To reduce the role of the triode, remember: energy does not occur so A thing has its cause., triode will not have the energy. But the central place of the transistor is fierce: it can be a small current to master the large current.
Narrowing the truth lies in: after a small exchange output, to master the static dc.
It is assumed that the transistor is a dam, the center of the singularity of the dam is, there are two valves, a large valve, a small valve. Small valve can be opened with manpower, large valve is very heavy, human power is not open, can only be opened by the hydraulic valve.
So, the usual task is, whenever the water when people turn to the small valve, a small water outflow, the trickle shock switch valves, valves opened, surging rivers under.
If you‘ve been changing small valve opening size, so the valve response has been changed, if strictly according to the proportion of change, so perfect master is complete.
Here, Ube is a little stream, Uce is the flood flow, one is the output signal. Of course, if the current than the current, then it will be more true, because the transistor is a master of the current components.
Area: it should be a small valve is not open enough, you can not open the valve, the situation is the cut-off area.
The saturated zone is small: should open the valve is too large, resulting in a large valve in the release of water once to its limit flow, but you can make small valves, triode supervision work from saturated zone to form linear region.
Linear area: the water is in the form of conditioning.
Breakdown area: for example, there is a reservoir of water, the water level is too high (in response to the Vce is too large), resulting in a gap occurs, the outflow of water. And, with the opening of the small valve, the breakdown voltage is low, it is more easily broken down. Terminology
First, the transistor
The two transistor is in a semiconductor pn junction is data, since each transistor has two PN junction, so called bipolar junction transistor.
Practice is the two transistor diode are connected. It is the current master element, specially constructed narrow base region after application, and composite dispersion carrier, complete mastery of the base current collector current, the transistor has a stronger ability to control. According to the external structure to identify, can be divided into PNP tube and NPN tube, two although in accordance with the method of linking up, you can form the tube, with a stronger ability to work. If the power consumption in accordance with the three transistors to the difference, you can divide them into small power transistors, power transistors, power transistors, etc..

Two, action and use
The transistor has the current signal, reduce the influence and affect the master switch. So, the transistor can be used to reduce the signal and control the on-off current. In the power supply, signal processing and other central can see the transistor, integrated circuit transistor circuit is composed of many in the way must link up with some useful components. The transistor is the most important element by telex.

Three, the main parameters of the transistor
1, beta value
The beta value is the most important parameter of transistor, because the beta value is a description of the triode of current signal to reduce the size of. The beta value is high, the small signal reduction ability is stronger, and vice versa; but the beta value cannot do much, because too much, the transistor function is not too volatile, usually 30 to 80 beta value should be selected as appropriate. In general, the beta value of the transistor is not a specific finger, it is common with the components of the task and the small amplitude changes.
2, polar reverse current
The smaller the reverse current is, the higher the fluctuation of the transistor is.
3, the reverse breakdown characteristics of the transistor:
The transistor is composed of two PN structure, if the reverse voltage exceeds the additional value that will be like a diode breakdown, the function to reduce or permanent damage.
4, task frequency
The beta value of the transistor is only in a certain task frequency scale, if it is not the same, if beyond the frequency scale, they will be followed by a sharp reduction in frequency.

Four, classification
According to the narrow sense of the differences, the transistor is divided into bipolar transistor (BJT, Junction Transistor Bipolar) and unipolar (MOS/MES type: or MEtal Semiconductor Metal-Oxide-Semiconductor) transistor. In the BJT, there are two kinds of carrier conduction, and in the MOS type, as long as one kind of carrier conduction. BJT is the current master of the device, and MOS is a common type of voltage control devices.
Five, the use of
Make the use of digital circuits, mostly when the switch is used, only to ensure that the three transistors work in the saturation area and the area can be.