How does a Wye work?

Discussion in 'FAQs' started by spitfire, Jan 10, 2003.

  1. 60103

    60103 Pooh Bah

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    Track

    Val:
    The wiring differences are really between electrofrog (all rail frogs) and insulfrog (plastic). I think Atlas makes both types; their snap switches are the insulfrog but slightly different from the Peco.
    The major difference in wiring is that in electro there is a hunk of rail shorting over whichever track is not set. If there is a chance of power coming from that way, you have to put a gap in. Plastic frogs, though, mean that you have a short stretch where there is no power. The wiring diagrams will work with either type (except the one with the gap in the outside rail).
    I use almost all Peco in my layout, but I have almost every variation made in the last 30 years! My latest track is all code 70 and it seems to work well. I also have a huge variation in wheel standards (going back to 1960ish) and I'm slowly trying them through the new track. Anything to NMRA standards should work fine.
    Is your LHS on Mt Pleasant, by any chance, or do you use another one?
  2. spitfire

    spitfire Active Member

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    Re: Track

    :D :D :D :D :D

    That's one, and the other one is Credit Valley. I'm about midway between the two.

    cheers
    ;) Val
  3. Gary Pfeil

    Gary Pfeil Active Member

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    Val, The Atlas and the Peco Insulfrog work the same, and the Peco is mechanically superior. I was simply saying that the Atlas (and Peco) are simple electrically for beginners. No thought need be given about power routing. Power can be fed from the frog side, the only need for gaps is to electrically isolate a section for block control (not needed with DCC) and where a reverse block exists. Since we were talking about wyes, which contain a reverse block, the gaps are required.

    Now, concerning electro frog type turnouts, think of them as routing the power down whichever route is thrown. The first rule is that track power must always be supplied on the point side. Both stock rails will always be the same polarity(either + or -, depending on direction) but the frog and its closure rails switch polarity depending on which route is selected. Therefore, gaps are required beyond the frog to prevent power of the other polarity from coming from the frog end. Now, some "electrofrog" turnouts are powered thru the point rails contact with a stock rail, some need to be powered thru a microswitch or equivalent. This switch changes the polarity according to route thrown. Powering the frog thru point rail contact only is not very reliable over a long period, so most people add the microswitch anyway. So you see these turnouts do require a bit more wiring, which is why I said the Atlas and Peco Insulfrog are easier. On electrofrog type turnouts you can power the frog (if you don't you basically have an insulfrog, once you cut the gaps) with insulfrog the frog is always unpowered. This unpowered section is quite short. Slow speeds with a loco only picking up power from one truck can cause a stall. Please note that all the above is true with DC as well as DCC.
  4. marty w.

    marty w. Member

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    Gary,
    If I use Walthers turnouts with DCC and if I understand you correctly, then I would have to add gaps as below?
    Thanks,
    Marty
    BTW - This would be for any siding or spur, not a wye.

    Attached Files:

  5. Gary Pfeil

    Gary Pfeil Active Member

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    That's right Marty. If one ( or both) of the routes from the turnout were stub ended and you do not attach a feed to the track power buss beyond the frog, you wouldn't need the gap. Then the power to that track would be turned off when the turnout is thrown against it. This was handy in the days of DC to eliminate a toggle switch to kill the block. With DCC, this doesn't matter and in fact you may want power there even when thrown for the other route, for sound or lighting purposes.

    The other thing to keep in mind concerning Walthers and Shinohara turnouts is that the points are the polarity of the frog. This means that one of the point rails is always the opposite polarity of the stock rail adjacent to it. This is why these turnouts are not considered "DCC friendly". A wheel can bridge this gap and cause a short. This of course happens with DC also. DCC circuit breakers may be a little quicker to trip, and since the short is momentary, it is more annoying with DCC. I have several of these turnouts not modified in any way, and I never have this problem. That doesn't mean it won't happen to you of course. I did have the problem with one turnout on a previous (DC) layout. If you have this problem, check the wheelset gauge first. There are instructions on the net for modifying these turnouts, it is a bit involved.

    Thereis a review of turnouts by Tillig Pilz in the Feb MR. These look promising but are pricey at $18.90 list for a #6.
  6. marty w.

    marty w. Member

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    Gary,
    Thanks for the info and advice.
    Marty
  7. spitfire

    spitfire Active Member

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    Gary, thanks for the explanation, I think it's probably best if I use insulfrog as I can't seem to wrap my head around the electrofrog thing.
    In fact, now I am confused again. What do you mean by the "point side"? On Marty's picture, is the point side on the left or right of the frog?
    When you say a stub end, do you mean that it just goes off and then ends, not coming back to join with any other track?
    Sorry for my ignorance!
    Is there any way to acheive this kind of action pictured below?

    cheers
    :confused: Val

    Attached Files:

  8. Gary Pfeil

    Gary Pfeil Active Member

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    Val, The points are the rails that move to select a route. The "point side" on Marty's picture is the right side. The frog is where the rails cross. You see his gaps noted. While the wiring involved is really quite simple (my advise is to just trace the routes that current can flow and gap anyplace where opposing polarities connect, that will make you understand WHY you are doing what you read here) my advise for beginners is to use the Insulfrog types by either Peco or Atlas. There are so many things other than wiring turnouts to think about it is probably better to leave it alone till you have more experience. You really don't need one type or the other. It is mostly preferance. I don't like unpowered frogs. A lot of people use them and have no problem.

    A stub end is a used cigar. No, wait I mean a stub end is a dead end just as you surmised.
  9. Gary Pfeil

    Gary Pfeil Active Member

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    Val, Your diagram opens another can of worms entirely. The parallel tracks can be wired the same or differently, IE, Both north rails may be connected to one of the buss wires (lets say black) and the south rails to white. Or, if the two tracks are actually part of a circle, then one will have the north black and the other will have south black. This is important to know in placing the required gaps. It also determines whether you have created a reverse block. A drawing would be helpful here but no can do at work.

    There is away to do anything (well at least as far as track wiring goes!)
  10. 60103

    60103 Pooh Bah

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    Crossover

    Val:
    Another consideration is whether you're using only one or more than one controllers.
    If one track is controller A and the other is controller B and you have an insulated gap between the switches,
    AND if your loco picks up from one rail and your tender from the other,
    then your train may stop right in the middle of the crossover because of the two separate feeds.
    (Maybe we can handle this in another thread.)
  11. spitfire

    spitfire Active Member

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    Gary, thanks so much - you've really gone beyond the call of duty!!! I have found the concepts quite hard to understand, but your explanations really clarified a lot!

    David - you're right. Another thread would be a good idea about now!


    :D cheers
    Val