Thread: DIY Data-Logger
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Old 07-22-09, 09:39 AM   #9
AC_Hacker
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Default Power & Noise

Quote:
Originally Posted by NiHaoMike View Post
Actually, the voltage output is proportional to the derivative of the current. You'll need to integrate the output in order to get meaningful measurements if the load is not linear. Or use a hall effect current sensor which outputs a proportional signal.

And try adding capacitors to reduce the noise.
Can you give me a bit more detail regarding integrating the output? Can you reduce it to an algebraic equation? If so, I can include that in the spreadsheet.

Do you know where I can get Hall effect sensors?

I've also gotten other feedback regarding the voltage/current phase shift encountered when measuring inductive loads. but I'm not sure how to proceed. I also don't know if it yields a minor error in my case or a major error.

There's a local group called "DorkBotPDX" DorkbotPDX | people doing strange things with electricity. I showed them my data logger and they were very interested in my project, especially the power measuring part. Apparently there is much interest in being able to log power in many projects.

I appreciate your response and any additional suggestions you may have.

I have tried caps, the ones I have tried do reduce the noise but only by maybe 10%. That's why I think it may be internal.

Best Regards,

-AC_Hacker
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