Hi - can somebody explain the concept of cable shields to me? As in, why do they work, and how do you connect them? For my current purposes, I'm interested in shielding the outside world from what's going on inside of my cable.
Generally speaking, my understanding is that you typically connect one side of your shield to ground, and leave one side floating. However, I have seen both sides connected to ground, one side grounded and the other AC coupled, and various other combinations. I believe the shield blocks electric fields from leaving the cable, but why?
At first I was thinking that it was due to charge redistribution on the shield. Something along the lines of how a conductor will redistribute charge such that there is no electric field within the conductor. But that made me realize that it'd essentially just be re-radiating the signal. (yes no field within the conductor, but the charge distribution on the outside of the shield would be changing to match the changes inside the shield).
So I'm confused. It's been too long since school. Can somebody remind me how a shield works?