So pretty much I was correct then on the turnouts I was thinking? You just extended the red highlighted track up to the very beginning where the northbound passing track starts but do I have to put the auto reversing unit wired to that turnout or can I put it where I circled then left side turnout?
The track between the turnouts is the reversing section, one autoreverser per reverse section. You don’t need a reverser for each turnout , just the track connecting them. Insulated joiners go between the turnout and the track that is the reversing section, the turnout itself is electrically part of the track that comes before them.
It’s easiest to visualize the simple example of an oval with two turnouts and a diagonal line through the middle. The digonal track is the reversing sections, the insulated joiners or gaps are cut on the diverging side of each turnout, the turnouts themselves are part of the oval, not isolated from it. The diagonal track is then isolated from the rest of the track because of the gaps, it gets its power from the autoreverse unit.
–Randy
I have been taking a closer look at your track diagram, and I think that there is a simpler solution to the reverse polarity issue. Whenever reverse polarity situations occur, there is often more than one way to wire the layout, and the method chosen dictates where to isolate and gap the reversing section. A good example of this is the link provided early by Randy, showing two alternative wiring methods.
In your particular situation, you were pretty close with your track diagram with the two green circles. The section of track between those two green circles could be the reversing section. To accomplish this, you would need to wire the rest of the layout in phase.
For example, looking at the top of your track diagram, there are two tracks, an outer track and an inner track. If you wire both of these tracks in phase, say blue feeder wires on the top rail and red feeder wires on the bottom rail and continue this wiring protocol as you work your way down the layout, the only point of opposite polarity is where the outermost track connects at the green circle on the lower right.
In the track diagram that follows, the section of track colored red becomes the reversing section. You would isolate the reversing section by cutting gaps (or inserting insulated rail joiners) at the turnouts marked by the green circles. One auto-reverser would control that reversing section.
Rich
Awesome thanks guys! Thats exactly how I will do it then. In my mind I keep wanting to carry over DC wiring methods to this layout as I am as I said a DCC noobie. I will get morr used to it as time goes on. Someone asked me about when I said the AR1. I meant the Digitrax AR1 reversing unit which is what I planned to use.
At one time, I used Digitrax AR1s on my layout, and they worked just fine with my NCE PH-Pro 5 amp system. But, when I later installed solid state circuit breakers to protect power districts, the relay-controlled AR1 proved too slow and incompatible, so I had to switch to the solid state PSX-AR. The PSX-AR is more expensive than the AR1, but it is worth it and the PSX-AR is totally compatible with the NCE Power Cab.
Rich
Wiring a DCC-powered layout with one or more reversing sections is not necessarily complicated, but the wiring protocol needs to be thought out in advance to plan where the reversing section(s) will be and how many reversing sections may be needed. And, the reversing section needs to be longer than the longest train using the reversing section.
Rich
Ok then I will probably go with that since I only need 1 anyway. Now I just need to figure out if I will need a booster. I have the Power Cab starter set…2 amps. I guess that all depends on how many engines I will run at once i would say probably not more than 8 which is the guideline I saw for N scale for the Power Cab. More than 8 engines will require a booster. A few of my trains will have multiple engine consists though. Eventually I will probably get one but I am hoping I can get by without it for now. 7.5x9 foot layout but there is a lot of trackage as you all can see.
Just add the NCE SB5 Smart Booster to your NCE Power Cab. If you are going to run 8 locos plus a few more locos in consists, you are going to need more amps.
How far along are you with your track work and wiring?
Rich
No I meant no more than 8 including the trains with multiple engine consists. Probably 2 passenger trains, a 3 engine freight and a switcher so 4 trains and even that will probably prove too much for me to handle at once. I will probably get the SB5 at some point but was hoping to get by without it for a while. I just started laying track last week. Still short on some turnouts so I need those to come in. As far as wiring I have not done any yet. Hoping to run my bus lines after the weekend but I need to go get some 16ga wire.
Honestly it will probably be a bit before track is fully laid. The hidden track under the viaduct needs to be all done with a way to access it for cleaning and derailments before I can build and lay track on the viaduct above.
Hey quick question for you Rich…I was looking at the picture again and my reversing track that you traced in red. Unfortunately I could only fit 1 reversing track which is off of the southbound main and then ends up connecting back at the north main (which will simulate passenger trains returning from New York City) This may be a dumb question but it won’t matter which turnout I use to enter the reversing track and what direction I come from will it? No matter what the AR will switch polarity if needed right? I am just trying to visualize how it will need to be wired.
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
Correct, 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.
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.
Ahh, when you used the word “unfortunately”, I thought you meant that you couldn’t use that track as the reversing section.
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.
Rich
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
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.
Rich
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.
Robert