Transistor is the basis of semiconductor technology

A transistor is an element designed to amplify, generate, and convert electrical oscillations. Transistors are of two types: bipolar and field.

A bipolar transistor is a semiconductor device consisting of two pn junctions. The elementary transistor is built on a germanium crystal, it has two points: an emitter and a collector, which touch the surface of the crystal, separated from each other by a distance of 20-50 microns. In other words, one transition connects the emitter to the base (it is called the emitter junction), and the second one is the collector with the base (it is called the collector junction). Bipolar transistors are divided into two types: pnp and npn.

A field-effect transistor is a semiconductor device whose control is performed by changing the field in contrast to bipolar elements, where the output current value is determined by the change in the incoming current. Field instruments are single-gate and multi-gate.

Schematic diagram of the transistor is presented in the photo below. The scheme of the bipolar element is a short feature-base, it symbolizes a base into which two inclined lines enter at an angle of 60 ⁰ and 120 ⁰ , the line with the arrow is the emitter, the second is the collector. The direction of the arrow indicates the type of device. The arrow pointing to the base is a pnp type transistor , from the base - npn. Perpendicular to the base of the dash is the electrode of the base. The value of the electrical conductivity of the emitter must be known for the correct connection of the transistor to the power source. Instruments of type pnp on the collector and the base must be supplied with a negative voltage of the transistor, and npn of the type - positive. Field-effect transistors in the circuits are indicated as follows: the gate is usually indicated by a dash parallel to the channel symbol, the electrical conductivity of the channel is represented by an arrow placed between the source and the drain. If the arrow points in the direction of the channel, it means that the element belongs to the n-type, and if in the opposite direction, then the p-type. The image of a field effect transistor with an induction channel is characterized by three short strokes. If the field device has several closures, then they are represented by short dashes, the line of the first gate is always placed on the extension of the source line.

In conclusion, we add that the transistors did not immediately fix this name, they were originally called semiconductor triodes (similar to lamp technology). So the transistor is a triode, which is a controlled element, it has been widely used in pulse and amplifying circuits. Absence of heat, reliability, small overall dimensions and cost - these are the main advantages of these devices, thanks to which transistors were able to force out electronic lamps from many fields of technology. The main advantage of semiconductor devices is the absence of an incandescent cathode, which consumes considerable power, and also requires time for heating. In addition, the transistor is many times smaller than an electric lamp and is capable of operating at a lower voltage. All this has significantly reduced the size of electronic devices.