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Auto Reverse

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  • Member since
    January 2005
  • From: Southern Colorado
  • 752 posts
Auto Reverse
Posted by jxtrrx on Sunday, November 30, 2008 5:02 PM

I have a Digitrax Zephyr and use a Digitrax auto reverse circuit card for one of my loops.  As the loco rolls over the insulated joiners, it pauses for just a moment (headlight goes out briefly) and then it rolls on.

Is this normal, or do I have some adjusting to do?

-Jack My shareware model railroad inventory software: http://www.yardofficesoftware.com My layout photos: http://s8.photobucket.com/albums/a33/jxtrrx/JacksLayout/
  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Sunday, November 30, 2008 5:45 PM

I use the PSX-AR, and I have not noticed any flickering or hesitation at either end of my reversing section, and not with any of my engines. I haven't investigated this because my setup seemed right from the get-go, but I believe you can set the timing of the change-over, the reaction time, of your reverser.  The manual will tell you if it is so.

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Sunday, November 30, 2008 6:56 PM

I'm not familiar with the Digitrax auto reverse module but if it is not fully electronic and uses a mechanical relay, the hesitation is due to the relay not reacting fast enough.  On those types of modules, there is usually a delay adjustment.  Try to locate or download the Digitrax documentation and read the instructions on adjusting the relay's sensitivity.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Sunday, November 30, 2008 7:54 PM

Does the LED display on the Zephyr flicker when this happens? Since it's a short pause there isn't enough time for it to display the O's of overload, but it migth flicker - I suspect the Zephyr is also tripping but since the short clears almost immediately, it goes right back to working. Adjust the control on the AR-1 a bit at a time until it works nicely with no pauses. You'll know if you turn it the wrong way, it will stat tripping the Zephyr and not reversing.

                                       --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    July 2008
  • 1,206 posts
Posted by mfm37 on Sunday, November 30, 2008 8:03 PM

 

jxtrrx

I have a Digitrax Zephyr and use a Digitrax auto reverse circuit card for one of my loops.  As the loco rolls over the insulated joiners, it pauses for just a moment (headlight goes out briefly) and then it rolls on.

Is this normal, or do I have some adjusting to do?

 

You've got some adjusting to do.  You didn't mention which Digitrax AR unit . AR1 or PM42?

If it's a PM42 see the following tech note for use with Zephyr.
http://www.digitrax.com/appnote_pm42_dcs50sync.php

 If it's an AR1, adjust the TTC screw until no stalling occurs.

 
Martin Myers
 

  • Member since
    January 2005
  • From: Southern Colorado
  • 752 posts
Posted by jxtrrx on Thursday, December 4, 2008 9:09 AM

Thanks, everyone.  (It's an AR1).  I'll try the adjusting screw.  Glad to hear that this is not "normal" and can be smoothed out.

-Jack My shareware model railroad inventory software: http://www.yardofficesoftware.com My layout photos: http://s8.photobucket.com/albums/a33/jxtrrx/JacksLayout/
  • Member since
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  • From: Mpls/St.Paul
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Posted by wjstix on Thursday, December 4, 2008 11:46 AM

I used one on my last layout, it took a little trial-and-error to get it adjusted 'just right' but once set it worked great after that.

Only odd thing I found was the actual reversing section that it controlled was long enough for freight and passenger trains but wasn't quite long enough for my longest iron ore trains to fit on at one time, so occassionally if a car equipped with metal wheels at the rear of the train was entering the block the same time as an engine or car with metal wheels was leaving the block, it caused a hiccup in the system. Fortunately only about half of my ore cars have metal wheels (the Walthers ones have Proto trucks installed, the MDC ones still use the trucks and plastic wheels they came with) so I just made sure the last cars in the train had plastic wheels.

Stix
  • Member since
    February 2003
  • From: New Jersey, US
  • 379 posts
Posted by topcopdoc on Thursday, December 4, 2008 11:56 AM

Do the auto-reverse units have a delay mechanism to stop the locomotive for a set time period eg. one minute before reversing?

I have a commuter line with an RDC which I would like to circle the layout and stop at the station for a minute or so and then do the reverse loop.

Doc

Pennsylvania Railroad The Standard Railroad of the World
  • Member since
    July 2006
  • From: Vail, AZ
  • 1,943 posts
Posted by Vail and Southwestern RR on Thursday, December 4, 2008 3:42 PM

topcopdoc

Do the auto-reverse units have a delay mechanism to stop the locomotive for a set time period eg. one minute before reversing?

I have a commuter line with an RDC which I would like to circle the layout and stop at the station for a minute or so and then do the reverse loop.

Doc

This would be a totally different animal.  The DCC autoreveresers don't actually reverse the train, they just reverse the polarity/phase of the signal on the tracks to eliminate the short that exists when you traverse a reversing section.  To actually reverse the direction of the train, front to rear, you need to change the commands that are being sent to the decoder.  It's actually an easier thing to do automatically with DC than with DCC.

Jeff But it's a dry heat!

  • Member since
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Posted by Monkey Boy on Wednesday, December 24, 2008 8:57 AM

I just purchased an AR-1 and spent about 5-hrs trying to get it to work right, but I'm having no luck. Bottom-line upfront: I need to know if I got a bad reverser.  .

Here's a description of my problems: Following the instructions, adjusting the "pot" on the board in nearly 1/16-th increments at a time and individually using each of my three DCC locos, I experienced a "successful reverse" only four times using a balloon-loop created from a manually-thrown Atlas right-hand turnout (with the insulated joiners doubled-gapped right to the turnout). A "successful reverse" I define as a loco entering into and exiting the loop without a "trip" of the AR-1 or my Bachmann Dynamis controller circuit breaker, meaning the loco goes through the loop without hesitation.

Observations of my successes are as follows:

-Independent of which loco I use (eliminating this being a loco issue).

-Independent of what turnout I use. I've used three different turnouts just to verify it wasn't a turnout quality control problem.

-Independent of my track and joiners.  I've used various sections of tracks and made sure they're clean.

-Only works in one direction, i.e. the auto-reverser must be wired to the loop such that the loco "encounters" the AR-1 leads soon after crossing on the loop (right after it passes the insulated gaps).  In my configuration using right-hand turnout, the loco must go clockwise when I have the AR-1 wired nearest to the outbound straight section of the turnout (vice the right-hand turn section).

More often, I experience "partial success". If I throw the turnout to the right WHILE THE LOCO IS IN THE LOOP so that the loco may reenter the mainline, I get a short-circuit indication and a trip on the Dynamis when the loco crosses the second set of gapped rails, meaning it's getting ready to exit the loop. However, if I don't throw the turnout while the loco is in the loop, it will pass over the second set of gapped rails, then immediately come to a stop (meaning it's lost power). Then, if I throw the turnout, it regains power and reenters the mainline.

Is the AR-1 this difficult to set-up, or is it possible I've got a bad one?

 

Assuming I can ever get this to work, will this reverser (or any other brand) work on section of track in between two turnouts.  For example, if I have a simple oval setup, but place one left-hand and one right-hand turnout on it such that a section of track can be connected to them through the oval (looking like a half figure-8), would a autoreverser work?

  • Member since
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Posted by mfm37 on Wednesday, December 24, 2008 9:20 AM

 I'm confused by your description.

The AR1 (or any other auto reverser) should be the only thing connected to the reverse loop. Power from the main line comes into the AR1 and goes out to the loop. Loop must be completely isolated from the main. If you are getting a short when throing a turnout, something is wired wrong or a gap has closed up.

Martin Myers 

  • Member since
    December 2008
  • 2 posts
Posted by Monkey Boy on Wednesday, December 24, 2008 9:32 AM

Hard to describe without being able to post a picture...

Power from the mainline is going into the AR-1 pins 1 & 2, and reverse loop is wired to AR-1 pins 4 & 5, as called for in the instructions.  Loop is double-gapped also as described in the instructions.  Gaps were "clean", meaning they'd didn't close (used the Atlas-made insulated joiners)

Most often, the short does occur when the turnout is thown and as the loco crosses the second set of gaps, getting ready to exit the loop.  However, I did get it to work four times.  Speed of the loco was also a factor, as if the AR-1 couldn't switch the polarity fast enough.  For a Bachmann GP30 DCC-onboard loco (28-step decoder), speeds less than 12-step worked; anything over didn't.  But speed wasn't the only factor, as it failed many times at lower speed.

 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, December 24, 2008 10:48 AM

 If you get a short simply by throwing the turnout, you have a wiring problem with the loop or turnout. I would put a piece of track between the turnout and the gaps, not gap right at the turnout. There's no reason you should get a short just by throwing the turnout - Atlas turnouts aren't power routing. You're probably getting an additional short at the frog - and it's not the turnout, it's the wheels - check the gauage of your wheels.

 I am basing this on your original post and follow up, it sounds as if you have a turnout with insulated joiners on both the straight and diverging route, and that track loops around on itself and is powered by the AR-1. This would seem to make it impossible that somethign is crossing both gaps at the same time. If this is NOT the way you have the loop gapped - check that you don't have cars with metal wheels crossing one set of gaps while the loco crosses the other. This will NEVER work.

                                    --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Wednesday, December 24, 2008 3:17 PM

Hello Jack
Just so you don't feel like the Lone Ranger I had a simple loop that was entered from a "Y" that had it's own spur. I spent days and many calls to Digatrax. Never got it to work. I put in a simple DPDT and the Atlas slide switch. They are both thrown to the same direction as the train enters or leaves. works like a charm.

Good luckSmile

Lee 

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