Hi , I have 3 Arduino Nanos mounted on prototyping shields and was being guided on a model railway DCC computer controlled project to use them for controlling Eleven 2 aspect colour light signals ( 12 V led's) plus 5 RC servo operated Semaphore arm type signals and 2 Electromagnetic uncouplers ( 18V DC ), unfortunately the guy who was guiding me and sending me drawings and advice has disappeared of the net ( 2 months) when I had been receiving emails virtually every day , he sent me a list of all i'd need and I purchased everything he listed and he also sent me 2 of the 3 diagrams I would need to constuct 3 types of circuit on veroboard , the first circuit for a voltage and brightness adaptor was extremely simple and I have constructed eleven of those so i'm now turning my attention to the second circuit which is for the uncouplers , I have attached the drawing he sent me and have a question about it , Was it his intention that the Green 3 way screw terminal at the right hand end be connected to the uncoupler Red /Black leads and the 18 V DC supply , the Blue dots btw represent suggested mounting holes and the Grey dots are cuts to the tracks , if I can get these made I can then move on to the last circuit which I have no vero diagram for but I do have a Schematic i'll need help with .