... The difference between hard wire engineers (me) and electronic engineering Ring.
Carter
So true. It has confused more than one person.
Residential, commercial, and industrial wiring normally switch everything (contactors, controls, lamps, etcetera) to the positive rail. Electronic devices switch everything to the ground rail. There are sound reasons for this difference. In the former it is safer for people to be isolated from the positive rail. Electronics have no such people safety concerns and so are optimized for operational speed, cost, and size. NPN semiconductor devices (switch to ground rail) are faster than PNP semiconductor devices (switch to positive rail). NPN devices are also physically smaller than PNP and as such take up less space and are less expensive to manufacture.
Your fun fact for the day!