Ok so here is what i want, a valve that opens depending on its signal voltage. I know the input will be a voltage, and the output will be the variable actuation of a valve from closed to open depending on the voltage it recieves (ex. 0-5v is closed to open) what I dont know is how to make the logic in between the two. I work on cars for a living so i understand input-logic-output because it is a process used on all modern automobiles but i dont know how to make my own past the input and output. If anyone understands what I am saying and can point me in the right direction the help would be appriciated. Remember I am a technician not an engineer this is new waters for me.