A.) I do NOT have a Lenz, so I am not sure what they are saying about resistance (R) ratio... B.) HOWEVER... since we are talking ample current (I) to drive multiple engines, and given the voltage (V) is now fixed w/ your DCC system..... V = I/R... so the variable of interest pertaining to wire size is now R.. or resistance. So... therefore.. R=V/I and the current you want is: I = V/R So.. with voltage fixed, you can see the larger that R is in the denominator, the smaller the current (I) you can push through that little bitty peice of wire. Use the larger wire such that R gets smaller so I gets larger. While I do not "know", I BELIEVE that (R=V/I) is the resistance ratio that LENZ is probably talking about. ENJOY that DCC. I have loved mine since converting last August. [ 10. March 2003, 17:41: Message edited by: Kitbash ]
That's all well and good...but whatever ratio they were talking about had something to do with them wanting the wires to be either parallel or twisted.
What the wires being parallel or twisted have to do with the ratio is this, I believe. Having wires twisted or parallel usually means that the installer as taken means as best as possible to have the shortest total "circuit" distance of wire for his/her particular layout. The shorter the OVERALL circuit length, the lower the resistance. The lower the resistance in the ratio given above, the more amperage one can deliver to the track and engines.
I thought I might jump in here and try to clear some things up. DCC is designed to work with a very wide variety of layout wiring styles. You can do things neatly with large gauge bus wires under the track with frequent feeders or you can have a rats nest of wiring. It really does not matter in the transmission of the DCC signal. If you wiring is poor your trains will just run slower in those areas of poor wiring. The issue of twisted or parallel wiring has to do with FCC rules for interference. The high frequency component that is generated when you generate a DCC signal will cancel itself out when the two transmission lines are parallel or twisted. Our track is an excellent example of a parallel transmission line. If you have (like I do on one layout) bus wires that are totally independent of each other and go in all sorts of different directions, your trains will run fine but your wiring will act as an antenna and radiate the high frequency signals. If you place an AM radio next to such layouts and tune to an off band you will pick up the noise of your layout. Manufacturers must produce equipment that meets FCC requirements and must demonstrate that their equipment does not radiate high frequencies in the prescribed environment. The requirement in the manuals for twisted and or parallel wiring is simply to meet those requirements. BTW you can can also quiet up the noise on noisy layouts using simple filters that consist of a 100 ohm resistor and a .01 microfared capacitor. Hope that helps. Stan Ames
I was thinking, Stan Ames - Gee that name feels familiar, I hope the graemlin I chose shows a "sheepish" face....
Forgive my ignorance...and I wish I had a sheepish face too...but what book exactly did Mr. Ames write? I can use the excuse that I'm new to all of this...but I'm more interested in finding out what book it is so that I might possibly acquire it.
Stan, welcome to Trainboard The name of the book that Hoss is referring to is "DigiatalCommand Control" by Stan Ames, Rutger Friberg and Ed Loizeaux It is THE comprehenisive guide to DCC. It, unlike an other book is not geared towards any single manufacturer. My well worn copy is always at hand. If you are thinking about DCC You Need This Book. You can get it though any outlet that sells stuff from NMRA, or go to their webisite" www.nmra.org
Some day I will learn to spell, although as Watash says: probably by then we'll be speaking another language and I'll have to start all over again. The Correct spelling of the book is: Digital Command Control. BTW, for those of you newbies, Stan Ames is the original Chairman of the NMRA/DCC Working Group and the past chairman of the NMRA Conformance & Inspection Committee. (Those are the folks that say your stuff will work with other mfg's stuff.) Thanks
Geesh...everyone else always told me that "The Big Book of DCC" from Digitrax was THE book to have. So...I bought it and wasn't all that impressed (I didn't find it to be nearly as useful as Allan Gartner's "Wiring for DCC" website). I'll have to give this new book a shot now I suppose...
I don't want to sound like I am promoting my website, but if you hit the website button in this message it should take to it. (I want to apologize in advance for first page appearance as MSN has decided to pump up revenue with self promotion. When you get there click on GRR DCC links on left of page.) I have a large section on my DCC experience including wiring plus there is a link to the DCC Webring. Anyway, I have a 10X10 layout with dual main lines. I use two 12 gauge wires for power, 18 gauge drops to every track rail. Overkill? Maybe. I also keep good signals going by using metal polish to clean my tracks and wheels on locomotives. I use Brasso(tm) as it was available. But other good brands of metal polish will work. You can find it at any hardware or autoparts store. The command bus is plug in wire rj12 that was provided by the manufacturer. The command bus sends the command from your controller to the command station. The power bus sends commands from the command station to the track, as well as providing track power to the tracks. I hope that helps. [ 17. March 2003, 18:04: Message edited by: ajy6b ]
Hoss, Like I said Stan's book is not geared towards any specific manufacturer. Realize that it and the D****** book are a few years old, but Digital Command Control really gives a good overview on all the systems. If the truth be known, and I had an extra 'grand' I buy a Zimo system. I've seen one operate and it's really slick. But my Lenz 01 works just fine for my purposes.
Hoss, One other important point. Alan Gartner's web site is what your Sargent would tell you. The Books are what your Lieutenant(sp?) would tell you. I printed out all of Alan's webpages and it was my operating bible when I wired my layout. BTW, the resistance soldering station he talks about is the single best tool I have ever purchased for any purpose in my 60+ years. I can solder all the pins on a tortoise machine in 27 sec. When I solder 2 rails together, after the 1.5 sec, the rails are perfect and the plastic ties on my code 70 track have no idea they were almost toast.
