Yea, I started to write "~+-2V", but actually wrote "~2V p-p" because the former looked ugly.
Phil_Mod3 wrote: Mike: I read from your first scope image, that the sweeps under normal operation is between 4-6 V p-p, is that correct?
It's a 10 bit A/D, across a voltage range of AVcc = Vcc = 5.0 V. So, that's 5/1024 = 0.004884 V/step. The voltage divider is 1/83.98. So, the A/D is ultimately sensitive to 0.004884 * 83.98 = 0.41 V.
Phil_Mod3 wrote: If I understand the voltage sensing correctly, we could read HV voltages in a range from 0 to ~2486 V. The smallest step (one unit) in the output from analogRead() equals 2.43 V in HV.