Lightning Protection and Surge of an Industrial Photoelectric Isolated RS232 RS485/422 Bidirectional Active Converter | Инструменты

Lightning Protection and Surge of an Industrial Photoelectric Isolated RS232 RS485/422 Bidirectional Active Converter | Инструменты

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In kind shooting:

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There are many differences in the detail of product design, and we can't enumerate one by one.The following will be shown to you, to facilitate the reference and comparison, to select the suitable network wiring equipment:

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1. inherent RS485/422 terminal to avoid bad contact in construction due to loose terminal

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2. peripherals have 3 state LED indicator lights, which can accurately report the working state of the equipment in time and bring great convenience to the construction of the project.

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What is the effect of photoelectric isolation? Why do different manufacturers seem to have the same optoelectronic isolation products, the price difference is so big? How to choose the optoelectronic products of many brands?

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There are many transient pulses in the industrial application environment. These transient pulses will affect the transmission of data, or even damage the devices interconnected, in order to be able to operate at high speed.field busThe communication gets the error free data transmission, and the industrial system design engineer must deal with these disturbances, usually with the insulation isolation function.OptocouplerTo maintain the integrity of the data and to protect the interconnect devices.

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Optoelectronic isolator (optoelectronic isolatorEnglish abbreviationsOC) also calledOptocoupler,Optical couplerAbbreviated as optocoupler.Optical couplerTransmission of electrical signals in the medium of light. It has a good isolation effect on the input and output signals, so it is widely used in various circuits.

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Optical couplerGenerally, it consists of three parts: emission of light, reception of light and amplification of signal. Input electrical signal driven light emitting diodes (LED) the light of a certain wavelength is sent to the light detector to be received by the photodetector to produce the photocurrent, and then to be further amplified and output. This completes the electricity.—light—The conversion of electricity, so as to play the role of input, output, isolation. BecauseOptical couplerThe input and output are isolated from each other. The transmission of the signal has the characteristics of one way and so on. Therefore, it has good electrical insulation ability and anti-interference ability. Also because ofOptical couplerThe input end belongs to the low resistance component of the current type work, and therefore has a strong common mode suppression capability. Therefore, it can greatly improve the signal to noise ratio as a terminal isolation element in the long line transmission information. In the computer digital communication and the real-time control as the signal isolation interface device, the reliability of the computer work can be greatly increased.

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Optical couplerThe main advantages are: signal one-way transmission, input and output terminals fully realize electrical isolation, output signal has no influence on the input terminal, strong anti-interference ability, stable operation, no contact, long service life.transmission efficiencyHigh.Optical coupleryes70In recent years, new devices have been developed. They are widely used in electrical insulation, level conversion, interstage coupling, drive circuit, switch circuit, chopper, multivibrator, signal isolation and interstage isolation. A pulse amplification circuit, a digital instrument, a long distance signal transmission, a pulse amplification, a solid state relay(SSR)Instrument, communication equipment andMicrocomputer interfaceIn. In a single chip switching power supply, the use of linearOptical couplerIt can form a optocoupler feedback circuit to change the duty ratio by adjusting the current of the control end, so as to achieve the purpose of precision stabilizing.

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The optoelectronic isolator must be andDC-DCThe use of power isolators can achieve good results. Some manufacturers propagandize their products with photoelectric isolation, in order to save costs.DC-DCThe power isolator has been saved, and the manufacturer actually knowsDC-DCThe power isolator is much more expensive than the optoelectronic isolator.

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The 485 converter is divided into passive type, active lightning protection device, active lightning protection light isolation type.
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[1] 485 passive type converter for electricity to supply power to the computer through the RS-232 serial port, because it is through the serial port Qiedian, power is not too high and the volume is smaller, resulting in the use of the corresponding protective devices can not be too much, the passive type 485 converter is generally used for less load, short communication distance of 485 bus network.
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[2] active lightning 485 converter is an external power supply, with lightning protection function on port 485, can discharge effect on the 485 line in the external lightning conditions, so as to protect the port 485 chip can not be damaged, but if lightning exceeds a certain limit, will still cause 485 port chip damage and even lead to the damage to the computer.
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[3] active lightning optical isolation type 485 converter is in active lightning protection above 485 increase signal isolation and power isolation protection function two, 485 signal isolation optocoupler isolation, the electrical signal into optical signal through the optocoupler, through the optocoupler convert optical signals into electrical signals, optocoupler is similar to the role of the fuse, when when there is a strong current over, may cause the optocoupler burned, but will not affect the other end, power isolation is the use of DC/DC is similar to the principle of isolation, fuse, high voltage high current most burned DC/DC isolation device, will not affect the other end, which will not burn the computer serial port.

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