Friday, March 11, 2016

Controlling power to staging yard tracks

Back in September in the post Control center for the staging yard I briefly mentioned  the circuit I built to turn each of the sidings in the staging yard ON and OFF simultaneously with the routing of the turnouts.  In the post I want to give more details on this.  I'm running DCC so why do I need to do this ?  At this point I've not really gotten my head around the JMRI / Panel Pro stuff and I would like to do some automation of some parts of the layout in the future.

This is the pair of circuit boards I made to switch power between each of the tracks of the yard.

The smaller board is a diode matrix and the larger one contains the latching circuits and relays.

This is the schematic drawing for the larger board, the 5 track power routing board  I realize this is 1970's technology but it works.  It's a larger version of one I built for the Peninsula Ntrak staging yard several years ago.  More recently I have written some code and successfully bench tested with LED's the same function with an Arduino Uno micro controller.

To make this work with an Arduino I will need to build a special shield board with the necessary relays, circuits to drive the relays, and terminal strip connections.  When I get a chance to work on that, I'll be sure to share it in a post.

The diode matrix is something that also is worthy of more explanation and that will be another future post.


  1. Hi Brad. Is the purpose of this circuit to ensure that track power is connected only to the selected staging-yard track?

    1. Yes Ron, that is correct. One pole of a momentary DPDT switch selects the track to be connected through this circuit and the other pole is used to sent input to a Digitrax DS64 to align the turnouts.

  2. Brad, am following along with interest. I think our railway rooms are of a similar size but cant find your current track plan. Can you advise where I can find it?

    1. Hi Brendan,

      Yes, I think our rooms are about the same size. My layout is going to be around the room with the center open to work on modules. Staging is by itself below the layout along one wall. Most of the space under the bench work is used for work bench, module storage, etc.

      I realize I don't really have a full track plan posted on the blog. The closest thing I have is in this post: