Better DCC turnout wiring...

Discussion in 'N Scale' started by Leo Bicknell, Aug 14, 2008.

  1. Leo Bicknell

    Leo Bicknell TrainBoard Member

    I was reading Wiring for DCC ( about turnouts when I remembered something I thought about ages ago; a better way to wire turnouts.

    I'm planning on using a Peco Electrofrog for an upcoming project, so I reviewed the site and was reminded of the problem. The back side of the wheel comes dangerously close to the opposite polarity track when going through the frog. So I thought about the problem for a moment, and came up with this arrangement:

    It uses the DPDT on the bottom of a tortoise to control both the point sections and the frog. Note that when the turnout is thrown the opposite point is totally dead electrically, leaving no chance for a short.

    Am I missing anything? This sure looks like a much better arrangement for both DC and DCC to me....
  2. Mike Sheridan

    Mike Sheridan TrainBoard Member

    Some (maybe all these days) Peco turnouts have gapped switch rails with a jumper underneath. You can remove the jumper and then hardwire the switch rails to their respective stock rails, so there is no problem with metal wheel-backs. The frog is switched as normal.
  3. Leo Bicknell

    Leo Bicknell TrainBoard Member

    You're talking about picture 12c here:


    That has the problem, if you're going straight the frog will be "red" powered, and the back of the wheelset is right next to the blue closure/wing rail.

    Compare with my diagram where the closure rail is dead.
  4. digitraxuser

    digitraxuser New Member

    I am using Peco Insulfrog turnouts in HO (Code 83). I used them as they came out of the box, gap both rails in both frog ends, use pure DCC, and don't experience any problems with wheels (/me crosses fingers). ... JD
  5. Mike Sheridan

    Mike Sheridan TrainBoard Member

    No. 12c is Code 55, (75, 100 older). I'm referring to 12b Code 75, 83, 100.

    Let me guess - you're an N-scaler? Code 55? But even so I'd wait till you actually get your turnouts as Peco may have changed the construction by then :)
  6. Leo Bicknell

    Leo Bicknell TrainBoard Member

    Ah I see. Go Peco. My wiring trick would still work here, but is less necessary. The main short potential is in the frog area; but there is also a potential in the point area.

    For those who are kind of looking at me strange; no I don't think there are any problems with these turnouts in normal operation. The Wiring for DCC instructions are fine. What I'm actually trying to do here is prevent derailments from shorting the system; since I run on NTrak having a booster short out may take out multiple trains on multiple tracks (althoug that should be avoided with good booster design). The wiring for DCC pages use a SPDT switch, since the tortoise has a DPDT switch I realized I could do "better".

    So in 12b, rather than adding jumpers to the stock rail, to add them to the second set of contacts and power route the points/closure rail as well. If your locomotive say, picks a point there is almost no chance of it shorting, even if it hits the other closure rail with my idea. In the standard wiring if it hits that other rail it will short.

    For the record, I am looking at N Scale here, and the 12c picture on the right is an example of what I have to work with in this case. I was also thinking about this in terms of the fast tracks jigs; and how I would wire something built from scratch. My method saves cutting the closure rails at all in that case...
  7. Mike Sheridan

    Mike Sheridan TrainBoard Member

    Yes, I can see your system working fine, provided you can isolate the two closure rails and frog fairly easily.
    Certainly be better looking than having the gapped closure rails.
  8. dstuard

    dstuard TrainBoard Member

    I agree...

    Check out "SuperFriendlyTurnout.pdf" in the files area of the Digitrax Yahoo group.
    Last edited by a moderator: Aug 16, 2008

Share This Page