DrDiettrich
Your answer has been what I have been looking around for a week or even more!!!
Thank you.
So in simple words, what ever voltage i provide the npn open collector draw wire encoder, 5volt in case of the arduino, the same i will receive as output and if this does not exist the maximum (which seems pretty obvious, 5volt is not much), the encoder will be just fine, right?
Once again thank you for your time