How does a transistor work?
There are two kinds of transistor: Bipolar Junction Transistors (BJTs) and Field Effect Transistors (FETs). These two transistors work in two different ways. However, both types of transistors are based on the fact that when a voltage is applied to impure semiconductor such as Silicon, it changes from a conductor to an insulator or vice versa. FETs Field Effect Transistors contain a narrow conductive channel which passes near a “Gate” electrode. The two ends of this channel are connected to terminals called “Source” and “Drain.” When a voltage of the correct polarity is applied between the Gate and the transistor channel, the channel becomes wider, and if this polarity is reversed, the conductive channel narrows, or it even vanishes entirely. By changing the size of this conductive channel, the FET behaves as a voltage-controlled valve or switch.
Asked by: Tony Whelan Answer The design of a transistor allows it to function as an amplifier or a switch. This is accomplished by using a small amount of electricity to control a gate on a much larger supply of electricity, much like turning a valve to control a supply of water. Transistor terminalsTransistors are composed of three parts – a base, a collector, and an emitter. The base is the gate controller device for the larger electrical supply. The collector is the larger electrical supply, and the emitter is the outlet for that supply. By sending varying levels of current from the base, the amount of current flowing through the gate from the collector may be regulated. In this way, a very small amount of current may be used to control a large amount of current, as in an amplifier. The same process is used to create the binary code for the digital processors but in this case a voltage threshold of five volts is needed to open the collector gate. In this way, the transistor is being
