Hi, Everyone
I have three reverse loops on my layout. Two of them I have wired using DCC Specialties PSX-AR reverse boards and I have absolutely no issues with them (I first installed them in 2004.)
I never got around to wiring the third reverse loop until now, more of a wye actually, at my engine terminal area and I looked at PSXs again and see they're going for around $55 so I'm looking at the Digitrax AR1 at about half the price. http://www.digitrax.com/products/autoreversing/
Aside from the mechanical relay over solid state my question is what is the advantage to using the PSX-AR over the AR1 or is there any? This unit will only see occasional use and I don't find a click of a relay all that objectionable. Like I said, the PSXs are great, and silent, but at over twice the cost? http://www.tonystrains.com/products/type_powerprotect.htm
Also, the Digitrax documentation says the AR1 works with OR without Loconet. I do not see a Loconet plug on the AR1 so what do they mean by that?
Thanks, ED
I don't recall the details but on my modest 5 x 10 HO layout I needed 3 subdistricts on my planned DCC (NCE in my case) system as I had 2 reversing loops and a short mainline in between. I called Tony at Tony's Train Exchange and he listened to my plans and pointed out that in my modest, straightforward case the inexpensive OG-ARs (for reversing loops) and OG-CB (for the mainline section) were all I needed for my simple case, as opposed to more expensive items that would accomplish the same thing.
I forget what the more expensive items can handle that the cheaper ones maybe don't, not relevant in my case, but my points are that you may have a 3rd option, and perhaps more importantly if you're not an expert a conversation with Tony (why not?) can take out the guesswork. In my case, everythng has worked as advertised and I did not have to figure it all out (technically) on my own, which I could not do last year when diving in.
Paul
Modeling HO with a transition era UP bent
Both will work fine. The AR-1 has a small relay, and a 'pot' for setting the trip current level. The PSX-AR has configurable trip settings on the unit and is solid state. I consider the PSX-AR to be a little more 'HD'. That said, I have an AR-1 on my home layout that has been there since the late 90's - Still going strong. We did have an AR-1 start to fail on the club layout, but having to handle 3-4 unit consists wil the old QSI sound decoders that really suck juice really gave the AR-1 a workout over the past 8 years. I replaced it with an PSX-AR last summer and have not had a train stall going through the reverse loop since.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
I have mixed feelings about how to advise you. If you already have two PSX-AR units on your layout, it probably makes good sense in spite of the fact that the PSX-AR is twice the price of an AR-1. The PSX-AR is both an auto-reverser and a circuit breaker, for what that is worth. And, it is solid state as opposed to a mechanical relay, as you point out.
That said, I have five Digitrax AR-1 units on my layout, and all have performed flawlessly for years. I conceal each of them inside nearby structures, and I don't even hear the click, and I have pretty good hearing.
Rich
Alton Junction
I have 7 AR-1's that I installed last winter and after slight adjustment on each they work flawlessly. I don't even hear the slight click anymore. One of them controls a PECO double crossover with no problems so at this point I am glad I used the DigiTrax AR-1's and the cost was reasonable for me. Doug
I have an older PS-REV, the predecessor to the PSX-AR units. It is on a too-short crossover from one corner of an oval to the other. So, particularly now that I've converted almost all my rolling stock to metal wheels, occasionally a moving train has both ends on the gaps simultaneously. Most of the time, the solid-state PS-REV handles this, coasting over the mometary dead short and handlng the multiple polarity flips so well that I don't even notice it, and neither do my engines.
The speed of a solid-state reverser can be imporant at times. In other applications, it doesn't matter at all.
It takes an iron man to play with a toy iron horse.
Hi, Mr. Beasley
Now that you mention the PS-REV, it reminded me that it is what I have. On the confidence in Digitrax and the good reviews of Paul, Jim, Rich and Doug I'll go ahead with the AR1 but what I'll do is use it on the seldom occupied industrial section and use the PS-REV in the engine terminal that will see more use.
I sure appreciate your input and I'm glad this forum is here as the "go-to" source for advice!
Thanks again... I'll post an update when I get the AR1 installed.
Ed
Ed.
The PSX AR units can also flip turnouts via the software and some configuration. I don't believe the AR1 can do that. The AR1 is more comparable to the OG-AR. With some configuring you can automate the wye to flip the turnouts through switch machines. It is the decoder portion that increases the costs.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
I always avoided reverse loops with DC, and since going DCC< the two layouts I have built have been around the walls affairs with little call for a reverse loop. However, my next layout will be, I hope, my "big one" that will occupy me into retirement. There will be several locations that need reverse loops of some sort (more likely wyes, and at least one turntable). My intention is to prevent the short int he first palce, and not use any sort of autoreverser. How? Here's an example:
Take a basic balloon reverse loop. One turnout. You cannot throw the switch until the train has either completely entered the loop, or completely exited the loop. If the loop track can hold 20 cars and a loco, and you try to run a 25 car train in - the loco will impace the side of the 21st car - this is a track capacity issue and has nothign to do with DC or DCC power. So assuming you run trains throught he loop no longer than the loop itself - when you throw the switch, this can also via switch machine contacts, reverse the polarity of the loop track. Since we're talking DCC - you cna change the polarity (more correctly phase) under the moving train and nothing will happen. If you are worried about the contacts on your switch motors, like a Tortoise, have it operate a relay with a greater capacity contact set. If using manual throws, you can get fairly high current snap switches and trip them with a throwbar extension, or use small ones and a relay. With such an arragement, there never is any short, the act of throwing the switch to line it for the train existing the loop also aligns the polairty on the rails across the gap. And you aren't limited to traversing the loop in one direction, the polarity of the loop rails always matches the direction of the switch points.
ALL of the autoreverse unuts operate by waiting until the wheels cross the gap and cause a short. Instead of simply cutting power like a circuit breaker, they instead first switch the polarity. If the situation is a reverse loop, that's enough to make the 'short' go away.
A turntable is a bit more complicated. A split rail pickup for the bridge tracks avoids any shorts, but it will cause sound dropouts in sound locos, keep-alive or not, because the gap int he pit rail most be wide enough to span the pickup wheelbase of the bridge wheels. Plus a split rail artificially limits where you can locate stall, lead, or garden tracks. The polarity of the bridge track only needs to change if you turn through a full 180 degrees. So you could control it with some sort of sensor and a realy - there is at least one turntable control that actually incorproates this relay, and the controller keeps track of where the bridge is, but the controller alone costs more tham most turntables, even the Walthers powered ones. I don;t intend to use any fancy power drives on my turntable, I expect to locate it right up front where you can easily visually align the track you want to go out on, so indexing will not be required. We have one like that on the club layout, it's right at the edge (kind of silly to hide a visually appealing element like that way in the back where no one sees it) and it has a simple motor drive with an old DC throttle running it. It's split rail so sounds cut out on it though. Not sure how I will tackle that without just using an autoreverser.
Wyes, no problem, the polarity can be flipped with switch machine contacts same as a basic balloon loop.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy.
What you describe is exactly what I am doing. When I converted my layout to DCC I choosed not to invest in a reverser for the reversing loop and used the Turtoise switch to inverse the polarity. At the beginning, I stoped the trains after they entered the loop before actuating the switch. One day I forgot to stop the train and everything went right, I couldn't even see the train hesitate.
Guy
Modeling CNR in the 50's
Hi, Randy
Since you mention turntables, here's the way I did it even though I have one of those NY Railway supply stepper motors. I rigged this cam and microswitch up before I had the NYRS unit and I can't remember now but it was going to be a pain to use their relay anyway, or at least it wouldn't work for MY situation.
The cam and microswitch work flawlessly, the pit rail is not split but carries one phase of the DCC and the bridge fed through the collector on the other phase. The microswitch drops arelay to reverse the pit rail and bridge every 180° and I never have to worry, the engine always moves off the turntable in the direction my throttle is set at!
The relay acts so fast that sound does not drop out either, AND I even have a lamp post at each end of the bridge powered off the rails... that looks neat.
You see the worm gear from the original Diamond Scale nylon drive. I added the NYRS system in 2003. It is not all that great. I suppose I could add the brake but I am not going to bother, there is too much slop so you still have to make the final alignment with your finger! Hard to see but the disk that looks like a CD has a raised area to make the microswitch and the phase flops in an area where I don't have any radial tracks. Works perfect!
As for using Tortoise contacts to switch A-B phase, might work but I will have three entrance/exit routes so might get tricky. For $25 I have a Digitrax AR1 coming. I'll report back when I get it installed.
Thanks everybody! Ed
Yup, that's along the lines of how I was thinking it would be possible to flip a turntable without an autoreverser and without using split rail. I like the way you have the whole works held in place with wingnuts so you can drop the entire table and mechanism out.
I have to see what brand turntable kit the one is on the club layout again. It's the correct size and style for what I need (seeing how the club layout is also Reading), the drive is the crude type with a loco motor with a rubber cap on the shaft held against a plywood disk with a spring - no indexing. But it's right ont he edge, and easy to align. The motor turns it smoothly enough, yet there is enough friction that unless you fiddled witht he DC throttle and turned it up too far, you can easily stop it in position. I may go one better and have two toggles, a fast and a slow jog, similar to what the protoype has. Much as I love gadgets and a fancy electronics package that can automatically line up every track, and even figure the quickest way to turn for any given combination of starting and ending points, and all that stuff, it's a lot of money for that stuff, though perhaps I could make my own, but there's a mechanical precision involved to make sure it truly stops where intended - doesn;t take much of a gap to put the loco on the ground. I think I'd rather not deal with it.
A complex loop with multiple exit points - yeah, figuring out all the combinations by point position might be a little tough. Friend of mine built a beuatiful Code 40 N scale double slip that also had another set of points embedded it in. Mechanically - it worked perfectly. Oh yeah, it was N FINESCALE standards too. However, trying to figure out the proper combinations for frog polarities - never could get it quite right. This was before the Frog Juicers - now I would just get a Frog Juicer and hook up each frog and be done with it, let it figure out how to set each one. Instead, he modified his track plan and eliminated the extra set of points so now it is just a standard double slip.
I prefer to not create the short in the first place - but sometimes you just have to give up and get the automatic device.