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Trying to determine what signal systems for layout that does not have blocs

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  • Member since
    February 2020
  • 74 posts
Trying to determine what signal systems for layout that does not have blocs
Posted by Coastie71 on Friday, May 26, 2023 4:52 PM

I've tried researching different types of signal systems, but am totally confused on how I would wire the different types of signals.  Looked at various videos and read some of the forum topics, but either they were to confusing or did not provide enough or specific info.

My HO Digitrax DCC layout is already built and I did not set up blocs.  All my turnouts are Atlas and are controlled by Tortoise switches and they are connected to either a Digitrax DS74 or 64 and each powered with a PS14.  I'm modeling W. Virginia in the early to mid 1980s (CSX and NS and Chessie).  I think the type of signals they used back then where the round searchlight type.  Because of that I was thinking about purchasing the Atlas ones and necessary control boards, but I still cannot figure out how I could hook these up so that the DS64/74, Tortoise or the turnout powers or controls them.  The Atlas manuals either did not address this or were to confusing.  I did wire the frogs also.  I am also going to use pushbuttons to control the turnouts but currently I use the Digitrax controller to do this.

Any help or suggestions on what types of signal systems to use and especially how to wire them so signals change when the turnout is thrown.  I am very confused by resistors and what types to use and how to wire them properly as I was initially going to have LEDs to show which way the turnout is switched, but unless I can do that more simply I may avoid hooking up LEDs.

Any help or suggestions would be greatly appreciated.


Gary (Coastie 71)

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 15,918 posts
Posted by gmpullman on Friday, May 26, 2023 6:31 PM

From the very first signal I set up some twenty years ago I've used the 'Signal Animator' from Logic Rail Technologies. I am quite satisfied with a signal 'simulation' that causes the signal to go to red when a train 'enters' the block and, through an adjustable timer, goes through medium to clear.

There are modelers out there that want detection and essentially a full ABS system and for my purposes this would be impractical. Soldering resistors to wheelsets wasn't in my future.

In more complex trackage I've integrated several Signal Animators that work in conjunction with turnout position. I use one of the Tortoise contacts to 'force' an opposing signal to stop indication. In some instances I have signals setup to show a 'diverging medium' indication if the turnout is aligned for a track off the main. I even setup a flashing aspect for the signal itself.

Later I added 'current of traffic' toggle switches. Nothing worse than seeing a headlight coming at you while the wayside signal shows green for an obviously occupied block. Flipping the toggle to the proper traffic flow causes the opposing signals to show all red.

There are downsides to setting up decent looking signals. Cost. A recent bi-directional end of siding signal bridge I made ran about $200 for the whole works.

Also, there's no 'shake the box' signal manufacturers out there. Most of my signals are cobbled together using Oregon Railway Supply parts but these are not easy to find and since BLMA was bought by Atlas I haven't seen too many offerings from them lately. NJI and Tomar can be spotty at best and, while very nice models, can get up in costs quickly.

 IMG_6235 by Edmund, on Flickr

This signal is at the end of a passing siding. Roight now the main is clear. If I throw the turnout the siding signal will change to medium after a twenty-second delay. IR detectors between the ties will drop the signal to red when the next block is 'occupied'.

 IMG_2745fix by Edmund, on Flickr

Here is three Signal Animators wired to a pair of main line tracks with a 'controlled' siding. 

 Signal Bridge by Edmund, on Flickr

 IMG_2679 by Edmund, on Flickr

 Signal_DB-L by Edmund, on Flickr

 LED_Signal-head by Edmund, on Flickr

Various signal 'arms' under construction.

 LED_tri-color by Edmund, on Flickr

This is a 'tri-color' LED used in some of my searchlight signals. It has very pleasing color output. Some LEDs don't produce a nice green or yellow color for signals.

 PRR_Signal-View-3 by Edmund, on Flickr

One of my recent projects. Yes, the overhead and dwarf signals are redundant but I haven't gotten around to removing the dwarfs yet.

 PRR_PL1 by Edmund, on Flickr

This is a PRR position light signal next to a Kadee (HO) coupler for size comparison.

 PRR_PL2 by Edmund, on Flickr

 Signal_DB-west by Edmund, on Flickr

 Logicrail_SA-2 by Edmund, on Flickr

Pre-wiring several more SA boards brior to mounting under the benchwork. The early models used photocell detection but later versions could be ordered with IR detection which is a bit more reliable and isn't affected by ambient light as much, but still require careful placement and sensitivity adjustment.

Good Luck, Ed


  • Member since
    February 2020
  • 74 posts
Posted by Coastie71 on Friday, May 26, 2023 8:44 PM

Ed, I want to thank you for the quick response, informative info and beautiful pics of your layout signals and the electronics.  I just went to the Logic Rail Tech website you told me about and after I research the info there I probably will still have more questions, especially concerning your use of the Tortoise.

I did notice that your original Signal Animator pic shows quite a few resistors, but only 1 I think for the newer Animator 2.  Not sure about how I power these, but I did notice you actually had a 9V attached to one of your hand made signals.  Really nice hand made signals and signal bridge I must say.

One other thing you indicated "... wayside signal shows green for an obviously occupied block", but you also indicate you didn't setup an ABS system.  I just want to make sure as again I didn't set up blocks on my system.  I did setup 7 power districts that go from the two DCC Specialties PSX-4 circuit breakers so I limited my bus lengths to 30' or less, but its the turnout locations that I really need to make sure the signals change depending upon whether its thrown or closed.

Again, thanks for the very helpful and really quick input.  Have a great Day!


  • Member since
    May 2020
  • 948 posts
Posted by wrench567 on Friday, May 26, 2023 9:03 PM


 I can't remember the name of the company, but they had a signal system that used optical pickups between the rails instead of blocks. The problem with that kind of system is if the layout lighting is too dim then it was difficult to detect a train. The timer was adjustable so the train or light engine could be into the next block before a clear indication.


  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 15,918 posts
Posted by gmpullman on Friday, May 26, 2023 11:16 PM

Hi, Gary.

I don't have blocks either and also use a Digitrax DCC system. I thought about block detection and for my purpose it was way overkill for my goals. To actually use signals for train movements I realized many of the signals would be in places that were difficult or impossible to see and since I'm a 'lone operator' 95% of the time I pretty much knew where the trains were.

I suggest you start simple and place one or two automatic block signals somewhere appropriate on your main line. In HO the infrared LEDs are fairly easy to drill and install in the roadbed. It can get overwhelming if you try something too involved at first.

I believe the early Signal Animators output 5V DC to the signal LEDs and you had to choose your resistors appropriately. Red, yellow and green look best when individual LEDs are used as each color has a slightly different current value.

Some of my signals are too bright and as time permits I'm going back and correcting that. 

 Beeliner_1 by Edmund, on Flickr

 PRR_Motor-lineup by Edmund, on Flickr

In the above two examples all the signals show stop because in each case the train is coming in the opposing direction, other than the right hand track on the cantilever bridge and it is probably red because a train has just passed.

There are a few places where I still have simple bi-color LEDs wired to the Tortoise contacts and these show red/yellow or red/green as the points are thrown. However these are not all that realistic as they should turn to red as the engine passes the signal or they should already be red IF the engine is coming toward you and you can see the signal, it wouldn't be anything more permissive than stop.

What I have on almost all my mainline signals are toggle switches that can be set for whatever direction the train is travelling in. This switch disables the Signal Animator (basically grounds the photocell or IR) so the signal shows red. Therefore you won't see a green signal and an approaching headlight at the same time.

A while back I setup a semaphore signal, too.

I'd like to install a few more semaphores in the future. Each one requires a Tortoise and a Circuitron actuator kit. They are fun to watch, though.

Don't hesitate to ask for any further help.

Regards, Ed


  • Member since
    February 2020
  • 74 posts
Posted by Coastie71 on Saturday, May 27, 2023 12:20 PM

Pete, thanks for the reply.  I think you actually might be thinking of the LogicRail Technologies system that Ed is talking about as they apparently were using optical before they introduced infared that Ed's talked about in his posts.

Ed, thanks again for the help and I'm still doing my research, but it looks to me that LogicRail is the way for me to go with the infared.  I really appreciate all the help and not sure I would have ever figured anything out on my own.

Both of you have a great day.


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