I don't know that I posted a photo of these. I built them out of salvaged relays, and put them onto small wooden platforms. They get screwed under the layout and powered from track power, hence the choke for DCS and the resistor to limit the inrush current. They work very well on 18V, and I never have to go back and tinker with them, they're pretty bulletproof. It was a pretty crude assembly, I super-glue the relay upside down by the case. I also had a barrier strip for the connections so there'd be no soldering under the tables when we were installing them.
