Explanation of a Vacuum Tube

Vacuum tubes are older technology used in amplifiers and radio stations.

Vacuum tubes are electronic devices that produce energy flows in a controlled environment. These tubes, which have quite a history in electronics, were created in 1904 by British scientist John Ambrose Fleming.

Function

The conversion of AC (alternating current) power to DC (direct current) is a primary function of vacuum tubes. Known as a diode, the tube is essentially an incandescent lightbulb with an additional electrode. Heated up, the tube produces direct-current flows as the filament heats and the electrode remains cool.

Types

Vacuum tubes are primarily electronic devices encased in glass. Large tubes that produce more power --- often used by radio stations -- can use ceramic tubes. These are similar in nature to glass tubes, but they have a cooling system which pumps air or liquid through the tube to reduce heat.

Use

For the most part, vacuum tubes are an older technology. In the early years, they were common in televisions and monitors --- known as cathode ray tubes --- and audio amplifiers. Old-style amplifiers for guitars and similar instruments may still use tubes, as they produce a popular tone.

References

• Vacuum Tubes: How Vacuum Tubes Work
• PC Mag: Vacuum Tubes