Schematic for wiring MTH Cantelever lights

First there are some interesting discussions about this product already on the forum. Here's one that came up in a Google search: Installing MTH Cantilever Signals.

The instruction manual doesn't go into any detail about the circuit but it is clear what can be controlled. In particular, they describe two sets of wires; one for each signal head. These wires include a black common or negative lead and one red and one green lead. The operation includes a timed yellow signal when switching from red to green or from green to red. So the sequence is red-yellow-green or green-yellow-red.

Also, the instructions mention using an ITAD to control the changes to the signal. I believe that indicates a DC voltage to the wires. What do you plan to use to tell the change in direction for your turnouts?

Hello all.  I have a couple of Atlas item # 200 snap relays.  I think I will be using one of these for this "project."   I am presently using the Atlas #57 lighted switches to operate a pair of turnouts for this "through siding".  (I know the #57 switches were all re-called a few years ago, with no replacements.  I have modified all of mine and they work ok without sticking and burning up turnout coils)  In any event, when I activate the turnouts, I want this to activate the MTH cantilever lights to show which direction the train will go......and I want the lights to stay lit for the direction they are indicating......hence the relay to provide continuous power to the cantilever signal lights. What will happen here (I hope) is that one direction shows green for signal light #1 showing the train will go into the siding, the other light for the main line will show red, indicating the train won't go through the "main line".  Then when I switch the #57 position to have the train go through the main line, the light for the main line will show green for the main line, and red for the light showing the turn into the siding.  (clear as mud!) I think I can make it work, but I was hoping someone has gone down this path before .  One small obstacle:  The Atlas switch machines and the relay are supposed to have 16-18 volts, per the instructions.  I am using the fixed voltage terminal of the Z400 which is 14 volts.  14 volts makes the older Atlas turnouts work somewhat sluggishly.  I will be changing the coils on the two turnouts over to the latest design coils, which seems to work fine on 14 volts.  (I did notice that when I add the relay to the turnout circuit though, the turnout becomes even more sluggish on the 14 volts, to the point of not fully activating the turnout (can cause de-rail situation....can't have that!)  I have ordered, and am waiting for the Atlas coils, p/n 6099 to arrive, and then see what I can do  to make this work using the coils that work better with the available 14 volts.  This is the stuff that makes model railroading fun and interesting!

I went looking for some help and I see this site is now down?

http://www.jcstudiosinc.com/LoginPage

There have been some posts on that site being down for a week at least; but no answers why. 

I run my Atlas switch machines on 18vac. I got some used switches a few years ago and a couple had weak switching even with the 18vac. A couple of new Atlas switch machines fixed them up. I also found some problems with some of the throw bars, springs and linkages. Atlas has those parts and I was able to get the other switches working with new parts. I never found any reason the used switches were sluggish, but the new stuff fixed me up.

I have not tried any of them on 14vac, but I have fiddled around with their operation on DC and it seems to me like they perform a little better with DC. No scientific data, just from observing them operate. It's been a few years since I tried all that though. I was using 18 volts  with both ac and dc. Never tried anything with 14 volts. There was a forum member here that was operating his Atlas switches on DC and said he had been for years. That is what got me thinking about the DC. I never switched over from AC though.

Anyway, just thinking out loud here and thought it might be something for your consideration or you might want to fiddle with and see how it works for you. I believe the snap relay will do what you want as well, but I'm not familiar with the wiring of the MTH signals.

See this application note from Custom Signals about simultaneously driving a #200 snap relay and a turnout. 

I don't have any of your devices but if the "schematic" of the #200 relay is as shown, I'd think this would work:

Note that unless you want to muck around with the internal wiring of the signal heads, you will always get 10 sec of Yellow when going from Red to Green.  Green will turn Red instantly.

If you go the DC route (instead of AC), apply the positive (+) DC voltage to AC hot in the diagram, and apply the negative (-) DC voltage to AC common in the diagram. 

I take it your turnouts do not have any "outputs" indicating which position it's in.  I don't know what your turnouts look like but seeing as you're modifying the coils and what not, there have been DIY projects written up on OGR where micro-switch sensors or the like have been installed on the throw bars or whatever to provide feedback on the actual/physical turnout position.  As it stands now, the Cantilever color only indicates what you commanded the turnout to do - not what it actually did or is.

So the Atlas 200 Snap Relay is a latching type relay that maintains it's contacts even though the current to the coils (there are 2) has been dropped. This is similar to the operation of the Atlas Snap Switch and other solenoid driven turnouts; the current is sent to one of the coils momentarily and the mechanism stays engaged in that position after the control has been released. If you continue to hold the control in the active state, the solenoid will buzz.

Please note that other relays do not work in this way. Most have a normal position that they return to when there is no current to the coil. This is usually done with a mechanical spring. These types of relays have a normally open (NO) and a normally closed (NC) set of contacts and have only one coil.

For those interested in knowing more about switches, relays, and the proper terminology, this resource from National Instruments is worth looking over.

I have often wondered why Atlas hasn't come out with a combo turnout actuator WITH a built-in snap action relay (relay might be a SPDT rather than DPDT contacts due to inaccessibility to second set of screws).  Would insure that actuator and switch were always synchronized.  Maybe small market or unit would be too large physically?

That's a good idea, IMO. But, as you mention, the size might (probably would) be a problem. I had on place on my layout where the Atlas switch machine would not fit and had to replace it with a DZ-1000. The Atlas switch machine by itself was too big and would not fit the space. The DZ-1000s are very nice switch machines and have the DZ-1008 that fits right on them. However, I don't have a 1008 and have never used one so I can't speak directly to their operation. Both have a much smaller footprint and I think both together would be smaller still than the Atlas switch machine itself. I have not had any problems with my Atlas switch machines, but if any on my layout go bad I might just go with the DZ-1000s.

For the OP's application I would most likely use the snap relay per Stan's post above. The cost would be less and it would be easier than purchasing a new DZ-1000 and changing out the switch machine. Also, I have been quite happy with Atlas products so far. And I believe the Atlas switch machines are about $14-$15 street price and the snap relays are somewhat less, but I don't know the going prices of those. The DZ-1000s are somewhere between $25-$28 or so. At least last time I was looking at them anyway.