@barnun posted:...
2. More importantly, it's what I had laying around.
What is the optoisolator you show in your schematic?
Note that if the purpose of the bridge-rectifier is AC-to-DC conversion at signal levels/currents (as opposed to power levels/currents) you might consider replacing the bridge rectifier with an AC-input optocoupler. For your application these 4-terminal devices (2-terminal AC in, 2-terminal DC out) would then perform both functions, 1) AC-to-DC conversion and 2) electrical isolation. An AC-input optocoupler will be maybe a nickel or so more in cost than a DC-input optocoupler.
But, to your point, if you already have the components lying around...
