File:Commercial Fleming valves.jpg
From Wikimedia Commons, the free media repository
Jump to navigation
Jump to search
Size of this preview: 800 × 357 pixels. Other resolutions: 320 × 143 pixels | 640 × 285 pixels | 1,218 × 543 pixels.
Original file (1,218 × 543 pixels, file size: 146 KB, MIME type: image/jpeg)
File information
Structured data
Captions
Summary
[edit]DescriptionCommercial Fleming valves.jpg |
English: Early Fleming valves. Shows several different designs used by Fleming. The Fleming valve, invented in 1904 by John Ambrose Fleming, as a detector for radio waves in early radio receivers, was the first thermionic diode and the first vacuum tube. It consisted of an evacuated glass bulb containing two electrodes: a cathode in the form of a tantalum wire filament, and a anode (plate) consisting of a sheet metal cylinder surrounding the filament. A separate current through the filament heated it red-hot, releasing electrons into the vacuum of the tube. The AC voltage to be rectified was applied between anode and filament. When the anode is positive, the electrons from the filament are attracted to it and a current flows through the tube. When the anode is negative the electrons are not attracted so no current flows. |
Date |
between 1904 and 1919 date QS:P,+1950-00-00T00:00:00Z/7,P1319,+1904-00-00T00:00:00Z/9,P1326,+1919-00-00T00:00:00Z/9 |
Source | Downloaded July 18, 2013 from John Ambrose Fleming (1919) The Thermionic Valve and its Developments in Radiotelegraphy and Telephony, The Wireless Press, London, p. 53, fig. 28A on Google Books |
Author | John Ambrose Fleming |
Licensing
[edit]Public domainPublic domainfalsefalse |
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.
|
||
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
|
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 18:31, 21 July 2013 | 1,218 × 543 (146 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
File usage on other wikis
The following other wikis use this file:
- Usage on ca.wikipedia.org
- Usage on en.wikipedia.org
- Usage on eu.wikipedia.org
- Usage on fa.wikipedia.org
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
JPEG file comment | Created with GIMP |
---|
Structured data
Items portrayed in this file
depicts
image/jpeg
0b817acb7f29033767412e999f0c54eb0ad10b7b
149,945 byte
543 pixel
1,218 pixel
Hidden category: