Definition of thermionic valve in English:

thermionic valve

(US thermionic tube)


  • A device giving a flow of thermionic electrons in one direction, used especially in the rectification of a current and in radio reception.

    • ‘In 1914 the thermionic valve was in use as a receiver, but as a transmitter it was still in the experimental stage.’
    • ‘The speaker or singer uses a microphone feeding into the above-mentioned amplifier, which incorporates vacuum tubes (thermionic valves).’
    • ‘He is best remembered as the inventor of the two-electrode radio rectifier, which he called the thermionic valve; it is also known as the vacuum diode, kenotron, thermionic tube, and Fleming valve.’
    • ‘This is the fundamental operating principle of vacuum tubes, once called thermionic tubes.’
    • ‘In the West transistors had long replaced the thermionic tube in audio circuits.’
    • ‘The basic thermionic tube with three electrodes is called a triode in view of the number of electrodes.’
    • ‘All this time the thermionic tube played a major part and went through a lot of development by large corporations to engineer a superior device.’
    • ‘These methods are particularly adaptable for amplification of very weak impulses and require careful insulation and even special thermionic tubes for best results.’
    • ‘There is one particular wartime project which is of considerable historical interest, since it involved the first large-scale use of thermionic valves for digital computation.’
    • ‘It's rather odd therefore that even though we ditched thermionic valves for transistors and integrated circuits many years ago, the cathode ray tube has remained the most cost-effective display system.’
    • ‘The electromagnetic wave generator comprises a thermionic tube having a cathode, an anode and at least one grid.’
    • ‘To many people, the thermionic valve or electron tube is history.’
    • ‘At the time it was the world's most powerful transmitter using thermionic valves.’
    • ‘As their name suggests, thermionic valves need to be heated to work.’
    • ‘Fleming called his device the thermionic valve because it used heat to control the flow of electricity just as a valve controls the flow of water.’
    • ‘His work with the thermionic valve in 1904 and 1905 was important to the development of radio.’
    • ‘The same concept led to his creating almost complete vacuums in thermionic tubes.’
    • ‘It consists of a thermionic tube with a cathode, an anode and a third electrode which is called the collector or counter electrode.’