Should DCC bus wires be twisted?

Discussion in 'DCC Control' started by David Mitchell-Todd, Sep 11, 2020.

  1. Jim Freight

    Jim Freight Full Member

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    As I said above, you split both, buss and track.

    It is momentarily a loop at track level when metal wheels bridge the insulation gap, especially when a loco passes over the gap with multiple axles of pickups, but not much we can do about that though.
     
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  2. Walkingthedog

    Walkingthedog Full Member

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    I’ve never heard of doing that with a loop of track.
     
  3. RFS

    RFS Full Member

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    Personally I think we're worrying about nothing when it comes to having the DCC bus as a loop. Total bus length is far too small to cause a problem. My layout is 30ftx8ft and I've tried operating for long periods with the bus both as a U-shape and as a loop. Was unable to detect a scrap of difference - and my bus wires aren't twisted either. What is most important is to have bus wires of adequate size and droppers on every piece of track.

    As far as connecting droppers to the bus is concerned, I've used Scotchlok connectors to connect to mainly 5-way Wago connectors at intervals along the bus. These connectors then allow multiple bus wires to be easily plugged in, and above all it means no soldering under the baseboard. And individual wires can be easily unplugged for fault-finding or alterations.
     
    Last edited: Sep 12, 2020
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  4. paul_l

    paul_l Staff Member Administrator

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    Sorry, a bit late in this topic.

    Found it - Mark Gurries I found this site to be a great resource for DCC a lot is regarding NCE but most is applicable to all DCC.

    Twisted pair Bus wiring

    Like others I have at least one dropper per piece of rail - some time two for longer lengths.

    Ring mains can't be used as the messages will travel in both directions so can interfere with each other. On longer lengths it's recommended to fit snubbers at the ends of each bus

    Paul
     
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  5. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    Simple neat wiring, easy to access when soldering dropper wires... I don't twist my wires and they run a total length of approximately 20' - 22' in length and no, they don't form a circuit... I have had no issues with operation either. I don't use clips, I prefer to solder all joins in the wiring.


    I use this BUs Bar at the end of the wiring to connect a connector...


    I use the another two pieces of Bus Bar where the main bus wire needs to provide power to the sector plate.


    Cheers, Gary.
     
  6. Jim Freight

    Jim Freight Full Member

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    Hi Paul, yes, Mark's articles are quite exhaustive and technical, well worth reading especially for the techie minded of us that want to know what goes on under the bonnet.

    I tried RC filters (aka snubbers, which are not really the same thing) after viewing an almost out of control discussion on a Farcebook group. To check it out I used a digital scope attachment to my laptop and sometimes I saw signal improvements, in other places I did not. In fact having at least one loco in a DCC district did the job just as well! In the end I left them in place, however I would suggest that resistors of a higher wattage rating than is electrically adequate is used to avoid burning one's fingers inadvertently.

    I also dropped the output from my Lenz units by a notch to reduce disspiation and spikes, trouble is that meant I needed to tweak the speed settings on some of my locos again as it reduced their top speed accordingly, arrrgh!

    Jim
     
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  7. Andy_Sollis

    Andy_Sollis Full Member

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    Interesting reading and educational !

    thanks chaps!
     
  8. David Mitchell-Todd

    David Mitchell-Todd Full Member

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    I think there is huge potential for some serious research into this. Is there anyone on this forum who works at an EMC testing centre who would be willing to do some unpaid overtime? Seriously though, perhaps one of the DCC companies should look into this?
     
  9. Jim Freight

    Jim Freight Full Member

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    Look into which aspect?

    Lenz and Mark Gurries have already done a lot of research.
    I would expect that any emissions that EMC regulations would require enforcing were dealt with many years ago before mass production of these systems was started. :scratchchin:
     
  10. Andy_Sollis

    Andy_Sollis Full Member

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    I suspect David may have been referring to the circuit part of the conversation at a guess?
     
  11. Jim Freight

    Jim Freight Full Member

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    Maybe, well I think we have run into the buffers now :avatar:, g'nite Andy, Jim
     
  12. David Mitchell-Todd

    David Mitchell-Todd Full Member

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    Yes indeed.
     
  13. Davoetype

    Davoetype Full Member

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    Strongly agree with soldering and NO clips. It may have been covered earlier, but when we say ALL sections of track must be connected to the bus, do not forget that this applies to turnouts as well.
     
  14. gormo

    gormo Staff Member Administrator

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    This topic shows that nothing is ever easy as the manufacturers would have you believe.
    Reading the above replies, it sounds like just as much effort and trouble as DC, although most of you would probably disagree.
    I have often considered DCC, however having committed way back to DC, I felt I would just carry on with that method to an end.....which is still a long way off.
    However, if I were to change, I would leap frog DCC and go straight to battery with remote control, which has come on in leaps and bounds and will work with DCC decoders.
    The Americans seem to be at the forefront of development and it removes a lot of the issues associated with sending all your commands through the track.
    You can actually run a loco without track at all, which shows that frogs.....electro or insulated no longer matter......clean track no longer matters...... BUS wires and sections not required.....so essentially, apart from the original conversion of the loco and sorting out charging, that`s it.......trouble free model railways.

    https://www.s-cab.com/




    :tophat:Gormo
     
    Last edited: Sep 13, 2020
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  15. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    Yes and no Gormo. Each loco will requires a battery pack, decoder and board. Whereas with DCC, you purchase the controller then additional decoders for the locos which can be purchased quite cheaply...



    Cheers, Gary.
     
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  16. gormo

    gormo Staff Member Administrator

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    Well yes of course Gary,
    Each loco requires it`s own battery, board and decoder, but then you are free to do what you like without the headaches of BUS wires, dirty track etc. etc. etc.
    From memory, the remotes can handle up to 10 locos.??
    :tophat:Gormo
     
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  17. Andy_Sollis

    Andy_Sollis Full Member

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    Great if you have just one or two locos at one time, but can you imagine an MPD layout with 20 locos...?

    unless you still have a live rail somewhere and they charge via the track pickups.

    I think what we are really finding by our discussions is that although the DCC chaps (and ladies) will say “this is best” it doesn’t always suit everybody. Same with DC, it no longer entertains everybody as they want more..
    But the radio one has its limits... we’re all different and we all want different things.

    (as an aside, a mate of mine does have a radio system like above in his O gauge, but his sounds come from his phone or tablet from which he controls his layout... which I think is literally 2 loops.)
     
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  18. Andy_Sollis

    Andy_Sollis Full Member

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    I think that’s similar to what my mate Rob Riley has for his outdoor layout...

    now that is one place (in the bigger scale) that this would come in to its own.. I can’t see it being fitted in an OO terrier.?

    how long on average would a battery last? It’s obviously subject to how much use and speeds you run at (or if you even fit the sound decoder to it)
     
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  19. Jim Freight

    Jim Freight Full Member

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    Hi, just looked at the videos, interesting, but IMO it's got a long way to be viable in 4mm scale UK locomotives.

    There seems to be as many issues created as solved at this time, a few that initially come to mind :-

    1) How did he get all that kit in that small tender loco?

    2) How many UK locos have tenders as large as the one he showed running, even larger diesels have very little space inside these days, what about tank engines?

    3) Just look at the number of modules required!

    4) Bluetooth is not very reliable, lacks the data error recovery protocol available in wifi computer networking.

    5) Having to switch locos on/off by a magnet on a large layout, long magic wand required, steady hand and tough scenery.

    6) Still need some clean track somewhere to recharge and clean loco wheels too.

    7) There needs to be feedback from the loco to indicate it's state of battery charge, do these modules transmit too?

    8) I suspect that multiple controllers on different channels may interfere unless the protocol is up to it.

    This does not look any easier to me than a DCC installation at this time.
    DCC enhances the enjoyment I get from my railway and is well worth my effort, but I drive my railway and not my computer, it's my fun. :hammer:

    How you enjoy your railway is very personal, so to anyone reading this please, let's not start a heated discussion as so often happens over DC - DCC.

    Jim
     
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  20. gormo

    gormo Staff Member Administrator

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    G`day Jim,
    Yes actually this discussion about battery power is off topic, so apologies for that and we should return to the issue at hand.
    I don`t think it was ever headed for a heated discussion........lively maybe....but not heated............:avatar:
    :tophat:Gormo
     
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