Quoting Marcel Duchamp : > Have you looked at the LTC6101 from Linear Technology? Had not, but now that I check why it did not come up on my digikey =20 search, I am finding that "current sense amp" yields more results. This looks nice, though I have to figure out what it does for =20 bi-directional current sensing. Guessing for now that I'll need to =20 use two simultaneously around a single sense resistor. Will read the =20 datasheet tomorrow. > One thing about sensors like this is that they exhibit errors due to > offset voltage which means that as your measured current drops toward > zero, the error goes to infinity. You can possibly avoid this by always > loading your circuit with a known amount of current and then subtracting > that out of the readings. The other thing is to use as large of a value > of sense resistor as is possible since a large measured voltage vs any > fixed offsets improves the accuracy as well. I'll be sending the output to a PIC, so compensating for offset can be =20 done there. > You probably will have to figure out a way around the various sources of > errors as attempting to do analog measurements better than 1% over > temperature, line voltage, etc. quickly gets challenging. I can temperature compensate (same PIC measuring a temp sensor), but =20 was looking for simplicity. Not a big deal though. Cheers, -Neil. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .