IR Detection using Z Stuff with a relay

You can switch DC with the 153IR, no problem at all.  Use the common ground connection with one side of the DC power supply.

I'm with RiCKO, Azatrax is the way to go with lots of detector and application choices.  I've used Azarax to detect across multiple tracks, across a single track or embedded in tracks.   My experience has been great including customer service.

AS GRJ pointed out, the 153R will also deliver DC. As an alternate, I've used the Z-Stuff DZ-1011 trackside detector along with the companion DZ-1008 relay in many applications and this combo works quite well.

That Azatrax website is extremely well done and has lots of useful information. Think I will try out some of their products. Couldn't help but note that their two trains on one track section uses a design I created and published in 2007.

Gary Liebisch posted:

...My first device I used is the Lionel 153 IR.  Works well, but the limitation seems to be that it will only apply an AC input to the output device.  What I would like to do is trigger several devices at a crossing---2 gates, crossing signal, sound board for bells, etc.  To do this I would use a relay with multiple poles.  Since 12 VDC relays are easier to come by than 12 VAC relays, I would like an IR device that gives me only dry contacts to which I can apply DC to activate the relay: C, NO, and NC, instead of applying the AC input to the output...

The 153IR internally connects one of the two power input wires to the "C" of the relay.  The 153IR can be powered by AC or DC.  Hence this means you can have the 153IR switch DC+ or DC- to your loads via "NO" and "NC."  If your triggered devices (gates, signals, etc.) operate on 12V DC then you don't need an external relay.  The 153IR relay contacts in the unit I have is rated 3A 30V DC or 3A 250V AC. 

Separately, it's not clear to me why you say it's a limitation that the 153IR can only apply AC to the output devices?  Are you saying some of your O-gauge crossing devices cannot be powered by AC?

Stan2004.   It is nice to know that the 153IR can be powered by DC.  They don't specifically say that in the instructions and there is no schematic for me to determine this on my own.  Most legacy accessories were all AC.  If it can be powered by DC, then I can use it to power a mult-pole 4PDT relay with a 12 VDC coil (I've got a box load of 12VDC relays!) That , in turn can then power multiple devices signals or devices whether they happen to be AC or DC as there is complete isolation between the control device and the switched devices.  The implied use in the instructions is to apply AC 12-18V (or track power) to the input and the IR will then distribute that AC to the ACC PWR , NO, and NC contacts.  So I had concluded that there was no isolation between the power used to operate the IR circuit and the power sent to the switched accessory.

Gary Liebisch posted:

... So I had concluded that there was no isolation between the power used to operate the IR circuit and the power sent to the switched accessory.

Perhaps semantics, but there is "some" isolation.  I didn't draw out a full schematic but I did open up a 153IR to see what makes it tick.  See this post.

This new diagram might be of use to your question about DC operation and isolation.

What's implied but not spelled out in the 153IR manual/documentation are the internal connection of the common input and the "C" of the internal 153IR relay.  This is drawn as the black line inside the box.

The two power wires go to a bridge rectifier which converts AC or DC to the low-voltage DC to operate the internal electronics (IR sensors, timing) and ultimately drive the internal DC coil relay.

Let's say you have 4 accessories that all operate at different voltages.  Some may be AC, some may be DC.  As long as the DC power source is isolated (such as a wall-wart), you can tie its common to the AC accessory common.  The 153IR can then switch common to all 4 accessories each operating at a difference voltage (subject to the 3 Amp total capacity of the 153IR internal relay).  As drawn, accessory #4 is operating on 12V DC so this accessory could be a 12V DC relay to then switch even more power if 3A is not enough.  

I would like to point out that the 153IR diagram posted above by Stan2004 has an error.  The A and the U terminals are label reversed.  It would not make a difference if you are powering it from AC , but it DOES make a difference if you are powering it from DC, where you could end up sending the incorrect polarity  to a DC device.

Gary Liebisch posted:

I would like to point out that the 153IR diagram posted above by Stan2004 has an error.  The A and the U terminals are label reversed.  It would not make a difference if you are powering it from AC , but it DOES make a difference if you are powering it from DC, where you could end up sending the incorrect polarity  to a DC device.

It depends on the 153IR version.  I prepared the following for a previous OGR discussion bemoaning why Lionel changed the terminal labels and hookup instructions without changing the item number.  Note how The A and the U terminals are label reversed.