> Does anyone have any ideas of measuring a small AC current with the PIC
> A2D?
> A friend of mine has a hydroponic garden and wants to measure the
> current flow between 2 probes which are fed with 16VAC.
> I would imagine the current would be in the order of milliamps.

Sounds like a soil moisture sensor or water nutrient tester? You
could add a series resistor as suggested (to convert the current into
a voltage), capacitively couple this into a rectifier circuit of some
sort then feed into an ADC input. The 16VAC would need to be more
regulated than just the output of a transformer if you want accurate
results.

I have a small and simple circuit idea that I could post if it's of
interest. It uses the PIC to generate the AC as well.

Brent Brown
Electronic Design Solutions
16 English Street
Hamilton, New Zealand
Ph/fax: +64 7 849 0069
Mobile/text: 025 334 069
eMail:  brent.brown@clear.net.nz

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