A Passive Signal Isolator

Abstract

The invention provides a passive signal isolator, comprising a main board, the main board includes a sampling unit, an AD conversion unit, a drive output unit, a DA conversion unit and a constant current output unit; the sampling unit is connected to the drive output unit , the AD conversion unit is respectively connected to the sampling unit and the driving output unit, and the DA conversion unit is respectively connected to the driving output unit and the constant current output unit. The present invention can greatly shorten the transmission response time of the instrument; does not need the independent power supply of the third party, and can supply the power for the whole instrument to work and output the signal by obtaining the power at the signal end, thereby reducing the cost.

Description

technical field [0001] The invention relates to the field of industrial electrical automation, in particular to a passive signal isolator. Background technique [0002] In the process of industrial production, various automation instruments, control systems and actuators are needed to realize monitoring and control. , or even large signals of thousands of volts and hundreds of amperes; there are both low-frequency DC signals and high-frequency pulse signals, etc. After the system is formed, it is often found that the signals between the instrument and the equipment will interfere with each other during transmission, causing system Unstable, even misuse. In addition to the performance reasons of each instrument and equipment itself (such as anti-electromagnetic interference), there is also a very important factor that causes a "ground loop" due to the potential difference between the instrument and the signal reference point of the equipment. ”Causing distortion during sign...

AI Technical Summary

Problems solved by technology

[0003] The signal processing of the traditional signal isolator is through the process of sampling-AD-processor-DA-output. The internal use of single-chip microcomputer as the processor, so the signal processing cycle is very long, which cannot meet the transmission response time of some industrial sites. At the same time, the traditional instrument or signal isolator, because there is a single-chip processor inside, must be powered by an external power supply to work, then there will be a power supply ground and an analog signal ground inside, and a potential difference will be generated between the two grounds , thus forming a "ground loop" problem; in addition, in most industrial sites, the control room is far away from the primary sensor, and independent power supply requires additional wiring, which increases the tedious and messy work of the workers and increases the project cost

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