Converting a sprinkler system's 24V AC outputs to 3.3V DC logic inputs
the problem with your circuit is that the input can cross-talk via the bridge diodes and the capacitors.

in1-d1-c1-ground-d2-in2 and in1-d1-ground-c2-d2-in2 etc.

try this, it should give better isolation between inputs.







simulate this circuit &ndash; Schematic created using CircuitLab