Search Results for: Telephone answering machine sound reproducing
lee de forest lee de forest circa – born lee deforest ( - - )august , council bluffs, iowa , u.s. died june , ( - - ) (aged ) hollywood , california , u.s. nationality american alma mater yale college ( sheffield scientific school ) occupation inventor known for three-electrode vacuum-tube (audion), sound-on-film
famous invention, in , was the three-element " audion " ( triode ) vacuum tube , the first practical amplification device. although de forest had only a limited understanding of how it worked, it was the foundation of the field of electronics , making possible radio broadcasting , long distance telephone...
https://en.wikipedia.org/wiki/Lee_de_Forest