ho , Tai /. (%&&;). Introduction to Electromagnetic 2heor&: . odern Perspecti/e . 4udbury,ass.H Iones and 8artlett Publishers. p. $e Fonveille, W. (Ian %%, $55&). [Ras and lectricity in Paris[. Nature 41 (67 )H %57.8ibcodeH$55&"atur..%$..%5%>. doiH$&.$&75'&%$%5%b&. 3etrieved Ian @, %&&@.

=ughes, Thomas P. ($@@7). Networks of Power: Electrification in Aestern 1ociet&0 # ",#DYri, .E 8l thy, ?.T. [9nduction 1oil[. S.4. Patent 76% $&6, issued "ov. %, $55;.3etrieved Iuly 5, %&&@.

4mil, aclav (%&&6). Creating the 2wentieth Centur&: 2echnical Inno/ations of # =F#D#$ and2heir 3asting Impact . ? fordH ? ford Sniversity Press. p. iscovery of thelectron in $5@< (preliminary te t)[. 8udapest. 3etrieved Iuly @, %&&@.

4xford English 'ictionar& (%nd ed.). ? ford Sniversity Press. $@5@.=ospitalier, _douard ($55%). 2he odern .pplications of Electricit& . Translated by Iulius aier.

"e VorkH >. #ppleton A 1o. p. $&7. [?ttX 8l thy, iksa >Yri, J roly Diperno sky[ . 9 1 Techline. 3etrieved #pr $;, %&$&.

4krabec, ]uentin 3. (%&&


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1oltman, I.W.E (IanOFeb %&&%). [The Transformer *=istorical ?vervie +[. Industr& .pplications agazine0 IEEE 3 ($)H 5O$6.doiH$&.$$&@'%@ 7.@< 76%. 3etrieved Feb %@, %&$%.

Westinghouse, Reorge, Ir.. [ lectrical 1onverter[. S.4. Patent 7;; 7;%, issued Iuly $%, $55aniels, #.3. ($@56). Introduction to Electrical achines . acmillan. 948" &-777-$@;%


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D - lectric displacement field (1'm% )

" - lectric field ( 'm)

K - lectric flu ( m)

L e - lectric susceptibility M - lectric scalar potential ( )

+ , * , ME E - mf ( )

3 , - 9nductance (=)

- agnetic field (#'m) strength

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L - agnetic susceptibility

, - agnetic vector potential ( s'm)

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O - Permittivity (F'm) 1 , P , - #pparent, 3eal, 3eactive Po er ( #, W, #3)

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http://kn.wikipedia.org/wiki/%E0%B2%B5%E0%B2%BF%E0%B2%A6%E0%B3%8D%E0%B2%AF%E0%B3%81%E0%B2%A4%E0%B3%8D_%E0%B2%AA%E0%B2%B0%E0%B2%BF%E0%B2%B5%E0%B2%B0%E0%B3%8D%E0%B2%A4%E0%B2%95http://ka.wikipedia.org/wiki/%E1%83%A2%E1%83%A0%E1%83%90%E1%83%9C%E1%83%A1%E1%83%A4%E1%83%9D%E1%83%A0%E1%83%9B%E1%83%90%E1%83%A2%E1%83%9D%E1%83%A0%E1%83%98http://kk.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ht.wikipedia.org/wiki/Transf%C3%B2mat%C3%A8http://la.wikipedia.org/wiki/Transformatrumhttp://lv.wikipedia.org/wiki/Transformatorshttp://lt.wikipedia.org/wiki/Transformatoriushttp://hu.wikipedia.org/wiki/Transzform%C3%A1torhttp://mk.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ml.wikipedia.org/wiki/%E0%B4%9F%E0%B5%8D%E0%B4%B0%E0%B4%BE%E0%B5%BB%E0%B4%B8%E0%B5%8D%E0%B4%AB%E0%B5%8B%E0%B5%BC%E0%B4%AE%E0%B5%BChttp://mr.wikipedia.org/wiki/%E0%A4%B5%E0%A4%BF%E0%A4%A6%E0%A5%8D%E0%A4%AF%E0%A5%81%E0%A4%A4_%E0%A4%B0%E0%A5%8B%E0%A4%B9%E0%A4%BF%E0%A4%A4%E0%A5%8D%E0%A4%B0http://ms.wikipedia.org/wiki/Transformerhttp://mn.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://my.wikipedia.org/wiki/%E1%80%91%E1%80%9B%E1%80%94%E1%80%BA%E1%80%85%E1%80%96%E1%80%B1%E1%80%AC%E1%80%BA%E1%80%99%E1%80%AChttp://my.wikipedia.org/wiki/%E1%80%91%E1%80%9B%E1%80%94%E1%80%BA%E1%80%85%E1%80%96%E1%80%B1%E1%80%AC%E1%80%BA%E1%80%99%E1%80%AChttp://my.wikipedia.org/wiki/%E1%80%91%E1%80%9B%E1%80%94%E1%80%BA%E1%80%85%E1%80%96%E1%80%B1%E1%80%AC%E1%80%BA%E1%80%99%E1%80%AChttp://my.wikipedia.org/wiki/%E1%80%91%E1%80%9B%E1%80%94%E1%80%BA%E1%80%85%E1%80%96%E1%80%B1%E1%80%AC%E1%80%BA%E1%80%99%E1%80%AChttp://nl.wikipedia.org/wiki/Transformatorhttp://new.wikipedia.org/wiki/%E0%A4%A4%E0%A5%8D%E0%A4%B0%E0%A4%BE%E0%A4%A8%E0%A5%8D%E0%A4%B8%E0%A4%AB%E0%A4%B0%E0%A5%8D%E0%A4%AE%E0%A4%B0http://new.wikipedia.org/wiki/%E0%A4%A4%E0%A5%8D%E0%A4%B0%E0%A4%BE%E0%A4%A8%E0%A5%8D%E0%A4%B8%E0%A4%AB%E0%A4%B0%E0%A5%8D%E0%A4%AE%E0%A4%B0http://new.wikipedia.org/wiki/%E0%A4%A4%E0%A5%8D%E0%A4%B0%E0%A4%BE%E0%A4%A8%E0%A5%8D%E0%A4%B8%E0%A4%AB%E0%A4%B0%E0%A5%8D%E0%A4%AE%E0%A4%B0http://ja.wikipedia.org/wiki/%E5%A4%89%E5%9C%A7%E5%99%A8http://ce.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://no.wikipedia.org/wiki/Transformatorhttp://nn.wikipedia.org/wiki/Transformatorhttp://oc.wikipedia.org/wiki/Transformadorhttp://or.wikipedia.org/wiki/%E0%AC%9F%E0%AD%8D%E0%AC%B0%E0%AC%BE%E0%AC%A8%E0%AD%8D%E0%AC%B8%E0%AC%AB%E0%AC%B0%E0%AD%8D%E0%AC%AE%E0%AC%B0http://or.wikipedia.org/wiki/%E0%AC%9F%E0%AD%8D%E0%AC%B0%E0%AC%BE%E0%AC%A8%E0%AD%8D%E0%AC%B8%E0%AC%AB%E0%AC%B0%E0%AD%8D%E0%AC%AE%E0%AC%B0http://or.wikipedia.org/wiki/%E0%AC%9F%E0%AD%8D%E0%AC%B0%E0%AC%BE%E0%AC%A8%E0%AD%8D%E0%AC%B8%E0%AC%AB%E0%AC%B0%E0%AD%8D%E0%AC%AE%E0%AC%B0http://uz.wikipedia.org/wiki/Transformatorhttp://uz.wikipedia.org/wiki/Transformatorhttp://pnb.wikipedia.org/wiki/%D9%B9%D8%B1%D8%A7%D9%86%D8%B3%D9%81%D8%A7%D8%B1%D9%85%D8%B1http://pl.wikipedia.org/wiki/Transformatorhttp://pt.wikipedia.org/wiki/Transformadorhttp://kn.wikipedia.org/wiki/%E0%B2%B5%E0%B2%BF%E0%B2%A6%E0%B3%8D%E0%B2%AF%E0%B3%81%E0%B2%A4%E0%B3%8D_%E0%B2%AA%E0%B2%B0%E0%B2%BF%E0%B2%B5%E0%B2%B0%E0%B3%8D%E0%B2%A4%E0%B2%95http://ka.wikipedia.org/wiki/%E1%83%A2%E1%83%A0%E1%83%90%E1%83%9C%E1%83%A1%E1%83%A4%E1%83%9D%E1%83%A0%E1%83%9B%E1%83%90%E1%83%A2%E1%83%9D%E1%83%A0%E1%83%98http://kk.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ht.wikipedia.org/wiki/Transf%C3%B2mat%C3%A8http://la.wikipedia.org/wiki/Transformatrumhttp://lv.wikipedia.org/wiki/Transformatorshttp://lt.wikipedia.org/wiki/Transformatoriushttp://hu.wikipedia.org/wiki/Transzform%C3%A1torhttp://mk.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ml.wikipedia.org/wiki/%E0%B4%9F%E0%B5%8D%E0%B4%B0%E0%B4%BE%E0%B5%BB%E0%B4%B8%E0%B5%8D%E0%B4%AB%E0%B5%8B%E0%B5%BC%E0%B4%AE%E0%B5%BChttp://mr.wikipedia.org/wiki/%E0%A4%B5%E0%A4%BF%E0%A4%A6%E0%A5%8D%E0%A4%AF%E0%A5%81%E0%A4%A4_%E0%A4%B0%E0%A5%8B%E0%A4%B9%E0%A4%BF%E0%A4%A4%E0%A5%8D%E0%A4%B0http://ms.wikipedia.org/wiki/Transformerhttp://mn.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://my.wikipedia.org/wiki/%E1%80%91%E1%80%9B%E1%80%94%E1%80%BA%E1%80%85%E1%80%96%E1%80%B1%E1%80%AC%E1%80%BA%E1%80%99%E1%80%AChttp://nl.wikipedia.org/wiki/Transformatorhttp://new.wikipedia.org/wiki/%E0%A4%A4%E0%A5%8D%E0%A4%B0%E0%A4%BE%E0%A4%A8%E0%A5%8D%E0%A4%B8%E0%A4%AB%E0%A4%B0%E0%A5%8D%E0%A4%AE%E0%A4%B0http://ja.wikipedia.org/wiki/%E5%A4%89%E5%9C%A7%E5%99%A8http://ce.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://no.wikipedia.org/wiki/Transformatorhttp://nn.wikipedia.org/wiki/Transformatorhttp://oc.wikipedia.org/wiki/Transformadorhttp://or.wikipedia.org/wiki/%E0%AC%9F%E0%AD%8D%E0%AC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http://kaa.wikipedia.org/wiki/Transformatorhttp://ro.wikipedia.org/wiki/Transformatorhttp://rue.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ru.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://sco.wikipedia.org/wiki/Transformerhttp://stq.wikipedia.org/wiki/Transformatorehttp://simple.wikipedia.org/wiki/Transformerhttp://sk.wikipedia.org/wiki/Transform%C3%A1torhttp://sl.wikipedia.org/wiki/Transformatorhttp://ckb.wikipedia.org/wiki/%D8%AA%D8%B1%D8%A7%D9%86%D8%B3%D9%81%DB%86%D8%B1%D9%85%DB%95%D8%B1http://sr.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://sh.wikipedia.org/wiki/Transformatorhttp://su.wikipedia.org/wiki/Trafohttp://fi.wikipedia.org/wiki/Muuntajahttp://sv.wikipedia.org/wiki/Transformatorhttp://tl.wikipedia.org/wiki/Transpormadorhttp://ta.wikipedia.org/wiki/%E0%AE%AE%E0%AE%BF%E0%AE%A9%E0%AF%8D%E0%AE%AE%E0%AE%BE%E0%AE%B1%E0%AF%8D%E0%AE%B1%E0%AE%BFhttp://tt.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://te.wikipedia.org/wiki/%E0%B0%9F%E0%B1%8D%E0%B0%B0%E0%B0%BE%E0%B0%A8%E0%B1%8D%E0%B0%B8%E0%B1%8D%E2%80%8C%E0%B0%AB%E0%B0%BE%E0%B0%B0%E0%B1%8D%E0%B0%AE%E0%B0%B0%E0%B1%8Dhttp://th.wikipedia.org/wiki/%E0%B8%AB%E0%B8%A1%E0%B9%89%E0%B8%AD%E0%B9%81%E0%B8%9B%E0%B8%A5%E0%B8%87%E0%B9%84%E0%B8%9F%E0%B8%9F%E0%B9%89%E0%B8%B2http://tg.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://tg.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://tg.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://tg.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://tr.wikipedia.org/wiki/Transformat%C3%B6rhttp://tk.wikipedia.org/wiki/Transformatorhttp://uk.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ur.wikipedia.org/wiki/%D9%85%D8%A8%D8%AF%D9%91%D9%84http://vi.wikipedia.org/wiki/M%C3%A1y_bi%E1%BA%BFn_%C3%A1phttp://kaa.wikipedia.org/wiki/Transformatorhttp://ro.wikipedia.org/wiki/Transformatorhttp://rue.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ru.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://sco.wikipedia.org/wiki/Transformerhttp://stq.wikipedia.org/wiki/Transformatorehttp://simple.wikipedia.org/wiki/Transformerhttp://sk.wikipedia.org/wiki/Transform%C3%A1torhttp://sl.wikipedia.org/wiki/Transformatorhttp://ckb.wikipedia.org/wiki/%D8%AA%D8%B1%D8%A7%D9%86%D8%B3%D9%81%DB%86%D8%B1%D9%85%DB%95%D8%B1http://sr.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://sh.wikipedia.org/wiki/Transformatorhttp://su.wikipedia.org/wiki/Trafohttp://fi.wikipedia.org/wiki/Muuntajahttp://sv.wikipedia.org/wiki/Transformatorhttp://tl.wikipedia.org/wiki/Transpormadorhttp://ta.wikipedia.org/wiki/%E0%AE%AE%E0%AE%BF%E0%AE%A9%E0%AF%8D%E0%AE%AE%E0%AE%BE%E0%AE%B1%E0%AF%8D%E0%AE%B1%E0%AE%BFhttp://tt.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://te.wikipedia.org/wiki/%E0%B0%9F%E0%B1%8D%E0%B0%B0%E0%B0%BE%E0%B0%A8%E0%B1%8D%E0%B0%B8%E0%B1%8D%E2%80%8C%E0%B0%AB%E0%B0%BE%E0%B0%B0%E0%B1%8D%E0%B0%AE%E0%B0%B0%E0%B1%8Dhttp://th.wikipedia.org/wiki/%E0%B8%AB%E0%B8%A1%E0%B9%89%E0%B8%AD%E0%B9%81%E0%B8%9B%E0%B8%A5%E0%B8%87%E0%B9%84%E0%B8%9F%E0%B8%9F%E0%B9%89%E0%B8%B2http://tg.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://tr.wikipedia.org/wiki/Transformat%C3%B6rhttp://tk.wikipedia.org/wiki/Transformatorhttp://uk.wikipedia.org/wiki/%D0%A2%D1%80%D0%B0%D0%BD%D1%81%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%BE%D1%80http://ur.wikipedia.org/wiki/%D9%85%D8%A8%D8%AF%D9%91%D9%84http://vi.wikipedia.org/wiki/M%C3%A1y_bi%E1%BA%BFn_%C3%A1p


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Transformer - Electrical Machine

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Transcript of Transformer - Electrical Machine