1、 Definition of signal isolators, signal safety barriers, and surge protectors

1. Signal Isolator: Generally refers to the signal isolator in weak current systems, which protects the lower level signal system from the influence and interference of the upper level system.

2. Safety Barrier: Connected between intrinsic safety circuits and non intrinsic safety circuits. A device that limits the voltage or current supplied to an inherently safe circuit within a certain safe range. Safety barrier is a general term, divided into Zener safety barrier and isolation safety barrier, with isolation safety barrier referred to as isolation barrier.

3. What is a surge? Answer: Surge refers to the momentary overvoltage that exceeds the normal operating voltage.

What is a surge protector? Answer: Surge protector is an electronic device that can conduct and divert current in a very short time when there is a sudden surge current or overvoltage in an electrical circuit or communication line due to external interference, thereby avoiding damage to other equipment in the circuit caused by surges.

2、 Features and advantages

1. Signal isolator: Function to protect the lower level control circuit, weaken the impact of environmental noise on the test circuit, and suppress the interference of common grounding, frequency converters, solenoid valves, and unknown pulses on the equipment; At the same time, it has the function of limiting voltage and rated current for lower level equipment, which provides faithful protection for transmitters, instruments, frequency converters, solenoid valves, PLC/DCS input and output, and communication interfaces.

2. Isolation type safety barrier: It adopts a circuit structure that electrically isolates the input, output, and power supply from each other, and meets the requirements of intrinsic safety type energy limitation. Compared with the Zener safety barrier, although it is more expensive, its outstanding performance advantages have brought greater benefits to user applications: due to the use of a three-way isolation method, there is no need for a system grounding line, which brings great convenience to design and on-site construction. The requirements for instruments in hazardous areas have been significantly reduced, and there is no need to use isolated instruments on site. Due to the fact that signal lines do not require a common ground, the stability and anti-interference ability of the detection and control circuit signals are greatly enhanced, thereby improving the reliability of the entire system. Isolation type safety barriers have stronger input signal processing capabilities and can accept and process signals such as thermocouples, thermistors, frequencies, etc., which cannot be achieved by this Zener type safety barrier. The isolated safety barrier can output two signals that are mutually isolated, providing them to two devices using the same signal source, ensuring that the signals of the two devices do not interfere with each other, and improving the electrical safety insulation performance between the connected devices.

3. Surge protector: Surge protectors mainly provide overvoltage protection for electronic devices to prevent lightning strikes from causing huge transient voltages and overvoltage damage to electronic devices and electrical facilities. Surge protectors can prevent overvoltage and dissipate surge currents. With the rapid development of industrial technology and the increasing attention to lightning protection and other disasters, surge protectors have achieved rapid development.