One can create a very cheap and easy to build capacitive galvanic isolator for low freq (audio)?
In+ --||-- Out+ In- --||-- Out-
Adding resistors does not help much (in fact it increases the noise).
Obviously the two sides are galvanically isolated!!!!
There is no DC path between the in and out. Yet why doesn't this work or is used?
(I thought adding a load resistor on both sides would help with DC discharge if necessary)
Basic analysis says this should work! (cap open for DC == block signal DC and ground DC, cap closed allows signals only)
My guess is that capacitive isolation works but since it it still forms an electrical loop rather than an electrical break that one gets with opto's and magnetics, that ground loops still exist. Although it isn't quite as satisfying since there is still galavanic isolation and that, technically, should break any ground loops.