Fred...I'm building something very much like you describe. I had thought of using a 4-wire phone jack like you are using, but thought the wire gauge might be a little on the slender side...Have you had any issues with that..? Particularly on the 12v input side. How long of a cord are you using?
I like the idea of placing the Darlington on the aluminum base...!!! :thumb:
I like the idea of placing the Darlington on the aluminum base...!!! :thumb: