Fleming valve valve proved to be the start of a technological revolution. After reading Fleming's 1905 paper on his oscillation valve, American engineer Lee DeForest in 1906 created a three-element vacuum tube, the Audion, by adding a wire grid between cathode and anode. It was the first electronic amplifying device, allowing the creation of amplifiers and continuous wave oscillators. De Forest quickly refined his device into the triode, which became the basis of long-distance telephone and radio communications, radars, and early digital computers for 50 years, until the advent of the transistor in the 1960s. Fleming sued De Forest for infringing his
Triode 22.5V if an anode current of I = 2.25mA is chosen. If the input voltage amplitude (at the grid) changes from −1.5V to −0.5V (difference of 1V), the anode current will change from 1.2 to 3.3mA (see image). This will change the resistor voltage drop from 12 to 33V (a difference of 21V). Since the grid voltage changes from −1.5V to −0.5V, and the anode resistor voltage drops from 12 to 33 V, an amplification of the signal resulted. The amplification factor is 21: output voltage amplitude divided by input voltage amplitude. Triode A triode is an electronic amplifying vacuum