Roberto
For CE marking it's not so much how the schematic is laid out, It's the PCB that has got to mee the requirements, I used to work for a company that sent some stuff away to be CE marked and for what i can remember is
If it has got mains transofoemer on PCB it has to be protected with fuse on the input side and has to has a 8-10mm clearance all the way around the tracks that the AC mains supply run accors no ohter low voltage track run in that area, if you use opto-isolators then it's best not to but any GND plane unneath them,
I'm sure if you do a search on here you should find some books about PCB design
so what you need to do is get your PCB layout then suck and see, but if you do not intend to sell these has a peoduct then it does not need to meet the CE markings but to be honest unless you are goinf to sell them in the millions then i would not bother has CE marking are not cheap if i remember it cost my old company upto 10K or more
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