# Planing for control panel with LEDs



## mike_richling (Jun 8, 2015)

I've searched but it seems everyone does things just a bit different and I'm not having any luck sorting it all out. I am using MTL turnouts (three wires) which require the use of momentary on/off switches to operate. Now I want to go beyond the Atlas switch ones, and make a custom control panel which has LEDs that indicate which path is selected (since the switch goes back to center, the orientation of the switch doesn't help hence the need for LED's). I know its simple but it's the wiring and components I need help with. I could go out and buy the integrated switch thingy for $12 each (plus shipping to Canada, plus $conversion to our Canadian) but I've got 14 turnouts to do on my tiny layout and I think I could do it my self.

I've got a bucket of 0402 and 0602 SMD's if that works for this - of assorted colours as a bonus. So I could do the GREEN/RED thing.
Ideas? Drawings?


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## gunrunnerjohn (Nov 10, 2010)

First off, you need to have something that actually latches the position of the switch after you release the momentary switch. Do the switches have position feedback? If not, you'd probably need to add a simple electronic latch to the panel for each LED to remember the last selected position.


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## wvgca (Jan 21, 2013)

a simpler method may be to use a dptp [two position] switch, one side to feed the turnout with a momentary push button, and the other side to feed two leds [ie: red / green] through resistors .. simple enough, and remembers turnout direction after power down









this image, and more examples on 
http://www.awrr.com/indicator.html


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## Electrotech (Mar 28, 2016)

mike_richling said:


> I've searched but it seems everyone does things just a bit different and I'm not having any luck sorting it all out. I am using MTL turnouts (three wires) which require the use of momentary on/off switches to operate. Now I want to go beyond the Atlas switch ones, and make a custom control panel which has LEDs that indicate which path is selected (since the switch goes back to center, the orientation of the switch doesn't help hence the need for LED's). I know its simple but it's the wiring and components I need help with. I could go out and buy the integrated switch thingy for $12 each (plus shipping to Canada, plus $conversion to our Canadian) but I've got 14 turnouts to do on my tiny layout and I think I could do it my self.
> 
> I've got a bucket of 0402 and 0602 SMD's if that works for this - of assorted colours as a bonus. So I could do the GREEN/RED thing.
> Ideas? Drawings?


I'm by no means an expert but I'm currently going through the same dilemma. I was pointed towards the Stapleton 751D switches. They are already set up for LEDs and look pretty good to me. I just ordered 20 of them for my new layout.


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## Bwells (Mar 30, 2014)

This is the same circuit Wvgca posted but a little easier to understand. It will require 4 holes in the panel for every turnout.


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## Lemonhawk (Sep 24, 2013)

Seems like this would be a great Arduino project. Interface a push-button for each turnout to the Arduino then connect a N channel relay board to the Arduion that would actually connect a CD PS to the turnout motors. Interface LED's to the Arduion and do all the logic and structure in the Arduion. You could do ladder routes and all sorts of stuff with out much wiring.


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## DonR (Oct 18, 2012)

I use the DPDT switch and momentary
push button circuit similar to that of WVGCA.
It's on my main line turnouts.
It works fine, but it is awkward and error
prone to use. It's too easy to throw the DPDT
but forget to push the button, thus the
LEDs give a false indication. I would have
used the 751Ds had I known about them
when building.

If you have a yard with a ladder track for say 
6 to 8 tracks, you may want to use a 
different system. I have a diode matrix
on mine. Your panel has one button in each
track. You push that and all points in the
path to the main are set. It's a very simple
wiring set up. No LED indication is necessary.

All of my twin coil Peco Insulfrogs are powered
with a Capacitor Discharge unit to avoid accidental 
coil burnout.

Don


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## wvgca (Jan 21, 2013)

DonR said:


> It's too easy to throw the DPDT
> but forget to push the button, thus the
> LEDs give a false indication. I would have
> used the 751Ds had I known about them
> ...


Absolutely correct .. 
the 751 controllers are a much better solution, if the budget will allow it, and will make operations easier .. but can be retro fitted later on when your budget allows it ..


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## traction fan (Oct 5, 2014)

*Which Switch*



mike_richling said:


> I've searched but it seems everyone does things just a bit different and I'm not having any luck sorting it all out. I am using MTL turnouts (three wires) which require the use of momentary on/off switches to operate. Now I want to go beyond the Atlas switch ones, and make a custom control panel which has LEDs that indicate which path is selected (since the switch goes back to center, the orientation of the switch doesn't help hence the need for LED's). I know its simple but it's the wiring and components I need help with. I could go out and buy the integrated switch thingy for $12 each (plus shipping to Canada, plus $conversion to our Canadian) but I've got 14 turnouts to do on my tiny layout and I think I could do it my self.
> 
> I've got a bucket of 0402 and 0602 SMD's if that works for this - of assorted colours as a bonus. So I could do the GREEN/RED thing.
> Ideas? Drawings?


Mike;

I'm assuming the line in your post that says,"Since the switch goes back to center." you are referring to an electrical switch, not the actual track switch, or "turnout". If the turnout's points "went back to center" trains would derail. The best way to be sure which position the turnout is really in would be to have a micro switch, or other contact, operated by the turnout's own mechanism. This could feedback accurate position info to the LEDs. In the "toggle switch with a momentary button" setup, the LEDs really only tell which way the toggle switch, on the control panel has been thrown. If you forget to push the button, you will get a false LED indication. Also since you can see which way the toggle switch has been set, the LEDs are redundant. All that said, it is a workable system, just not necessarily accurate. By getting feedback from the turnout, you have a better idea of its actual position. 
I am not familiar with MTL turnouts, but from your description, I gather that they employ a twin coil switch machine; similar to Atlas. Are they similar enough to have the switch machine above the layout base and next to the turnout? If so do they have a piece of stiff wire projecting from the switch machine that operates the throw bar of the turnout, and moves the points? The Atlas machine's stiff wire has been used to create a simple electrical switch for feedback. Two small brass brads are positioned right at each of the extreme limits of the wire's travel. When the turnout is set for the main line that stiff wire shorts the two brads on that side. This closing connection is used to power the LED for the main line. When the turnout is thrown for the siding, the same wire shorts the other two brads and turns on the LED for the siding. Very cheap, reasonably reliable method of showing which way the turnout is set. An improved reliability version would use a micro switch at either end of the throw bar's travel to do the same thing. The micro switches make better contact and are less susceptible to dirt and oxidation than the brads and stiff wire.

Hope that helps you;

Traction Fan


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## emmetd (Aug 1, 2012)

i used a capacitive discharge circuit , a 2 pole momentary switch and a bicolor led.
i will try to find the circuit. haven't done ho in a few years. i think it was posted on one of the yahoo HO
train groups a few years ago.


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