Well, not very high AC voltage, around 50 P-to-P from a transformer. The voltage is expected to fluctuate between 49v and 51v, and I'd like to see the changes with high resolution. That is voltage dividing 50v to 5v range would not work as the steps would be 5/1024*10 = 0.05v resolution. If I could …

Measuring small changes in high AC voltage

system November 7, 2012, 12:32pm 10

the attached op-amp negative peak detect circuit

How's that going to work?