File:Carbon button microphone cutaway.png

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Description
English: Drawing of a Bell Telephone carbon button microphone from about 1912, shown with the structure cut away to reveal the construction. It was used in their telephones into the 1940s. The active element, (center) is a cylindrical "button" consisting of two electrodes with carbon granules between them. This was attached at the front to the center of a cylindrical aluminum diaphragm, and the back to a stationary bracket. When someone spoke into the horn mouthpiece (right), the sound waves vibrated the diaphragm back and forth, which put varying pressure on the carbon. Current from a battery was applied to the electrodes, and the varying pressure caused the carbon's resistance thus the current to vary.
Date
Source Retrieved April 18, 2014 from Harry Randolph Van Deventer 1912 Telephonology, 3rd Ed., McGraw-Hill, New York, p. 62, fig. 85 on Google Books
Author H. R. Van Deventer

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This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.
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current12:33, 18 April 2014Thumbnail for version as of 12:33, 18 April 2014727 × 874 (134 KB)Chetvorno (talk | contribs)User created page with UploadWizard

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