Purpose of the blue capacitors in the OMRONs module

[eladn]

Thanks! I think now it's much more clear to me. It's very valuable we have this DIY community here to grasp a better understanding of these underlying concepts and make the best use of KinCony devices.

I read online that overvoltage occurs when the relay switches off, and it may harm the relay load contacts. I'm interested in why does this overvoltage even occur when switching off, and why the exact same effect doesn't happen for example to classic mechanical switches. Where does this overvoltage come from? Do you happen to explain it in one of your videos?