Triode Triode A triode is an electronic amplifying vacuum tube (or "thermionic valve" in British English) consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode). Developed from Lee De Forest's 1906 Audion, a partial vacuum tube that added a grid electrode to the thermionic diode (Fleming valve), the triode was the first practical electronic amplifier and the ancestor of other types of vacuum tubes such as the tetrode and pentode. Its invention founded the electronics age, making possible amplified radio technology and long-distance telephony. Triodes were widely used in consumer
William McLellan (American electrical engineer) William McLellan (American electrical engineer) William Howard McLellan (December 1, 1924 – September 30, 2011) was an American electrical engineer, who achieved some fame in 1960 by succeeding at an engineering challenge set by Nobel Prize-winning physicist Richard Feynman. McLellan was born in Casper, Wyoming, grew up in Orland, California, and fought in the Canadian Army in the Second World War. He met his wife Patricia Price in England during the war, and afterwards the couple settled in Pasadena, California, where McLellan attended California Institute of Technology (Caltech). In December 1959, Feynmann offered two challenges relating to nanotechnology at the