http://wikiless.i2p/wiki/Vacuum_tube?lang=en
For experiments in an evacuated pipe, see Free fall . For the transport system, see Pneumatic tube . For blood sampling, see Vacutainer . Later thermionic vacuum tubes, mostly miniature style, some with top cap connections for higher voltages A vacuum tube , electron tube , [ 1 ] [ 2 ] [ 3 ] thermionic valve (British usage), or tube (North America) [ 4 ] is a device that controls electric current flow in a high vacuum between electrodes to...