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 Planning a Layout – DCC Explained

The DCC (Digital Command Control) advantages over DC (Direct Current Analog) operations come through the ability to control individual locomotives without any complicated switches and wiring. With DC, all you ever control is the track. It either has power on it, or not. With DCC, you control the locomotives, so you drive the trains! You have control of the speed, direction, lights and possibly sounds. You can put multiply locos on the same track without having to worry about extra wiring, switches or additional power supplies to control them.

 

Comparing Analog to Digital Command Control

DCC controls your locos, not your track. DCC allows you to control multiple locos at the same time, while avoiding complex wiring and track block assignments needed for analog operation.

Analog (DC)

For standard analog controls, the ‘throttle’ or 'power pack' puts a variable direct current (DC) voltage onto the track, so you are controlling the track. The locomotive's motors and headlights are directly connected to the track through the wheels. This is how the speed and direction of the locomotive are controlled - more track voltage, more speed. Reverse the DC polarity of the track and the locomotive changes direction. Headlights will only come on when there is voltage on the track and their brightness depends on the amount of voltage, but regular lights don't care about polarity and will work in both directions, but LEDs won't work in both directions.

Digital Command Control (DCC)

With DCC, the command station puts a constant voltage on the track all the time. This is not DC (Direct Current) voltage, instead it is AC (Alternate Current). This AC allows for digital information to be sent along the track to the locos, so they can operate with the use of a DCC decoder installed.

Therefore, all the locos on the track will have power to their wheels all the time, but waiting to receive a command to operate. Instead of the voltage level on the track controlling the trains as with DC, a receiver (DCC decoder) installed inside each locomotive listens for commands sent out over the rails from the command station. These commands tell the decoder to make the loco go forward, reverse, fast, slow, start, stop and even turn on/off lights or sounds. Each locomotive responds only to commands specifically addressed to it using its own DCC Address and ignores all others, allowing you to control any loco anywhere on the layout. With DCC, you control and drive the locos, and not the track as with DC. Because of this, DCC is able to control multiple trains on the same track all simultaneously without having to deal with complex wiring to isolate each section of track to control each train.

 

The Benefits Of Digital Command Control On Your Layout

Quite simply, Digital Command Control is a system for controlling locos in a more realistic fashion compared to your old DC-based power pack.

DCC allows:

  • Multiple locomotives on the same track to operate independently on a layout.

  • You control each locomotive, not the whole layout at once.

  • Independently or interactively control the locomotive's headlights, marker lights, ditch lights and other lighting at any time.

  • Multiple Unit Consisting allows to replicate prototype operations by creating a consist of several locomotives to haul a train.

  • Support multiple operators, operating multiple trains simultaneously anywhere on a layout.

  • Add realistic sound to your locomotives that can be independently or interactively controlled 

What Do You Need To Operate DCC On Your Layout

If you have an existing layout and wish to convert from DC to DCC, in most cases you can simply install a DCC system in place of the DC cab throttle and power pack. For small layouts, simply disconnect the two track wires from the analog power pack and connect them up to the DCC system's booster. It should be noted, that this is the most basic way to get your track running on DCC in just a few minutes.

For larger layouts using multiple power supplies and track blocks, the conversion is a little more complex. All the DC power supplies must be disconnected to avoid the risk of damaging your new DCC system. A power bus will be needed to connect the DCC system to all the tracks previously supplied by the individual DC power supplies, so that all the track power on the layout is now connected to the DCC output. If a reversing loop or cross over track is used, then it will require an auto reverser to make them suitable for DCC operation.

So what you will need to run a DCC layout:

  • Digital Command Control System

The Command Station is a dedicated computer that communicates with all other parts of the DCC system. Selecting the brand and model of Command Station is key to selecting the type of Throttle controls, as well as feature expandability of the system. Purchasing a DCC system from an authorised Australian dealer will generally include the correct power supply suitable for the system. Be careful if purchaing overseas as it may not include a power supply or a power supply not suitable for use here in Australia.

Here are some recommended systems:

NCE PowerCab - The best solution for a small layout or anyone starting out with DCC. Extremely easy to set up in less than 10 minutes.

The 2 amp starter system can run about 4–6 HO scale locos simultaneously, it has an easy to use throttle with a maximum of 4 cabs / operators on the layout. This system can easily be expanded into a 5 amp system to run about 12-14 HO scale locos simultaneously, which is ample for operating a larger home layout.

NCE ProCab - Available in 5 and 10 amp systems to suit bigger layouts using a throttle. Wireless throttles are available, but can be expensive.

Digikeijs DR 5000 - A universal DCC control centre with almost all currently available bus connections that can be operated with all LocoNet® and XpressNet devices, like Digitrax, Lenz, Roco and via WLAN with mobile wireless hand controllers. It can be connected to a PC via LAN, Wi-Fi or USB. The LocoNet®, Z21®, DR Command® or XpressNet® protocol can be selected for communication with the PC which allows the DR5000 to communicate with any supporting software such as iTrain®, Koploper® Windigipet® Train Controller® and RocRail®. Peripherals such as the Roco® Multimaus®, Roco® WLAN Multimaus®, Roco® Z21 App, the Lenz LH01®, the Daisy II® (wired or wireless in connection with the radio master) and other LocoNet® or XpressNet® compatible devices can be connected and used simultaneously. DCC Solutions recommends the DR5000 as a great system for a low cost wireless option using a computer, free software like JMRI, a mobile phone or tablet loaded with the Engine Driver Throttle or WiThrottle apps.

ESU ECoS Central Unit - A comprehensive, multiprotocol command station allows you to run locos via two integrated cabs with large, easy-grasp motor driven throttle knobs and a full colour touch screen. The ECoS Central Unit can manage up to 16384 locos with each loco characteristics and picture stored so in the future you can call up each engine by name.

A high-end system for those who have a big budget, as it is expensive.

Digitrax - Offers a range of different systems to suit all different size layouts.

  • Digital Decoder Installed In Each Locomotive

While the Command Station is the intelligence of the layout, DCC Digital Decoders are the brains of the locomotives. Each decoder is programmed with a unique DCC address assigned to loco. The decoder monitors the DCC data being sent along the track and listens for commands with its DCC address. All power in the loco flows from the rails, to the decoder, and then on to the motor, lights, and sound. These electronic decoder devices create the PWM signal for motor control, as well as controlling any lighting or sound effects they may be capable of performing. The decoders are user programmable with new information any time you like, allowing you to change the DCC address, motor performance, lighting and sound effects.

There are plenty of brands of DCC decoders on the market. The advice is to stay away from the cheap ones, you get what you pay for.

You can go for non-sound decoders to get your locos up and running in DCC, or sound decoders to add realism to your locos.

Here are some recommended decoder brands:

ESU - DCC Solutions prefer and recommend ESU decoders. From the extremely low returns and warranty claims at DCC Solutions over the past years, the ESU LokPilot and LokSound decoders are the most robust, reliable and feature packed decoder on the market that offers the user trouble free operations with all function outputs and the motor current output overload protected providing the lowest chances of destroying it and releasing the 'magic smoke' contained inside.

ESU wants you to have fun with your decoder for as long as possible!

Soundtraxx - Offers a range of sound Tsunami2, Econami, Blunami decoders and non-sound decoders suitable for a wide range of applications.

TCS - Offers a range of "WOW Sound" decoders as well as non-sound decoders suitable for a wide range of applications.

NCE - Offers a range of simple and basic non-sound decoders suitable for a wide range of applications.

  •  Electronic Circuit Breaker Protection Device

Protecting your layout from the excessive currents which flow during a short circuit event prevents damage to your Digital Command Control System, DCC Decoders and most of all, your models. It doesn't take much time or current to cause some very expensive damage, so it is very important to install a device for your protection. 

The simple old school setup on DC layouts of using the 1156 automotive light  bulb to limit the current is just not suitable for DCC layouts.It will not stop the current from rising to the high level generated during a short on a DCC layout, so this method is not appropriate. This is an analog solution to an analog problem, and should not be considered for digital layouts.

Most DCC systems and boosters have built in over current sensing for basic self-protection of the unit that will continuously / automatically try to reset every half second (500ms) until the unit is damaged . They do not have manual breakers that will trip or fuses that will blow to prevent damage, so DO NOT simply rely on these to protect your DCC system or what is on your layout. Some damage is simply not repairable.

Here are some recommended circuit breakers:

DCC SPECIALITIES PSX-1 - A highly efficient circuit breaker for ONE power district or power section, generally for a whole small layout. Adjustable trip current. The PSX series of overload protection devices are fully electronic for the highest possible reliability. Available in 1-2-3 or 4 power district/sections to split up larger layouts in sections, so only individual areas will shut down rather than the whole layout.

NCE EB1 v1.1 - Provides short circuit protection for ONE power district. Can be used with most other DCC systems. Default trip time is 30 times faster compared to the basic overload setting in all NCE systems. More than one can be used on larger layouts.

  • Locomotives For DCC Operation

To be able to run any locomotive on a DCC layout it will require to have a DCC decoder installed.

Just about all DC locomotives can be converted to DCC. Older models may require more complex hard wired DCC decoder installations while others might offer a plug in option. Even some DCC plug in option models may need to be modified for a hard wired sound installation if space is limited.

Many locomotives manufactured since around 2002 have come at least "DCC Ready".  Don't be confused, DCC Ready does not mean it has a DCC decoder installed but simply it is a DC model that will only run on DC but has a socket inside ready for the installation of a DCC decoder and may or may not have provision for a speaker to complete a sound installation. 

Some models now come "DCC Sound Ready" which means they are also a DC only model that includes a DCC socket and a speaker installed for a future sound installation. Generally, the speakers are not the best quality and would benefit from being replaced with a better speaker.

Some loco manufacturers have now added a DCC decoder or DCC factory sound decoder options to their models making them out of the box ready to run on a DCC layout.

 

Are you confident in building a layout but not so in installing DCC decoders and Sound into you locomotives?

Don,t worry, DCC Solutions has DCC installations covered.

That's what we specialise in, so go to our                                   and see what we can do with your locomotives. 

 

OK, now that I know more about DCC, what next?

The first step is to decide on the size of your layout. Will you start with a simple oval, maybe an end to end track, a small layout with a few points (turnouts) and a yard or go big from the beginning with long runs, branch lines a fiddle yard and more.

If you already have a DC layout then look at will it be a simple swap over to DCC or will I need to make a few changes for DCC.

 

Next step is to buy a Digital Command Control System suitable for the size of your layout and most important an Electronic Circuit Breaker Protection Device. Connect these up to the layout and you are ready to go DCC.

 

Finally buy a loco that already has a DCC decoder installed or install DCC decoders into your existing DC locos. If you have a large fleet of locos, start by picking your most favourite locos and convert them first to begin enjoying the world of DCC. The rest can be done in time.

 

There is so much more to explore with DCC and once you start, you will be hooked for life.

 

 

 

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