Lee De Forest was the « creator of electronics ».
It started with the creation of the triode in 1907.
Its name is Audion.
What is it composed of ?
It is composed of :
- the first triode (= a grid is placed between the anode and the cathode of a diode lamp)
- and a vacuum tube causing amplification of an electrical signal.
What is it used for ?
This is the first invention that can amplify an electronic device.
Why was it created ?
It allowed to create talking pictures, the radio and later, the computer science. It will also allow improvements in the field of the telephone communications (the amplification of the signal will be more important and without distortion effect).
They are used in preamplifiers and in amplifiers (for power)…
What’s in the lamp ?
In the lamp, there is a filament (cathode) under a grid (= grille). The grid is under a plate (anode). They are all in a glass enclosure. 
Brandon
