Why does the current have to flow back to the SAME ground?
In a battery the current does not flow back exactly to where it came from but to the separate other pole.
And that leads to my confusion.I understand the concept of needing a complete signal/power path but if I have 2 Power requirements, 6v and 3.3v, I don't yet see the reason for needing to hook them together. Then throw in a signal path and things get hairier.
Thank you for your explanation... but I still don't get it! I am very sorry!Why can the current from device 1 not simply flow off into ground of device 2? I understand that there must be a current flow. But why does the current have to flow back to the SAME ground? For batteries, I imagine that there could be some kind of capacity/limit of how much current can be dumped into their ground. But if the power supply uses a power socket ground, the need for common ground is completely mysterious to me. For circuit 1, why does it matter if some current is lost along the way? For circuit 2, why does it matter if its ground has to sink a little more than the + side of the power supply provides?