Return loop

You need to insulate both the entry and exit of the reverse loop.

You must isolate the whole section between turnouts. This will be a "reversing section."

You need two or more direction switches, one for the layout outside the revsring section(s), and one for each reversing section.

Label the Master switch "East" and "West". It controls the direction of the locomotive relative to the layout outside the reversing section(s). Label the revesring section's switch East and West, too. The two switches must be wired so that both select, say, East, when a loco running East enters the reversing section. While the loco is in the reversing section, throw the Master direction switch to West, since that will be the direction of the loco when it exits the section.

A reversing section is any piece of track that allows you to reverse the direction of the lcocomotive from "east"" to "west" or vice versa. They are sometimes hard to spot. Eg, suppose you have an up-and-over figure eight main line. If you put in a cut off track, it may or may not be a reversing section. To find out, trace the route of a train through the cutoff, and see whether it has reversed direction relative to some point elsewhere on the mainline, such as a station.

HTH&GL

Thank you. That explains it very well I have the sidings to deal with also Time to get to the wiring.

Other than the reverse switch on your controller, you only need a reverse switch on the return loop section. However you need to stop the train in the return loop. The above is only one way to get around the reverse loop using DC without stoping the train.

You do need to isolate both ends of the loop, as other posters have suggested. But here's a way to avoid stopping the train, and you will not need an additional reversing switch for the loop.

This only works if you ALWAYS enter your reverse loop from the same side, and exit on the other side. i.e. go in on the left and exit on the right ALWAYS.

I'm also assuming this isn't a DCC system, which can handle all this for you. And I'm assuming you are just using an ordinary power pack of some sort, with a reversing switch on it.

Get a full-wave bridge rectifier. You can get these at Radio Shack. Buy one that can handle at least an amp for N-Scale, 2 amps for HO, more for bigger scales (it has to carry the train current). Take an extra pair of wires off the + and - DC outputs of your powerpack, and hook them to the two "AC" terminals on the bridge rectifier. (yes, that's right, hook the DC from the power pack to the AC terminals on the rectifier).

Hook the two DC terminals from the bridge rectifier to the track inside your reversing loop. Hook NO OTHER POWER to the reversing loop.

Now, trains will only run in one direction around the reversing loop, no matter which way you throw the reversing switch on your power pack. (That's why you have to be willing to always enter from one side of the loop).

The bonus is that once your train gets into the loop, you can throw turnout and the reversing switch on the power pack WHILE the train is running. That will have the mainline properly set for when the train exits the loop, but won't reverse the train INSIDE the loop because of the bridge rectifier.

Another drawback to this is that the bridge rectifier will drop about 1.4 volts, so your trains may noticeably slow down a bit in the loop. But this may not be a big deal to you. If you had access to the inside of the power pack, or built your own, you can take a pair of feed wires off the DC output of the pack BEFORE it goes through the reversing switch, and power the loop off that. Then you don't need the rectifier, and you don't have a slow-down.

-- Max

betruger wrote: