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Braun_wireless_receiving_transformer_1905.jpg (258 × 345 pixels, file size: 14 KB, MIME type: image/jpeg)
Summary
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 |
Licensing
Public domainPublic domainfalsefalse |
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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 |
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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:
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Captions
Ferdinand Braun's tuning coil
Items portrayed in this file
depicts
copyright status
public domain
inception
29 July 1905Gregorian
media type
image/jpeg
checksum
00c2678b8130d1315e82e2288bfbf85fb1886c77
determination method: 0702186578
data size
14,420 byte
height
345 pixel
width
258 pixel
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 02:50, 5 February 2016 | ![]() | 258 × 345 (14 KB) | Chetvorno | User created page with UploadWizard |
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