In looking at several AC to DC regulator circuits, I've notice that if one wants a positive output voltage, say 5V, one could obviously use a +5V regulator or use a -5V regulator while tying the output to ground. In the first case (+5V reg) the input AC supply is attached to the same ground as the regulator. But with the -5V regulator to supply the +5V, the AC supply is left floating or isolated from the regulator.
My question is what is the advantage of using the negative regulator for a positive output with the AC supply floating? Does it supply some sort of protection for what is downstream of the regulator?
Thanks
My question is what is the advantage of using the negative regulator for a positive output with the AC supply floating? Does it supply some sort of protection for what is downstream of the regulator?
Thanks