Of all the model railway controllers the device that is familiar to many enthusiasts is the traditional analogue device. Analogue model railway controllers work by controlling the flow of power to the track. The trains will increase speed with increased voltage and vice versa. To reverse the direction of the train the polarity of the voltage being fed to the track is reversed and again the speed of the train in reverse is directly proportional to the amount of power fed to the track.

Analogue model railway controllers are particularly suited to small train layouts with just 1 or 2 trains. This is because all trains on the track that is being fed power will be controlled by the same power feed. A way around this is to partition the layout into blocks and have a separate power supply for each block. In this way trains can be controlled individually but it can become quite complicated to do this with a large layout. A major benefit of analogue model railway controllers on small layouts is that they are easy to connect up and are very cheap.

Digital Command Control (DCC) model railway controllers are the most popular device for operating a scale train set. DCC works by sending power and a signal to the track. The signals that are sent are picked up by a decoder that is inside the locomotive. The signals that are sent are specific to each decoder and therefore it is possible to control a number of trains on the same track with the same device. DCC model railway controllers can also send additional signals to a decoder that will turn lights on or off, beep a horn, change the engine noise, control the speed and the direction of the train.

For large layout installations DCC model railway controllers therefore offer the advantage that the layout does not have to run in blocks and it is therefore easier to install than an analogue device on a large layout.

It is possible to convert existing locomotives and stock so they can be controlled by your DCC unit but it has to be said that this is an expensive job if you have a lot of stock that you would like to convert. You can also add decoders to your points so that these can be controlled by your digital device.

DCC model railway controllers therefore have a number of advantages over analogue model railway controllers but the main one is that the DCC system allows you to control multiple trains on the same track without having to design complex wiring systems to accommodate each train whereas analogue model railway controllers are really only designed so that you can control the power feed to the track. You can find a comprehensive breakdown in the difference between model railway controllers in the recommended book Model Train Help.