I would like to create a circuit that detects if there is 220v AC present on the inputs
The requirements i set out to achieve are:
- Must be able to detect 220v AC that is switched less or equal to 5Hz
- Must be robust and safe for the electronics on the other side, so can withstand surges and other factors typical mains voltage is subjected to.
- Outputs are already filtered out meaning 3.3v DC for 220v is present and 0v DC if there is none, not a square wave looking signal for "on"
Looking through circuits online i found this module
It has an optocoupler which provides isolation which i think is good, but i do not like that its using an electrolytic capacitor which is very prone to failure especially in 220v AC setting when surges are not uncommon.
another circuit which i think i like better since it does not use an electrolytic, I think i would need to add a MOV to protect from surges and there are cheap full bridge rectifier like the
MB10sCan anybody suggest an improvement to the circuit or a better type of circuit. I think a good place to imitate a circuit are those used in industrial applications as they have stricter requirements does anybody know how its done there?