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Reverse loop question

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Posted by mfm37 on Tuesday, November 2, 2010 4:00 AM

steamfreightboy

 

I checked the gaps and they all look isolated but this one gap looks narrow to me. Is it possible that the wheel is simply bridging the gap? The reverse loop will sometimes work but sometimes not. Does that help?

 

Do they "look" isolated or are they actually isolated after checking with a meter?  The rails at  that tight gap may make contact with a little expansion from temperature  or humidity change.  Could be the reason it works sometimes. Turn track power off and check the rails across the gaps with an ohmmeter.

BTW, he wheels are supposed to bridge the rail gap. That's what causes the AR1 to change phase on its output.

Martin Myers

JRP
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Posted by JRP on Monday, November 1, 2010 10:22 PM
I had this problem for 2 years or longer. I had the AR-1 but it did not work well. I went on-line, talked to many model train store "experts" and still could not get this problem solved. When I was up in the Seattle Tacoma area 2 years ago, I spoke with an electronics engineer who was also in a model train club. He suggested the PSX-AR auto reverser made by DCC Specialties Products and swore by it. You can order it from Tony's Train Exchange and I suspect some other places too. It cost me about $50, but it was worth every penny. It works!! I use DCC with sound and I was told that sound is part of the problem as sound is even more sensative to types of reversing systems and receiving. But not the PSX-AR. Check it out...good luck. JRP GSW&P
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Posted by steamfreightboy on Monday, November 1, 2010 7:33 PM

richhotrain

 steamfreightboy:

 Vail and Southwestern RR:

Check your gaps.  If you moved things, something could have shifted.

 

Okay, I will.

 

steamfreightboy,

Update us.  What is happening?

Rich

Sorry about thatWhistling

I checked the gaps and they all look isolated but this one gap looks narrow to me. Is it possible that the wheel is simply bridging the gap? The reverse loop will sometimes work but sometimes not. Does that help?

"It's your layout, only you have to like it." Lin's Junction
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Posted by selector on Tuesday, October 26, 2010 7:41 AM

Do we know for a certainty that no metal wheels are bridging the rearmost gap? IOW, is the consist fully contained within the confines of the gapped reversing section?

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Posted by richhotrain on Tuesday, October 26, 2010 7:38 AM

steamfreightboy

 Vail and Southwestern RR:

Check your gaps.  If you moved things, something could have shifted.

 

Okay, I will.

steamfreightboy,

Update us.  What is happening?

Rich

Alton Junction

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Posted by fwright on Sunday, October 24, 2010 7:36 AM

Yes, an auto reverser will work with DC - but with limitations.

With DC, because the engine reverses when the polarity is changed, the auto reverser must change the polarity of the track the train is entering into, not where it is.  So the auto reverser is wired to the main and trips off the exit reversing loop gaps.  Note this only works for the exit from the reversing section, and cannot match the main and reversing loop at the entrance to the reversing loop - this must be done via another method.  A second auto reverser does not help unless they are wired to separate sections of track so they can detect shorts independently.

There is also the issue of operating trains at low enough voltages on DC that the auto reverser might not sense the "short" and change the polarity in the desired milliseconds.

There are automatic solutions for DC that use position detection to set the polarity of the track ahead of the train, rather than waiting for a short circuit to happen.

Fred W

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Posted by superbe on Saturday, October 23, 2010 10:35 AM

This thread is very timely. My reverse loop has worked flawlessly for several years with a PSAR reverser. Recently a section of track at one end or the loop lost power and I was in the process of adding feeders to it from the main bus.

Rich, thanks to you comments I now know better. After several years I had forgotten how it was wired.

As for the op's question this may or not be applicable. I did have a problem with plastic rail joiners. The track joints were so tight that the track expanded through and made contact with each other. Cutting a gap with a razor saw solved that problem. 

Happy Railroading

Bob

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Posted by mfm37 on Saturday, October 23, 2010 9:00 AM

Yes and no. An AR1 autoreverser will "see" a short circuit and reverse its ouputs even with DC power.  Solid state reversers may not, I've never tried it with one.

Problem is a DC engine will also reverse direction when the polarity is reversed. It backs up until it attempts to cross the gap at the other end. AR1 sees the shrt circuit, reverses polarity. The DC engine reverses its direction and heads back to the other end of the reverse section. Kind of like a game of Ping Pong.

Martin Myers

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Posted by Vail and Southwestern RR on Saturday, October 23, 2010 8:40 AM

Medina1128

I was interested in the auto reversers, but was told that they only work with DCC, is this true? Yes, my layout is "old school" DC.

Yep, it's true.  I believe the autoreverser would resolve the short (never done this, so that's just a guess), but when the train was leaving the reversing section the polarity would get switched under the train, so it would immediately reverse itself, until it tried to leave the other end, where it would reverse itself.....

In DCC the phase can be reversed under the train, and it will continue in the same direction, that's why it works in DCC, but won't in DC.

Jeff But it's a dry heat!

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Posted by Medina1128 on Saturday, October 23, 2010 2:13 AM

I was interested in the auto reversers, but was told that they only work with DCC, is this true? Yes, my layout is "old school" DC.

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Posted by steamfreightboy on Thursday, October 21, 2010 5:15 PM

Vail and Southwestern RR

Check your gaps.  If you moved things, something could have shifted.

Okay, I will.

"It's your layout, only you have to like it." Lin's Junction
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Posted by Vail and Southwestern RR on Thursday, October 21, 2010 4:48 PM

Check your gaps.  If you moved things, something could have shifted.

Jeff But it's a dry heat!

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Posted by richhotrain on Thursday, October 21, 2010 3:18 PM

steamfreightboy

 richhotrain:

 steamfreightboy:

I check and it seems like everything is wired right. Should I try disconnecting it and starting over?

 

If you are absolutely convinced that it is wired correctly and the ends of both rails are gapped at either end of the reversing section, then you might check the suggestion to try turning the adjustment screw on the AR-1 counter clockwise.  This reduces the trip current before the AR-1 switches the phase.  If that doesn't solve the problem, let us know.  No point in having a non-functioning layout.  Just out of curiosity, how many sets of feeder wires are there inside your reversing section.  I ask because if there are not too many, you can easily trace the few feeder wires you have to be sure that none are connected to the main layout bus wires.

Rich

 

There is only one set of feeders going to the section and I checked the entire run of the wires from ar1 to the section as well as the ar1 to bus connection and it was hooked up acording to the diagram. I'll play around with the trip current.

If you still have a problem after turning the adjustment screw on the AR-1, disconnect the AR-1 and innstall a DPDT switch in its place.  If that works, then something is wrong with the AR-1.  If it still doesn't work, something is wrong with your wiring.

Rich

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Posted by steamfreightboy on Thursday, October 21, 2010 3:09 PM

richhotrain

 steamfreightboy:

I check and it seems like everything is wired right. Should I try disconnecting it and starting over?

 

If you are absolutely convinced that it is wired correctly and the ends of both rails are gapped at either end of the reversing section, then you might check the suggestion to try turning the adjustment screw on the AR-1 counter clockwise.  This reduces the trip current before the AR-1 switches the phase.  If that doesn't solve the problem, let us know.  No point in having a non-functioning layout.  Just out of curiosity, how many sets of feeder wires are there inside your reversing section.  I ask because if there are not too many, you can easily trace the few feeder wires you have to be sure that none are connected to the main layout bus wires.

Rich

There is only one set of feeders going to the section and I checked the entire run of the wires from ar1 to the section as well as the ar1 to bus connection and it was hooked up acording to the diagram. I'll play around with the trip current.

"It's your layout, only you have to like it." Lin's Junction
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Posted by Vail and Southwestern RR on Thursday, October 21, 2010 9:57 AM

steamfreightboy

I check and it seems like everything is wired right. Should I try disconnecting it and starting over?

Checked with your eyes or checked with a meter?

Jeff But it's a dry heat!

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Posted by richhotrain on Thursday, October 21, 2010 8:24 AM

steamfreightboy

I check and it seems like everything is wired right. Should I try disconnecting it and starting over?

If you are absolutely convinced that it is wired correctly and the ends of both rails are gapped at either end of the reversing section, then you might check the suggestion to try turning the adjustment screw on the AR-1 counter clockwise.  This reduces the trip current before the AR-1 switches the phase.  If that doesn't solve the problem, let us know.  No point in having a non-functioning layout.  Just out of curiosity, how many sets of feeder wires are there inside your reversing section.  I ask because if there are not too many, you can easily trace the few feeder wires you have to be sure that none are connected to the main layout bus wires.

Rich

Alton Junction

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Posted by steamfreightboy on Thursday, October 21, 2010 7:52 AM

I check and it seems like everything is wired right. Should I try disconnecting it and starting over?

"It's your layout, only you have to like it." Lin's Junction
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Posted by richhotrain on Thursday, October 21, 2010 7:02 AM

steamfreightboy

I am pretty sure that it is wired correctly but I'll go check. I'll keep you posted.

steamfreightboy,

Where are you?

What happened?

Rich

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Posted by Vail and Southwestern RR on Wednesday, October 20, 2010 4:53 PM

steamfreightboy

I have a reversing loop with an AR1 on my layout. I was running my E7 the other day and when I tried to go through the Reversing loop I heard it trip but it still shorted. It is a 4 by 8 and I resently took the AR1 off the layout for a move and reconnected it. It worked fine before the move so I don't know what the problem is. Can someone help me?

sfb

Well, almost every time, the problem is where the hands were last.  It worked, you disconnected it, you reconnected it, and now it doesn't work.

Double check everything.  Also, perhaps in the move, you created a short somewhere.  Get your meter out, and triple check.

Jeff But it's a dry heat!

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Posted by richhotrain on Wednesday, October 20, 2010 4:09 PM

If you do have your layout wired similar to the diagram above and are still getting booster tripping problems:

 Try turning the adjustment screw on the AR-1 counter clockwise.  This reduces the trip current before the AR-1 switches the phase.  Your AR-1 manual will tell you how to do this. 

(This bit of advice is attributable to DigitalGriffin)

Rich

 

Alton Junction

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Posted by richhotrain on Wednesday, October 20, 2010 4:03 PM

This diagram may help.

Alton Junction

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Posted by steamfreightboy on Wednesday, October 20, 2010 3:59 PM

I am pretty sure that it is wired correctly but I'll go check. I'll keep you posted.

"It's your layout, only you have to like it." Lin's Junction
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Posted by richhotrain on Wednesday, October 20, 2010 3:55 PM

steamfreightboy

I have a reversing loop with an AR1 on my layout. I was running my E7 the other day and when I tried to go through the Reversing loop I heard it trip but it still shorted. It is a 4 by 8 and I resently took the AR1 off the layout for a move and reconnected it. It worked fine before the move so I don't know what the problem is. Can someone help me?

sfb

This has become a recurring question as of late.  To operate properly, the reverse loop must be isolated (both rails on each end of the reversing section must be gapped) from the rest of the layout.  No feeder wires from the reversing section can be wired to the bus wires for the main layout.  The main layout bus wires feed into the input side of the AR1.  From the output side of the AR1 a separate set of bus wires must be used to power the reversing section.  Within the reversing section, multiple feeder wires may be used but all of the feeder wires in the reversing section must be connected to that separate set of bus wires on the output side of the AR1.

Rich

Alton Junction

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Reverse loop question
Posted by steamfreightboy on Wednesday, October 20, 2010 3:32 PM

I have a reversing loop with an AR1 on my layout. I was running my E7 the other day and when I tried to go through the Reversing loop I heard it trip but it still shorted. It is a 4 by 8 and I resently took the AR1 off the layout for a move and reconnected it. It worked fine before the move so I don't know what the problem is. Can someone help me?

sfb

"It's your layout, only you have to like it." Lin's Junction

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