File:William Sturgeons first induction coil.png

William_Sturgeons_first_induction_coil.png (550 × 462 pixels, file size: 33 KB, MIME type: image/png)

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Description
English: Drawing of one of the first induction coils, built by British physicist William Sturgeon in 1837. The primary of the coil (B) was 260 ft. of bell wire wound on a wooden bobbin with an iron core, and the secondary was 1300 ft of thinner wire, insulated with a wax coating, wound on top, and soldered to the primary wire to make an autotransformer. The primary was powered by a liquid battery cell (0). The zinc sawtooth interrupter wheel (D) dipping in mercury was turned by hand to break the primary current, to create the flux changes necessary to induce a voltage in the secondary. The magnitude of the voltage produced was judged by how strong a shock it gave when the copper handles (H) were held.

It was one of the first transformers to use a divided iron core to prevent eddy currents. Sturgeon experimented with several cores and found that a core made of separate iron wires (F) gave more powerful shocks than a solid iron core when the interrupter wheel got above a certain speed (although Prof. G. H. Bachhoffner had discovered this a few weeks before Sturgeon, using one of Sturgeon's own coils.) Demonstrated to the London Electrical Society in August, 1837
Date
Source Downloaded 2012-05-20 from John Ambrose Fleming (1893) The Alternate Current Transformer in Thory and Practice, Vol.2, The Electrician Printing and Publishing Co., London, p.11,fig.6 on Google Books
Author John Ambrose Fleming

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Date/TimeThumbnailDimensionsUserComment
current22:50, 20 May 2012Thumbnail for version as of 22:50, 20 May 2012550 × 462 (33 KB)Chetvorno

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