de Forest, Lee (1873–1961)

Lee de Forest

Lee de Forest was a US inventor of the audion triode valve (see electron tube). This three-electrode valve, invented in 1907, was one of the most important inventions in electronics. It could amplify signals, and had numerous applications. Valves became essential in radio, television, radar, computer and other electronic systems, and remained so until the transistor was invented in 1947.