It is a vacuum electronic device that works by controlling the intensity of the flow of electrons moving in a vacuum or rarefied gas between the electrodes.Currently, almost completely replaced by semiconductor devices.
Their principle of operation is based on the phenomenon of thermionic emission (emission of electrons by a heated solid body) and the effect of an electric field on moving charges.
Under the influence of the potential difference between the anode (+) and the cathode (-), the electrons reach the anode and form the anode current in the external circuit.
With the help of additional electrodes (grids), the electron flow is controlled by applying electric potential to these electrodes.
The first electronic lamp — a diode — was invented by D. Fleming (England) in 1904,
which opened the age of electronics.
The main elements of the diode are the cathode and the anode. In the diode, the current flows only in one direction — from the cathode to the anode.
Current applications:
Due to the principle of operation, electron tubes are devices that are much more resistant to such damaging factors as the electromagnetic pulse.
Vacuum tube equipment can be designed for a larger temperature and radiation range of conditions than semiconductor.
Vacuum tubes are still used in sound engineering, both amateur and professional. Designing tube sound engineering devices is one of the directions of the modern amateur radio movement.
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