An Introduction to DCC For Your Model Railway

An Introduction to DCC For Your Model Railway

Introduction:

Digital Command Control (DCC) gives you many benefits over (DC) analogue control. You can individually control several locomotives at the same time, operate headlights, operate sounds (if the loco has a sound decoder fitted) and even control points, signals and other accessories on your layout if you wish.

Jumping into DCC can be a costly exercise as opposed to DC, but for many it’s a worthy investment.

To get running with DCC you will need two things…

  1. A DCC controller
  2. Decoder(s) to suit your locomotives(s)

Another thing to keep in mind is once you go DCC, you have to commit to DCC. You can't run DC locomotives on a DCC system so if you have a fair collection of locomotives you will need to install decoders on any locomotives you want to run.

System:

DCC has become very popular and many brands have jumped on board including Bachmann, NCE, Digitrax, Roco and many more. A good system to start out with is the NCE PowerCab. The PowerCab is a powerful controller with a lot of functionality at a very reasonable price. Everything is provided to get you started, aside from a decoder for your locomotive (we'll get to that soon).

With a unit like the PowerCab, you have the ability to upgrade components of the DCC system which will give you greater control and power, such as a 5 or 10 amp booster which will allow you to run more locomotives and may be necessary to power larger layouts.

Depending on what DCC system you go with, check if the brand is NMRA Compatible. This allows locomotives with various NMRA compatible decoders to run on your layout.

Do your research on a few system before making a choice. Make sure that the system you go with has the features that you need. Here's a few things to keep in mind:

  • How many Locomotives do I want to run?
  • How much of my layout do I want to control digitally (signals, points, etc...)?
  • How big will my layout be and how much power will I need?
  • How compatible is the system with other brands?

Decoder:

All of your locomotives will need to have decoders installed in order to work with the DCC system. Decoders generally come as a 6 pin, 8 pin, 21 pin or Next18 pin. Decoders come in multiple different sizes with different functionalities. Newer locomotives will come either 'DCC Ready' or 'DCC On-Board'.

DCC Ready - Most locomotives produced now will come DCC Ready. This means out of the box the locomotive will only run DC, but inside the locomotive there is a small plug (sometimes there is a blanking plug installed). Simply plug your DCC decoder into the locomotive (making sure its the correct way around) and program it to your controller.

DCC On-Board - Many brands are now offering DCC On-Board. This means out of the box the locomotive has a DCC decoder installed and is ready to go. Some loco's with DCC On-Board may also come with built in sound.

DC Only - Older locomotives will be DC only, a few manufacturers are still producing DC only locomotives as a way of reducing costs. DC only means that there is no plug in the locomotive for plugging a decoder into. This doesn't mean the loco can't be fitted with a decoder, it will just need to be soldered in instead.

Older or basic locomotives such as an old Lima locomotive will require soldering skills to install the decoder. These decoders have 9 wires coming out of the decoder or harness. Your job is to follow the diagram provided with the decoder, and solder those wires to the respective places on the mechanism. If in doubt, you can always contact us at Hearns Hobbies (03 9629 1425) for help. You need a soldering iron, solder and heat shrink, plus extra wire and cutting equipment. Although difficult at first and scary, once you do it the first time, it is relatively easy to go on and do it the second time and so on.

Depending on your locomotive, its lights may not be the right voltage for the decoder. You will need to fit resistors to them before chipping in your decoder or this will result in damaging your decoder. I recommend LEDs with resistors as they last longer and look better than incandescants. LEDs and resistors can be purchased from certain hobby shops or Jaycar.

A feature (that can be turned off if desired) is the ability to run your DCC decoder equipped locomotive on a normal DC layout. Various decoder brands will perform better in this than others. But note there are decoders out there that can only run on DCC - mainly older sound decoders. Double check by reading the instructions accompanying your decoder! When you do run your DCC decodered locomotive on a DC track you will note how long it takes to get the train running. This is becasue every time you apply voltage you are booting the chip up, it then senses DC/DC then act accordingly.

Only then will the train move. So you cannot doublehead with a non DCC loco for instance. You have this delay everytime from 'off' to 'moving away'.

It is best to purchase decoders which are NMRA compatible. That way you can buy many decoders which are NMRA compatible depending on your taste, but they will all run together and fine on your NMRA compatible controller and layout.

Sound:

Sound in a locomotive can really bring things to life! It gives a very realistic impression of your train running on your layout. Although compatible on DC layouts, it's fully accessible on DCC. All functions are available, from bell, whistle, horn, coupler crash, cooling fans, etc... Your DCC controller should be able to cater for all sounds that are accessible on your locomotive.

Some companies such as Austrains & Hornby have sound available on certain locomotives. These are already sound equipped, and ready to run on your layout with sound.

Accessories:

You can get accessory decoders to control points, signals etc...

These are specific for the job - some example control items are like Peco point or Tortoise motors. Others are more flexible in what they control.

Most systems allow you to throw a point (activated from the accessory decoder) from your controller. There are devices allowing you to convert your control panel to issue these commands as well.

Computer Control:

Many systems have a computer interface either built in or as a extra unit. These can let you do whatever you can on a throttle, such as drive a train, throw a point or sense a train in a section.

For example, when programming a loco, you can keep files for a loco so reprogram it can all be done from the PC!

Layout:

You need to make sure your layout is DCC compatible. Track must be very clean and no obstructions. As you can control trains separately, points do not need to have isolation functions commonly found with Insulfrog points. The best bet is to use Electrofrog points which when wired correctly will give very smooth operation.

Ready?

Once your locomotive is chipped, and your layout connected to your DCC controller, you can place your locomotive on your layout and play. Default settings have the locomotive's address number at 3. You can tweak around with the decoder's settings to change its address, motor control, headlight functions, etc... Refer to the user's manual for instructions.

There's a lot of work related to DCC, and plenty to ponder. But DCC is a lot of fun when you get the hang of it, and it's easy to expand by purchasing a more advanced controller, or adding a booster pack to increase the number of trains operating on your layout (ordinary controllers allow around 3-4 HO/N scale trains to run at one time).

Last but not least, it's simply up to you on what choice system or decoder you choose. You choose the best for you. Check out its features and compatibility to determine your end preference.