Brief introduction to the transistor:

Transistor, the full name should be the semiconductor transistor, also known as bipolar transistor, crystal transistor, is a current control current of semiconductor devices and its role is to enlarge the weak signal to a large number of electric signal, also used as a non-contact switch. Crystal transistor, is one of the basic components of the semiconductor, with current amplification, is the core element of the electronic circuit.

The two transistor is fabricated in close proximity of the PN junction on a semiconductor substrate, the semiconductor pn junction block two is divided into three parts, the middle part of the base area, on both sides of part of the emitter and collector regions, PNP and NPN two kinds of arrangement.

The principle of the transistor:

Crystal transistor (hereinafter referred to as the transistor) according to the material is divided into two kinds: germanium tube and silicon tube. NPN and PNP two kinds of structural forms, but the use of silicon NPN and germanium PNP two kinds of transistor, which, N said in high purity silicon in the presence of phosphorus, is to replace some silicon atoms, in the voltage stimulation to produce a free electron, and P is the addition of boron to replace silicon, produce a lot of holes for conductive. In addition to the polarity of the power, the work principle is the same, the following is only the current amplification principle of NPN silicon tube.