cobalt ip digital wiring

[mishmash64]

Hi all.  Two questions really :

1. I have a point and a long crossing together. I have wired the power terminals correctly and the far frog to the third terminal on the cobalt,  and everything is working very well. However I dont know where the nearest frog wire goes to?

2. Also, if I wire the frogs from my points to the third terminal the frog is not powered / polarity and my little shunter which I use to test these scenarios stalls. If I disconnect the wires everything is fine?? Strange I know. Do I need to swap the power wires around to reverse the polarity?

Thanks in advance, mungo

[Chrissaf]

I have a point and a long crossing together.

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Just for clarity, do you mean as per my first image below?

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Since you are talking about frog wiring. Then I assume that you are using PECO Electrofrog points and a cross-over with part numbers that start with SL-E.

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The only PECO cross-overs with Electrofrogs that I am aware of are Code 83 and Code 75. The last time I checked there were no PECO Electrofrog cross-overs in Code 100. It would be helpful if you could specify using the exact PECO??? part numbers what track parts you are querying.

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EDIT: I have just looked at your previous posting history and see you are using PECO N gauge track. The principle outlined for 00 track in this reply is still applicable.

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Mine are wired like this:

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/media/tinymce_upload/4a00db28d2f8f1da199198d640172d6a.jpg

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Do I need to swap the power wires around to reverse the polarity?

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Yes.

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The phase (polarity) of the frogs on the cross-over will need to reverse subject to which route through the cross-over is being used. Thus the DCC signal phase (polarity) on the frogs is not constant - see next para.

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The frogs on a Electrofrog cross-over, when full frog switching is implemented, need to be opposite DCC phase - see the last image in this reply (with DCC it is not technically correct to use the term polarity, but most do because it is harder for some to visualise and/or understand the correct term 'phase'). This can be achieved by using a RLM (Reverse Loop Module). I find that the solution above works fine with my PECO Electrofrog track.

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The evidence for supporting my solution can be found in the PECO Wiring Booklet (I highly recommend you invest in getting a copy of these PECO publications, orderable from the PECO website). There are about 13 booklets in the range, but only 3 of them directly relate to PECO track wiring.

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No 21 Wiring The Layout - Part 3 Turnouts and Crossings.

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/media/tinymce_upload/2e07d18cf67eab9aa1cfb32b253d349d.jpg

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On page 9 of this booklet, the following schematic can be found. All I have done in my solution is replace the mechanical switching arrangement with an ALL electronic RLM one, that is much simpler to wire up and more reliable in operation.

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In the PECO schematic below. The red and blue phase (polarity) show correct for the diagonal route going to and from the bottom right point. When the route is left and right on the cross-over horizontal, then the red and blue phase of the cross-over frogs would need to be reversed to that shown in the schematic. In other words the left blue frog needs to be red and the right red frog needs to be blue.

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/media/tinymce_upload/5d097e5b7a226dac7a9d0e83b190457d.jpg

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Also, if I wire the frogs from my points to the third terminal the frog is not powered / polarity and my little shunter which I use to test these scenarios stalls.

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There is a high possibility that the shunter stalls because the frog phase is wrong and the loco is short circuiting on the track. This is an easy fix, you just swap the wires over on IP Digital terminals 1 & 2 (DCC in).

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TIP: I write long posts. If you intend to write a reply, it would be appreciated if you didn't use the 'White Arrow in Blue Box' button. This is not a 'Reply to this post button. It is best to write any reply you want to make in the 'Reply Text Box' at the very bottom of the page and click the Green 'Reply' button.

 

Particularly as my reply includes images. If you use the blue button, any reply you write, may be held back for image approval. Even though it is already a previously published image.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

[mishmash64]

Hi, sorry the track is n gauge peco code 55 and yes the first diagram is right.  Can I ask what RLM means?

 

Thanks.

[mishmash64]

and I am using railmaster.

 

Thanks

[Ruffnut Thorston]

RLM = Reversing Loop Module.

 

Originally designed for track reversing loops, but can be useful in other scenarios, including some Turntable arrangements...

[Chrissaf]

Can I ask what RLM means?

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I did actually say what RLM stood for in my first reply.

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/media/tinymce_upload/0ce69d8f84c8b54b2fe0d4500aa10d61.jpg

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If you want to know more about RLM products look at Chapter 7 of my downloadable RLM Tutorial.

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Downloadable on this link (when the page opens, click the document name in the top left corner to initiate the download):

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https://btcloud.bt.com/web/app/share/invite/TAIW63ObNS

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For this application you ideally need a RLM with a relatively low trigger current. Say under 2 Amps. There are a few products in my list in Chapter 7 that fit the bill. The AR1 product current adjustment is via DCC CV configuration. A RLM that is configured by physically changing links on the board instead would probably suit you best. I use the TamValley set to 1.7 Amps and it works very well for this cross-over application.

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However for the 1.7 Amp setting to work, the DCC controller supply needs to be 4 Amps and not 1 Amp. If your DCC controller supply is 1 Amp you need a trigger current of about 600 mA to 700 mA. Efficient and reliable operation may not be robust at these low trigger current levels. I would recommend upgrading a Hornby 1 Amp power supply to the Hornby P9300 4 Amp supply. I am assuming that you are using eLink with your RailMaster software. If you are using an Elite, then that has the 4 Amp P9300 supply already.

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[mishmash64]

So the cobalt will only take the two power supply cables, the frog for the turnout and the wire for the furthest frog?  Surely the nearest frog must go into one of the other terminals somewhere?

[Chrissaf]

A Cobalt iP Digital is not inherently designed to support the solution you are trying to implement.

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There are two metallic contacts inside a Cobalt iP Digitial, the arrangement of which I have drawn below in a simplified form.

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/media/tinymce_upload/b035711f9ca403cfec7798936f1a4fbb.jpg

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PB = Push Button, L = Left, R = Right, Com = Common, Aux= Auxiliary.

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The first set of contacts are internally wired to the DCC in wires. Thus Pin 3 can only be used for a Frog.

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The second Auxiliary set of contacts are 'free form'. That is to say they can be used for any general purpose use.

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In the example above, they are being used to operate a pair of LEDs. These LEDs could either be a simple dual aspect signal. Or more likely, they will be used to illuminate LEDs on a layout mimic panel to indicate to the operator the point position.

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The manual point override buttons are just external push buttons that could be placed on a mimic panel next to the LEDs to allow the points to be changed optionally by pressing the buttons rather than using the DCC controller.

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In this second schematic below, the Auxiliary contacts could potentially be used for a second 'frog' but to do so, additional connections from the 4 & 5 terminal contacts need to go to the 'DCC in' wires as well.

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/media/tinymce_upload/c9773da0a627f1a3cd6ea8f2224f8f04.jpg

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As you can see, there is absolutely no way of using the internal contacts to independently power a third frog.

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A possible 'work around' that would need testing. I cannot guarantee that this would work.

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If you look at the PECO schematic with the 'Red & Blue' DCC phase indications. The frog furthest away from the point is 'blue' phase, the same as the frog on the point. With the middle frog set at 'red' phase.

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Now consider what happens when the point route is now changed to set the route for the horizontal path. The point frog becomes 'red' phase. But if the point is set for the horizontal route, then the cross-over would also be set for the horizontal route as well. This would mean that the furthest frog would swap from being 'blue' to 'red' phase (matching the point frog phase). The middle frog changes from 'red' to 'blue' phase.

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So, if these frog phase combinations are ALWAYS true. Then theoretically, the local point frog wire (Pin 3 on the iP Digital) could also be used to connect to the furthest frog on the cross-over in parallel to the frog on the point. The middle frog (nearest one on the cross-over to the point) would then connect independently on its own to iP Digital Pin 6.

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If this was to work without creating a short circuit. Then the wires on Pin 1 & 2 and the wires on Pin 4 & 5 would all have to be the right way round. If you look closely at the schematic directly above, you can see that the 'DCC in' line phases on Pin 3 and Pin 6 are reversed and will always be reversed to one another when the contacts change over. This is the key to getting this possible solution to work. This consistent reversal replicates a RLM at its basic operational level. As the normal 'power off' state of the internal contacts are unknown at this stage (that is to say, what contacts are made and what ones are broken), then some experimentation might be required to get the wires connected correctly the right way round.

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