I am thinking of something like a mobile charger that would plug in a
regular 3-pin plug at one end and a computer at the other, and some
software/sensor combo that would read the (DC) voltage at the computer end.
If there is no voltage, there is no power in the mains and ergo - we are in
the middle of a power outage, so take action. Know of something along these
(idea is to detect power failures, while powered by a "dumb" UPS unit - one
that cannot communicate with the a computer. Any other