thermionic valve
Quick Summary
A thermionic valve, also known as a thermionic tube, is an electronic component that utilizes the emission of electrons from a heated electrode. This phenomenon, called thermionic emission, was observed by Thomas Edison and further explored by scientists like John Ambrose Fleming.
Fleming developed the first thermionic valve, a two-electrode vacuum tube, in 1904. This device was crucial for rectifying radio signals, converting alternating current to direct current, which was essential for early radio receivers. Later, Lee De Forest added a third electrode, a grid, creating a three-electrode vacuum tube called the Audion. This innovation allowed for the amplification of radio signals, paving the way for advancements in radio broadcasting, television, and early computers. While solid-state devices have largely replaced vacuum tubes, they are still used in specialized applications requiring extreme power or frequency handling.12
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- electronicsThe vacuum tube era
Coolidge and Flemingās thermionic valve (a two-electrode vacuum tube) for use in radio receivers. The detection of a radio signal, which is a very high-frequency alternating current (AC), requires that the signal be rectified; i.e., the alternating current must be converted into a direct current (DC) by aā¦
Read MoreCoolidge and Flemingās thermionic valve (a two-electrode vacuum tube) for use in radio receivers. The detection of a radio signal, which is a very high-frequency alternating current (AC), requires that the signal be rectified; i.e., the alternating current must be converted into a direct current (DC) by aā¦
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history of technologyCommunicationsā¦was the development of the thermionic valve, a device for rectifying (that is, converting a high-frequency oscillating signal into a unidirectional current capable of registering as a sound) an electromagnetic wave. This was essentially a development from the carbon-filament electric lightbulb. In 1883 Edison had found that in these lampsā¦
Read Moreā¦was the development of the thermionic valve, a device for rectifying (that is, converting a high-frequency oscillating signal into a unidirectional current capable of registering as a sound) an electromagnetic wave. This was essentially a development from the carbon-filament electric lightbulb. In 1883 Edison had found that in these lampsā¦
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