How was the vacuum electronic transistor invented

Forrest's vacuum triode is based on the technology of vacuum diodes invented by predecessors. In 1904, Fleming from the University of London invented the vacuum diode diode. Vacuum diodes can only conduct in one direction and can rectify AC currents or detect signals, but they cannot amplify signals. Without devices that can amplify signals, electronic technology cannot continue to develop.

Fleming invented the vacuum diode

In order to improve the sensitivity of vacuum diode detection, Forrest added a fence like metal mesh inside the glass diode to form the third pole of the electronic diode. He was surprised to see that this "grid" seemed like a louver, capable of controlling the electron flow between the cathode and the screen; As long as there is a weak current passing through the gate, a larger current can be obtained on the screen, and the waveform is completely consistent with the gate current. That is to say, adding an electrode to Fleming's vacuum diode became a new device capable of amplifying, which he named the triode.