Say If I have 3 power sources in the same schematic: Mains AC, 9v DC adapter (and then regulated to 5v), and high voltage DC like 180v (say rectified from the mains by full bridge).
How should I connect ground to each one of them? All I know is that each power source MUST have it's own ground - so connecting HV DC ground to the 9v one is not correct.
However, if the HV DC is rectified from the mains... should it be connected to the same ground point as the AC mains ground? of course mains AC don't have a "ground", it's Line and Neutral.
I hope someone help me understand this in theory, practical and PCB stuff. In PCB I only want to know if this can be achieved or not... I am not gonna try it soon.
Big THANKS.