Build Manual: Module Wiring Standards

Discussion in 'Modutrak Public Forum' started by Mike Skibbe, Mar 17, 2014.

  1. Mike Skibbe

    Mike Skibbe Crash Test Pilot Staff Member N scale Modutrak

    [​IMG]

    So lets start wiring Main 1 (blue) for a block signal. We need two circuit boards in order to set up this block. The first is the brown Chubb DCCOD detector on the right. The second is the purple Modutrak signal driver board. These signal drivers are patterned after the TracTronics signal driver boards, which can also be used, but we've added a microprocessor in order to mimic the bouncing mechanism in a searchlight signal mechanism. More on that later, but for the time being we'll look at how these signal driver boards are wired.

    Also appearing in this diagram is the Cat5 cable whose brown and brown/white wires are broken out at this block.
     
    Last edited: Mar 20, 2014
  2. Mike Skibbe

    Mike Skibbe Crash Test Pilot Staff Member N scale Modutrak

    [​IMG]

    One of the first things I do is to hook up the 12v power to the boards. The red and black bus wires should be broken out to the terminal strip. Then from the terminal strip you can hit the +12v (red) and Ground (black) pins on both the detector and the signal driver boards.

    Also on this module we need to break the blue/white bus wire. Track to the left will feed back through the previous detector board on another module. On this module we will run the non-detected (blue) bus wire into one side of the coil on the detector board (Track 2b), and then the other side of the coil (Track 1a) to the detected (blue/white) bus wire. This effectively powers the blue/white bus segment through the detector and covers this new signal block forward of this location. We can then power the front rail of Main 1 from this blue/white bus as well. See the connections in the graphic above.
     
    Last edited: Mar 20, 2014
  3. Mike Skibbe

    Mike Skibbe Crash Test Pilot Staff Member N scale Modutrak

    [​IMG]

    The last pin out on the detector board is the detector output. This goes to ground when the detector shows occupied. As we noted before, this detector needs to cause the signal immediately next to it to go to red for a stop indication. So we wire the detector output to the stop pin on the signal driver with a grey wire. But, we also need to send this detector output back along the mainline to the previous signal. That's why you see it also running to the Cat5 cable and back to the previous block via the brown/white wire in the Cat5.

    The last connection is to pull the brown/white Cat5 wire from the next block upline into the approach pin on this signal driver. This way, when the next block upline turns red, this block we're working on now will go yellow.
     
    Last edited: Mar 20, 2014
  4. Mike Skibbe

    Mike Skibbe Crash Test Pilot Staff Member N scale Modutrak

    [​IMG]

    Now that all the logic inputs are connected, it's time to wire in the signal. We use BeNscale signals which have three separate color LED's in a single package. They are also wired to use a common +12v and separate ground wire for each indication: red, yellow, and green.

    That's it! Now repeat for Main 2 (orange) in the opposite direction and utilizing the brown wire in the Cat5 to carry the approach, yellow, indications.
     
    Last edited: Mar 20, 2014
  5. Mike Skibbe

    Mike Skibbe Crash Test Pilot Staff Member N scale Modutrak

    [​IMG]

    So what happens when you have a passing siding or another branch line that splits from the mainline? On the Milwaukee Road that we model, many of these lines were undetected, or dark territory. There would be a lunar, or white, signal displayed to show that a train could enter the dark territory but also as a reminder that the track segment was not signaled.

    We can drive a double headed signal with help from the remaining set of contacts on the Tortoise. In the example shown above, the top head on the dual head signal can display red/yellow/green when the turnout is lined for the main. It simply acts as a block signal as before. But, when the turnout is thrown, we want that top head to display red, and the lower head to govern the siding. That lower head can display red or lunar. It would be red when the turnout is lined for the main, but lunar when the turnout is lined for the siding.

    Basically we feed a ground (black) wire through the Tortoise contacts and into stop pins on the signal driver boards. When lined for the main, the lower head's signal driver board is fed a stop indication. When lined for the siding, the upper head's signal driver board is fed a stop indication.

    The lower head is wired such that the lunar indication is driven off the green indication on the signal board so that it defaults to lunar as a normal signal would default to green. (We know this isn't how prototype signals function, but the logic boards are much easier to design this way for model railroad use when lives aren't at stake. Prototype signals fail to RED!)
     
    Last edited: Mar 20, 2014
  6. Mike Skibbe

    Mike Skibbe Crash Test Pilot Staff Member N scale Modutrak

    [​IMG]

    We frequently set up with end loops that connect Main 1 (blue) to Main 2 (orange). And we use Tony's Train Exchange reverse loop controllers to handle the polarity swap. In order to do this and allow the signals to carry through the end loop, just be aware that the reverse loop controller always draws current. Therefore, the output will need it's own detector on the output side of the controller as shown above. It's also good practice to have a small stretch of track on either side of the reverse loop section which is fed from the same booster, hence the small bit of blue main before transitioning across a double gap to the orange mainline power. Input to the reverse loop module should come from a non-detected bus! And you might as well wire an entrance signal to this module while you're at it.
     
    Last edited: Mar 20, 2014

Share This Page