03
2026
-
04
The Working Principle and Transmission Characteristic Matching of Signal Surge Protectors and Their Fundamental Role in Overvoltage Protection of Communication Lines
Through a thorough understanding of the principles and selection of signal surge protectors, engineers can provide reliable overvoltage protection for various communication lines.
Author:
Signal surge protectors are overvoltage protection devices specifically designed for communication, control, and data acquisition lines. Their working principle is based on the effective suppression of lightning overvoltages and induced overvoltages intruding into signal lines. Unlike power surge protectors, signal surge protectors must ensure the integrity and quality of signal transmission while providing overvoltage protection. Their internal core components typically employ a combination of gas discharge tubes, transient suppression diodes, or multilayer varistors. Under normal operating voltage, the protector presents a high impedance state, having almost no impact on signal transmission. When an overvoltage exceeding the rated value occurs on the line, the protector quickly conducts, discharging the overvoltage energy to ground and clamping the voltage within the tolerance range of the interface circuit. After the operation is completed, it automatically returns to the high impedance state.
The transmission characteristic matching of signal surge protectors is a key technical parameter for ensuring communication quality. Different types of signal lines have different operating voltages, transmission rates, interface types, and impedance characteristics; the design of the surge protector must match these characteristics. Surge protectors for analog signal lines should have low insertion loss and high common-mode rejection ratio to reduce attenuation and interference with weak signals. Protectors for digital communication lines must meet the bandwidth requirements of specific frequency bands. For example, protectors for different protocols such as industrial fieldbus, RS485 communication, and Ethernet require precise design of their capacitance and inductance parameters to avoid signal reflection and distortion. The interface type of the protector should match the protected equipment; common types include RJ45, RJ11, DB9, and terminal blocks for easy field installation.
The fundamental role of surge protectors in protecting communication lines from overvoltage is to protect the communication interface circuit from damage caused by lightning strikes and electrostatic discharge. Industrial communication lines often require long-distance laying and are prone to induced lightning overvoltages. Communication interface circuits typically use integrated circuits with low voltage withstand levels, making them highly susceptible to damage. After installing surge protectors, overvoltages are limited to a safe range before reaching the interface circuit, protecting expensive communication equipment. In system-level surge protection design, signal surge protectors are used in conjunction with power surge protectors to form a complete equipotential bonding and graded protection system. For communication lines passing through different surge protection zones, appropriate signal surge protectors should be installed at the interface to prevent overvoltage from entering indoor equipment along the line. Through a thorough understanding of the principles and selection of signal surge protectors, engineers can provide reliable overvoltage protection for various communication lines.
RELATED NEWS
Shandong Cresin Electric Co., Ltd. SEO CEGLOBAL Privacy Policy
Contact Us
Address: No. 978 Tianchen Road, High-tech Zone, Jinan, Shandong,China
CAN’T FIND THE PRODUCT?
The product range includes production technologies for smart capacitors, digital display meters, surge protectors, dedicated backup protection devices for surge protectors, self-resetting over/under-voltage protectors, control and protection switches, and automatic transfer switches for dual power supplies.
Search HistoryClear All Records
- 全部
- 产品管理
- 新闻资讯
- 介绍内容
- 企业网点
- 常见问题
- 企业视频