Model railroad signal wiring

Steve’s been in touch with his model railroad signal wiring:

“Hi Al,

After seeing a recent post, it prompted me to send this description of how I wired my point signals.

I use this circuit to control my point signals. Its as simple as it gets, using the rails to control LED’s. It will work with DC and DCC.

This is because LED’s are actually diodes and rectify the DCC signal (square pulses of AC).

This circuit could also be used as a display to indicate position of points.

Please note that some points are labelled as “INSULFROG”. This means that there is NO electrical connection from the movable rail and the distant rail.

As this idea relies on such a connection, it will NOT work with INSULFROG points. If you have Insulfrog points, you can always wire a connection.

In the first diagram, the points are normal, and there is a distant rail that is connected to SOUTH at ‘X’.

In the second diagram, the points are thrown, and the distant rail at ‘X’ , will have NO connection to SOUTH.

model railroad wiring signals

I use these conditions to control LED’s.

As LED’s work well with 20mA, they need to be protected from 12v with a resistor. A value of 560 ohms will do this job.

Here is the basic circuit.

wiring circuit model railroad

If point X is connected to SOUTH ( 0v ), LED 1 is ON via POS and 560 ohm resistor to X at 0v. LED 2 is OFF because the diode shunts the 0v from X, onto LED 2 anode.

If point X has no potential, LED 1 is OFF. LED 2 is ON via POS and 560 ohm resistor and, 270 ohm resistor, to a permanent South rail.

POS is from the controller output (+12V). Do NOT use a North rail connection in lieu because the controller may be set at a low speed, meaning no LED’s.

Do not use the controller NEGATIVE in lieu of a south rail. This is because there may be a difference in potential, which could cause problems.

This circuit can be used for any points configuration.

I used a common resistive Positive to serve all model railroad signal wiring circuits, like this:

model railroad signal wiring

The ANODE (long lead) from the LED will be connected to a positive.

The CATHODE (short lead) from the LED will be connected to a negative.

Here are some examples of how to use the circuit:


Model railroad signal wiring diagram


Model railroad signal wiring diagram


Model railroad signal wiring


Model railroad signal wiring

Hopefully I have explained this idea well enough.

Enjoy your trains!

Steve (Sydney)”

A big thanks to Steve for sharing his model railroad signal wiring.

There’s been quite a few of you posting on signal wiring:

HO scale scale signals

HO scale railroad signals

Model train signal lights

Model railway signals

Now on to Dangerous Dave, has been been back in touch.

Unfortunatley he’s being living up to his name and he had a fall – but he’s on the mend now, and has managed to get back up into his loft to see run some trains:

“Hi Al…

well Im back in the loft again after my falls, its been shocking weather so thought it was time to get back with my Railway and get them running again.

I put to gather a video and uploaded it, hope it can give a few ideas to others for there layouts.



dangerous dave model railway

loco and carriages model railway

loco sidings model railway

model railway scenery

steam loco model railway

A big thanks to Hall of Fame member Dave.

That’s all for today folks.

Please do keep ’em coming.

And if today is the day you decide to start laying track and join in the fun, the Beginner’s Guide is here.



PS Latest ebay cheat sheet is here.

7 Responses to Model railroad signal wiring

  1. Don says:

    great setup, love passenger trains but also the freight trains as well with auto carriers filled with cars & trucks. this video was great to see.

  2. Peter Briggs says:

    Dave, your layout from the view of the camera car is just fantastic – so so realistic the sounds adding to the reality. Now, your biggest achievement to come: adding smoke! now wouldn’t that be the icing on the cake? Thank you for sharing and I am sure motivating so many to equal your efforts
    Thanks Dave
    from Australia

  3. Regel Bisso says:

    You appear to run only passenger trains. Do you ever run freight trains?

  4. george zaky says:

    Very clever approach to signaling and it took a while for me to get it. As I am a mechanical guy, and engrained in old HVAC control technology, I keep electrical to the simplest, rudimentary, way so I can readily troubleshoot with my Old brain. Micro switches, relays, solenoids, and contacts are for me- diodes for smarter people. The exception is IR detection and signals which are stressing my old brain cells.
    Dangerous Dave
    Hey- No falling!! Us old guys take longer to heal.
    Your unwritten contract with the Alastair Lee Fan Club is to take no unnecessary risks, no ladders, no roof repairs, no sky diving, no deep water dives, no high speed racing, no mountain climbing etc that will jeopardize your contributions to this cause. Your very high status mandates extreme caution!! 😁
    Always great to see your movies with my morning coffee.
    Be well damn it!

  5. TJK says:

    HOLY MOLLY!!!!! Dave you have it all going on……that garden is BEAUTIFUL!
    We need a garden video 🤣

  6. Larry Paxton says:

    Dave, at 75 I’ve had my share of falls. Fortunately I’ve recovered from them with a few mementos like a permanently bent pinkie finger! It just happens. I LOVE the photo backdrops! Adds so much depth and realism and you’ve blended them beautifully. You inspire us all! Love your tutorials as well. Larry in Nashville

  7. David Howarth says:

    Hi All thank you for your comment , yes at 80 and falling is a no no , takes longer to recover , but all going ok now so no holding me back , I will pit a bit of video showing my garden on the end of my next video , these are my 2 favoured hobbies Railways and Gardening with a Koi Pond …and Regel ..yes i do run freight will again try and show in my next video …Dangerous dave

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