Plate electrode

From Wikipedia, the free encyclopedia
Cutaway diagram of a triode vacuum tube, showing the plate (anode)

In electronics, a plate, usually called anode in Britain, is a type of electrode that forms part of a vacuum tube.[1] It is usually made of sheet metal, connected to a wire which passes through the glass envelope of the tube to a terminal in the base of the tube, were it is connected to the external circuit. The plate is given a positive potential, and its function is to attract and capture the electrons emitted by the cathode. Although it is sometimes a flat plate, it is more often in the shape of a cylinder or flat open-ended box surrounding the other electrodes.

The plate must dissipate heat created when the electrons hit it with a high velocity after being accelerated by the voltage between the plate and cathode. Most of the waste power used in a vacuum tube is dissipated as heat by the plate. In low power tubes it is usually given a black coating, and often has "fins" to help it radiate heat. In power vacuum tubes used in radio transmitters it is often made of a refractory metal like molybdenum. and is part of a large heat sink that projects through the glass or ceramic tube envelope and is cooled by forced air or water.[2][3]

See also

External links

Wikimedia Commons has media related to Vacuum tubes.

References

  1. ↑ Thomas A. Edison U.S. Patent 307,031 "Electrical Indicator", Issue date: 1884
  2. ↑ C H Gardner (1965) The Story of the Valve, Radio Constructor (See particularly the section "Glass Base Construction")
  3. ↑ Robert B. Tomer, Getting the most out of vacuum tubes, Howard W. Sams, Indianapolis, USA 1960, Library of Congress card no. 60-13843, available on the Internet Archive. Chapter 1
  • Shiers, George, "The First Electron Tube", Scientific American, March 1969, p. 104.
  • Tyne, Gerald, Saga of the Vacuum Tube, Ziff Publishing, 1943, (reprint 1994 Prompt Publications), pp. 30–83.
  • RCA Radiotron Designer's Handbook, 1953 (4th Edition). Contains chapters on the design and application of receiving tubes.
Semiconductor devices
Vacuum tubes
Vacuum tubes (RF)
Cathode ray tubes
Gas-filled tubes
Adjustable
Passive
Reactive
Theoretical principles
Types
Numbering systems
Examples


This article is issued from Wikipedia. The text is available under the Creative Commons Attribution/Share Alike; additional terms may apply for the media files.