Relay question.

Two most common options are infrared detection or insulated outside rail triggering.

Here’s a link to a highly recommended maker of infrared detection/activation devices Azatrax

They have very good installation instructions.

Ditto to Steve H.  I use Azatrax MRAPR 12V DPDT relays to control four 153 block signals on my 027 layout.   Their website has good wiring diagrams.  You're going to need a few pieces of track with insulated outside rails, and a pile of insulating track pins.   

It took a little fine tuning (and a couple of train wrecks) to get the "coasting" distance figured out so the trains don't roll through the red light.   It was a lot of fun getting everything to work. 

This may not be exactly what you are looking for but it might be.  This is for the train detection light (red=train in zone; green= no train in zone).  The rail between the two X's is an insulated rail.  Sorry about the mess with the lines in the bottom diagram: as noted, in the top diagram I have two wires that need reversed - that's what the bottom diagram is trying to show.

Here's a diagram that was posted on the OGR forum quite a while back by ????.    There's a big difference is how things are powered.  I prefer to power the relay with a small DC trannie as I showed.

Hey Walt,

That was me who had created that relay diagram. I realize that most now seem to gravitate toward a DC powered solution but I prefer to keep it all AC if possible.

@Munster518 posted:

Afternoon everyone, Happy early Thanksgiving. Just a quick and I "think" simple question for the forum for here goes.

I'm in the process of building a layout for my son and me roughly 4x10, postwar styled btw with all postwar lionel trains and accessories.

The question is I'd like to use the 450 signal bridge, 153 block signal and a few other signals lionel had during the postwar era. Wondering what relay can I use to operate these with? I'd like to avoid using the common track trip, pressure plate design these accessories came with.

Hopefully I worded this question correctly, also if someone could link me the product and possibly a wiring schematic that would also be extremely helpful, pictures also go a long way with me. Even if anyone knows of a youtube video tutorial that would be great also, thanks

Johnathan.

Jonathan,  You'll need to slightly modify any postwar 3 rail track, or any of the newer modern era track that has the "steel ties" holding the  track together.   The steel tie cross members will not produce the "insulated rail" that you're looking for to trigger the relays.   

It's not difficult to do, but when I used that track, O or 027 gauge, you have to pry the clips up for one of the outside rails, and then create an insulator like the center rail has on it.   I have used the heavy duty manila cardboard from older quality file folder, index cards, etc.   Just make sure you block any electrical conductivity from one of the outside rails to the metal track tie. 

Once you insulate say 4 -6 track sections, or what ever your block length is, then use the nylon insulating pins at either end.   The system works by the wheels/axles of the engines and cars completing the circuit and powering the relay coil.   If you don't actually create a section of "insulated outside rail" the relay will be energized and won't change states from NO to NC,  normally open to normally closed, so your signal lights won't activate as you desire.

Here's a very short insulated track section I used to trigger a crossing signal.  Note that I always ran trains in the same direction, so one insulated section was enough.  (It would trigger after the train was over the crossing in the other direction.)

@graz posted:

Hey Walt,

That was me who had created that relay diagram. I realize that most now seem to gravitate toward a DC powered solution but I prefer to keep it all AC if possible.

@graz - I just now re-looked at your diagram.  To try to keep helping the originator of this thread, I'll point out that the BIG difference between yours and mine is that you have an AC relay where I have a DC relay.

To be honest I know next to nothing about relays.  I don't even know if there is a difference between and AC relay and a DC relay, but I'm guessing there is since you have it clearly spelled out in your diagram.  Plus, I wouldn't buy a small DC trannie for this if I didn't have to since it is the only thing that I use it for.

- walt

Walt

Can you tell me who has 12AC relays available.?
thanks

Here are a few...

• Mouser
• Amazon
• Amazon Relay Module
• McMaster-Carr
• Ebay
• Grainger

Since track voltage often exceeds 12v, does putting over 12v through an AC relay hurt it?

Insulated Track Signal Driver, Rev. 2

Here's the diagram of my insulated track module, it's easy enough to wire one up for yourself if you don't want to buy them.  The relay is a Songle, and all the part values are in the diagram.

@Patrick1544 posted:

Walt

Can you tell me who has 12AC relays available.?
thanks

@Patrick1544 - you need to ask @graz that question.  I use a DC one.

sorry - walt

Thank You Walt.