Hello All,
We are monitoring an AC voltage (200Vac) using a diode and resistor and photo LED of Opto-coupler in series. Here the Reverse break down voltage of diode is 700V, Resistor value is 200K ohm, Opto-coupler reverse break down voltage is 6V.
How to analyze impact of negative voltage (i.e. reverse break down voltage)? Where the reverser voltage will be dropped in this path? How to analyse this circuitry?
Diode leakage current and unspecified permitted LED reverse current suggests to modify the circuit rather than "analyze" it. Place an reversed diode in parallel to the LED and everything is fine.