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Reply to "Bus or Star Wiring?"

@AGHRMatt posted:

There's been a long debate of Buss vs. Star wiring. Lost in the discussion is the real culprit -- signal feedback. The key thing to remember is that there should NEVER be more than one feed in a block as the signal will interfere with itself between the feeds. Also, the feeds should be at one end of the block rather than in the center due to "bounce-back" from the ends (you only get a bounce-back from one end reducing signal loss). Ironically, even though the protocols are different, DCC wiring practices seem to work well with DCS, including "sbubbers" at the ends of a buss. The snubbers (also referred to as "Deats Filters" for Susan Deats' son) neutralize the signal when it reaches the end of the buss to prevent bounce-back.

If you're using insulated rail to trigger block or grade crossing signals, put .1uF capacitors across the gaps in the trigger rails to preserve the TMCC signal.

If you want to run a buss, DO NOT "LOOP" it (tie the ends together).

 

Excellent advice, Matt!  One thing:

"If you're using insulated rail to trigger block or grade crossing signals, put .1uF capacitors across the gaps in the trigger rails to preserve the TMCC signal."

I tend to use 1 specific outside rail for ground & TMCC signal.  The other (in the appropriate places) is reserved for use as an insulated rail to trigger signals.  I don't use the .1uF capacitors.

George

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

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