Auto Reverse Modules

[Anonymous]

I received a Prodigy Express Dcc system for Christmas and I have a question. My current layout is Atlas Spaghetti Bowl #33. This particular layout has three wyes joined together to make a triangle of track. Do I need a MRC auto reverse module for each wye? The wiring instructions for the Atlas components just show wiring an Atlas Auto Reverse Module into the power feeds to the whole layout. Is there an easy way to do this? Recommendations? Do I have to use the MRC module or can I use the Atlas module or should I use something else? Thanks!

[Anonymous]

I have two MRC reverse modules on my layout and am about to add another.I dont know about the atlas system.If they have instructions on reverse loops and a module try it out.You can also go to there website or call there service dept.

[rolleiman]

[image]http://www.atlasrr.com/Code100web/images/10033.jpg[/image]

Do you mean this one?? If so, and even if not, for that WYE track arrangement you only need one reversing module.. In fact, that same module will service Several WYEs as long as 2 trains don't demand reversing at one time. Items like lighted passenger cars also fall into the catagory of a 'train' when it comes to these modules. The MRC module is (I believe) a simple circuit that detects a short via a high current spike and then throws a relay to basically correct the situation. I don't know anything about the Prodigy system but I have to say that the MRC module was less than reliable on my digitrax based layout. I don't know if the relay was weak or what but half the time, it would fail to detect and reverse. I replaced it with a Digitrax PM4 and for me, it works great.. Here's a compare of autoreversing modules / circuits commercially available..

http://www.tonystrains.com/technews/dcc_autoreversers.htm

By the way, if this IS your layout, and it's built as shown, remember that the turntable track is a reverse loop (electrical) too.

Good luck,
Jeff

[Texas Zepher]

QUOTE: Originally posted by rolleiman
By the way, if this IS your layout, and it's built as shown, remember that the turntable track is a reverse loop (electrical) too.

I've always liked that layout......
Good response, but one possible correction. I believe that Atlas has rotating contacts in their turntable that reverses the polarity while it turns. I don't remember having any special wiring considerations on the one's I've installed (or maybe I've just been very lucky?).

[Anonymous]

Thanks for the link. I don't think there is an issue with the turntable, but I'll double check to be sure.
This has become a nice layout, but I ended up with 5x9 because it's hard to ballast track that is on the edge of the table. Also, I've read too many posts about trains hitting the floor.
Thanks all!

[rolleiman]

QUOTE: Originally posted by Texas Zepher

QUOTE: Originally posted by rolleiman
By the way, if this IS your layout, and it's built as shown, remember that the turntable track is a reverse loop (electrical) too.

I've always liked that layout......
Good response, but one possible correction. I believe that Atlas has rotating contacts in their turntable that reverses the polarity while it turns. I don't remember having any special wiring considerations on the one's I've installed (or maybe I've just been very lucky?).

You may be right the atlas in saying no special consideration is needed. Last time I owned one was 20 years ago.. Though all turntables that pick up track power from the ring rail, or in the atlas case from a wiper ring internally reverse the polarity on the bridge rails. But it gets reversed out of necassaty to have 2 power point pickups (much like regular track feeders),, The potential problem isn't in the bridge itself but when entering or leaving the bridge to the service tracks or roundhouse tracks. I'm just suggesting that drewsdaddy watch out for that..

Jeff