Hey, I want to build my own PLC with an Arduino Nano. For this propose I want to use a relay (5 V/dc to 230 V/ac), an impulse switch/ impulse relay for 230 V/ac. The Arduino PLC and its components should be passive and din rail mountable. Should it stop working I would still be able to turn my lamps on manual.
Currently I searching for a solution to get an on/off status of the 230 V/AC circuit. I found some self-soldered optocoupler circuit but I try to avoid them because of safety reasons.
Another approach would be to use an 5V mains supply but this would take much space and is not optimal for din rail mounting.
The best approach I found are "coupler"-relays 230 V/ac to 5 V/dc but I have problems understanding the specs. or match them with my requirements.
With this post I would like to start a collection of solutions and products. As this system would deal with 230 V/ac I would prefer 230 V certified products.
You can use this simple circuit for AC detector.
For 230V, likely use 30K resistors instead.
The output, what I show as D4, goes to an Arduino input pin with pullup resistor enabled.
Are there any vendors providing such modules for din rail mount because i couldn't find one (at least for a decent price). If I would create such a circuits there are possibilities for an electric shock, fire hazard, ...
If there are any modules what would be the estimated prize?
Till now I found following relays to sense 230 V/ac. Can someone confirm that some of this products are correct for this purpose. Does someone have other products/vendors?
