billtee Posted September 15, 2011 Share Posted September 15, 2011 I have a three-way point in my station approach (throat), and would like to fit a signal gantry (with 2-aspect electric signals) above the pointwork to show which road a train will travel. I have spent HOURS trying to figure out how I can use the unused SPDT switch on the two slow-action motors under the baseboard to give me this indication, but no success (gets me to sleep late at night though!). Can some clever person please help? I would only want red/green signals, and there are only two Tortoise-type point motors working a Peco Electrofrog three-way point, so there's only one SPDT switch free for each motor. Thank you, (a very frustrated) Bill Link to comment Share on other sites More sharing options...
Grovenor Posted September 15, 2011 Share Posted September 15, 2011 I take it you want to have a signal green for the set route and the other 2 signals red. In this case it is simple to light up the greens from the tortoise contacts but there is no direct way to switch the reds off. What you need is a set of 6 diodes so when each green is lit there is a feed from the same contact via diodes to the other 2 reds. The diodes stop backfeeds to the red you want to be out. No time to do a drawing now but I can after work if needed. Regards Keith Link to comment Share on other sites More sharing options...
RMweb Gold Donw Posted September 15, 2011 RMweb Gold Share Posted September 15, 2011 You could do it with the relays, one for each signal the relay would be arranged to have the signal at red until it operated when it it would turn it to green. The Tortoises connections would be arrange so that the first motor would if opearted operate the relay for that route if normal the feed would pass to the next switch that would operate one of the other two relay depending on whether normal or reversed. Other than that you could look into logic circuits- I am a bit rusty on them so cannot advise. Don Link to comment Share on other sites More sharing options...
billtee Posted September 15, 2011 Author Share Posted September 15, 2011 I take it you want to have a signal green for the set route and the other 2 signals red. In this case it is simple to light up the greens from the tortoise contacts but there is no direct way to switch the reds off. What you need is a set of 6 diodes so when each green is lit there is a feed from the same contact via diodes to the other 2 reds. The diodes stop backfeeds to the red you want to be out. No time to do a drawing now but I can after work if needed. Regards Keith Link to comment Share on other sites More sharing options...
billtee Posted September 15, 2011 Author Share Posted September 15, 2011 Keith, a drawing might be useful! I am familiar with diodes, and thought I could work it out, but no - I'm stumped! Thank you for your help, Bill Link to comment Share on other sites More sharing options...
smokebox Posted September 15, 2011 Share Posted September 15, 2011 Try this, I think it should work Link to comment Share on other sites More sharing options...
Grovenor Posted September 15, 2011 Share Posted September 15, 2011 Yes, that is what I was describing, thanks for doing the drawing Keith Link to comment Share on other sites More sharing options...
billtee Posted September 16, 2011 Author Share Posted September 16, 2011 Thank you, gentlemen. I'll get out my soldering iron this weekend! Bill Link to comment Share on other sites More sharing options...
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