electron tube

American  

noun

1. an electronic device that consists, typically, of a sealed glass bulb containing two or more electrodes: used to generate, amplify, and rectify electric oscillations and alternating currents.

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electron tube British  

noun

1. Sometimes shortened to: tube.  Also called: vacuum tube.  an electrical device, such as a valve, in which a flow of electrons between electrodes takes place

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electron tube Scientific  

1. A sealed glass tube containing either a vacuum or a small amount of gas, in which electrons move from a negatively charged electrode, the cathode, to a positively charged one, the anode. The cathode is usually heated by an electric current to free the electrons. Other electrodes in the tube can vary the electric or magnetic fields in the tube to control the strength and direction of the moving electrons. Electron tubes are used to amplify signals, rectify AC currents, and produce x-rays, among other uses. They have been mostly replaced by transistors but are still used in television screens, computer monitors, and microwave technology.

2. Also called valve

3. See also vacuum tube

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Etymology

Origin of electron tube

First recorded in 1920–25

Example Sentences

Even at the very hour that war began the electron tube was the first to serve the nation.

From Time Magazine Archive

On Dec. 7, 1941 the electron tube caught the mutter of Japanese aircraft when they were 132 miles away from Pearl Harbor.

From Time Magazine Archive

The incredible accuracy of U.S. naval guns at Casablanca, which at 26 miles smashed the hull of the French battleship Jean Bart in two salvos, was a triumph for the electron tube.

From Time Magazine Archive

There is no glass envelope, as in an electron tube, and no complicated insides.

From Time Magazine Archive

Lee de Forest, 77, inventor of the electron tube, who sometimes worries about its development into radio and television, had a moment of mellow reflection following General MacArthur's coverage on TV.

From Time Magazine Archive