Also called an electron tube vacuum tube or even light, is an active electronic component, usually used as an amplifier. The vacuum tube rectifier or amplifier has been replaced in many applications in different semiconductors, but is invaluable to date in areas such as amplification or high power microwave.

Electronic tubes means the components that use electrodes, placed in a vacuum or in a gas insulated from each other in this medium, and comprising at least an electron source. Durable temperature isolates all from the outside. Although the envelope is usually glass, power tubes often use ceramic and metal. The electrodes are connected to terminals that pass through the passages sealed envelope. On most tubes, the ends of the pins are designed to be installed in a vacuum tube holder for easy replacement

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