@SteveH posted:EDIT: I originally thought that a Latching Dual Coil DPTD circuit using a single 5VDC power supply might be possible and tried to conceive one that would work. After discussing it offline with @gunrunnerjohn, the design I had would have been problematic in providing switched power to the relay coils. He has a better solution than mine using a Boost Converter with + and - 5VDC outputs from a single 4.5VDC power source. His solution is a couple replies down the page.
I'm not sure where you guys are going? 
I thought the objective, per the topic title, was to come up with a FasTrack Switch Simulator ... since using the real McCoy is not practical given its price tag. In other words, I figured this was one of those "walks like a duck, talks like a duck, etc." situations.
So if this Simulator is to debug/troubleshoot RSC controller wiring and such, it stands to reason it should be wired like a FasTrack Switch. In other words, it should be powered with whatever the FasTrack Switch would be powered by...presumably 14V AC Accessory or 18V AC Track...and with a common ground/black wire to the RSC controller wiring.
That's why I'm not clear on why you'd use a 5V wall-wart. I can see value from a Forum Discussion point of view and was about to comment on some theoretical issues therein; the circuit has/had a so-called race condition that might lead to its demise but I see the diagrams have vanished.
@LIRR-Jim posted:Thanks so much for the recipe @stan2004 I'm assuming a 1N4001 is sufficient for the diodes ..do you have a suggested value for the Caps?
So are you good to go? I see the most recent posts show how to add red/green LED direction indicators which I presume the actual switch-machines have (separate from the RSC LED indicators). That makes sense to make the Switch Simulator look/behave more like the prototype.
