ٽرانسفارمر

This article is about the electrical component. For other uses, see ٽرانسفارمر (disambiguation).

ٽرانسفارمر
غير فعال
Transformer
هڪ او-ڪور ٽرانسفارمر جيڪو ٽامي جي تار جي ٻن ڪوئلن تي مشتمل آهي جيڪو هڪ مقناطيسي ڪور جي چوڌاري ويڙهيل آهي.
اليڪٽرانڪ علامت
ڪم ڪندڙ اصول	اليڪٽرومگنيٽڪ انڊڪشن
موجد	مائيڪل فيراڊي
ايجاد جو سال	1831
جزو جو قسم	غير فعال

مختلف ٽرانسفارمر

ٽرانسفارمر جو خاڪو

ٽرانسفارمر (transformer) هڪ ڊوائيس آهي ايڪو متبادل ڪرنٽ جي وولٽیج کي وڌائڻ يا هيٺ ڪرڻ لاءِ استعمال ڪيو ويندو آهي. ان جي ايجاد مشھور سائنسدان مائيڪل فيراڊي ڪئي هئي. ٽرانسفارمر ڊي سي (ڊائريڪٽ ڪرنٽ) تي نہ هلندا آهن يعني بيٽري جي وولٽيج کي مٿي يا هيٺ نہ ٿا ڪري سگهن.

اليڪٽريڪل انجنيئرنگ ۾، ٽرانسفارمر هڪ غير فعال جزو (passive component) آهي جيڪو هڪ برقي سرڪٽ کان ٻئي سرڪٽ، يا ڪيترن ئي سرڪٽس ۾ برقي توانائي منتقل ڪري ٿو. ٽرانسفارمر جي ڪنهن به هڪ ڪوائل ۾ هڪ مختلف ڪرنٽ ٽرانسفارمر جي ڪور ۾ هڪ مختلف مقناطيسي وهڪرو (magnetic flux) پيدا ڪري ٿو، جيڪو ساڳئي ڪور جي چوڌاري ڪنهن به ٻئي ڪوائل ۾ هڪ مختلف اليڪٽرو موٽو فورس (EMF) کي جنم ڏئي ٿو. برقي توانائي ٻن سرڪٽس جي وچ ۾ ڌاتو (conductive) ڪنيڪشن کان سواءِ الڳ الڳ ڪوائلن جي وچ ۾ منتقل ڪري سگهجي ٿي. سال 1831ع ۾ دريافت ڪيل فاراڊي جو انڊڪشن جو قانون، ڪوئلي جي چوڌاري تبديل ٿيندڙ مقناطيسي وهڪري جي ڪري ڪنهن به ڪوئل ۾ انڊسڊ وولٽيج اثر کي بيان ڪري ٿو.

ٽرانسفارمر AC وولٽيج جي سطحن کي تبديل ڪرڻ لاءِ استعمال ڪيا ويندا آهن، اهڙن ٽرانسفارمرن کي ترتيب وار وولٽيج جي سطح کي وڌائڻ يا گهٽائڻ لاءِ اسٽيپ اپ يا اسٽيپ ڊائون قسم سڏيو ويندو آهي. ٽرانسفارمر سرڪٽس جي وچ ۾ ۽ سگنل پروسيسنگ سرڪٽس جي ٻن مرحلن ۾ گيلوانڪ آئسوليشن مهيا ڪرڻ لاءِ پڻ استعمال ڪري سگهجن ٿا. سال 1885ع ۾ پهرين مسلسل-ممڪن ٽرانسفارمر (constant-potential transformer) جي ايجاد کان وٺي، ٽرانسفارمر متبادل ڪرنٽ برقي طاقت جي ٽرانسميشن، ورڇ ۽ استعمال لاءِ ضروري بڻجي ويا آهن. اليڪٽرانڪس ۽ اليڪٽرڪ پاور ايپليڪيشنن ۾ ٽرانسفارمر ڊيزائن جي وسيع رينج ملي ٿي. ٽرانسفارمرز سائيز ۾ هڪ ڪيوبڪ سينٽي ميٽر کان گهٽ آر ايف (RF) ٽرانسفارمرز کان وٺي، پاور گرڊ کي ڳنڍڻ لاءِ استعمال ٿيندڙ سوين ٽن وزني يونٽن تائين آهن.

ٽرانسفارمر ڪيئن ڪم ڪندو آهي؟

هڪ ٽرانسفارمر ۾ ٻہ ڪوائل ھوندا آهن. هڪ کي سيڪنڊري ڪوائل ۽ ٻئي کي پرائمري ڪوائل سڏيو ويندو آهي. عام طور تي اهي ٻہ ڪوائل لوھ جي پٽڙين (جيڪي انسوليٽڊ ھونديون آھن) تي ويڙھيل هوندا آهن. ٻنهي ڪوائلن ۾ تار جي موڙن جو تعداد انهن جي وچ ۾ وولٽیج سان تناسب ۾ ھوندي آهي. جڏهن هڪ ڪوائل ۾ ڪرنٽ وهندو آهي تہ مقناطيسي انڊڪشن ذريعي ٻئي ڪوائل ۾ بہ ڪرنٽ وهندو آهي. آئوٽ پٽ وولٽیج کي موڙن جي تعداد کي وڌائڻ يا گهٽائڻ سان سيٽ ڪري سگهجي ٿو.

ھيوي ڊيوٽي ٽرانسفارمر

گرڊ اسٽيشنن تي لڳل ھيوي ڊيوٽي ۽ ھاءِ وولٽيج ٽرانسفارمر انتھائي گرم ٿي ويندا آھن. انهن کي ٿڌو ڪرڻ لاءِ ٽرانسفارمر تيل استعمال ڪيو ويندو آھي.

History

Discovery of induction

Faraday's experiment with induction between coils of wire

Electromagnetic induction, the principle of the operation of the transformer, was discovered independently by Michael Faraday in 1831 and Joseph Henry in 1832. Only Faraday furthered his experiments to the point of working out the equation describing the relationship between EMF and magnetic flux now known as Faraday's law of induction:

$|{\mathcal {E}}|=\left|{{\mathrm {d} \Phi _{\text{B}}} \over \mathrm {d} t}\right|,$

where $|{\mathcal {E}}|$ is the magnitude of the EMF in volts and Φ_B is the magnetic flux through the circuit in webers.

Faraday performed early experiments on induction between coils of wire, including winding a pair of coils around an iron ring, thus creating the first toroidal closed-core transformer. However he only applied individual pulses of current to his transformer, and never discovered the relation between the turns ratio and EMF in the windings.

Induction coil, 1900, Bremerhaven, Germany

Induction coils

اصل مضمون جي لاءِ ڏسو Induction coil

Faraday's ring transformer

The first type of transformer to see wide use was the induction coil, invented by Irish-Catholic Rev. Nicholas Callan of Maynooth College, Ireland in 1836. He was one of the first researchers to realize that the more turns the secondary winding has in relation to the primary winding, the larger the induced secondary EMF will be. Induction coils evolved from scientists' and inventors' efforts to get higher voltages from batteries. Since batteries produce direct current (DC) rather than AC, induction coils relied upon vibrating electrical contacts that regularly interrupted the current in the primary to create the flux changes necessary for induction. Between the 1830s and the 1870s, efforts to build better induction coils, mostly by trial and error, slowly revealed the basic principles of transformers.

First alternating current transformers

By the 1870s, efficient generators producing alternating current (AC) were available, and it was found that AC could power an induction coil directly, without an interrupter.

In 1876, Russian engineer Pavel Yablochkov invented a lighting system based on a set of induction coils where the primary windings were connected to a source of AC. The secondary windings could be connected to several electric candles (arc lamps) of his own design. The coils Yablochkov employed functioned essentially as transformers.

In 1878, the Ganz factory, Budapest, Hungary, began producing equipment for electric lighting and, by 1883, had installed over fifty systems in Austria-Hungary. Their AC systems used arc and incandescent lamps, generators, and other equipment.

In 1882, Lucien Gaulard and John Dixon Gibbs first exhibited a device with an initially widely criticized laminated plate open iron core called a 'secondary generator' in London, then sold the idea to the Westinghouse company in the United States in 1886. They also exhibited the invention in Turin, Italy in 1884, where it was highly successful and adopted for an electric lighting system. Their open-core device used a fixed 1:1 ratio to supply a series circuit for the utilization load (lamps). However, the voltage of their system was controlled by moving the iron core in or out.

Early series circuit transformer distribution

Induction coils with open magnetic circuits are inefficient at transferring power to loads. Until the turn of the 20th century, the paradigm for AC power transmission from a high voltage supply to a low voltage load was a series circuit. Open-core transformers with a ratio near 1:1 were connected with their primaries in series to allow use of a high voltage for transmission while presenting a low voltage to the lamps. The inherent flaw in this method was that turning off a single lamp (or other electric device) affected the voltage supplied to all others on the same circuit. Many adjustable transformer designs were introduced to compensate for this problematic characteristic of the series circuit, including those employing methods of adjusting the core or bypassing the magnetic flux around part of a coil. Efficient, practical transformer designs did not appear until the 1880s, but within a decade, the transformer would be instrumental in the war of the currents, and in seeing AC distribution systems triumph over their DC counterparts, a position in which they have remained dominant ever since.

Shell form transformer. Sketch used by Uppenborn to describe ZBD engineers' 1885 patents and earliest articles.

Core form, front; shell form, back. Earliest specimens of ZBD-designed high-efficiency constant-potential transformers manufactured at the Ganz factory in 1885.

The ZBD team consisted of Károly Zipernowsky, Ottó Bláthy and Miksa Déri

Stanley's 1886 design for adjustable gap open-core induction coils

Closed-core transformers and parallel power distribution

In the autumn of 1884, Károly Zipernowsky, Ottó Bláthy and Miksa Déri (ZBD), three Hungarian engineers associated with the Ganz Works, had determined that open-core devices were impracticable, as they were incapable of reliably regulating voltage. The Ganz factory had also, in the autumn of 1884, made delivery of the world's first five high-efficiency AC transformers, the first of these units having been shipped on September 16, 1884. This first unit had been manufactured to the following specifications: 1,400 W, 40 Hz, 120:72 V, 11.6:19.4 A, ratio 1.67:1, one-phase, shell form. In their joint 1885 patent applications for novel transformers (later called ZBD transformers), they described two designs with closed magnetic circuits where copper windings were either wound around an iron wire ring core or surrounded by an iron wire core. The two designs were the first application of the two basic transformer constructions in common use to this day, termed "core form" or "shell form" .

In both designs, the magnetic flux linking the primary and secondary windings traveled almost entirely within the confines of the iron core, with no intentional path through air (see Toroidal cores below). The new transformers were 3.4 times more efficient than the open-core bipolar devices of Gaulard and Gibbs. The ZBD patents included two other major interrelated innovations: one concerning the use of parallel connected, instead of series connected, utilization loads, the other concerning the ability to have high turns ratio transformers such that the supply network voltage could be much higher (initially 1,400 to 2,000 V) than the voltage of utilization loads (100 V initially preferred). When employed in parallel connected electric distribution systems, closed-core transformers finally made it technically and economically feasible to provide electric power for lighting in homes, businesses and public spaces. Bláthy had suggested the use of closed cores, Zipernowsky had suggested the use of parallel shunt connections, and Déri had performed the experiments; In early 1885, the three engineers also eliminated the problem of eddy current losses with the invention of the lamination of electromagnetic cores.

Transformers today are designed on the principles discovered by the three engineers. They also popularized the word 'transformer' to describe a device for altering the EMF of an electric current although the term had already been in use by 1882. In 1886, the ZBD engineers designed, and the Ganz factory supplied electrical equipment for, the world's first power station that used AC generators to power a parallel-connected common electrical network, the steam-powered Rome-Cerchi power plant.

Westinghouse improvements

E-shaped plates for transformer cores developed by Westinghouse

Building on the advancement of AC technology in Europe, George Westinghouse founded the Westinghouse Electric in Pittsburgh, Pennsylvania, on January 8, 1886. The new firm became active in developing alternating current (AC) electric infrastructure throughout the United States. The Edison Electric Light Company held an option on the US rights for the ZBD transformers, requiring Westinghouse to pursue alternative designs on the same principles. George Westinghouse had bought Gaulard and Gibbs' patents for $50,000 in February 1886. He assigned to William Stanley the task of redesign the Gaulard and Gibbs transformer for commercial use in United States. Stanley's first patented design was for induction coils with single cores of soft iron and adjustable gaps to regulate the EMF present in the secondary winding (see image). This design was first used commercially in the US in 1886 but Westinghouse was intent on improving the Stanley design to make it (unlike the ZBD type) easy and cheap to produce.

Westinghouse, Stanley and associates soon developed a core that was easier to manufacture, consisting of a stack of thin 'E‑shaped' iron plates insulated by thin sheets of paper or other insulating material. Pre-wound copper coils could then be slid into place, and straight iron plates laid in to create a closed magnetic circuit. Westinghouse obtained a patent for the new low-cost design in 1887.

Other early transformer designs

In 1889, Russian-born engineer Mikhail Dolivo-Dobrovolsky developed the first three-phase transformer at the Allgemeine Elektricitäts-Gesellschaft ('General Electricity Company') in Germany.

In 1891, Nikola Tesla invented the Tesla coil, an air-cored, dual-tuned resonant transformer for producing very high voltages at high frequency.

Audio frequency transformers ("repeating coils") were used by early experimenters in the development of the telephone.

وڌيڪ ڏسو

• ڪرنٽ
• اليڪٽرڪ پاور
• ڊائيوڊ
• ڪيپيسيٽر
• پاور اليڪٽرانڪس

ٻاهرين ڳنڍڻا

عام ڳنڍڻا:

• (وڊيو) پاور ٽرانسفارمر جو ان رش ڪرنٽ (اينيميشن)
• (Video) Power transformer inrush current (animation)