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.
Bipolar transistor is a semiconductora device consisting of two p-n junctions. The elementary transistor is built on a germanium crystal, it has two points: an emitter and a collector that touch the surface of the crystal, remote from one another at 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: p-n-p and n-p-n.
Field-effect transistor is a semiconductoran instrument in which 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 shown in the photo below. The scheme of the bipolar element is a short feature-base, it symbolizes the base in which at an angle of 600and 1200there are two inclined lines, the line with the arrow is the emitter, the second is the collector. The direction of the arrow indicates the type of device. An arrow pointing to the base is a p-n-p type transistor, and n-p-n from the base.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 proper connection of the transistor to the power source. Instruments of the type p-n-p must be supplied with a negative voltage of the transistor to the collector and the base, and the n-p-n type must be positive. Field-effect transistors on the circuits are designated as follows: the gate is usually shown with 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 gates, 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 transistors are notat once such name was fixed, they were initially called semiconductor triodes (similar to lamp technology). So the transistor is a triode, which is a controlled element, it has been widely used in pulsed 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 allowed to significantly reduce the dimensions of electronic devices.