采用两线制传输方式的配电器，既要为诸如压力变送器等一次仪表提供24V 配电电源，同时又要对输入的电流信号进行采集、放大、运算、和进行抗干扰处理后，再输出隔离的电流和电压信号，供后面的二次仪表或其它仪表使用。 Industrial sites generally require isolated safety barriers that use two-wire transmission mode power distributors.They must provide 24V power for primary instruments such as pressure transmitters, and at the same time collect, amplify, calculate, and calculate the input current signals. After anti-interference processing, the isolated current and voltage signals are output for the secondary instrument or other instruments. However, some special industrial sites not only require two-wire transmission, not only provide power distribution and signal isolation functions, but also have safety spark-type explosion-proof performance, reliably prevent mixed contact between high-voltage power and signals, isolated safety There are basically two types of barriers: detection-side safety barrier and operating-side safety barrier. The detection side safety barrier is used in conjunction with a two-wire transmitter; the operating side safety barrier is used in conjunction with an electrical converter or valve. There are also types of isolated safety barriers such as signal inputs. As the isolated safety barrier adopts measures such as voltage limiting, current limiting, and isolation, it can not only prevent dangerous energy from entering the dangerous site from the intrinsically safe terminals, improve the intrinsically safe explosion-proof performance of the system, but also increase the anti-interference ability of the system and greatly improve This improves the reliability of system operation.
的原理是：模块电路将通过本安能量限制电路输入的电流或电压信号转变为0.2-1VDC后，送入模块内进行采集、放大、运算和进行抗干扰处理后，再经变压器调制成输出隔离的电流和电压信号，供后面的二次仪表或其它仪表使用。 The principle of the isolated safety barrier at the detection end is: After the module circuit converts the current or voltage signal input through the intrinsically safe energy limiting circuit to 0.2-1VDC, it is sent to the module for acquisition, amplification, calculation, and anti-interference processing, and then It is modulated by the transformer to output isolated current and voltage signals for subsequent secondary or other instruments. The module also needs to output an isolated voltage of 18.5∽28.5VDC, which is used as the working voltage for the two-wire transmitter through the intrinsically safe energy limiting circuit. Intrinsically safe energy limiting circuits can limit dangerous signals with high current or high voltage from entering dangerous scenes. The principle of the isolated safety barrier at the operating end is: Isolate the 4-20mA DC signal output by the regulator or the operator and then output the 4-20mA DC signal, which is supplied to the electrical converter or the on-site electrical valve through the intrinsically safe energy limit circuit.器用。 Use. An energy-limiting circuit can limit dangerous signals with high current or high voltage from entering the dangerous scene.
应用的优点：① 隔离式安全栅与齐纳式安全栅相比，虽然价格要高一些，但是它许多优点和特点还是给用户带来许多方便，使越来越多用户偏向的选择隔离式安全栅。 The advantages of isolated barriers: ① Compared with Zener barriers, although the barriers are more expensive, many of its advantages and characteristics still bring a lot of convenience to users, making more and more users prefer Choose an isolated safety barrier. ② The use of an isolated safety barrier can effectively isolate the on-site circuit signals in the danger zone from the safety zone circuit signals. In this way, the intrinsically safe automatic control system does not require an intrinsically safe grounding system, which simplifies the construction when the intrinsically safe explosion-proof system is applied. ③ The use of an isolated safety barrier greatly enhances the anti-interference ability of the detection and control circuits and improves the system reliability. ④ Use an isolated safety barrier to allow field instruments to be grounded and allow field instruments to be non-isolated. ⑤ The isolated safety barrier has many protective function circuits, and the possibility of accidental damage is small. It allows the field instrument to be repaired with power on, which can shorten the project preparation time and stop time. ⑥Isolated safety barrier has strong signal processing ability. Such as switching value input state control, mV, Pt100 becomes 4 ～ 20mA and so on. This provides greater convenience, rationality and effectiveness for the application of field instruments and control systems. 用户 When the user applies DCS and ESD at the same time, the one-in two-out safety barrier can be used to effectively isolate the two systems and avoid mutual influence between the systems. 供电 The loop-powered isolated safety barrier not only maintains the advantages of an active isolated safety barrier, but also has the same wiring as a Zener safety barrier, and does not require another 24V power supply. It is especially suitable for DCS systems that are directly powered by I / O cards.