Transistors

Transistors are miniature electronic components which can work as amplifiers or switches. Essentially three-terminal devices, transistors are made from a semiconductor like silicon which has been treated with impurities in a process called doping so as to behave differently. The extra conductivity comes from having neutral atoms of impurities, which move freely and carry the current. The contacts are joined to all layers and transistors work by controlling the movement of electrons. Working as amplifiers, transistors convert the tiny current (the input) to produce a higher one (the output). As switches, a tiny current through one part makes a bigger current flow through another part. Computer chips contain hundreds of millions of transistors and their continuous switching on and off causes the computer memory to work. FET (field effect transistors) work by controlling the movement of electrons while the junction transistor is hooked up to the logic gates so the output connections feed back into the input and allow it to stay on even when the base current is removed. Transistors exist in every computer and allow it to make very simple decisions and carry out applications. For audio equipment, they act as amplifiers of sound in devices like hearing aids or loudspeakers.