Well Guys-n-Gals,
Hope all is well with not only your layouts, but your health and lives as well, I have a question, I installed an Atlas DPDT switch for a Reversal loop, since I don't have the money to buy a reversal loop decoder I thought I would use an old Atlas DPDT, that I had in my parts box, well I sodered all connections, the way it is on the diagram,I screwed the other wires to the DC power pack,which is a jump port to my Zephar, did I mention I'm running DCC? I placed my insulated rail joiners in the right places on the track, ran a loco, it ran slowly, (the loco is anolog,) it ran (slowly) across the 1st connection to the DPDT and sparked!!!! I didn't want to fry my loco, so I just stop there, and figuerd It's not meant to have a reversal loop on the layout, Want could be the problem?????? Thanks Trainsrme1
Wait, What??? Say HUH?
**Looks utterly bewildered**
**Scratches head**
Do I understand you correctly?
**Shakes head**
OK, first, the basics. Do you have the DCC track wires connected to the "inputs" on the DPDT? And from the "outputs" to the reverse loop? What is the power pack hooked to? Is it just providing power to "flip" the switch?
You do *NOT* want DCC on one set of rails and DC on the others. You'll need DCC on everything. While most will suggest an auto-reverse module, we got by just fine for *years* using a DPDT for DC based reverse loops. The key is to ensure correct polarity for whichever way you are entering/exiting the reverse section, just as we did for ages. The A/R module just does this for us automatically. But I see no reason it can't be done with the DPDT switch/relay, as long as it's set up to reverse with the corresponding turnout (fairly straightforward if using Atlas/Peco twin-coil switch machines). All that's left is to ensure the polarity matches for the direction the turnout is set.
**Still rubbing his forehead**
Brad
EMD - Every Model Different
ALCO - Always Leaking Coolant and Oil
CSX - Coal Spilling eXperts
You can have a reverse loop on your layout, you just have to wire it correctly.
If you are running in DCC, the input side of the DPDT switch should be wired to the main bus, not a DC power pack. The output side of the DPDT should be wired to the rails somewhere inside the isolated reversing section. The DPDT switch should be thrown before the loco enters the reversing section to prevent a short.
I cannot address the issue of running an analog loco on a DCC layout other than to say that I wouldn't do it.
Rich
Alton Junction
If the toggle is in the wrong position when you cross into the loop, you will get a spark and a dead short. If it's in the right position, you should cruise across the gap just fine. You must then flip the toggle once the train is entirely in the loop so the polarity will match on the other side.
But, there's something you should know. This isn't going to work on analog engines, only DCC decoder-equipped engines. Analog engines are still running DC. When you flip the toggle, they will reverse.
It takes an iron man to play with a toy iron horse.
LION does not use a switch for this purpose. First you gap the tracks right at the switch. (Think a Tortoise Machine with extra contacts on it---otherwise use a relay of some sort) The loop gets its power from the switch machine according to which way the switch is aligned. You probably want to stop your train on the loop when you move your switch points.
The other way to do it is backwards but works just fine: You apply your power to the LOOP and allow the mainline to be powered by the loop depending on the position of the loop switch. I did this for staging yards for years. Works great.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Tear it out and start over. Buy a real DPDT switch, the Atlas switches are very cheaply built. Do not connect ANYTHING to any DC power. At this moment in time I do not have access to a diagram that shows how to wire the switch, but I'm sure someone will post one soon. It is very simple. You then need to mount the switch so that the direction it should be thrown is obvious to any user.
Dave
Lackawanna Route of the Phoebe Snow
A DPDT switch has three pairs of terminals in a row.
The two outer pairs of terminals are cross wired to form a X pattern.
The center pair of terminals connect to the rails somewhere inside the reversing section with two feeder wires.
The two feeder wires that connect to the bus wires can be attached to either pair of outside terminals.
Follow Rich's idea, however connect the imput side wires to the buss as already mentioned, not the dc powerpack. As already stated when you throw the switch with the loco in the revers section, the loco will change direction, so you have to change the direction on the zephyer to keep going in the right direction.. When running a dc loco with a Zephyer, the loco cannot be run through a reversing section that has an auto reverser, it will stop at one of the ends depending on how the reverser has the power set.
You received very good advices so far, all I will add is that you are a lucky one, if you did not smoke the Zephyr.
Jack W.
At this point, you have the possibility of destroying multiple pieces of electronic equipment. So stop.
Take the time to read and learn how to wire a layout for DCC:http://www.amazon.com/Basic-Wiring-Your-Model-Railroad/dp/0890247935
The street price of an autoreverser is around 25 bucks. Is saving that $25 worth risking your other gear?
Layout Design GalleryLayout Design Special Interest Group
You have a good point, I thought they were alot more than that! If that is all they costt, than I'll go that route, Thanks!!!!
There's absolutely nothing wrong with using a DPDT switch with DCC. It's just - you don't have to have that manual action, it's possible to automate things, and an autoreverser isn;t the only way. You cna also do this with switch machine contacts.
What I don;t get is the disconnect that made you think this should be installed anywhere connecting the jump ports on the Zephyr, instead of simply in with the track power exactly as shown for wiring one for DC. It's more 'traditional' in DCC to have the switch in the isolated reverse section, but there is no technical reason why a reverse loop toggle in the main, the same way it was done in DC, would not work. The only real different here is that with DCC, you can change the 'polarity' under a moving train and nothing happens - it will keep moving in the same direction, since with DCC the polarity of the track has nothing to do with the direction of movement.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinkerThere's absolutely nothing wrong with using a DPDT switch with DCC.
Agreed -- if the builder understands basic DCC technology and remembers to throw the DPDT switch at the right time (or wires the switch machine connections properly if going that route).
But without a basic fundamental understanding of how DCC works, the odds of a first-timer getting that right are somewhat low -- and the Original Poster seems to have some gaps in his basic DCC understanding which have led to errors such as connecting both the DCC booster output and DC power pack output directly to his layout at the same time.
rrinker It's more 'traditional' in DCC to have the switch in the isolated reverse section, but there is no technical reason why a reverse loop toggle in the main, the same way it was done in DC, would not work.
Well, yeah, but there are still reasons not to do that. It depends on what you mean by "work."
If you put the toggle on the main, you will be interrupting all of the engines on the main every time you flip that toggle. This may be fine for some, but electrically speaking, the time it takes you to get from one side of the toggle to the other, across the "dead zone," is an eternity. This will cause engines to stop and sound systems to go back to startup if it takes too long. All your passenger car lights will wink off for a moment, too, which isn't an effect you want.
What's more, you will be putting the full power load of the layout, minus the loop, across the contacts of the toggle. Eventually, that will wear out the toggle with arcing, if you are running enough stuff.
If you decide to replace the toggle with an autoreverser, you'll have a different problem. Most autoreversers have limited capacity. Instead of the 5 amps, for example, that your DCC system provides, an autoreverser might only have 2 amps. So, if you've got your whole layout on the autoreverser you would be severely limiting your available power.
I was a little surprised that Randy even mentioned that about the toggle on the main.
Why would you want to do that, especially if you are a newbie?
richhotrain Why would you want to do that, especially if you are a newbie?
Well, to play Devil's Advocate....
If you had two reverse loops connected by a single length of track, then you could put the toggle on that track and it would be the more efficient system. Of course, that assumes you're only running one train and you'd never be entering / leaving both loops at once.
If the loop isn't "simple," but instead contains a yard or engine facility, then the track attached to the loop might actually be more significant in terms of power draw than the rest of the layout.
And then, there's that DC engine from the original post. You can't run a DC engine on DCC through an autoreverser, or through a toggle-controlled reverse loop, but it will work, with some conditions like what direction you run through the loop, if you put the toggle on the main.
Why? because if you had the layout wired for DC, you'd have it that way. Repalce the power pack with a DCC system, and you CAN operate the layout just as before. It's not the BEST option, but it does work - again because DCC doesn't really care. Just flip the switch once the entire train is in the reverse loop - the exact same way you had to do it for DC. No, this is not practical on a large layout, especially with multiple power districts and multiple operators, but the OP mentioned buying the Atlas components, and you definitely CAN take one of Atlas's plans, with the wiring diagrams as shown, and swap out the power pack for a DCC booster and start running trains.
As for current - I dunno about the others, but the relay used on the AR1 is rated for 8 amps (and UL rated for 20000 operations with a 10 amp continuous load on the contacts, at 85C, keep the load down and it's rated for greater than 30,000,000 mechnical operations) (yes, I dug up a large enough clear photo of an AR1 and found the datasheet for the relay used - I'm crazy like that ). There does seem to be a tendency to confuse capacity with actual load - just because you have a 5 amp booster doesn;t mean there's 5 amps in the circuit. If a train is exiting a reverse loop there hopefully won;t be another train right there on the main - unless you are playing Gomez Addams on purpose. The OP sounds pretty much like this is a solo opereation with just one train going, so it makes not one wit of difference if the switch if reversing the loop trackage or the main. As the layout gets bigger and more throttles are added - certainly it makes more sens to control the loop and not the main, but the primary point is, the Atlas product could be wired exactly as shown in the instructions and it would work. My main point was trying to figure out how a diagram showing this reversing switch wired between the main and the power pack got translated to wiring it between the main and the jump throttle terminals on the Zephyr.
rrinkerJust flip the switch once the entire train is in the reverse loop - the exact same way you had to do it for DC.
Actually, I think you'll find that you need two DPDTs with DC if you want to keep the train in motion into and exiting from the reversing connection and trains move through it in both directions.
Not that this has anything to do with OP's issue.
This thread has annoyed me a little bit. I see tons of assumptions in almost all the posts and other than Randy's none are answering the OPs question.
A manual reversing loop control works exactly the same in DCC as it does in DC. I don't understand why some insist that it is "so hard" with DCC -- it is identical. How can a circuit that served the model railroading industry for over 60 years suddenly be too hard to deal with?
Second the OP is not a newbie. Newbies don't have Altas controllers sitting around in a junk box. Had he connected the reversing switch unit to the output of the Zephyr instead of the output of the jump-port throttle it would have worked perfectly and this thread would not have existed.
My assumption is that the OP is using the Atlas 220 Controller. If so the unit DOES have two DPDT switches built into it.
So to the OP, are you using the Atlas 220, and did Randy's response answer your question such that your loop is working right now?
cuyama rrinkerJust flip the switch once the entire train is in the reverse loop - the exact same way you had to do it for DC. Actually, I think you'll find that you need two DPDTs with DC if you want to keep the train in motion into and exiting from the reversing connection and trains move through it in both directions. Not that this has anything to do with OP's issue.
True, with a self contained power pack, since you can;t (easily) tap in ahead of the direction switch. Too much reading old MR, building cabs with a total of 2 reversing switches because you built the whole works yourself and so could wire everything as needed. Then there were always those MRC packs which already had a second direction switch for reverse loops...
Texas Zepher This thread has annoyed me a little bit. I see tons of assumptions in almost all the posts and other than Randy's none are answering the OPs question. A manual reversing loop control works exactly the same in DCC as it does in DC. I don't understand why some insist that it is "so hard" with DCC -- it is identical. How can a circuit that served the model railroading industry for over 60 years suddenly be too hard to deal with? Second the OP is not a newbie. Newbies don't have Altas controllers sitting around in a junk box. Had he connected the reversing switch unit to the output of the Zephyr instead of the output of the jump-port throttle it would have worked perfectly and this thread would not have existed. My assumption is that the OP is using the Atlas 220 Controller. If so the unit DOES have two DPDT switches built into it. So to the OP, are you using the Atlas 220, and did Randy's response answer your question such that your loop is working right now?
TZ, your reply has annoyed me a little bit.
First, why are you annoyed? It seems to me that most, if not all, of our replies addressed the OP's question. The question was: what's the problem? Answers to that question have been provided. Speaking of which, I don't see anywhere in your reply where you answered the OP's question.
Second, you object to the term "newbie". Since I mentioned the word in my reply, you are obviously annoyed with me. But if you read my reply, I did not call the OP a newbie. I mentioned that word in response to Randy's reference to wiring a DPDT to the main line rather than the reversing section, suggesting that it could confuse a newbie. There are a lot of self-admitted newbies lately who participate in this forum and might well be following this thread.
Third, you feel that some insist that it is "so hard" to wire a DPDT in DCC. Actually, no one said it was so hard. Only you used the term "so hard".
Why get so worked up over such a trivial matter? Personally, I feel that this is one of the more interesting and informative threads currently running on the Electronics and DCC forum.