Signal Wiring

Daniel,

You can use an insulated track section.  I do not have your particular signal, but rather the Pennsy Signal Bridge - 30-11030 and the cantilever signal - 30-11009 and the instructions all read similar - I believe MTH used the same activation mechanisms across their signals.

You will need an SPDT AC relay to activate the signal through the isolated track.  The ITAD is essentially equivalent to a SPDT relay that is activated through the sensor in the iTAD instead of an isolated rail.

I have mine set up with a SPDT relay with a 12VAC coil.  I also have numerous transformers powering the layout - they are all phased - which is important when connecting various parts of the layout with multiple transformers.

The relay will typically have five connections - two for the coil and three for the switch portion of the relay.  The switch connections are usually labelled normally open (NO) normally closed (NC) and common.

I have things wired as:

1.  All transformer commons / neutrals are tied together.

2.  The common wire of the signal heads are also all connected to the same common of the transformers.

3.  One lead of the relay's AC coil is tied to a fixed 12VAC source.

4.  The other lead of the relay is connected to the isolated rail.  When a train is in the block connecting the the isolated rail to the other outside rail the relay coil "sees" 12VAC and closes the relay.

5.  The common connection of the relay's switch is tied to a 12 VAC source.

6.  The normally open relay connection is tied to the red signal indication.

7.  The normally closed relay connection is tied to the green signal indication.

Here is one method of using an insulated rail to control a signal.  The DC voltage supply and DC relay can be replaced with a fixed AC supply and AC relay. (I used DC relays because they were so tiny and I had many signals to wire.)

You can also replace the the ITAD with Z-Stuff detectors:
DZ-1075/A/M (contact Dennis Zander and ask which sensor would be best for your block signal)
DZ-1011

Don't use the 1070 - it only operates other Z-Stuff signals

Z stuff DZ1075 should work .  I think you'll need one sensor for each head.Easy peasy:

"OPTION A – The WHITE and GRAY wires are connected directly to the GREEN and RED wires of an MTH signal with the BLACK wire of the signal connected to common. The BLUE wire connects to ACC power. The MTH bridge and cantilever signals a typical examples. For these signals, (2) DZ- 1075 will be required. One for each track."

Full  instructions here: http://www.z-stuff.net/instruc...Z1075%2012-26-08.pdf

Or you can get an MTH ITAD, instructions are here: https://mthtrains.com/sites/de...ction/30as15690i.pdf

The Z Stuff sensors are probably much easier to obtain>