Wiring with DCC

beevee

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Aug 24, 2005
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Being another one new to DCC I have bought a MRC Prodigy Express outfit for use with my up and coming small layout.Its going to be about the same size as the Stoney Creek railroad being built in the Model Railorader.

Now, I am obviously mistaken here, but I thought that DCC was supposed to be 2 wire wiring, ie connect it up and away you go, the electric travelling to all parts thereby saving a lot of electrical connections.

I see on the Stoney Creek set that the author has seven sections. Whyso? when the decoder will isolate all locos unless selected to work. The wiring reminds me of a conventional layout where the sections can be used to stand locos on and isolate them when not required.

Any comments please. I will be using Peco Electrofrog turnouts.
 
What you are seeing are several connections made to the single 2 wire main bus from the DCC pack.

All the tracks are still connected, and theirs no isolation/cabs/etc...

Having multiple connections throughout the layout makes sure you have the full amount of power passed through the tracks and to your trains. If you had a single connection the power can drop at the far end of the tracks (and thus your train stopping in these "dead zones".)

So basically with DCC you still want a lot of drops to the bus, but only for distributed power, not for blocks of power.

Make sense?
 
I think on a small DCC-layout you dont need any elctriical blocks (although Cid is right about the possible benefits of blocks), just the main bus and some feeders. If you use Peco Electrofrog turnouts (I use them on my layout too, they don’t cause any problems, but I recommend to powerroute the frogs) you have to use insulated railjoiners to connect the inner rails leading to the frog to prevent shorts. That leaves the track behind or between your turnouts without power, so you have to attach feeders to these parts of the track anyway.

Kurt
 
I just acquired the Prodigy Express as well, using it with Kato Unitrack. Since I've converted all of the turnouts to non-power routing, I expect that I will have to run a feed to each siding. I think the recommendation I read is that with DCC it's a good idea to connect a feeder for every four feet of track to prevent voltage drop from the natural resistance of the rails. Fortunately, you don't have to isolate each block, but you need to make sure your feeders are all going in the same direction ;)
 
If you have electrically isolated places (no feeder wire, and switches that control the electricity), and you park a DCC loco there, how long does it take until the loco drains power and forgets how you programmed it. I'm assuming that all locos go back to channel 3 when they have lost power for a period of time. New to DCC, just guessing.
 
All my DCC equipped locomotives are in storage boxes, so well away from power. However, they are properly programmed with their respective road numbers on their chips. The technology used means that once the decoder is programmed, it isn't necessary to keep power going to the decoder in order for the information to stay on it. It works in a similar way to memory flash cards on digital cameras or computer USB "Thumb" drives... the cards themselves don't need power to retain the pictures that are stored on them.

So you don't have to worry about the loco reverting to Channel 3... Once the number is programmed, it stays that way until you change it otherwise...
 
George...

With many DCC systems capable of 4 digit addresses, most people will program the loco's number as the decoder address. Some people go with the last two numbers (2 digit addressing). If you have many locos, it behooves you to devise a system and stick to it! ;) :D

The modular club that I run with also requires loco cards. These list the road name and loco number for identification purposes, then the manufacturer (Kato, Bachmann, etc), and the settings for most of the major Configuration variables (CV's) programmed on the decoder. They are usually stored with the loco when not in use.

Andrew
 
GeorgeHO said:
If you have a lot of locos, how do you remember what the number is? Do you put it on the storage box or do you use part of the locos number?

I use (and I believe that most others do also) use the loco number in either the 2 number or 4 number convention (whichever you feel most comfortable with programming). There are probably other systems around but you would have to maintain a listing of what you programmed.:)
 
Missouri Pacific F-units and Alcos had 3 digit numbers when built (time I model) but carried the prefix "A" and "B" on respective units so I added a "1" to the A-unit number and "2" to the B-unit number to retain identity.