Hi,
I would like to build a voltage logger with mV resolution.
I would log AC voltages induced in a coil randomly excited by a permanent magnet.
They would range from 0.01 V to 10V maximum.
If any harmonics would be present at all, they should reach a maximum of 15 Hz, but probably somewhere around 2-5 Hz so 50 Hz measurement rate is more than enough.
I need to capture the full wave.
It needs to be small, battery operated, light/wearable and be able to log for at least 4 hours at a time.
I found this on your site:
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SparkFun OpenLog
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SparkFun Logomatic v2
As I said I need to capture the whole wave, and not rectify anything as this would be used in a scientific experiment.
I guess would need to condition the signal somehow, divide it and bias it if it was bigger than 3.3V? Via an operational amplifier? (SparkFun OpAmp Breakout - LMV358 ??)
Would it also be possible to capture data from the ‘SparkFun 9DoF Razor IMU M0’ at the same time?
I’m not satisfied with what the market is offering regarding AC voltage logging. .
And I’ve never built anything like this.
Thank you in advance for your help,
David