Originally Posted by Corvinus

Hi all!

Got an electrifying question for the experts on this subject. I'm after detailed theory learning for future setups so I can take ground issues into consideration. I got the need to know how my things work, not just that they do... It's a curse.

Example
I power the RX from an ESC internal bec, since it can only deal with 6V.
I power the steering servo from an external CC BEC 10A at 7.4V since I want to use its full potential.

What I'll do
My first thought was to just take the signal wire from the servo to the RX. That's it.

But wait!
Then I learned about ground loops. If there is no ground back to the RX for the signal voltage, it will take the path through the BEC, ESC, until it gets back to the RX. Which I guess would work, but be a very noisy path since the ESC throttle signal is in the same path. After a lot of googling I have found that people solve this issue by taking ground from servo back to BOTH BEC AND RX with an extra wire, split or whatever. Some receivers don't need this, others do. Either way it should lessen noise in the system.


I need to understand this:
What I'm having a difficult time wrapping my head around is how the electric traffic is handled. 7.4V comes into the servo from BEC, so I assume the ground carries a similar negative charge back out through ground from the servo - and that the 6V signal from RX travels in the same stream. How does this effect eachother? In details please!

This leads me to wonder if I split the ground from servo - won't the RX be hit with 7.4V negative charge as well as the signal? Will the RX be required to handle 7.4V current, or does it not work that way? I'm a bit unclear on how negative charge acts opposed to positive... And honestly feel kinda dumb about it. So any clarification is greatly appreciated.