Transistor - electronic semiconductor device for amplifying, generating and converting electrical signals. Tranzistor allows you to adjust the strength of the electric current. Two main functions of the device in an electric circuit - a switch and an amplifier.

Transistor strengthens weak energy supplied to it by the energy of the signal power source.

In transistor three conclusions: the collector, base and emitter.

Between the collector and emitter current, it is called the collector current, between the base and emitter - weak control current base. The magnitude of the collector current depends on the magnitude of the base current. Moreover, the collector current of the base current is always greater than a certain number of times. This value is called the current gain. Different types of transistors , this value varies from a few to hundreds of times.

Transistors is divided into two major groups:  

• bipolar transistors;
• unipolar transistors, yet they are called field.

Bipolar transistors consists of three layers of the semiconductor structure and are divided into 2 types: pnp and npn. The first type (pnp) transistors are sometimes called forward conduction and the second type (npn) - reverse conduction transistors.

Bipolar Transistor is controlled by the current. That is, to the collector-emitter current to flow (i.e., opened to the transistor), - current must flow between the base and emitter (or between the collector and base - for the inverse mode).

Currently, bipolar transistors is dominated by analog technology.

The company GreenChip offers you to buy various bipolar transistors .