Celebrating the 70th year of the Transistor
It was December 23, 1947 when the first Transistor was made functional by John Bardeen and Walter Brattain—William Shockley was their leader.
It seemed to have all been initiated by the Telephone—Alexander Graham Bell had received a patent for it on March 7, 1876 (not necessarily the first to have created a working model)—he later formed American Telephone and Telegraph company—aka AT&T.
As they grew their business and spread wires all over the country, signals were weak and distorted. Trying to make a call from New York to Denver resulted in noisy and distorted discussions where the sound of voice was but an unclear whisper. In the early 1900s they wanted to be able to transmit a call from New York to California but needed something to boost the signal. From there the vacuum (triode) was invented, but it was power-hungry, large and unreliable. The company knew they needed to find something better to enable long-term customer growth and expand distances worldwide. They needed a good, reliable repeater or amplifier, so the transistor was invented. Transistors changed the world; they helped create the transistor radio, integrated circuits, the microprocessor, and much more! It is truly one of the most important inventions ever created!!
There is a lot more to the story of how it came to be—see our article on the history of the transistor under our Transistor Basics article.
To find out more about the basic operation of modern transistors like 2N3904 and 2N3906, see this article.