Wiring up LED lights on your model railway – the simple guideOn November 8, 2016 Digital 4 Comments Tags: Lights
I’ve covered the mechanical aspects of making street lights before, this post however focuses on the electrical element of wiring up LEDs.
When most people think of lights they think of street and room lights. But Model railway builders aren’t so limited in their imagination.
There are so many uses for lights around a layout, from simulating the warm glow of a bonfire to house and building lights to illuminated neon shop window and advertising signs LEDs and lights have a multitude of uses on model railway layouts.
Extra: If you’re still new to LEDs there’s a great summary on using them here.
But no matter what you use them for you’ll have the same challenge — how to power, wire and control them.
Assuming you’ve got your hands on some LEDs that you want to use around the layout the first question is how to power them.
Power supply for LED lights
If you just have one or two lights and will only use them occasionally batteries are probably the easiest option.
A standard 9volt battery will be more than capable and depending on use will last some time.
If you have a lot of lights or don’t fancy crawling around under the baseboard changing batteries a permanent mains fed supply is what you’ll need.
For this you’ll need an adaptor that changes the juice coming out of the wall sockets to see something less harmful for a model railway, a 12v DC supply.
Note, as covered in a recent reader q&a on lights and controller terminals, you can’t use the 16v accessory terminals on your controller for this.
I use these to power my lights.
They’re actually power supplies for other household electronics but work a treat for railway lighting, they’re also cheap which keeps Mrs MRE happy.
(If you want to know more about AC and DC power and LEDs there’s a walk through in LEDMagazine).
Connecting them up
With the LEDs and power supply sorted you’re nearly ready to connect them up and test things out but before you do one other element is needed.
The electricity coming out of the battery or power adapter will be way to much for the tiny LEDs.
To change it down resistors will be needed.
There are lots of different versions available depending on the power source, how many LEDs you have and how much each one consumes.
Luckily there’s a handy calculator here.
Just type in the numbers required and it’ll spit out details of the resistors you need and even draw you a little diagram showing where to connect them. There’s a handy guide if you’re unsure what values to use, just click on the ‘I’ next to each field on the calculator.
Make a note of the Ohm ratings of the resistors shown, jump over to eBay and search for ‘resistor x ohms’. Obviously replacing x with the Ohm rating shown on the LED Calculator website.
Now all that remains is to solder wires from the power source to the resistors and then to the LED (remembering to solder the wires to the positive and negative connections of the LED) and try them out.
Assuming all works as expected, place them on your layout, in your buildings etc, turn on the power and watch it spring into life and light.
Extra – lighting effects
This guide covers permanently-on lights. But with a few extra bits you can have your lights flicker or change to give the illusion of flickering flames, traffic lights or even a welding effect for engine sheds and garages. Take a look at the wonderful Train Tech range of lighting products that provide the electronics for these effects. They’re simple to wire up, come with the necessary LEDs and work with both DC and DCC layouts.
What you’ll need to get:
- 12Volt DC power supply
- LED lights and resistors from eBay or a local electrical supply (Maplin etc). Use the calculator above to work which.
- Optionally, Train Tech lighting effect controller(s)
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