thermionic valve


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

thermionic valve

(esp US and Canadian), tube
an electronic valve in which electrons are emitted from a heated rather than a cold cathode
References in periodicals archive ?
Having had Sir John Ambrose Fleming, the inventor of the thermionic valve, as the first chair of electrical technology in the late 1800s, UCL built on this pioneering work, often with Marconi, in the following years.
Later, he developed the thermionic valve that allowed further radio advancement and patented an early form of sonar, before his death in 1949.
Dear Editor, Chris You-ett's revelation (Memory stack of facts on computing, Post, Jan 12) that the thermionic valve was invented by Prof Tommy Flowers in 1938 will cause surprise, not to say consternation, among those of us who have long believed that it was the work of Sir Ambrose Fleming in 1904 and also of Doctor Lee de Forest in 1907.