Auto reversing modules

[pacchardon]

I am planning on expanding my DCC layout. I was going to add two reverse loops that send the train back and forth with a fairly short run btwn them so they will be used heavily. Would there be any danger of the auto reversing modules overheating?

[Doneldon]

paccy-

Are you considering a single line of track on which your train will go back and forth or a track with loops at each end which will allow your train to actually reverse direction? You shouldn't need to worry about overheating either way, but you will need different electronics. For the single line you'll need the reverser which can be used with the trolley set. If you have loops you'll need a reverse loop module. Assuming this track isn't connected to any other track which might interfere and you'll only run one train at a time, one reverse loop module will work for both ends. Run a feeder from your DCC system to the connecting track and the reverse module. Then feed both loops from the module. Be sure to electrically isolate both ends of both loops. Since your train can only occupy one loop at a time, a single module will suffice. Good luck!
                                                                                                              -- D

[pacchardon]

There will be two reverse loops with a straight run in btwn. The straight run will have a double crossover to an outer loop.
From the wiring diagram for the module it would appear that I will need two modules, one for each loop and each loop will need to be isolated.

[Doneldon]

paccy-

One should suffice but I'm not certain of that when you might have other traffic
entering the system. Perhaps others can clarify this detail.
                                                                                      -- D

[pacchardon]

Thinking some more about what you said I think I understand why you are saying 1 module should handle it. We will give that a try and see what happens.

[Jim Banner]

As a rule of thumb, a single module will handle the job if you are running only one train.  The corollary is that if you run more than one train and it is almost impossible for both trains to simultaneously cross into or out of loops, they will manage to do so at the worst possible time.

Jim

[jward]

from your description it sounds like you'd only need one autoreverser. you'd locate it on the straight section between the two loops. just make sure that both of the entry switches  to the loops are part of the reversing section.

an alternate method avoids the use of autoreversers altogether, by using the contacts on the switch motor, if available, or an atlas snap relay to reverse the "polarity" of the loop tracks when the switch is thrown, this only works for loops where the entry and exit are through the same switch. this method also has the advantage of being compatable with both dc and dcc.

[Doneldon]

jward-

Using the reverser on the loops means the connecting track will always be the same polarity as the crossover tracks. That would reduce wear and tear on the reverser and, more important, make it less likely that the reverser has to match both the polarity for a train exiting one of the loops and a train negotiating a crossover simultaneously. Remember Jim's corollary to Murphy's Law.
                                                                                                                                -- D

[jward]

if you are worried about that, just wire the loops through the switch motor contacts. even if you are using ez track which doesn't have the contacts, you can use a snap relay wired in parallel with the loop switch, so that when you throw the switch the polarity of the loop is automatically corrected. it would then be impossible for a train to be on the loop and the crossover without both being the same polarity. even if you had to buy the relays you could do both loops for less than the cost of one autoreverser. and the circuit isn't hard to wire. i don't have a web ready drawing of this circuit but if you are interested email me and i'll draw one up.



it all depends on how much money you want to spend.

[pacchardon]

Due space limitations I have to shorten the straight run btwn the two reversing loops. Now I have the situation that the train will be on both the reversing loops and the straight section in btwn at the same time.  I can't see how one reversing module would handle this. Is there a way that I can imbed a diagram in this thread to show what I am trying to do?

[NarrowMinded]

Make a drawing using paint or another program and post it as an image

[pacchardon]

How do you post it as an image? Is it posted as an attachment or is one of the unlabeled BBC tags used? The Post Reply isn't clear on how to do it.

[Doneldon]

paccy-

I think one reverser will still do the job as you'll only be changing polarity on one section of track at a time. I'd probably avoid any power using equipment on the train other than the loco. I hope your reverse loops will be long enough to hold your whole train even if the straight connector is not. Else you'll have a much more serious problem than track polarity; you'll have one end of the train ramming the side of the other. Perhaps you should be planning either a longer mid section, a continuous loop instead of two reverse loops or a shorter train.
                                                                -- D

[pacchardon]

The loops will be more than long enough. Maybe there is something I dont understand. When the train has crossed over the straight connecting section and into the next reversing loop, is the fact that train has not totally cleared the other reversing loop relevant? In other words, if the one auto reversing module changes polarity in the both reverse loops because the train crosses over into the second loop before the train has cleared the first is it going cause a short?

The original design was going to have a longer middle section but this structure of double reversing loops was longer than I realized
I want to go with this design because I want a inner loop that is
1) less boring than just a plain loop because by playing with the turnout switches there are 4 paths the train follow thru this structure
2) when the train moves out to the outer loop in can go in either direction
3) it should provide some interesting train wrecks

[Doneldon]

paccy-

No, I don't think it matters that the end of the train is still partly in the "previous" reverse loop. That's why I said one reverser should still do the job.  Interesting train wrecks? I would think so, and often. Don't you also have a crossover in the middle section? I can almost discern the weeping from here.

                                               -- D