What is a vacuum tube?

Before replacing transistors and integrated circuits, vacuum tubes (thermionic valves) were used mainly in electronic devices such as television, radios and computers. They are still used in several specialized devices. Edison noted that the current flows between the bulb fiber and the plate in the vacuum when the plate is connected to the positive end of the fiber.

Since the first computers ran on vacuum tubes instead of today's small computer chips, one computer had to contain thousands of vacuum pipes and could fill the entire room. Early stereo amplifiers also used vacuum tubes, and even today some audiophiles prefer them because they produce less distortion. In some electric guitar amplifiers, vacuum tubes are still used. In some military applications, tubes are also still used, as UBE Telektronics are not affected by radio waves made by atomic explosions.

vacuum tubes are usually closed in a glass cover, although some tubes instead use ceramics or metal. In its most basic diode construction, the tube or envelope is sealed to form a vacuum. The electrodes in the envelope are connected to the guide that protrude from the envelope and connect to the socket. The basic vacuum tube contains fibers in the envelope, similar to the bulb. The government warms up and then releases electrons and create a negatively charged electron cloud. The electrons are attracted to an anode or a small metal plate, inside a tube that is positively charged, and a one -way flow is determined between the fiber and the plate.

Another electrode in the form of a small grid similar to a screen is sometimes contained in a tube, which is then called the TRIODA, which is more efficient and able to amplify the voltage. Once the voltage is applied to the grid, the flow between the fiber and the plate can be changed. In addition to diodes and triod, other innovations, including tetrodes, heXODS, Heptods and eights, designed for various special applications and minimal distortion. Some vacuum tubes combine the function of two or more diodes or triod in one unit.

One of the main disadvantages of vacuum tubes is that the thread becomes unstable over time. In addition, if the air escapes into the tube, oxygen will react with hot fiber and damage it. The tube properties will change with age, and therefore the timely television files of the vacuum tube must often be modified to create a good picture.