Circuit structure for evaluating positive and negative mains half-waves identifies the switching status of a button switch with a low-voltage neon-glow lamp wired in parallel in the lamp's path

摘要

A current limiter circuit at maximum current flow has two diode circuits (OPTO1,OPTO2) wired antiparallel to detect mains half-waves and wired in series to a resistor (R7). A bridge connected rectifier (BR1) is downstream to the diode circuits in series. Output signals for the circuits are fed separately to inputs (A,B) for an evaluation circuit (mu C).