DCC - What does it all mean?

2005-9-11

We cannot ignore the fact that we live in a “digital” world. Watches, TVs, radios, sound systems, and cameras to name a few all use digital technology. It provides users with dramatically improved output and quality in its applications.


So what does it mean in the world of model railways?
Digital Command & Control or DCC means that you no longer have to be an expert in electronics. Gone are the days when if you had anything but a very simple layout it involved complex wiring diagrams, isolation switches etc. All gone with DCC your only concern is to wire to every section that is isolated by closed/open points. The days of short circuits are past. Well almost, you still have to consider polarity. If you do not feel 100% on electrics ask someone who does. Electricity even in small amounts is dangerous not only to you, but also to your expensive locos.


The really exciting part is what you can do with your locomotives. From one controller you can operate individual locos, sending them different commands to suit your running patterns. You can park several locos at one platform or siding. Locos can run in tandem or rolling stock can be shunted on to a loco on the same line.


However the chances of a collision are greater, therefore most controllers have a red button, which cuts power to whole layout if you see a disaster developing.


How does it work?
The operator allocates a unique name or number to each loco on the layout using the controller. The operator can then select an individual loco and control its speed and direction regardless of the position of other locos.


Each loco is fitted with a decoder which receives a digital signal from the operators controller which it reads as direction speed and acceleration. In technical terms the digital signals are superimposed over a constant track voltage. This means that conventional systems controlled the track, DCC controls the loco.


Some of the more expensive controllers can operate lights, points, signals and even sound.


What do I need to go digital?
First you need to purchase a DCC controller . Prices start at around £60 and rise to several hundred pounds.


Second you need some locos to run. There 3 types:
(I) A pre-digital loco. This will need a suitable decoder wiring to the motor. Although decoders are becoming smaller, you may have a problem with space.

(2) A DCC ready loco. There is an increasing range of loco available. You can purchase the loco together with a decoder ( cost around £15 each).
Fitting is straight forward as these locos have a source to accommodate a decoder bad a standard socket to plug into.

(3) These loco you unwrap and place on you layout. They have the decoder fitted.

Last you will have to wire the layout. So that the entire track is powered. In simple terms every Section of track has to be wired direct to the controller. So
you will need some central hub into which you feed your wires. One of the lines in is of course the wire to the main controller.


DCC is becoming increasingly popular in the UK with several manufacturers offering products that are compatible with each other. There have been similar systems in the past. The difference with DCC is that the technology is open, and standard has been set making it possible to mix and match products.


So shop around before purchase a system and subsribe to Model Rail Magazine a great source of information on whats ? what?


You can see many examples of David Dibb's layouts in the User Gallery.