DCC and a reverse loopgreenspun.com : LUSENET : Wiring for DCC : One Thread
I am very new to the train world and did my research and decided to go DCC, I bought a Bachmann E-Z Command and really enjoy it. However, I have a problem, I have a reverse loop in my lay out. I have looked at the many sites and I am totally lost on the wring diagrams as they want to show entire layouts and Iím far from an electrical engineer. Can any body help me on a simple hook up for my reverse loop? Thanks, Michael Steveley Anatomy34@hotmail.com
-- michael L. Steveley (firstname.lastname@example.org), January 26, 2005
With DCC, reverse loops are very easy. As the track comes off say a switch and enters the loop you gap both rails within a short distance. Right at the end of the switch track or after the first section of track. This means that there is an air space between two sections of track. Either leave out the joiners and have about a fingernail width of space or insert platic rail joiners. In any event you want to make sure power does not pass from one section of track into the loop section. You need to gap the rails again just before the track finishes the loop and goes back into the switch.
At this point you will have track power before the loop and after the return but no power in the loop.
Next. From the same power source as the rest of the track, run a pair of wires to the loop section. Anywhere along these pair of wires they have to be cut and a Reverser Module has to be wired in.
The reverser module is a small unit that electronically senses the polarity change and changes positive and negative as needed in the loop. The polarity change is quick and no hesitation occurs in the engines. I use the MRC reverser and all I get is a slight click from the track when the power reverses. As far as wiring in the module, the instructions that come with the module tell you which wires go where. Not hard at all.
The only caution is that the loop must be long enough that all powered engines or lighted cars have to be able to be in the loop before it reaches the end of it or a short will occur.
I also use a reverser module on my turntable in case you turn an engine around on it. Good luck...
-- Dan Ferrick (DTFerrick@msn.com), January 27, 2005.
connect to www.wiringfordcc.com. select DCC topics select the read the DCC for Beginners section. there several links directly to reverse loop topics.
-- Don Vollrath (email@example.com), January 31, 2005.
An even better way (much cheaper) is to double gap the tracks leaving the turnout and now this isolated reverse loop is powered by a power changeover switch connected to the turnout. When the train enters the reverse loop which must be lonnger than the longest train, and the last wagon/coach has passed the turnout, you through the turnot which changes the polarity of the DCC signal in the loop to now match the polarity of the turnout at the loop exit route.
In a reverse loop you generally just use the same turnout to reverse the train so the same action of throwing the turnout can change the polarity, so an auto reverser is not necessary thus saving quite a few dollars.
If using a return loop like on a dogbomne layout, you will not come back in the reverse direction on the same track so you must use an auto reverser. I would suggest a solid state one with short circuit protection.
-- Marcus Ammann (firstname.lastname@example.org), February 05, 2005.