- Retired Electrical Engineer - Power Systems
If you treat the source as a black box you can analyze it any way you want.So we have you down for camp #2: "I'm going to have to see if these voltages were taken from a single-phase transformer before I can tell if they actually have a 180? angular difference or if your meter is playing mathematical tricks on you." :grin:
If you want to connect multiple sources togther, how they are created is very important.