[Al Skierkiewicz]

Gary,
You are right on in both of your illustrations. The one thing you are leaving out is that fact that there is other current flowing through the conductors (supply and return) on the circuit breaker panel. If you were to add two FP motors at position 1 and 3, then add a Globe to 5 and all of the solenoids to 7 and finally connected the RC power to 9, (extreme case but I have seen teams do this.) then you have the ability to max out current in stall to close to 200 amps for these loads. Taking the current through the resistance of the board on just the supply side, then the loss becomes 200 x .0005 ohms (guessing on the actual resistance) for a voltage drop of 0.1 volts. The drop is very small I know. But add to that the internal resistance of the battery (.011 ohms at full charge) current draw through the #6 (.0005ohm/ft.), current in a few Chalupa motors and the resistance in the connectors, terminals, breakers, etc. and the required 8 volts to the RC becomes an issue. After a minute or so of competition pushing, it is easy to drop the battery and added losses to the point where the RC is seeing only 8-9 volts. At that point I want every 0.1 volt of margin I can get my hands on. I make this recommendation because I want all my alliance partners to have the best power margin available.
As to the term "ground" it is unfortunate to use this term on any of our electrical system. It's use in other areas implies the the return side current flows through a nearly lossless conductor, i.e. chassis or metal common. Since it is not legal for any electrical tie to robot frame, "supply return" just seems more appropriate and descriptive. The use of "ground" has unfortunately caused many teams to ingnore the losses when troubleshooting electrical problems such as the inability to reach free speed or output power on kit motors.