Download PDF, EPUB, MOBI Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19
Download PDF, EPUB, MOBI Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19
Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19.cEngineers' Society Pennsylvania
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Author: Engineers' Society Pennsylvania
Number of Pages: 226 pages
Published Date: 01 May 2012
Publisher: Rarebooksclub.com
Publication Country: Miami Fl, United States
Language: English
ISBN: 9781236012081
File size: 22 Mb
Download Link: Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 Excerpt: ...Wire. 9th. Phono-electric Wire. 10th. Phosphor Bronze Wire. nth. Bimetallic Wire. When the American Bell Telephone Company first started in business they used galvanized iron wire, for all their outside lines. It was found, before long, that iron wire did not last and had a rather high ohmic resistance. Besides the high ohmic resistance the resistance of the line increased very materially to the pulsating current used in transmitting speech. This resistance to a pulsating current increased with the frequency. At a frequency of about 400 per second, (not high for telephone currents), the resistance of a No. 2 iron w'ire increased over six times its ohmic resistance. Now, the resistance of hard drawn copper for pulsating currents, is but little greater than its ohmic resistance. For long distance Telephone lines No. 6 B. & S. hard drawn copper is used. The resistance of this wire is.403 ohms per 1,000 feet. The ohmic resistance of the same sized galvanized iron wire would be 2.32 ohms per 1,000 feet, or six times as great. Now, if the ohmic resistance of iron wire is six times that of copper and the resistance of iron wire increases three or four times as much with pulsating currents, it is apparent that hard drawn copper is twenty to thirty times a better conductor than galvanized iron wire of the same size. The American Bell Telephone Company soon recognized this, but copper wire at that time had a very low tensile strength, and was not suitable for line work; so they sent one of their men (Mr. Doolittle), to the wire mills of the Bridgeport Brass Company for the purpose of securing a copper wire that would have a high tensile strength. After considerable experimenting he succeeded in producing a hard drawn copper wire with a reliable tensile strength o...
Read online Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 Buy and read online Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 Download and read Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 ebook, pdf, djvu, epub, mobi, fb2, zip, rar, torrent Download to iPad/iPhone/iOS, B&N nook Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 ebook, pdf, djvu, epub, mobi, fb2, zip, rar, torrent
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Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19.cEngineers' Society Pennsylvania
Author: Engineers' Society Pennsylvania
Number of Pages: 226 pages
Published Date: 01 May 2012
Publisher: Rarebooksclub.com
Publication Country: Miami Fl, United States
Language: English
ISBN: 9781236012081
File size: 22 Mb
Download Link: Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19
---------------------------------------------------------------
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 Excerpt: ...Wire. 9th. Phono-electric Wire. 10th. Phosphor Bronze Wire. nth. Bimetallic Wire. When the American Bell Telephone Company first started in business they used galvanized iron wire, for all their outside lines. It was found, before long, that iron wire did not last and had a rather high ohmic resistance. Besides the high ohmic resistance the resistance of the line increased very materially to the pulsating current used in transmitting speech. This resistance to a pulsating current increased with the frequency. At a frequency of about 400 per second, (not high for telephone currents), the resistance of a No. 2 iron w'ire increased over six times its ohmic resistance. Now, the resistance of hard drawn copper for pulsating currents, is but little greater than its ohmic resistance. For long distance Telephone lines No. 6 B. & S. hard drawn copper is used. The resistance of this wire is.403 ohms per 1,000 feet. The ohmic resistance of the same sized galvanized iron wire would be 2.32 ohms per 1,000 feet, or six times as great. Now, if the ohmic resistance of iron wire is six times that of copper and the resistance of iron wire increases three or four times as much with pulsating currents, it is apparent that hard drawn copper is twenty to thirty times a better conductor than galvanized iron wire of the same size. The American Bell Telephone Company soon recognized this, but copper wire at that time had a very low tensile strength, and was not suitable for line work; so they sent one of their men (Mr. Doolittle), to the wire mills of the Bridgeport Brass Company for the purpose of securing a copper wire that would have a high tensile strength. After considerable experimenting he succeeded in producing a hard drawn copper wire with a reliable tensile strength o...
Read online Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 Buy and read online Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 Download and read Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 ebook, pdf, djvu, epub, mobi, fb2, zip, rar, torrent Download to iPad/iPhone/iOS, B&N nook Proceedings of the Engineers' Society of Western Pennsylvania Volume N . 19 ebook, pdf, djvu, epub, mobi, fb2, zip, rar, torrent
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