File:Braun wireless receiving transformer 1905.jpg
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Braun_wireless_receiving_transformer_1905.jpg (258 × 345 pixels, file size: 14 KB, MIME type: image/jpeg)
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DescriptionBraun wireless receiving transformer 1905.jpg |
English: An early resonant transformer invented by Ferdinand Braun used in the coherer radio receivers in wireless telegraphy radio systems made by the Telefunken company in 1903. The antenna is connected to the primary winding (center). The secondary winding inside it is connected to a capacitor to make a tuned circuit, and to the receiver's detector. A sliding contact on the inner winding allows more or fewer turns of the coil into the circuit, tuning the receiver to different stations. The coupling between the two coils can be increased or decreased by sliding the primary up or down on the rails. Braun is credited with discovering the benefits of inductive coupling in radio transmitters and receivers. He found that "loosely coupled" tuned circuits like this had much narrower bandwidth than single tuned circuits. For these discoveries he shared the 1909 Nobel Prize in physics with Guglielmo Marconi. Information from Sarkar et al (2006) History of Wireless, p. 358 |
Date | |
Source | Retrieved January 14, 2016 from "Telefunken System of Wireless Telegraphy" in The Electrical Magazine and Engineering Monthly", The Electrical Publishing Co., London, Vol. 5, No. 1, July 29, 1905 p. 96, fig. 4 on Google Books |
Author | Unknown authorUnknown author |
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Public domainPublic domainfalsefalse |
This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929.
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Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Braun_wireless_receiving_transformer_1905.jpg |
Public domainPublic domainfalsefalse |
This UK artistic or literary work, of which the author is unknown and cannot be ascertained by reasonable enquiry, is in the public domain because it is one of the following:
This tag can be used only when the author cannot be ascertained by reasonable enquiry. If you wish to rely on it, please specify in the image description the research you have carried out to find who the author was. The above is all subject to any overriding publication right which may exist. In practice, publication right will often override the first of the bullet points listed. Unpublished anonymous paintings remain in copyright until at least 1 January 2040. This tag does not apply to engravings or musical works. More information |
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current | 02:50, 5 February 2016 | 258 × 345 (14 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
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