I was playing with getting my servos to be on dedicated power, separate form the Arduino entirely, but obviously controlled by the Arduino. I originally had the ground of the Arduino joined with the
- of the battery, but to my surprise my Arduino continued to control the servos when I remove the ground wire entirely from the Arduino.
I was under the impression that all electricity must form a complete circuit, and be a closed loop. But my Arduino can obviously send a signal to a component that has no return path to itself.
I feel like I'm missing something fundamental about a electricity. So my question is:
Why does this work?