The tubes also required so much power that big and complicated circuits were too large and took too much energy to run. The vacuum tubes tended to leak, and the metal that emitted electrons in the vacuum tubes burned out.

As the electric circuits became more complicated, one needed more and more triodes. The vacuum tube triode also helped push the development of computers forward a great deal, but the limits of these tubes were soon reached. In 1906, Lee De Forest made the vacuum tube triode, or audion as he called it, a three terminal device that served as the basis of an amplifier for audio signals enabling AM radio. The Vacuum Tube TriodeĪt the same time as physicists were trying to understand what cathode rays were, engineers were trying to apply them to make electronic devices. Thus, Thomson had discovered the electron, for which he received the Nobel Prize in physics 1906.Ī replica of the first working transistor. He showed that the cathode rays were really made up of particles that were contained in all material. Joseph John Thomson developed a vacuum tube to carefully investigate the nature of cathode rays already at the end of the 19th century.

The vacuum tube triode preceded the transistor by nearly 50 years. But, the transistor was not the first three terminal device that could be used for amplifying or switching circuits. By cascading these switches (switches that control switches that control switches, etc.) very complicated logic circuits can be designed. With the three-terminal transistor one can also make an electric switch that can be controlled by another electrical switch. This three terminal character of the transistor is what allows us to make an amplifier for electrical signals, like the one in our radio. In a three terminal device one can control electric current or voltage between two of the terminals by applying an electric current or voltage to the third terminal. The transistor is a three terminal, solid state electronic device. Vacuum Tubes as Predecessor of Transistors On December 22, 1947, John Bardeen, Walter Brattain and William Shockley at ATT‘s Bell Labs developed the first transistor, the key active component in practically all modern electronics. John Bardeen, William Shockley and Walter Brattain at Bell Labs

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