Crossing Signal Question

Why not power the cantilever from the source before the switching of the blocks?

I am going to assume this is the flashing crossing signal and not the cantilevered block signal.  The only way I can think to do what you want is with a relay.  DaleH has great diagrams on his web page.  Don't be intimidated by relays, they are inexpensive and solve a host of issues like yours.

Paul... What Cantilever signal are you hooking up ? got a pic or link to the signal?

Gregg & NECRAILS - sorry I'm hooking up the MTH 30-11006 crossing signal 

How about a picture of what your to accomplish here. Maybe I can help out a little here.

Yes there is,, Normally you  would    tie both reds together and run a wire  back to the hot accessory post on the transformer , ( Or to  only one center rail power) .  one black would go the  an  insulated track section,,,  The other black to the other insulated track section.   Normally,, but we don't  know  what  you 're using for a transformer.

You could try putting a diode in between each power rail and the signal, each diode oriented in the same direction.  That way current can't pass from one power rail to the another.

But that depends on the MTH signal being happy with half-wave AC, vs. full-wave.  You'll have to see if the crossing signal works when there's a diode in the circuit.

Sounds like Gregg's suggestion should work for you.  The power (red wire) from the MTH accessory needs to be connected to an accessory AC post on the transformer, not the center rail AC track line power.   The black wire(s) from the crossing signal(s) need to go to the insulated rail which should be an outside rail ( AC common ).   If you are using more than one transformer, and they are post war they need to be in phase with each other... If your using modern transformers, the AC common should be hooked together and go to the outside rails.  As Gregg noted, it would be helpful if you described what transformer(s) you are using.....

When the train enters the insulated section you can think of it as the metal wheels and axles are connecting the black wire of the MTH cronssing signal to the AC common and turning the accessory on.... The accessory is getting it's AC hot 12 - 14 VAC from the accessory post but won't turn on till the train enters the insulated section and completes the circuit.   Hope this helps. 

cjack posted:

Why not power the cantilever from the source before the switching of the blocks?

This was my first thought too.  It appears you want to operate off of track power.  Connect one flasher wire directly to one of the INPUT hot terminals on the TIU.  It doesn't matter which input hot and you may even be using one xfmr to power two TIU channels.  The point is this hot power will always be active whether or not you turn off one of the tracks.  Then connect the two insulated sections of the parallel tracks and send that to the 2nd flasher wire.

Excellent !

Sounds like Gregg and Stan's idea will work for me - since I've been diagnosed as "electrically impaired" I'm going to avoid using diodes and relays but thanx anyway, Prof. Chaos!   Chris, thanx for clarification in your second sentence.  I'm using 2 PW ZW's to power the tracks and a MTH Z750 to power accessories - all are phased.

Stan - your drawing is perfect!  My only question is:   if I do not have power on the right hand track in your drawing and only "on" the left hand track how is the signal receiving its power?

If you turn the track off with the transformer handle, you are correct. The signal should be connected to an Acc post so it always has power.

Thanx, John.

Hi Paul... The ZW is perfect, I went to bed too early last night. The blacks should also have been tied together and then a wire  to each insulated section.... The guys have you fixed up.

Don't fear the relay!!!!  That being said, what was described above should work for the crossing signal since all you need to do is activate it when there is a train on the insulated section.  The great thing about 3 rail is you can use insulated rails for all sorts of things.  Have fun!

Harleylito posted:

Stan - your drawing is perfect!  My only question is:   if I do not have power on the right hand track in your drawing and only "on" the left hand track how is the signal receiving its power?

You're right, when you mentioned TIU I assumed you were using the TIU to turn off power to the track section.  That was why I suggested you pick up power at the TIU INPUT which would have power all the time.  But if you are toggling power before the TIU input to turn the tracks on/off, then you need to pick up power before the toggle switch...or if using a transformer handle then you need to find a different source of always-on power.

As John H suggests, that could be the Accessory output.  As long as that separate power source has a shared common with the track transformers (which must be the case if you phased them), I think you're good to go.

Thanx everyone - Gregg's solution worked without a hitch!  Wired the power wire of the crossing signal to a terminal block which was wired to my accessory transformer.  Wired both common wires coming from the outside 2 rails of the parallel tracks to the common on the crossing signal.  Made sure both ZW's were phased and magic happened!!!

Thanx to all -

Paul

chris a posted:

Sounds like Gregg's suggestion should work for you.  The power (red wire) from the MTH accessory needs to be connected to an accessory AC post on the transformer, not the center rail AC track line power.   The black wire(s) from the crossing signal(s) need to go to the insulated rail which should be an outside rail ( AC common ).   If you are using more than one transformer, and they are post war they need to be in phase with each other... If your using modern transformers, the AC common should be hooked together and go to the outside rails.  As Gregg noted, it would be helpful if you described what transformer(s) you are using.....

When the train enters the insulated section you can think of it as the metal wheels and axles are connecting the black wire of the MTH cronssing signal to the AC common and turning the accessory on.... The accessory is getting it's AC hot 12 - 14 VAC from the accessory post but won't turn on till the train enters the insulated section and completes the circuit.   Hope this helps. 

 

Interesting discussion, I just bought a MTH 30-11014 RailKing Scale Crossing Flasher with Sound. I am using an insulated section of track to activate the signal. The diagram shows using power from the center track. In my case that would be 20 amps, 360 watts, 17.8-18.0 volts continuous. I was going to experiment with a 330 ohm in line resistor to bring the voltage down to about 10 volts going to the signal. Reading your comments, it sounds like I can apply a lower voltage from the MTH 4000 and use the common ground to complete the circuit. AC drives me crazy because I am never sure which direction the current is flowing. Did I get it right, outside rail ground on the signal and power for the signal from a lower voltage source from the MTH 4000? Parallel bricks (180 watts each) power the tracks.

... it sounds like I can apply a lower voltage from the MTH 4000 and use the common ground to complete the circuit. AC drives me crazy because I am never sure which direction the current is flowing. Did I get it right, outside rail ground on the signal and power for the signal from a lower voltage source from the MTH 4000? Parallel bricks (180 watts each) power the tracks.

Thank eddiem for the following pic from this thread:

https://ogrforum.ogaugerr.com/t...83#37611054860323383

The "Accessory" is your Crossing Flasher. 

The "Accessory Transformer" is your MTH 4000 set to a suitable voltage for your accessory. 

The "Transformer" is your track brick.

As for going crazy , if you read the thread (there have been other similar threads) you'll see it can be challenging to get your arms around multiple transformers or voltage sources sharing a common.

Two good schematics.

Good luck, John  

Paul,

I have the same crossing signals.  As others have mentioned simple wiring is all that is needed.  No relays, resistors, diodes, etc. etc.

Just like the drawing provided, below is a picture of my wiring setup. A simple terminal block separated with half + and half -. 

For my application, track A is comes from TIU Fixed voltage 1, so it is always on no matter what trains I'm running.

Works like a charm.

Have Fun!  Ron

Ron045 posted:

Paul,

I have the same crossing signals.  As others have mentioned simple wiring is all that is needed.  No relays, resistors, diodes, etc. etc.

Just like the drawing provided, below is a picture of my wiring setup. A simple terminal block separated with half + and half -. 

For my application, track A is comes from TIU Fixed voltage 1, so it is always on no matter what trains I'm running.

Works like a charm.

Have Fun!  Ron

 

 

   Thanx, Ron - that's basically how I wound up wiring them - your picture is crystal clear!!!

    Paul