How does the transistor work?

Once a transistor was called a radio receiver, but the question in our article will not be about a radio receiver. So what is a transistor and how does it work.

There is a class of materials called semiconductors for their properties. Their distinctive feature is conductivity - they can be both conductors of electric current, and dielectrics, i.e. Insulators and do not conduct electric current.

Here such material is used for manufacture of the transistor - the semiconductor device widely applied in the industry and serving as a basis of almost all modern electronics.

Not touching the manufacturing technology, the types of transistors, their application, we simply note that there are transistors of different types, for example, npn transistor. This name he received because of the material used and the type of conductivity. What has been said is still not enough to go deep into the manufacturing technology and the variety of transistors.

How does the transistor work? It is designed to control the electric current, it is structurally manufactured in a metal or plastic casing and has three outputs, called an emitter, a base, a collector. The name of the conclusions already speaks of their appointment: the emitter emits electrons, the base is controlled by them, the collector collects them. All these processes occur inside the transistor.

To understand how the transistor works, consider a much simpler example - a water tap.

He also has three conclusions: one by one the water enters the tap, the other is poured out of the tap, the third is the valve that controls the operation of the crane. When the valve is open, water flows freely through the tap, when the valve is closed, water does not flow. This is an imitation of one of the options for how the transistor works. This mode of operation is called the key mode - the transistor is open - the current flows , or it is closed, then the current does not go. To open the transistor on the base voltage is applied, if there is voltage, then the transistor is open, if not, it is closed. Everything happens, as in a water tap, the valve is open - water flows, the valve is closed - there is no water.

Above, we considered the operation of a transistor when it is used as a key: either it is closed or opened. However, there are other modes of operation. Again, as an example, consider a water tap. If you slightly open the valve, the tap water will flow constantly, and the water pressure will be determined by how much we opened the tap.

Approximately the same mode of operation is also in the transistor. A voltage is applied to its base, it opens, and current flows through it. By changing the value of the voltage on the base, it is possible to regulate the amount of current passing through the transistor. Full analogy with the position of the valve on the tap: more open - more water flows (ie current for the transistor); Less open - less water flows (current for the transistor). This mode of operation of the transistor is called amplifying, when by means of a small voltage applied to the base, it is possible to control a significant current that is removed from the collector.

In conclusion, it should be noted that the transistors can be of different types, all determined by the material used in the manufacture. They can differ in power, they can control and pass through themselves significant fluxes of electric current. Transistors can be of different design. There are other modes of operation of transistors, which differ from those considered. But the basic idea of how the transistor works is given above.

All that is stated about, but still allows you to understand the operation of the transistor. In fact, the work of the transistor is much more complicated. There are special parameters that you can use to calculate formulas and set the necessary mode of operation, but this is a completely different topic for the conversation and for another article.