Coupling means that there is close coordination and interaction between the input and output of two or more circuit elements or electrical networks, and the phenomenon of transferring energy from one side to the other by interaction; Generally speaking, coupling means that two or more than two entities depend on each other for a measurement. Coupling as a noun in communication engineering, software engineering, Coupler mechanical engineering and other projects have relevant terminology.
Coupling is one of the ways of signal transmission in a circuit, which is different from filtering.
In the circuit often need to transfer the level of signal to the next level of the circuit, the transmission is called coupling. According to the different components used, Coupler the coupling mode is inductance coupling, capacitance coupling, photoelectric coupling, DC coupling and many others. Capacitive coupling is the way to achieve this signal transmission. Amplifier is a common kind of electrical appliances, the front-level amplifier to the microphone weak audio signal amplification, need to transmit to the power amplifier level, Coupler output enough power to promote the Speaker sound. Between the front and the power amplifier often with a capacitor to connect, according to the capacitance "AC, DC" characteristics, the useful audio signal (alternating current) transmission to the amplifier level. DC will be cut off, so there is no direct current transmission between the two levels, Coupler without affecting the working state. This is the specific meaning of capacitive coupling.
The filter circuit is often used capacitance, although all is the use of capacitance "communication, isolated DC" characteristics, but there are differences in:
1. The function is different. Coupling is the transfer of useful AC components to the next level, and filtering is to remove harmful AC components.
2. The size of the capacity is different. The coupling often uses 10 micro-method and the following capacity, while the filter often uses hundreds of, Coupler thousands of micro-method capacity.
3. Pressure difference. Coupled capacitor voltage is generally low, and the filter capacitor pressure is generally high.
4. The volume is different. The capacitance of the coupling capacitor is small, Coupler and the size of the filter capacitor is much larger due to its large capacity.
The coupling has three characteristics:
First, the two systems are independent of each other;
Secondly, there is communication and connection between the systems;
Third, there is interaction and influence between the two systems and the elements within the system. For example, the marine industry agglomeration and the regional economic development are two independent systems, Coupler which constitute a larger marine industrial agglomeration-regional economic development coupling system through mutual influence, interaction and interdependence.
The coupling also has different types according to different criteria. According to the direction of the development of the system, including: positive coupling, the development of two coupled systems is upward, positive, positive; negative coupling, the development of two coupled systems or two are downward, Coupler or one downward, one upwards. According to the system development time, including: static coupling, refers to the coupling at a certain moment of interaction, the state of mutual influence, dynamic coupling, Coupler refers to the coupling with the time change of interaction, the state of mutual influence. According to the nature of the system, including: homogeneous coupling, refers to two of the same properties of the interaction of the system interaction; heterogeneous coupling refers to the interaction of two different properties of system interactions. According to the influence of the system, including the equivalent coupling, the coupling of the two systems exerted by the same effect and impact is the same, Coupler the different coupling, the coupling of the two systems exerted by the role and impact is different, the role and impact of the system is the dominant type of system.