Hello everyone,
I have installed Atlas turnouts and associated slide and push remote controls. I would like to install dwarf signal lights (from Orgegon Rail Supply) which display constant green or red dependant on the orientation of the turnout. I can’t figure out how to wire this up due to the momentary voltage which operates the turnout, however I suspect that someone will have encountered this before and will have some advice for me. Any advice would be welcome
Cheers
JamesK
Standard Atlas twin-coil switch machines and controls don’t have the extra contact closures required to do this. The Atlas push-buttons are designed as momentary-contact, so they only supply current when they are being pushed. (These controls have a high rate of failure, by the way. Sometimes they fail in the closed position, which leads to a burned-out switch machine.)
Atlas makes a “deluxe” under-table machine which does have contact closures on it. They also have a separate relay unit which does the same thing. You would wire it in parallel with the switch machine. The trouble with this is that you need a unit for each turnout, and that starts to get expensive after a while.
I’ve got a number of turnouts in tunnels, so I bought some cheap relays from www.demarelectroncs.com and connected them up. I’ve seen similar relays at other on-line electronics places, but the one I remember doesn’t seem to be stocking them anymore. Anyway, these are called “latching” relays, and you should try to match up the voltage of the relays with the voltage you’re using for your turnouts. The ones I use are DC relays, so you need to supply DC to their coils to throw them properly. (Atlas switch machines will work on AC or DC, by the way.) I use a Capacitive Discharge circuit to drive my switch machines, which gives me DC.
James below is a circuit that I designed to deal with a reversing section of my proposed layout I am planning, in it I use Atlas snap relays and Leds to show the polarity of the main-line and the reversing section. by adding just the snap relay and Leds to the switch relay you are already using to control the turn-out it wound solve your problem.
The relay is wired to the turn-out control just like it would be if controlling another turn-out at that same time, only Leds.
Please note: That you only need one Atlas snap relay and two Leds and that the Leds are 12 volt Leds so no drop down resister is needed in the circuit. The Leds in your case would indicate weather the turn-out is set for the siding or the main.
If you need me to redraw this circuit to reflect the circuit as you need it, just let me know.
MisterBeasley, you effectively use the cheap latching relays just like you would the Atlas Snap relay? I’d like to add indicators too, but to be honest, I’m just too cheap to buy that many snap relays. I considered latching relays before, but I thought I had read somewhere that you need to be very careful of what you activate them with. I also use a CD system.
Thanks.
This is what I did. Just buy the relays one or two at a time, when you place an online order, and use them where you need them the most.
Yes, that’s exactly what I did. I think the latching relays were about $5 at Demar Electronics. A while back I saw some at www.allelectronics.com, the same things, but for about $2 or 3. They don’t list them anymore, though.
I drive them off my CD circuit, right in parallel with the switch machines. Note that, unlike the switch machines themselves, the latching relays are polarity-sensitive, so it matters which side goes to plus and which to minus. I’ve been running a bunch of them for 2 years now with no problems.
Incidentally, I drive both dwarf signals and control panel LEDs off the same relays. I use dual-color LEDs, so I only need to throw a SPDT contact. The latching relays are DPDT, so I use one side for the signals, and the other for the panels. (Since I’m using identical LEDs, I could have wired them together. However, I use separate feeds for my signals and panels, so I kept them separate.)