I am not sure which track you are talking about. Can you mark it somehow?
The section of track that I colored red is the reversing section. Why can't you use that track as such?
Rich
Alton Junction
CTConrailbut it won't matter which turnout I use to enter the reversing track and what direction I come from will it?
Correct, the reversing section only gets power from the AR and is electrically isolated from the main bus.
Henry
COB Potomac & Northern
Shenandoah Valley
BigDaddyCorrect, the reversing section only gets power from the AR and is electrically isolated from the main bus.
Thanks Henry...I'm sure I will have a better mental handle on this once I actually start wiring. Its easier for me to have things in front of me to reference and physically see.
richhotrain I am not sure which track you are talking about. Can you mark it somehow? The section of track that I colored red is the reversing section. Why can't you use that track as such? Rich
Yes the reversing track which you highlighted is what I meant. My question was it doesn't matter which direction or which of the 2 turnouts I use, the AR still works either way.
CTConrail richhotrain I am not sure which track you are talking about. Can you mark it somehow? The section of track that I colored red is the reversing section. Why can't you use that track as such? Rich Yes the reversing track which you highlighted is what I meant. My question was it doesn't matter which direction or which of the 2 turnouts I use, the AR still works either way.
As to your question, you will need to gap the ends of two turnouts to isolate the reversing section. In the crude little diagram that follows, it is a highly simplified version of your layout showing only the affected sections of track and the two turnouts that form the entry/exit points to/from the reversing section.
The red/blue horizontal lines at the top of my diagram are those outer and inner mainlines shown at the top of your track diagram. The black circles represent the gaps (or insulated rail joiners). The two rails are colored red and blue to show polarity. The black circle on the right identifies the point of opposite polarity where different colored rails meet. The black circle on the left is the other location that must be gapped to isolate the reversing section.
I have shown three pairs of feeders inside the reversing section to illiustrate how the auto-reverser is wired. Trains entering and exiting from either direction will run without hesitation through the reversing section. The auto-reverser will instantly detect mismatched polaroties and flip them to match inside the reversing section with the polarity of the adjacent non-reversing section that triggers the auto-reverser.
Like several others, I tried to tackle this problem but the trackplan was just too difficult to decipher; even the simplified view that Randy suggested.
So I'd ask for even more simplification: remove all stub spur tracks and all obviously parallel sidings and remove the buildings and landscape colorations. And when I say remove, I don't mean eliminate and toss away. AutoCAD allows me to turn layers on and off to isolate certain features and de-clutter the view. I don't know if the software the OP is using allows something similar.
Some have said this layout is a folded dogbone, but it looks more like an oval that has one side kinda stoved in and pushed under the far side. With the added adventure that a single track snakes off and joins the curve on the opposite side in the SW quadrant of the layout. I think this creates a reversing loop. There may be two or three others. I dunno. It takes a lot of mental activity and I am willing to help, but I just can't get very far.
One thing I will mention is that there is no rule that says you can't have more ARs than you really need. Simply gap and isolate discrete sections of track in suspicious areas. The AR will reverse polarity when it needs to and won't when it doesn't. Might cost a bit more, but imagine how many headaches can be solved with forty or fifty dollars.
Also, I second the opinions to use electronic PSX reversers instead of the mechanical Digitrax ARs. There is a small little tiny delay with the Digitrax; not huge, but noticeable and annoying.
Keep at it. I will continue to follow along.
Robert
LINK to SNSR Blog
When all is said and done, this is what it looks like you have:
All the crossovers and double crossovers and turnouts and sidings and turntables and whatnot do not add anything to the issue.
I need somebody to verify if my reduction is correct.
Robert, if that were your track plan, then it would depend upon how you wired the two ovals. If both ovals were wired the same way, a reversing section would be created. But if the two ovals were wired the opposite way from one another, there would be no reversing section.
But, if they were wired the same, such as that was the only reversing section, you could have all the crossovers you wanted between the two loops and no more reverse sections would be created. If you wire the two loops such that that wouldn't be a reverse section, then every simple crossover would be a reverse section, and be too short to really use an autoreverser on.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker But, if they were wired the same, such as that was the only reversing section, you could have all the crossovers you wanted between the two loops and no more reverse sections would be created. If you wire the two loops such that that wouldn't be a reverse section, then every simple crossover would be a reverse section, and be too short to really use an autoreverser on. --Randy
Yes, exactly.
I vote to put insulated gaps on both rails at both ends of the red track and attach the output from the AR to make that the reversing section. Leave the green ovals with whatever crossovers and sidings as needed.
But there is another issue . . .
With only one reversing 'loop', once a train reverses itself by taking one of the facing turnouts, it won't be able to un-reverse itself unless it backs down through a trailing turnout.
rrinker If you wire the two loops such that that wouldn't be a reverse section, then every simple crossover would be a reverse section, and be too short to really use an autoreverser on.
If you wire the two loops such that that wouldn't be a reverse section, then every simple crossover would be a reverse section, and be too short to really use an autoreverser on.
But, Robert's track plan bears no resemblance to the OP's track plan, so I'm not sure what it adds to the discussion.
richhotrain But, Robert's track plan bears no resemblance to the OP's track plan, so I'm not sure what it adds to the discussion. Rich
Um . . . yeah.
My little green-and-red sketch took the OP's trackplan and reduced it to its essential elements, and in doing so it provided me the clarity to answer the OP's original question.
Sorry that it was too abstract.
Thanks guys this all helps very much and I appreciate all of you taking the time. This is what I can't wrap my dcc novice of a noggin around for some reason. I attached my "simplified" (if you can call it that) track plan with notations.
If the train enters the reversing track from the South main (left side) and exits onto the North main (right side) the polarity will flip when it enters to match the main. What happens when it comes to the end of the reversing track and exits the isolated reversing track and the north main is different polarity than the reversing track the engine is on? Is this one of those things that the AR just works and that's all I really need to know? Lol I guess I just have a hard time getting my mind out of DC mode.
CTConrail Thanks guys this all helps very much and I appreciate all of you taking the time. This is what I can't wrap my dcc novice of a noggin around for some reason. I attached my "simplified" (if you can call it that) track plan with notations. If the train enters the reversing track from the South main (left side) and exits onto the North main (right side) the polarity will flip when it enters to match the main. What happens when it comes to the end of the reversing track and exits the isolated reversing track and the north main is different polarity than the reversing track the engine is on? Is this one of those things that the AR just works and that's all I really need to know? Lol I guess I just have a hard time getting my mind out of DC mode.
An engine equipped with a DCC decoder does not care what the polarity of the track under its wheels is; whether it's +/- or -/+. When the throttle says 'Forward', the decoder takes whatever power it picks up from the rails and arranges it to make the wheels roll forward. When the throttle says 'Reverse', the decoder takes whatever power it picks up and makes the wheels roll backwards.
When a train enters a reversing section and the polarities of the main and the reversing section are different, the front wheels of the front truck of the engine cause a short against the rear wheels of the front truck. The AR recognizes the short and reverses the polarity of the rails in the reversing section. This happens in a matter of milliseconds and is not discerned by the human eye.
When the train exits a reversing section and the polarities do not match, the AR recognizes the short and the polarity of the rails in the reversing section are reversed.
If the polarities of the rails on the main and in the reversing section are the same (which happens half the time), nothing happens as the train crosses the gap.
Hope this helps.
CTConrail If the train enters the reversing track from the South main (left side) and exits onto the North main (right side) the polarity will flip when it enters to match the main. What happens when it comes to the end of the reversing track and exits the isolated reversing track and the north main is different polarity than the reversing track the engine is on? Is this one of those things that the AR just works and that's all I really need to know?
If the train enters the reversing track from the South main (left side) and exits onto the North main (right side) the polarity will flip when it enters to match the main. What happens when it comes to the end of the reversing track and exits the isolated reversing track and the north main is different polarity than the reversing track the engine is on? Is this one of those things that the AR just works and that's all I really need to know?
So, the job of the auto-reverser is to match the polarity of the reversing section to the moving train. The auto-reverser makes a binary decision each time a train crosses the gap entering or exiting the reversing section. The polarity of the reversing section either matches the adjacent non-reversing section or it doesn't match the adjacent non-reversing section. The function of the auto-reverser is to ensure a match.
Yes this helps me to understand that better thanks guys. As I said its like I have to retrain my brain to not think in DC terms lol. Going to order my PSX this week. I have noticed I have found multiple. DCC specialties AR models like the PSX-ARFB, PSX-AR OG-AR and maybe 1 or 2 more. I am guessing they have other functions built in in addition to the Auto reversing?
Nick
CTConrailYes this helps me to understand that better thanks guys. As I said its like I have to retrain my brain to not think in DC terms lol. Going to order my PSX this week. I have noticed I have found multiple. DCC specialties AR models like the PSX-ARFB, PSX-AR OG-AR and maybe 1 or 2 more. I am guessing they have other functions built in in addition to the Auto reversing? Nick
The DCC Specialties website seems to have gone away
This page on Tonystrains.com list differences for 4 of their models
https://tonystrains.com/product/dcc-specialties-psx-arscfb-power-shield-auto-reverser-circuit-breaker
Thank you! Without getting too off topic....when it comes to powered turnouts which I will only have in hard to reach spots and on this reverse track. I don't plan to use them with my power cab, at least not anytime soon. just going to use individual switches to flip them. Can I use a seperate 12v power supply to power the motors or will that screw with or mess up any of the DCC components?
A separate DC power pack for turnout motors, control panels, signals, etc. will not interfere with the DCC components. I have a series of 18 volt MRC 1370 power packs spread across my DCC powered layout for such purposes. No problem.
richhotrain A separate DC power pack for turnout motors, control panels, signals, etc. will not interfere with the DCC components. I have a series of 18 volt MRC 1370 power packs spread across my DCC powered layout for such purposes. No problem. Rich
Thanks Rich. Didn't think so but had to be absolutely sure.
Ok so another question as I have been slowly laying track and don't want to have to find out I should have done something different. In essence this shoukd probably be a new thread topic but I figured since those who have helped me already may already be slightly familiar with my track plan Ill ask here. Where else should I isolate. Power districts? I was thinking 1 for the mains, 1 for the union station area, 1 for the yard, 1 for the harbor area and street running section and 1 for the engine servicing facility which woukd make for a total of 5. Does this seem like a viable plan? For a better look at my whole track plan refer to page 1 or I can post it again if need be. Is there anywhere else I should isolate other than a programming track? Thanks again guys.
One of the advantages of power districts is to keep trains running on the mainline should a short occur in a yard or train station or engine servicing facility, just to name a few. In effect, a reversing section is its own power district so if you turn the mainlines into a separate power district, you will now have two of them. The rest of the layout could be the third power district if you add a circuit breaker there as well. Whether you need another two power districts depends upon how many operators you anticipate. If you operate as a lone wolf, three power districts may be enough.
richhotrain One of the advantages of power districts is to keep trains running on the mainline should a short occur in a yard or train station or engine servicing facility, just to name a few. In effect, a reversing section is its own power district so if you turn the mainlines into a separate power district, you will now have two of them. The rest of the layout could be the third power district if you add a circuit breaker there as well. Whether you need another two power districts depends upon how many operators you anticipate. If you operate as a lone wolf, three power districts may be enough. Rich
Ok thanks Rich. The reason I mentioned 5 was to have the layout broken down into more sections to more easily be able to isolate and pinpoint any potential shorts if and when they occur. But I guess less districts would work fine as well.
CTConrail Ok thanks Rich. The reason I mentioned 5 was to have the layout broken down into more sections to more easily be able to isolate and pinpoint any potential shorts if and when they occur. But I guess less districts would work fine as well.
I mean technically, if you only operate by youself, you don't need any power districts, the only one you will inconvenience by derailing or running a turnout set the wrong way is yourself.
But even 5 amps to the track is enough to melt things if not caught, so dividing things into multiple sections with a lower current limit is ALWAYS a good idea.
If you install a PSX-AR on that reversing section, the PSX-AR is both an auto-reverser and a circuit breaker, so the reversing section will be its own power district. The rest of the layout will be a booster district unless you divide the rest of your layout into separate power districts.