Vacuum tube: Difference between revisions

[[File:cgs photo 6me8.jpg|thumb|left|250px|A 6ME8 beam-deflection tube.]]

[[File:cgs_photo_ts1.jpg|thumb|right|300px|A vacuum tube synth.]]

 

Simply put vacuum tubes are arrangements of electrodes in a vacuum within an insulating, temperature-resistant envelope, (most often of glass). Except for some special-purpose tubes which use a gas in the envelope. The electrodes are attached to leads which pass through the envelope via an air tight seal which are designed to plug into a tube socket for easy replacement. A filament (the cathode) is heated so that it releases electrons into the vacuum (thermionic emission). These are drawn to a metal plate (the anode) inside the envelope. Another electrode (the grid) is placed between the filament and plate. A [[voltage]] applied to the grid will control the plate plate [[current]].<ref name "vtbet"/>