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mitchf14
- 16th January 2009, 22:27
I am using a 0.1 ohm resistor with the adcin on my pic measuring the voltage drop. Which works great they only problem is that the pic can only read up to 5vdc and I'm calculating the current from a 12vdc battery, which after the 0.1 ohm is around 11.80v. I tried running it trough a voltage divider but the added resistance of the divider makes my calculations very off. Is their a way i can buffer that resistance out so my pic will read a accurate reading.

mjmccarron
- 16th January 2009, 23:44
I use this part for all of my current measurement. It works off the 5v supply and gives a nice 0 - 5v feedback that is easily read by the PIC.
--Mike

http://www.allegromicro.com/en/products/part_numbers/0755/0755-130.pdf

Gusse
- 17th January 2009, 18:49
Put your sense resistor between load and ground. Then you see same current but DC voltage is only 0.2v. This is the most common way to measure current with sense resistor.