Valve amplifier thermionic valves. The simplest valve was invented by John Ambrose Fleming while working for the Marconi Company in London in 1904 and named the diode, as it had two electrodes. The diode conducted electricity in one direction only and was used as a radio detector and a rectifier. In 1906 Lee De Forest added a third electrode and invented the first electronic amplifying device, the triode, which he named the "Audion". This additional "control grid" modulates the current that flows between cathode and anode. The relationship between current flow and plate and grid voltage is often represented as a series
Don Carpenter (electrical engineer) dynamics and for development and use of whistler-mode waves as diagnostic probes of the magnetosphere". He was elected a Fellow of the American Geophysical Union in 2002. Don Carpenter (electrical engineer) Donald L. Carpenter is a Space Scientist, Professor (Research) Emeritus in the Electrical Engineering Department at Stanford University. He co-discovered the sharp dropoff in the plasmasphere surrounding Earth. Known as co-discoverer of the “knee,” or sharp dropoff (later called the plasmapause) in the radial profile of the dense plasma cloud (later called the plasmasphere) that surrounds the Earth to typical equatorial distances of several Earth radii. Carpenter was awarded