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Auto Reverse to buss wires?

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  • Member since
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  • 595 posts
Auto Reverse to buss wires?
Posted by mreagant on Thursday, May 3, 2012 10:20 AM

Is there any reason that the two wires of an AR designated to go to the main  section couldn't be connected to terminals on the buss wires  SO LONG AS the other pair designated to connect to the reversing loop are properly connected inside the loop?

For a particular application I have, it would be the simplest  and easiest way.

Mike 

  • Member since
    January 2007
  • From: Eastern Shore Virginia
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Posted by gandydancer19 on Thursday, May 3, 2012 10:29 AM

No problem whatsoever.

Sometimes it is easier to write instructions in a way so that it is real clear what needs to be done rather than the best way to do it.

You can also make a special independent bus for powering your reversing loop if the loop is large, connecting the track to that special bus, then connecting the output of the AR to that special bus that is only used for the reversing loop.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

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  • From: Bedford, MA, USA
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Posted by MisterBeasley on Thursday, May 3, 2012 11:26 AM

That's fine, if you aren't going to break your layout down into separate districts protected by individual circuit breakers.  If you put the auto-reverser on the bus wires, it will become part of the district and will also be part of the load from that district.

For a small reverse section, say a simple loop that only one train will run on, the load should not be an issue.  However, at this point you need to start looking at the combination of parts you are using.  If you have a slow-acting auto-reverse unit connected to a fast-acting circuit breaker, the breaker may trip first, which would shut down the entire district instead of just flipping power on the loop.

If you're doing this to save a few feet of wire, play it safe and run the auto-reverser directly off your DCC system.  Even if you don't have districts and breakers now, you may decide to do it in the future, and this will greatly simplify that task.

It takes an iron man to play with a toy iron horse. 

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Posted by mreagant on Thursday, May 3, 2012 9:45 PM

Thanks for the confirmation.  One option I have is to use an Atlas Twin (2 DPDT toggles) with one set to a feed from the buss and the other connected to the rails inside the reverse section.  They would be thrown in opposite directions.  I've checked continuity on the Twin and that ought to work.  Any thoughts?

Mike

  • Member since
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  • From: Bedford, MA, USA
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Posted by MisterBeasley on Friday, May 4, 2012 9:28 AM

The Atlas Twin is two double-pole, double-throw (DPDT) toggles, internally cross-wired to act as reversing toggles.  You can use a single DPDT to run a reverse loop with DCC.

But, that's just so 20th century.  Compared to even the slowest auto-reverser, manually flipping that toggle takes an eternity of microseconds.  Your locomotives may stall and restart, and your sound engines will shut down and then recycle their power-up sequences.  Sooner or later you'll go with an auto-reverser, so you'd might as well do it now.

It takes an iron man to play with a toy iron horse. 

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Posted by mreagant on Friday, May 4, 2012 9:53 AM

Ooops!  I forgot to clarify my last post by saying that the auto reverser would be wired to the Atlas Twin--which is already in place and has been used for years-- with the main line wires from the AR to one DPDT and the inside the reversing section wires to the other DPDT.  Each DPDT would be set opposite the other.  Does that make sense?

Mike

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  • From: Dearborn Station
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Posted by richhotrain on Friday, May 4, 2012 10:17 AM

mreagant

Ooops!  I forgot to clarify my last post by saying that the auto reverser would be wired to the Atlas Twin--which is already in place and has been used for years-- with the main line wires from the AR to one DPDT and the inside the reversing section wires to the other DPDT.  Each DPDT would be set opposite the other.  Does that make sense?

Mike

Why are you opposed to simply wiring the input side of the AR to the main bus and wiring the output side of the AR to somewhere within the reversing section?

Rich

Alton Junction

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Posted by mreagant on Friday, May 4, 2012 12:00 PM

Not opposed to it at all.  Just looking for the simplest way.  Using existing connections to the greatest extent feasible  means less opportunity to  mess something up.  This way I hook up 4 wires and don't have to disconnect anything.  All other options would involve one or more disconnections/reconnections plus the four new connections. 

Mike

  • Member since
    December 2004
  • From: Bedford, MA, USA
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Posted by MisterBeasley on Friday, May 4, 2012 12:58 PM

One of these days, your hand will brush across that Twin, and set one of the toggles to the neutral position in the middle.  Then, you will spend 2 hours troubleshooting the "problem."

The underside of any layout gets to be pretty confusing after a while.  Anything you can do to make everything as simple and direct as possible will save you time in the long run.

It takes an iron man to play with a toy iron horse. 

  • Member since
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Posted by mreagant on Tuesday, May 8, 2012 2:30 PM

I ended up connecting the AR wires to the reversing section through one of the Twin switches (already attached to the track) and the AR main section wires to the buss posts on the Twin.  Works fine with one curious quirk.  The first time I run a loco into/out of the reversing section, the AR does not kick in.  When I run the loco back through, it works fine on both ends of the section.  I'll keep testing it using different locomotives and see what happens.

Mike

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  • From: Eastern Shore Virginia
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Posted by gandydancer19 on Tuesday, May 8, 2012 3:46 PM

If I read what you are saying correctly, you already have a set of switches that operate your reversing loop and the mainline.  (That is the typical set-up for DC.)

Take the one switch out that switches the reverse loop and replace it with the Auto Reverser.

Then just remove the other switch that that changes the mainline because you don't need that one at all.  (Connect the input wires to the switch to the output wires of the switch.)

The DCC signal can be changed under a locomotive while it is still running and the locomotive will not be affected.  This is the nature and one advantage of using DCC, and this is what the Auto Reverser does when the loco is exiting the loop.  As was mentioned before, if you don't remove the switches, you will have a problem with them sooner or later.  (Don't ask me how I know.)

Now having said that, we realize that it is your layout and that you can do anything that you wish.  We are only trying to get you to understand that you should do things the right way and why, and not necessarily the easy way.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

  • Member since
    December 2001
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Posted by Stevert on Tuesday, May 8, 2012 4:13 PM

gandydancer19
  We are only trying to get you to understand that you should do things the right way and why, and not necessarily the easy way.

 Yes

My experience has shown me that doing things the right way, no matter how hard that may seem, is almost always easier than fixing the problems that are sure to result from doing it the wrong way.

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