take two wires..
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The subject of electricity and model railways is something that could easily consume another entire website. Large books have been written on the subject, and in a hobby that embraces changes in electronics and computers, the basic methods of control are ever changing. This guide, then, is aimed at a complete novice who has just started laying track, looks at their controller, and wonders how the two things join together.. (It's also primarily aimed at those modelling in N or OO scale, wiring pointwork may be slightly different if you are going to model in the larger scales)..
A Very Basic Guide To Wiring Your Layout
For this particular guide I'm going to assume that you know that inside each one of your model railway locos is a small motor that turns when an electrical current is applied to it. I'll also assume that you know just a little enough of basic electricity to know that there are such things as positive and negative, and that what you really want to know is how to get your loco running, how to have more than one loco running at the same time, and why sometimes once you've applied electricity to a track the controller hums really badly before turning itself off...
Oh, I should also point out that this guide is aimed at modellers using the old fashioned way of wiring layouts up using millions of miles of cable, spaghetti junction style control panels and lots of burnt fingers from misuse of the soldering iron. The DCC guide will have to wait until I actually know something about it ;)
The Electricity Supply
Unlike the AC electrical circuit in your house, the electricity that moves your locos is DC, ie. Direct Current. The supply to your layout comes by plugging a transformer into a wall socket that takes the AC supply, steps it down to, say, 16 volts, converts the output to DC, filters the DC to purify it, then outputs the supply from the terminals on the back of your controller, along a couple of wires to the tracks (regulated by the speed setting you place on the controller) where it is picked up by your locomotives wheels, turning the motor within. DC electricity is directional, so the electricity flows along the wires in a certain direction, and the locomotive moves in the direction set by the directional switch on your controller. (or left and right if your controller has a centre off type control knob)
The Controller
Generally speaking, you need one controller for each locomotive that you want running at the same time. So, for instance, if you have a four track mainline and you want four trains to be running on each of those mainlines at the same time, you will need four controllers. Perhaps you want a train to be running a loop on the mainline while you shunt wagons in a freight yard? In that case you would need two controllers.
Controllers for model railways come in many types. There are single centre off types that control a train by moving the knob to the left or right, or there are types that have separate throttle and brake levers and the direction the train travels in is determined by flicking another separate switch. There are also controllers that have a 'feedback' function that can supply a constant voltage to a train so that if the load on a locomotive increases (ie as it travels up hill or around a bend) the train speed stays constant. A lot of beginners to the hobby will start with a power supply that came with a trainset. While these controllers can be quite good a lot of them are quite unrefined in build and won't allow for the same quality of locomotive control that a decent controller will.
To a complete novice the vastness of the range of control devices can seem bewildering. There are handheld devices, panel mounted controllers, twin power units, quad power units and so on. Now, as wonderful as the internet is, and as good as the advice found on it can be, there is no substitute for seeing and feeling these units in the flesh. The best advice anyone can give a modeller using the internet for researching railway modelling is to get down to a good model shop and see and touch as many controllers as you can before you buy. Things to look for include comfort in use and good slow speed control of a loco (although different locos will provide different results with the same controller). If you want recommendations then drop a message into the newsgroup at uk.rec.models.rail and not only will people be only to happy to help you choose, but will let you know what is current or on special offer somewhere.
Connecting To The Track
Now, all controllers are different, but usually at the back are a couple of terminals, sometimes marked with a + or -. Don't confuse these terminals with any others your controller may have, as it's common for a controller to have outputs at 12volts DC and 16volts AC that allow you to power devices such as point motors and house lights.
Looking down at the controller, and with the unit facing towards you, connect a wire to the left side terminal. Run this wire to the nearest rail of your trackwork. Now connect a wire to the right side terminal and run this to the rail furthest away from you. When you connect your track this way any loco placed on the track will run to the left when you turn your control knob to the left and to the right when you turn your control knob to the right.
NOTE:Before you attach the wire to your track you need to drill a couple of small holes into your baseboard, one per rail, and thread the wire from your controller up through it. Never be tempted to run your electrics across the baseboard top in the hope of burying them in the scenery. If a fault should develop you won't have any way of correcting the problem without destroying any scenic work since done.
There are several ways to connect the wire to the track. The most common is to strip off a couple of millimetres of insulation from the end of the wire and while holding the exposed end of the wire against the track, apply a little solder. Always apply the solder quickly so the heat doesn't damage your trackwork, not to mention burn your fingers if they are resting nearbye! (I've done this myself so no worries!), and always solder the wire to the outside of the rail, not the inside where it would foul your rolling stock's wheels.
Another method of fastening wires to track is to use special connectors that are supplied by the likes of Hornby and Peco. These are usually push fit, slide between the rails and sleepers and are really only suitable for Setrack users. They can also be slightly unreliable, especially if they have been connected to more than one piece of track over time.
A third, nice method of connecting the wires to the track is to strip a small amount of insulation from the wire and solder the exposed end to the underside of a fishplate. When the fishplate is pushed onto a rail, that rail will be electrically active.
The Basic Loop
The techniques so far explained will allow you to power up a basic oval and drive a train around it, but for more interesting operation it is essential to add more loops, sidings and stations to your trackplan. The wiring required is essentially the same but with the addition of isolating sections that will prevent short circuits, and blocks that will allow you to have more than one train moving. To add extra trackwork to your layout you will need to add pointwork! Read on to the next page for the next step in wiring your layout...
