Should DCC bus wires be twisted?

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

  1. Sol

    Sol Full Member

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    Now in reply to one of the posts, DCC is perfect for loco control but many in the USA are now going to LCC for signals etc
    https://www.nmra.org/search/node/lcc

    regarding not having a complete loop for the DCC bus - well to confuse everyone, I do have a complete loop 12 x 20 ft layout ,as my signalling circuit requires common return so not only the track power but signal relay 40 v, LED 12 & other 12v relay power ( all separate transformers) use a common ( as did telephone exchanges with different voltages etc )
    Mark Gurries, a reasonably knowledgeable DCC user https://sites.google.com/site/markgurries/home/about-mark-gurries did say to me when I questioned him about a loop and the "story" how a decoder coyuld get confused getting command signals from two directions. he pointed out the the time differnce is almost so small, it would affect a thing - it would need al ayout of over 1mile/ 1.5km in length to give a difference.

    Twisted buss - yes but if not, then keep the two buss wires a a few inches/ cms apart.
     
    Andy_Sollis likes this.
  2. Jim Freight

    Jim Freight Full Member

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    Wrong place :hammer:
     
    Last edited: Sep 14, 2020 at 8:41 PM
  3. Jim Freight

    Jim Freight Full Member

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    I thought the loop/circuit length would be in that ball park because it is related to the signal wavelength, and at approx 100kHz (I believe) that is almost 3km.

    My parallel buss wires are nominally 3 - 4 cms apart, but the rails are not, oh dear! :facepalm:

    Jim :avatar:
     
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  4. jcm@gwr

    jcm@gwr Full Member

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    You'd be okay with Gauge 1 at 45mm!
     
  5. Jim Freight

    Jim Freight Full Member

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    :giggle: If I could build my railway in Gauge 1 it would be steam powered, ride on or RC control. :rolleyes:
     
  6. Jim Freight

    Jim Freight Full Member

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    :gday: No apologies necessary Gormo. :)
     

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