Reading mVAC with PICs

[Dave]

Atom058, Have a look at these circuits.

Dave Purola,
N8NTA

[Atom058]

bbarney, Dave - Thanks for all the great information! Let me digest it and get back to you.

Thanks again!

[precision]

You can use hi precision current measurement ac or dc with this chip.

ACS706
you can order free sample upto 4 nos.




http://www.allegromicro.com/sf/0706/index.asp

http://www.allegromicro.com/datafile/0706-05C.pdf

[Ron Marcus]

Would there be a problem using an internal comparator on the PIC for the rectifier op amp? I did this for an S meter for a tracking receiver monitor.I used a germanium diode in series with the feedback resistor. As I understand it, before the diode conducts, the op amp gain is very high. After it forward conducts, the op amp gain becomes the ratio between the two gain setting resistors, effectively reducing the diode voltage loss to a very low value. Even though the comparators are not meant for high frequency work, the circuit worked quite well.But...What if the AC voltage goes below Vss?

Ron

[Atom058]

Hello All! Sorry about the lack of communication this last week - Had an emergency project that needed all of my attention. Anyway, thanks for all of the information. I had no idea that this was going to be as complicated as it has turned out to be. Just trying to keep this as simple as possible. If I can't come up with a simple solution, I may have to cut my losses. Maybe I can convince my client to bite the bullet and change transducers to ones that output DC voltage (he didn't seem too excited when I mentioned that before).

Anyway, thanks again! And if anyone has any new ideas, please let me know!

Atom058