Someone mentioned previously that very high isolation was needed (which I really do not believe as long as you tie the equipment
grounds together) and the wall-warts internal isolation is not necessarily that good.
Analyze and define what type of transients that the circuit is supposed to protect from:
Lightning induced? Local transients? Ground surges? Inductively or capacitively coupled into the wires?
If the wall wart is powered from the AC line near the PC will it bridge the isolation gap and limit it to the internal breakdown
of the transformer. How is the capacitive noise coupling through the transformer?
Ideally, one should power the PC side with a power source either from internal to the PC or a wall-wart plugged into the same
outlet as the PC. The other side of the board should be powered from the load side or a wall-wart plugged into the outlet where
the load is getting AC power from.
Bertho Boman
