Vakuumröhren

Vakuumröhren, also known as thermionic valves or electron tubes, are electronic components that control electric current by using a vacuum sealed between electrodes. They were fundamental to early electronic devices, including radios, televisions, and computers, before the widespread adoption of semiconductor transistors. The most basic vacuum tube is the diode, which contains a cathode and an anode. When heated, the cathode emits electrons, which are then attracted to the positively charged anode, creating a current flow.

More complex tubes, such as triodes, tetrodes, and pentodes, incorporate additional grids between the cathode and anode. These grids, when supplied with a control voltage, can modulate the flow of electrons, allowing the tubes to amplify signals or act as switches. This amplification capability made vacuum tubes essential for strengthening weak electronic signals in applications like radio transmission and reception.

While largely replaced by more efficient, smaller, and robust solid-state devices, vacuum tubes still find niche applications today. They are favored by some audiophiles for their unique sound characteristics in high-fidelity audio amplifiers and are used in specialized high-power radio transmitters and certain scientific instruments where their specific properties are advantageous. The development of vacuum tubes marked a significant milestone in the history of electronics, paving the way for many of the technologies we use daily.