Originally Posted by
Yaatri
What is the advantage of a 12 volt dc power supply for in-seat power on aircraft.
Disclaimer: I'm not an EE.
My impression is that 12v systems are used because they are safer to the user than 110v. A 12v system isn't going to give a noticeable shock, a 110 zap will wake you up, and can potentially be harmful.
As you mentioned, in either case the actual power draw is the same. The larger amp draw of 12v is not going to cause greater danger of shock at that voltage. The main issue is that larger gauge (heavier) wiring is required to the seats, unless they use a higher voltage for distribution and step down to 12 at each seat.