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Vacuum tube

28:39

Vacuum Tubes: Episode 1 - The Basics and the Diode

4:24

Vacuum Diode

12:31

Vacuum tube diode ( principle of operation and internal construction )

15:12

1942 ARMY RADIO TRAINING FILM “ ELECTRON THEORY AND THE DIODE TUBE ” VACUUM TUBE ELECTRONICS 72782

3:51

How Vacuum Tubes Work

In electronics, a vacuum tube, an electron tube, or just a tube, or valve is a device that controls electric current between electrodes in an evacuated container. Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a heated cathode. This type is called a thermionic tube or thermionic valve. A phototube, however, achieves electron emission through the photoelectric effect. Not all electronic circuit valves/electron tubes are vacuum tubes (evacuated); gas-filled tubes are similar devices containing a gas, typically at low pressure, which exploit phenomena related to electric discharge in gases, usually without a heater.