The main function of the transistor is to put it a little more incisively

There are many applications of transistors in circuits, and their main functions are amplification and switching.

The transistor is a kind of control element, the role of the transistor is very large, it can be said that without the invention of the transistor, there is no such diversity in the modern information society, the electron tube is his predecessor, but the electron tube is large in size and consumes huge electricity, and has now been eliminated. The transistor is mainly used to control the size of the current, taking the common emitter connection method as an example (the signal is input from the base, output from the collector, and the emitter is grounded), when the base voltage UB has a slight change, the base current IB will also have a small change, controlled by the base current IB, the collector current IC will have a big change, the larger the base current IB, the larger the collector current IC, on the contrary, the smaller the base current, the smaller the collector current, that is, the base current controls the change of collector current. But the change in collector current is much greater than the change in base current, which is the current amplification effect of the transistor.

As mentioned earlier, current amplification is the function of the crystal triode, and its essence is that the triode can control the large change of collector current with a small change in the base current. This is the most basic and important characteristic of a transistor. We refer to the ratio of δic δib as the current amplification of the transistor and is denoted by the symbol " ".

The current amplification factor is a fixed value for a certain transistor, but it will also change to a certain extent as the triode works as the base current changes. According to the role of the transistor, we analyze that it can turn a weak electrical signal into a signal of a certain intensity, of course, this conversion still follows the conservation of energy, it only converts the energy of the power supply into the energy of the signal. An important parameter of the transistor is the current amplification factor.

When a tiny current is added to the base of the triode, a current that is times the injection current can be obtained on the collector, that is, the collector current. The collector current changes with the change of the base current, and a small change in the base current can cause a large change in the collector current, which is the amplification effect of the transistor. The role of the transistor is also an electronic switch, and it can also form an oscillator with other components, and the transistor also has the role of voltage regulation.

1. The transistor has two states, namely cut-off and conduction, and the conduction is divided into amplification state and saturation state, and it can also be said that the transistor has three working states (cut-off, amplification, and saturation). According to the working state characteristics of the transistor and the need, the transistor is divided into two different types of transistors, one is used to amplify the signal (that is, it works in the amplification area), and the other is to play the role of switching in the circuit (that is, on, off, that is, saturation and cut-off).

2. The use of transistor is very common and is used in general circuits (weak current).

It is a semiconductor material, a semiconductor electronic device that can play the role of amplification, oscillation or switching.

The main features of the transistor bai

It has the function of DU current amplification, taking the common emitter connection method DAO as an example (the signal is input from the base, output from the collector electrode, and the emitter is grounded), when there is a slight change in the base voltage UB, the base current IB will also have a small change, controlled by the base current IB, the collector current IC will have a big change, the larger the base current IB, the larger the collector current IC, on the contrary, the smaller the base current, the smaller the collector current, That is, the base current controls the change of collector current. But the change in collector current is much greater than the change in base current, and this is the amplification effect of the transistor. The ratio of the change in IC to the change in IB is called the magnification of the transistor ( =δic δib, δ indicates the amount of change. The magnification of the transistor is generally in the tens to hundreds of times.

As long as there is a small base current, the triode will have a large collector current and emitter current, which is determined by the characteristics of the triode, different transistors have different current amplification factors, so the amplification ability of different transistors to the base current is different.

The base current is the signal input current, the collector current and the emitter current are the signal output current, and the signal output current is much greater than the signal input current, indicating that the transistor can amplify the input current. In various amplifier circuits, this characteristic of the transistor is used to amplify the signal.

When the transistor is working normally, its base current, collector current and emitter current exist at the same time and disappear at the same time.

The output characteristics of the triode in the circuit are also very simple, just look at it and understand, this is the basic, it is recommended to master.

The transistor has amplification characteristics when it operates in the amplification zone.

The transistor has switching characteristics when operating in the cut-off and saturation regions.

The transistor has rectification and amplification.

There are three poles, a cathode, a collector, and an emitter.

1. The size of the control current, taking the common emitter connection method as an example, when there is a slight change in the base voltage UB, the base current IB will be followed by a small change, under the control of the base current IB, the collector current IC will have a change, the larger the base current IB, the larger the collector current IC, on the contrary, the smaller the base current, the smaller the collector current, that is, the base current controls the change of collector current.

2. The transistor can control the large change of collector current with the small change of the base nuclear pole current. The current amplification factor is a fixed value for a certain transistor, and the change of base current will also change with the operation of the triode. According to the role of the transistor, we analyze that it can turn the weak electrical signal of the front draft into a signal of a certain intensity, of course, this conversion still follows the conservation of energy, and converts the energy of the power supply into the energy of the signal.

3. When a tiny current is added to the base of the triode, one is the injection current obtained on the collector, that is, the collector current. The collector current varies with the change of the base current, and the change of the base current can cause a large change in the collector current.