Help needed wiring MTH crossing gates

Rick, attached are some diagrams that were produced by a forum member a year or so back.  Hopefully the one where there are 2 MTH signals going to one Lionel ITAD will help solve your problem.  I have never used a MTH ITAD, but have to believe that Lionel & MTH have similar wiring hookups for these devices.

Thanks. The diagrams didn't help, but the statement at the bottom of the page helped. It basically says that I can't control one set of signals with two different itads. I guess I'll be picking up some isolated track sections and try that way.

Wish I knew what I was doing!

Thanks again.

Rick

Each ITAD has SPDT contacts. The gates are always powered. Wire them so that the down is in parallel so that either relay will put it down but that the up is in series,where both relays have to be off to power the gates up.

Dale H

Problem is I don't see how to series wire the up line, and yet paralell the down lines with SPDT contacts.  Or am I missing something.  I posted what I think is a possible solution.

Dave Hikel, has a diagram for those specific gates, using an Isolated track section and a Z-Stuff foor trains DZ-1008 relay. It works GREAT, I wired two sets of those same gates on our small Halloween layout. Ome of the wiring is counter-intuitive, ie; wiring red wires to black wires and vice-versa, but just follow the diagram, and things will work flawlessly. If I ever have to wire another set, I will do it the same way again.

Doug

Here are a few pictures of how it works.
Wiring Diagram

Power to the gate.
Red and Black to power the gate.  Red center rail power or Aux power, Black outside rail common

Blue and White together  Gate should go down and stay down.

Blue and Yellow together Gate should go up and stay up.


EDIT ADD.
Amazing what we can do if we all work together
Unfortunately these relays are no longer available.

Gate is connected to this relay board.
Brown is common (track common) parallel to the Black in on the gate.
Red is AC in to the board, parallel to the Red in on the gate.
Green Isolated rail input does not wire to the gate.
Blue is the common (C) connection on the gate. Blue wire connects to Blue on the gate.
Yellow is the Normally Open (NO) in the de-energized state, connects to the Yellow on the gate.  
White is the Normally Closed (NC)  in the de-energized state, connects to the White on the gate. 

Best wishes
Mike CT

I am guessing that the original poster did not want to hassel with isolated track section and chose the two ITAD route.  You can shift ITADs around to extend/shorten block while moving an isolated block is harder especially if roadbed is ballasted or hard to get at (yes I know, dremel a cut then superglue a piece of plastic in cut area, been there done that).

I suspect that Dave solution using the ZStuff relay and isolated track section, is probably like mine with a relay being controlled by two ITADS.  Same thing just different approach. 

Hi Dale,

Looking at the ITADs and its instruction sheet, I believe that MTH ties the relay common to the outside rail common rather than leave it isolated for other uses.  Too bad they didn't have a tie bar strap from common to the the relay common, so the relay common could be isolated if desired for other confiurations where no tie to track common is wanted.

Hi Sam

I run mine not using the blue wire as that was the direction on the pack I had. However I will use all 5 as explained in the below post by Mike CT. Blue and white down,blue and yellow up. red and black gate power. First I assume the ITADs have 2 circuits,1 for the relay coils, and another leaving 2 SPDT sets of contacts unencumbered.I assume the coil circuits work properly either connected to track power or to a separate source..

Red and black to the power source, whatever used AC current so polarity should not matter.

As for the contact sets

relay has 1 common, NC and NO.

Relay 2 has common, NC,NO

Blue wire goes to common of relay 1

A jumper wire goes from NC of relay 1 to the common of relay 2

Yellow wire goes to the NC of relay 2

If both relay coils are off the blue and yellow wires are connected, If either relay 1 or 2 or both are energized,they are disconnected.

White wire goes to the NO of relay 1 and also relay 2

If relay 1 only is down blue and white are connected

If relay 2 only is down blue and white are connected

If both relay 1 and relay 2 are down blue and white are connected

Please trace this on a piece of paper,I think it works.  Right now I do not have access to a pen and paper..

I also went to the MTH site,they list 2 ITADs. Both have 5 terminal screws,I think. Why they would tie the commons,relay-coil circuit together is incomprehensible to me. Easy way to find out is with a meter.

Dale H

Thanks Dale. This makes some sense to me and I will try it tomorrow before I purchase more parts.

Rick

Rick

If you have a volt meter,set it on the ohm setting,the highest. When you touch the 2 test leads,it should go from 1 to zero. Test the ITAD this way to see if there is continuity. It has 5 leads. The common of the relay contacts should not have continuity with either lead of the relay coil power circuit. So touch the common of the contacts and touch one,then the other of the coil circuit,the meter should stay on 1 and not register anything. If that is the case the circuit should work as described. There is no logical reason for the coil circuit and the contact circuits to be connected in any way,but then again MTH electronics is not always logical.

Dale H

Hi Dale,

Brilliant!!   So much simpler and no need for extra relay and complications.  Just drew this out this morning.  Would work as you said, AS LONG as MTH did not connect the relay commons to the ground outside rail.  I just took MTH instructions at face value and the drawing SEEM to indicate the common went to ground.  But then MTH is not known for obvious.

Hi Sam

Hope this works for Rick.

I was up in Canada,the Grand kids were sleeping and I was on a strange laptop computer. I was trying to sketch the circuit in my head without benefit of a pencil and paper. I am an old pinball machine repair man so circuits still linger in my head from years back.

The way MTH presents it in the instructions is a bit confusing and ambiguous. I think the blue and the black wire are the same on the gate. My instructions said not to use the blue one so it just hangs there with a piece of tape on the end of it. Well at least that mystery is solved. Glad I never got into DCS and run conventional.

Dale H

 Amazing what we can do if we all work together  

Unfortunately these relays are no longer available.

Gate is connected to this relay board.

Brown is common (track common) parallel to the Black in on the gate.

Red is AC in to the board, parallel to the Red in on the gate.

Green  Isolated rail input does not wire to the gate.

Blue is the common (C) connection on the gate. Blue wire connects to Blue on the gate.

Yellow is the Normally Open (NO) in the de-energized state, connects to the Yellow on the gate.    

White is the Normally Closed (NC)  in the de-energized state, connects to the White on the gate.  

Best wishes

Mike CT

I think Rick said in another post he wanted to use the IR devices. Not always easy to tear up track and make an outside insulated rail. Not the only way but here is how I do it. Good relays are about $8 with sockets. IR detectors I think are about $25 and not as flexible or as reliable IMO. For 3 rail relays are a good method.

For those wishing to do so,a common 12 or 24 VDC relay can be used,described here

http://www.jcstudiosinc.com/Bl...=410&categoryId=

a more complicated bi-directional crossing gate method is described here for those wanting gates up right when the train leaves the intersection.

http://www.jcstudiosinc.com/BiDirectionalCrossingGate

Dale H

Mike CT

I think you might have the white and yellow reversed,at least the way it is described in the pictures you posted,it is opposite your relay hookup. .

Maybe my gates are wired backwards, compared to yours. I just looked at them. Blue-yellow is down on mine,blue-white is up.   The white wire then would go to the NC not the yellow,and the yellow to the NO.  Please check this again and post. it is possible not all MTH gates are the same colors.

Rick,you may have to reverse your yellow and white wires.

here is what I have in my notes for a single relay,click to enlarge

Dale H

Dale,

FWIW, I have a new one right here and get continuity between Red & Blue?  Using a 12vac supply for the Red & Black, gives 12v on Blue.  Blue to White or Yellow operates gate. As Mike CT shows in pictures above.   Was thinking at one time I operated one using Black to White or Yellow, must have been wrong there. 

Why can't they just tell you which wire is which in their directions?

Tom

Dale,

Just saw your drawing above and that's the way I could have sworn I had some of these working at one time. Seems to be different from what I just checked. I have the Blue wire to common of the relay not Black. I may have to do some wire swapping later to check further.

Hope I don't see any smoke. 

I also have White to NC and Yellow to NO as you say above.

Tom

Tom

The gate is always powered via black and red where 12VAC is applied. The continuity through black and red is just the continuity through for the relay coil circuitry ,there is probably some resistance there if you set your meter lower around 1000 ohms or less. Forget the blue wire,it really is an extra black. The MTH hookup is very confusing this way. 

When power is on red and black,Connecting white and black(or blue) raises the gate. Connection the yellow and black (or blue) lowers the gate. Not sure if Mikes are different his relay hookup differs from the photo description. Connecting white,yellow and black at the same time is ugly as it will make the gate chatter.

Dale,

I was trying to say that my real surprise was the continuity between Blue & Red and the fact I got 12v on Blue. I was expecting, as you stated that Blue & Black would be the same (common or ground).  From what I saw it was Blue & Red that were the same and Blue was 12v. That's really got me confused?

The one I have had hooked up for a while is wired just like your drawing, except I have Blue on Common.  Could have been your drawing I used for original hookup? I have followed your posts and drawings and learned a lot about model RR wiring. I also like relay logic. Thanks for sharing your knowledge with us!

Tom 

FWIW again... After some more fiddling, Black on relay Common works the gate just as well as Blue (as stated in your post), but there was still 12v on Blue the whole time, and nothing on Black?  Although tempted, I was afraid to touch Black & Blue together for fear of smoke. Something odd here.

I am using two MTH 45-1028 ITADs

With the ITAD disconnected from any wires my meter shows that the NO terminal is not connected to any other terminals.

It shows a connection between NC and AUX+.

It also shows a connection between COM and AUX-.

Is this what you would expect?

Rick

Rick

This has me baffled.  Aux+ and Aux - should not be connected to any of the relay contacts. This makes no sense at all to do this. If they can not be separated somehow,then they are only good for only narrow usage. To get any flexible usage like you are trying to do you would have to add a relay to get an independent circuit. Whatever powers the aux has to power the device if it is wired that way.  Sounds like there is a solid state relay or circuit enclosed,not an electromechanical one.Please check again to verify your findings.

If you want to do the relay alteration as Sam suggested,Email me and I will send you a couple of 24VAC relays free. These will work assuming you are running off 18VAC track power.  If you want to simply do an outside insulated rail I can send you a DC one and you can get rid of the ITADs.

After more thought if it is a solid state only device the "contacts" could be isolated from the load when aux power is applied. It may even work with the previously suggested wiring. No way to tell without trying it. The manual is not a exactly a fountain of information.

Dale H

I agree Dale this is a weird configuration unless meter is reading leakage paths thats fooling the meter.

Maybe someone who has electrical/electronic knowledge and recogizes components by sight, AND has had to open up the base to repair, might recall if there was a minature electomechanical relay. Though looking at the base height, I suspect probably a solid state relay which will give strange readings as current bleeds through the relay's intrincit diode paths in the unpowered state.  But this is just a guess.

Now you have me curious.

Thanks Sam,you are right I think.

After dinner I thought about it and am amending my previous post. It may even work like the EM relay.

Dale H

Tom

The way this topic is going if it is working I would leave it alone. The black and blue wire I think go to the same place and should be the same color.

I always liked relay circuitry, as you could trace wires and see on schematic what was what.  Used to design stuff as kid with old relays and stuff.  Kids thought I was weird and nerdy.

Back in the 70s after I got out of college, I went to work for a telephone company.  All electromechanical relays, stepper switches.  Copper slugs and sleeves to make relays slow pickup or slow release.  Supervisors were happy with me as I often was sent to fix weird PBX problems because I could visualize what was happening or should happen.  Then quit to persue my engineering degree and got involved with ICs and processors and though I could design etc, it was never the same as good old electromechanical stuff, where you could force a relay to operate to see if something would/not happen.

But this is digressing from the topic at hand.

My thoughts exactly. Hooked it back as it was and leaving it alone!

I don't have any itad's (using isolated rail & relay) or I would be happy to try & do some testing for you.

Thanks,

Tom

I removed the second ITAD from the layout.

Testing using my IDEAL 61-310 Multimeter.

Same results with meter set at 20M, 200k, 2k or 200.

NO to any other terminal, no change in meter.

NC to aux+ meter drops from 1 to 0

com to aux- meter drops to zero

same results with continuity setting.

I reconnected the ITAD to axillary power, and changed the meter to test AC voltage.

With power turned on and nothing in the beam I get:

14 volts between aux+ and aux-

14 volts between aux+ and com

14 volts between aux- and NC

No voltage readings for any other combination.

If I place an object in front of the ITAD you can hear it switch and now I get

14 volts between aux+ and aux-

14 volts between aux+ and com

14 volts between aux- and NO

No voltage readings for any other combination.

Rick

I suspect that the meter is not providing a load to the leads and they are "floating" picking up voltages.

Try this:  get a 28V or wire two 14V in series lamps with socket(s) and put one lamp lead on one meter lead, put other lamp lead on other meter lead.  This will provide a load to the ITAD terminals as you measure.  The lamp need not light or very dimly if at all, but will load down the ITAD terminals.  Repeat the above measurements again and see what the results are.   

Hi Sam,

I connected 2 14.4 volt  lamps in series then connected the leads from the lamps across the meter leads. I tested the ITAD as before. The lamps lit brightly and I got the exact same results as I did without the lamps.

ITAD was connected to auxiliary power supply (from CW80 transformer) but not connected to the crossing gates.

Wow, I'm beginning to feel like an electronics guy. I actually did take a digital electronics course, but that was a long, long time ago.

Thanks for all of your suggestions.

Rick

I will try a last suggestion,then I will punt this thing to Sam,who is an EE. Hook the ITAD Aux leads to track power. Hook the contacts to a block signal. If Aux power feeds the contacts it will light red or green depending on if it is activated. If it dont light hook the contacts to another power source such as a different transformer shown below or an Acc power tap of the track transformer. If the block signal works that way the contacts I think are separated from the Aux power. Click to enlarge

Dale H

GrampaRick,

Sorry been away from here and I am puzzeled by the readings you are seeing.  Out of ideas at the moment.  Sorry

I was searching the forum and came across this thread because I had a similar issue I was trying to resolve and came up with a solution using two ZStuff 1075 ITAD's and MTH crossing gates. What you need to do is control the gates with one ITAD and activate that ITAD with the 2nd ITAD. Wire both crossing gates red to 1075 red and blue and the power source, black to black, white to white, crossing gate yellow to 1075 gray. Crossing gate blue is left unconnected. Next connect the 2nd 1075 red and black to the same power source and connect the 2nd 1075 green to the 1st 1075 yellow. When a train passes the 2nd 1075 it activates the first 1075 which lowers the gates. Not sure if MTH ITAD or Lionel ITAD have similar wiring scheme but you can't seem to find them these days anyway and the Zstuff 1075's are available.