|Reference||STATE OF THE ART||Stan Augarten|
|The Birth of Modern Electronics|
The Point-Contact Transistor
One of the greatest inventions of the twentieth century, the transistor was an unexpected outgrowth of research on radar in the United States and Great Britain during World War II. While working on this new method of detecting flying objects, scientists began studying an unusual and then little-known class of solids called semiconductors. Materials like silicon and germanium, which occupy the same column in the periodic table of elements, seemed to have great potential as amplifiers and, therefore, as substitutes for vacuum tubes.
Even before the war was over, in the summer of 1945, Bell Labs inaugurated a research project on semiconductors. The scientific arm of the phone company, Bell Labs was, and still is, the largest industrial research organization in the world, with a unique combination of scientific talent, managerial expertise, and financial resources. Bell Labs has been responsible for many of the most important advances in electronics, including the jerry-built contraption shown on the right.
What the phone company wanted from the semiconductor program was a solid-state alternative to the vacuum tube, the fragile, expensive, and energy-hungry switch and amplifier then being used in the phone system. The project was placed under the direction of physicist William Shockley and succeeded in just two and a half years when he and colleagues Walter Brattain and John Bardeen, also physicists, created the point-contact transistor on 23 December 1947.
By the time this unassuming little gadget was introduced to the public in 1948, it had been improved substantially. In place of the conglomeration shown here, the device was encapsulated in a sleek metal cylinder about half an inch long, with three protruding wires that reached down to a pinhead-sized bit of germanium soldered inside the tube. The germanium (silicon transistors didn't come into being until 1954) amplified the current conveyed to it by two wires, while a third was linked to a ground.
In other words, a low-powered signal, like that produced by a radio wave, went in one end, and a high-powered one went out the other. It was that simple, and that revolutionary.
|The triangular wedge is made of plastic and is covered with gold foil slit in half at the wedge's tip. One side of the wedge serves as the emitter, the other as the collector. The irregular-shaped material directly under the wedge is germanium, which acts as the base. Gains in current of up to a hundredfold may be attained with this device. (A re-creation.) Actual size: the wedge is 1.25 inches to a side.|
|STATE OF THE ART
©Copyright Stan Augarten
|This book is provided for general reference. The National Museum of American History and the Smithsonian Institution make no claims as to the accuracy or completeness of this work.|
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