Turnout position indication

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I want to add turnout position indication using leds to my layout. I'm using Atlas turnouts with switch machines attached. My thought is to add a green led for thru position and red for divert. When I throw the momentary toggle switch for the turnout to THRU, the green led will light. When I throw the toggle switch to DIVERT, the red led will light. Because the switch machines cannot be energized continously, the led will not stay lit.

Could someone provide me with an electronic circuit to accomplish this. I could use an Atlas 200 snap relay, but being retired on a fixed income, I'm trying to limit my expenses. I have 14 turnouts on my layout.

I already have adequate leds, resistors of various values, capacitors of various values and bc547 npn transistors to build the circuits.

Thank you for any help you can provide.
 

ShermanHill

Well-Known Member
Could someone provide me with an electronic circuit to accomplish this.
I don't know about any 'circuits' to accomplish this using existing rail voltage (I'm kinda dumb in that dept), but I could envision using the physical position of the switch points (or throwbar) to operate a SPDT micro-switch to accomplish this action.
 
I don't know about any 'circuits' to accomplish this using existing rail voltage (I'm kinda dumb in that dept), but I could envision using the physical position of the switch points (or throwbar) to operate a SPDT micro-switch to accomplish this action.
I'm planning to use an auxiliary power supply to power the circuit. Thanks for your quick reply.
 

ShermanHill

Well-Known Member
I'm planning to use an auxiliary power supply to power the circuit. Thanks for your quick reply.
I think the hardest part would be to design some kinda 'break-over' that won't allow the tension of the switch in the thrown position to back tension the throwbar and mis-align the points.
 

Red Oak & Western

Active Member
How good are your circuit wiring / soldering skills? The circuit you are looking for is called a "flip-flop" and can be built with a minimum of components, but, I don't know of any already designed PCBs that you just add components to. You could also accomplish the same task using relays, but again, the circuit is something ypou would need to build. I can easily design the circuits, and give you how to instructions.
 

dennis461

Active Member
In my mind, the low cost simple method would be to make an electrical switch and connect it to the throw bar of the turnout.
Bare copper wire and some springy steel or bronze wire.

Maybe a mini micro limit switch.

As for the snap relay, you can find less expensive devices e.g.
Mouser #: 80-EC2-12TNU
 
How good are your circuit wiring / soldering skills? The circuit you are looking for is called a "flip-flop" and can be built with a minimum of components, but, I don't know of any already designed PCBs that you just add components to. You could also accomplish the same task using relays, but again, the circuit is something ypou would need to build. I can easily design the circuits, and give you how to instructions.
I don't need a pcb. I can build without and solder as needed. Please provide schematic and instructions. Thanks.
 

MHinLA

Well-Known Member
ShermanHill in post #2 is the best. Why ? I, and many others have done this but just to power the frogs of Atlas CustomLine switches, which are metal but have a coat of black on them which can be rubbed off.
Purchase a Caboose Industries powered ground throw for each switch...They both throw the points and can turn on position lights at the same time with the right wiring... The G throws have 3 metal rods which reach to the bottom of the ply via a pre-drilled small hole..2 tiny holes are drilled to have wires go from under up to the 2 rails at the throw rod end ot the switch. The center rod gets a 3rd (common) wire up to the frog..(On Atlas CustomLine switches the frog has a tiny ring at the bottom as part of the frog. Regular Atlas switches have plastic frogs. So no can do this job). All these wires must be soldered in place.. The Caboose throw rod is a bit tricky to snap together. But after a while you get it and the rest of the switches you do the same thing..
Now, position lights: You can solder one wire of each bulb onto the same 2 wires up to the 2 rails. Their remaining wires get twisted into one wire and soldered to the center common wire, or rod, to the frog...In other words it's essentially follows the same wiring as the G throw wiring alone.
For sure there are other gadgets that can do this...But this is probably the least expensive.... 🛤☀🛤 🏘
 

Red Oak & Western

Active Member
I don't need a pcb. I can build without and solder as needed. Please provide schematic and instructions. Thanks.
Sorry for taking so long to get back to you. Shortly after my last post, my right hand had a close encounter of the third kind with a spinning table saw blade. I can now move my fingers independently, but still haven't been back in the shop. At my last appointment (Tuesday), the surgeon said I should be able to get back to the shop in two to three weeks.
 

MHinLA

Well-Known Member
NO problem at all..I just hope you are expected to heal completely back to normal. It' doesn't sound like you lost a finger, which is a miracle ! OUCH !!
 
Been there and done that. I took off the tip of one finger on my table saw and tip of another finger on my jointed. Both times I was hurrying to get done. Now both fingers healed, but I take my time when working around machinery.
As for the schematic, I found a dual coil latch relay that does exactly what I tried to do electronically, and only fo $1.85 each relay.
Thank you for you response.
John
 

trailrider

Well-Known Member
You might be able to attach a wire to the throwbar on the Atlas turnouts that would gently contact fixed tabs, but the throws on the Atlas machines have very little positive pressure, and you could wind up with the points misaligned. I definitely sympathize with the cost of using the Atlas Snap Relays, although that would be a very good option. Are you wanting the LED's to be on your control panel, or to light track signals? Either way, one choice (which might not be anymore economical than the Relays), would be to use DPDT toggles wired in series with momentary pushbuttons. One pole of the toggle would be wired to the LED's while the switch machine would be connected to the other pole with the pushbutton supplying momentary current to the switch machine. I have also used rotary switches and a momentary pushbutton to show both routes and illuminate signal lights on the layout. You may have enough components to create the right electronics, but I am not an electronics guy. I would bet there is one or more articles in Model Railroad magazine that would do what you describe.
 

MHinLA

Well-Known Member
Caboose Industries makes a powered ground throw. It has 3 copper posts long enough to reach thru 1/2" ply...A small hole is drilled for the posts..
Of the 3 posts 3 wires are attached to them. 2 go up thru tiny holes and soldered on either side of the rails at the single-end of the switch (TO)..
A third wire goes to the frog.. On Atlas CustomLine switches the frogs are metal and have a tiny ring at the bottom side of the frog..The 3rd wire goes up thru that and is screwed to the ring (can't solder here).. The mechanism attaches to the throw rod of the switch and holds the points firmly one side or other side.. When you throw the lever the points shift and the polarity changes to whichever route you choose; the frog being the neutral of the 3 wires.
The job has a learning curve to the installment. But after doing one, the rest are easier.
Note: Atlas HO CustomLine switch frogs have an erasable black coating on them which causes people to think they're plastic..I believe the coating is to protect the pot metal frog from pitting if sitting on a dealer's shelf/rack a long time...This coating is erasable...
Another method is by using a small slider switch mounted in a hole; it's lever is linked to the throw rod via a hard metal (piano) wire which throws the points, and is wired same as the Caboose ones..
Either method turns the TO into a 'power-routing' type from an 'all-live' type TO...It's important to understand the difference..M
 
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