If you're interested in adding signals to your model railroad (in any scale) and are prepared to do some of the electronic work yourself, you may have already stumbled on the work Bill Payne and I have done using the circuits designed by Bill Hudson and the ones John Houghton has designed following Paisley's circuit ideas..
Or maybe you just landed here by accident. Either way, adding an automatic signal circuit to your model railway is not beyond the ability of the average model railroader who has a smattering of knowledge about electricity and soldering.
Roger Race is a modeller who contacted me after seeing what we have done. He has developed an alternative Do-It-Yourself automatic signal circuit.
You can built it yourself and make your own circuit boards or you can source the boards and parts from Roger. I have not tried to build his boards yet. They should work much the same as the ones we have been making. The prices also look reasonable (July, 2011). Instead of trying to describe Roger's circuit I offered to give him his own page so he can describe it himself.
Click on this link to Roger Race's page to download a pdf he sent me.
You'll need Adobe Reader to view the file and to print it. If you don't have Adobe Reader you can download it from the Adobe site.
If you build Roger's design please let me know how you make out so that I can share your experience with others.
By the way, our experience is that you have to be prepared for a lot of wire and crawling around under your benchwork to install a system.
Bill Payne of our Nottawasaga Model Railway club came up with the idea of using telephone plugs and cabling to make the installation neater. As each 3-colour signal head uses 4 wires it means you can use one cable for each signal back to the circuit board. If you use 6-wire cable, disregard the outer two wires. This helps to avoid a rat's nest of wire under the layout. Labelling the cables also helps to keep things organized. I've learned the hard way!
I have been using current detector method to sense the presence of trains. Roger also talks about using reed switches as an alternative.
My model railroad is DCC-equipped and the CTs work well. You could also use photo sensors for detection. Check out my other pages about signals for model railroads.
Go from "automatic signal circuit" to the model railroad wiring overview.
Go from "automatic-signal-circuit" to my experiments building model railroad signal circuits.
Go from "automatic-signal-circuit" to John Hougton's layout using jmri and detectors.
Go from "automatic-signal-circuit" to photocell train detector.
Build a cheap HO dwarf signal.
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