DCC Wiring: Loop to loop

Discussion in 'DCC & Electronics' started by ScottyB, Aug 10, 2005.

  1. ScottyB

    ScottyB Member

    OK, the first tracks are about to be laid but a quick question. My layout is a loop to loop. The "main" section connecting the two loops is less than one train length. The two reverse loops are large and comprise the remainder of the layout, and each loop has a few sidings.

    In my limited knowledge of DCC, the most logical (and obvious) thing is to wire the short "main" section as the mainline, and the two reverse loops as reverse loops (with autoreversers). Sounds simple enough. But before I do, I was wondering if I'm overlooking anything, including a "simpler" way of wiring?

    Thanks for the input!
  2. railwaybob

    railwaybob Member

    Sounds okay to me. You have the long train length in your reverse loops. What kind of auto-reverser are you planning to use?
  3. ScottyB

    ScottyB Member

    Yup, plenty of room in both loops for a number of trains.

    Not sure about the reverser yet. Probably Tony's, just from the description on their site about the solid state, no-relay, no spark idea. I'll take advice about other reversers as well.

    Thanks railwaybob.

  4. tillsbury

    tillsbury Member

    Don't make the reversing loop longer than you need it to be. You say you have room for a 'number of trains'. You can't have another train enter the loop before the first one has got out. The 'length' of the train depends upon how you're using it -- if you use lighting or power in the caboose, the train is the full length. If you don't, the train is only as long as the locos. All of the significant 'length' of the train must be out of the loop when the next train arrives at the reverser. And the loop must be long enough to completely contain the entire significant length of the train.

    I use the Tony's NCE Reverse-it and it works just fine...

  5. ScottyB

    ScottyB Member

    Ok, hold on. My reverse loops are simple reverse loops -- one way in and out. Each reverse loop has multiple sidings that stay inside of the reverse loop. My understanding is that you can have multiple trains inside a reverse loop, as long as two trains do not cross the gap to the mainline at the same time. Since there is only one way in and out, this situation is not possible on my layout.

    Or am I wrong?

    And also, since it is only one way in and out, I was thinking of just wiring up a relay to the switch and controlling polarity automatically that way. I think that will work until I run a train into an opposite switch, but in theory it works.

  6. baldwinjl

    baldwinjl Member

    If I am thinking right:
    If you have a plain loop, where the exit and the entrance are the same switch, then a reverser works, and it doesn't matter how many trains you run in from which direction. The key is that you can change the polarity of the reversing track without bothering any trains that are already in it. Since only one train can enter or exit at a time, the reverser will can flip any time it needs to.
    Now, if the reversing track is a diagonal across on oval, for example, a train entering or leaving at each end is trouble. I need to think about that one, and how to solve it, since that is (conceptually) a situation I may have! :confused:
  7. Gary Pfeil

    Gary Pfeil Active Member

    Scott, what you descibe is the right way to do it, you'll have no problems. You are right about the only potential problem being crossing gaps at either end at the same time. In fact if your track connecting the two loops were a train length long, you could've used one reverser for both loops. Seeing as how only one train could traverse that section at a time. But since it is not a train length long, it would cross gaps at each end at the same time, requiring two reversing units. I use and highly recommend Tony's units.

  8. 60103

    60103 Pooh Bah

    What is the amp capacity of a reverser? Are they intended to take the full 5a or just enough for one train?
    I think you should see if you have a train length of plain track in the reversing loop and use that as the reversing section.
  9. ScottyB

    ScottyB Member

    Thanks Gary. I was beginning to question my DCC learning experience on The Gauge!

    OK. One more question. I plan on using the Caboose Indusries ground throws on my layout. (I know they are big, but tough -- my layout). All switches were designed to be well within arms reach of the end (furthest one is just beyond 1ft). Instead of using auto-reversers, on the two switches that initiate the reverse loop, could I install a #220S ground throw (pic here) connected to some sort of latching relay to control the polarity of the loop? There must be a way, just wondering if someone might know a RadioShack part number to use?

    Thanks all at The Gauge!

    Edit -- would an Atlas 200 snap relay work? Or too many amps? Hmm...

    Edit again -- nope it wouldn't -- constant power from the ground throw contacts would burn out the relay. Other ideas?
  10. Gary Pfeil

    Gary Pfeil Active Member

    Scott, I used one of those...once. Perhaps I didn't assemble it quite right or something, I suppose others use them successfully. Mine just wasn't dependable. If you want to avoid switch machines you might consider using an electrical slide switch. Drill ahole thru its handle and glue in a brass rod, solder a wire in the rod. There is a thread somewhere on the Gauge about this type thing. There are several ways to go about it. End result is you can throw the points and change polarity by sliding the switch.

    David may have a valid point about what the recommended max current is on the reverser unit, you should check Tony's site or call. I have loops with five staging tracks within each one but use a reversing unit for each one, not out of concern about power but so I can run in and out at the same time. I don't have a single turnout like you do.

  11. Gary Pfeil

    Gary Pfeil Active Member

    Just checked Tony's site, reverser is rated 8 amps.


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