Signal surge protective device (SPD) is a type of surge protective device (SPD). It is a lightning protection device connected in series on the signal line, which is used to limit the transient overvoltage and shunt the surge current in the signal line. In the modern society where microelectronic equipment is widely used, signal surge protective device (SPD) is very important for the lightning protection of electronic system. Today, Zhongpeng lightning protection technology introduces the importance of signal surge protective device in detail.
1、 Nonlinear components of signal surge protective device
The two important functions of signal surge protective device (SPD) are discharging lightning current and limiting surge voltage, which are completed by the nonlinear components of signal surge protective device (SPD). The nonlinear element in signal surge protective device (SPD) is not only a nonlinear resistor, but also a switching element. It usually refers to varistor.
Its working principle is that the non-linear resistance is connected between the line and the ground, which can be considered as open circuit under normal conditions. In the case of over-voltage in the electronic system, the transient over-current exceeding the system can withstand is discharged to the ground, so as to reduce the over-voltage on the line or equipment and ensure the safety of the signal line and equipment.
2、 Classification of signal surge protective devices
According to the different types of protected lines, signal surge protectors can be divided into network signal surge protectors, monitoring signal surge protectors, control signal surge protectors, video signal surge protectors, telephone signal surge protectors, explosion-proof signal surge protectors and other types. Each type has many models, parameters and different appearances.
3、 Function of signal surge protective device
Signal surge protective device (SPD) is mainly used to protect all kinds of signal lines and equipment against lightning
One is to limit the transient overvoltage caused by induced lightning in signal line. According to the survey, more than 80% of the electronic system lightning is caused by induction lightning. Therefore, with the wide application of microelectronic equipment in modern society, we should strengthen the lightning protection of electronic system and install appropriate signal surge protective devices.
Second, limit the surge caused by the start and stop of electronic system. In addition to the lightning induced surge, the most important reason is caused by the start and stop of electronic equipment. This kind of surge is widespread. The installation of adaptive signal surge protective device on the circuit can effectively suppress the surge caused by the operation of electronic system, effectively reduce the deterioration and failure of electronic sensitive devices, ensure the stability of signal circuit, and extend the service life of electronic equipment.
To sum up, we can understand the importance of signal surge protective device. According to the requirements of technical code for lightning protection of building electronic information system (GB 50343-2012), when carrying out lightning protection design of building electronic information system, we should carry out comprehensive planning, coordination and unification according to the characteristics of building electronic information system and the overall requirements of the project, and do a good job in safety, reliability, advanced technology and economy Economical and reasonable, using comprehensive signal surge protection device.