Triode were invented, Philipp Lenard used the principle of grid control while conducting photoelectric experiments in 1902. The first vacuum tube used in radio was the thermionic diode or Fleming valve, invented by John Ambrose Fleming in 1904 as a detector for radio receivers. It was an evacuated glass bulb containing two electrodes, a heated filament and a plate (anode). Triodes came about in 1906 when American engineer Lee De Forest and Austrian physicist Robert von Lieben independently patented tubes that added a third electrode, a grid, between the filament and plate to control current. Von Lieben's partially-evacuated three-element tube, patented
Scott Hudson (electrical engineer) by Edward Bowell at Lowell Observatory in 1986, was named in his honour. The official naming citation was published on 9 September 1995 (). Scott Hudson (electrical engineer) Raymond Scott Hudson (born 1959) is a professor of electrical engineering and computer science at Washington State University. Hudson was educated at Caltech, where he received his bachelor's degree in engineering and applied science in 1985, his master's degree in electrical engineering in 1986, and his PhD in electrical engineering in 1990. His research interests include radar imaging, optical signal processing, and radar astronomy. From August 19 to 22 of 1989, Hudson