Quote Originally Posted by The Master View Post
The frequency is 50Hz (UK AC) but because its DC ripple i guess that makes it 100Hz......................
To make it even worse the pic chip will have to deal with 8 ADC pins. It might be an idea to split the work between multiple PICs
If you run that 100hz DC ripple across a capacitor with a very small value bleed resistor, said capacitor will quickly charge up to the peak value of that ripple, thereby negating your need to quickly sample the output, maybe even isolate it with a diode so it (the cap) can't bleed back into your supply. Basically, you end up with a full wave filter without much of a load.