Page Navigation - Go to: site index | start of page content | icon category menu | links to related material | links to more icons
MAKING THE MODERN WORLD
Stories about the lives we've made

Icon:De Forest's triode valve, 1907

related ingenious images © Science Museum/Science and Society Picture Library

The triode valve is a switch device and an amplifier of electrical signals. It became a key component of radio, television, radar and computer systems before the development of the transistor in 1947.

The first triode valve was patented in 1907 by American wireless pioneer Lee De Forest and was called the Audion. It was initially used as a radio detector, like Fleming's diode valve of 1904, but its true potential was not realised until 1912 when it was incorporated into a circuit which could amplify audio and radio signals. For 50 years, valves were a fundamental component in all radio equipment, until being generally replaced by the transistor. In the USA, De Forest is known as 'the father of radio'.

Inv. 1955-143
GO BACK TO TECHNOLOGY GO BACK TO TECHNOLOGY
Scene
Scene  Rich Media