An introduction to vacuum tubes.


A vacuum tube is an electronic component that controls the flow of electrons in an electrical circuit. The electrodes involved in the work are encapsulated in a vacuum container (mostly glass walls), hence the name. In China, vacuum tubes are called "electron tubes".

In Hong Kong and Guangdong Province, the vacuum tube will be called "Ball". Generally speaking, there is a vacuum in the vacuum tube. But it is not necessarily with the development: there are gas-filled shock tubes, gas-filled voltage stabilizer tubes and mercury rectifier tubes.

Before the middle of the 20th century, because semiconductors were not yet popular, basically all electronic equipment at that time used vacuum tubes, which formed the demand for vacuum tubes at that time. However, with the development and popularization of semiconductor technology, vacuum tubes were replaced by semiconductors due to high cost, indurability, large size, and low efficiency.

But vacuum tubes can be found in audio amplifiers, microwave ovens, and high-frequency transmitters in satellites; many speakers use vacuum tubes specifically because of their special sound quality. In addition, such as cathode ray tubes in televisions and computer cathode ray tube monitors, and X-ray tubes in X-ray machines, are special vacuum tubes.

For high-power amplification (such as megawatt radios) and satellites (microwave high-power), high-power vacuum tubes and traveling wave tubes are still the best choice. For high-frequency welding machines and X-ray machines, it is still the mainstream device.