Modify analog circuit

xumin888

Modify analog circuit [Copy link]

   I'm looking for an expert to help me modify the circuit, the price is negotiable.

okhxyyo

It is recommended to state the specific requirements. If you don't have any description, netizens don't know what you need to change and whether it will work.

xumin888

I made a sensor, 24v power supply, 4-20ma output, to measure conductivity. I copied someone else's board. After making it, there was no problem with the 4 and 20ma points, but if I took three points in the middle to measure the linearity, the error would be relatively large. I think it would be best to have something that can adjust the linearity to keep it within a reasonable range.

xumin888

Because I copied someone else's board, with the same circuit and components, the linearity is different. Others' linearity is very good, but mine is very poor.

xumin888

If possible, I have some samples of my own with poor linearity, and others' with good linearity, including circuit diagrams, which I can send to you together.

hdwcyzyy

Take out the picture and study it

maychang

xumin888 posted on 2018-7-20 12:48 Because I copied someone else's board, the same circuit, the same components, the linearity is different, others' linearity is very good, mine is very poor

Without the schematic diagram, without your sensor information, and without the measurement data of "After you make it, there is no problem with the 4 and 20ma points, but if you take three points in the middle to measure the linearity, the error will be relatively large", no one can help you.

maychang

xumin888 posted on 2018-7-20 12:47 I made a sensor, 24v power supply, 4-20ma output, to measure conductivity. I copied someone else's board. After I made it, the 4 and 20ma points were fine...

模拟电子技术基础-童诗白第二版(1988).part1.rar (20 MB, downloads: 13)

2018-7-20 15:24 上传

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模拟电子技术基础-童诗白第二版(1988).part2.rar (17.03 MB, downloads: 11)

2018-7-20 15:25 上传

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To learn about the zigzag line circuit, this book has a little bit of content about the zigzag line circuit. Starting from page 569, the book talks about the method of converting a triangle wave into an approximate sine wave. The second method is the zigzag line method.