File:UY224 tetrode plate current negative resistance.svg
![File:UY224 tetrode plate current negative resistance.svg](https://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/UY224_tetrode_plate_current_negative_resistance.svg/736px-UY224_tetrode_plate_current_negative_resistance.svg.png?20131129082749)
Original file (SVG file, nominally 1,374 × 1,119 pixels, file size: 34 KB)
Captions
Captions
Summary
[edit]DescriptionUY224 tetrode plate current negative resistance.svg |
English: Graph of plate (anode) and screen grid current vs plate voltage in a UY224 1920s era tetrode vacuum tube, showing region of negative resistance (grey) used in dynatron oscillator circuit.
When electrons from the cathode hit the plate, they knock secondary electrons out of the metal, a process called secondary emission. If the screen grid is made positive with respect to the plate, the secondary electrons will be attracted to it, representing a current away from the plate. For a certain plate voltage range (grey) an increase in plate voltage will cause a greater increase in secondary electrons than primary electrons, so the plate current will decrease. Thus the differential plate resistance is negative:
This negatve resistance was used in the dynatron oscillator circuit to cancel the resistance in a tuned circuit, creating oscillations. The dynatron oscillator was used in some instruments in the 1930s and 40s. In modern tetrodes the surface of the plate is treated to greatly reduce secondary emission, so they don't have negative resistance. Note:
|
Date | |
Source | Tracing of a graph retrieved 18 October 2013 from Basic Theory and Application of Electron Tubes, US Dept. of the Army Technical Manual TM 11-662, February 1952, US Dept. of Defense, p. 90, fig. 71 on Pete Miller's tubebooks.org website |
Author |
|
Licensing
[edit]Public domainPublic domainfalsefalse |
![]() |
This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code.
Note: This only applies to original works of the Federal Government and not to the work of any individual U.S. state, territory, commonwealth, county, municipality, or any other subdivision. This template also does not apply to postage stamp designs published by the United States Postal Service since 1978. (See § 313.6(C)(1) of Compendium of U.S. Copyright Office Practices). It also does not apply to certain US coins; see The US Mint Terms of Use.
|
![]() |
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights. |
https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 08:27, 29 November 2013 | ![]() | 1,374 × 1,119 (34 KB) | Chetvorno (talk | contribs) | Removed color |
20:28, 20 October 2013 | ![]() | 1,374 × 1,119 (34 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 en.wikipedia.org
- Usage on ja.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.
Width | 1374.2292 |
---|---|
Height | 1118.5416 |