Fully-Functional LEGO Traffic Signal Lamp

Picture of Fully-Functional LEGO Traffic Signal Lamp
As many of you know, most of my LEGO creations are a blend of my childhood passions, notably Transformers, Nintendo, and uh, traffic lights? Yes folks, it's a little-known Baron von Brunk fact, but when I was a wee lad, I had an offbeat obsession with roadsigns, traffic signals, and road construction equipment. When others in my age group at the time were doodling pictures of Batman with crayons, I was drawing countless images of various road signs and orange construction cones. In fact, my mama used to snag roadcones from construction sites and give 'em to me as strange playthings. I dreamed of growing up and not only living in a house filled with LEGO bricks, Nintendo games, and Transformers figures, but also with authentic roadsigns and lights on the walls. That being said, as I've traditionally built LEGO Transformers or LEGO Zelda/Mario-related projects in the past, I decided to build a fully-functional (and near life-size) traffic signal lamp, constructed almost entirely from LEGO pieces -- sans the electrical wiring/lights! The actual traffic light itself is constructed from LEGO pieces (totaling about 1,700+), whilst only the wires, lights, power plug, and switch are non-LEGO -- with no other modifications, such as painting, glue, sanding, nor cutting.

This project is not an easy build to say the least, nor is it a cheap thing that you can slap together with random electrical parts. The LEGO construction was a heavily-modified project that went through a ton of revisions in both the 3D program LEGO Digital Designer, as well as in real life. As a result, the physical LEGO portion of this project via the LDD file may differ slightly than what you see in the final outcome, and if you attempt to build one yourself, you may notice a few differences.

The electrical system seems rather tricky, but is actually somewhat simple, if you have a basic understanding of soldering/wiring. The "brain" of the project is actually a model railroad traffic signal controller that I purchased on eBay, and then ultimately wired into the infrastructure of the traffic lamp. The light bulbs are pricey LED spotlights that use very little electrical power yet have a strong illuminated output. In simple terms, the LEGO structure serves as a house, inside the "house" are three spotlights each rigged up to a microchip which cycles through the colors like a real traffic light, and the front of the "house" uses a grid of colored transparent LEGO pieces which act similar to a Lite Brite set (or almost resembling a cluster of LEDs lit up). This "Lite Brite" system was covered in my popular Mosaic LEGO Lamps tutorial, which explains the principles behind colored light grids.

Like my other LEGO projects that I encourage fans to duplicate and make changes upon, this particular model can be altered according to your desire. You can forgo the whole electrical portion I've built and instead incorporate an Arduino system and control it via your computer. You can even mess with the colors or design, such as making the green light into a green arrow. It's all up to you.

Here are the following resources for parts:
  1. LEGO Digital Designer (free download) - 3D CAD program for making custom LEGO models - officially produced by LEGO Group, and not a third party program.
  2. My Traffic Light Signal LDD file (hosted on my site) - download the above program and import this model, which has its own 3D building guide included within. Here's a mirror link on my Google Drive. The instruction guide and parts list in an HTML format slideshow can be seen here.
  3. - a superb website for purchasing LED bulbs. The particular lights I used in my model can be found directly here - 48SMD-LED MR16, cool white, $9.95 each.  You'll need three of them if you plan on making a direct duplicate of my design. I would highly recommend getting the solid white 6,500K bulbs, as they have great brightness, as opposed to the red, amber, and green lights (of the same product), since they're sort of dull. If you purchase these lights, you'll need this specific type of base to house the bulb (you'll need three, of course). These particular bulb sockets have two small holes drilled into them, which are just the right clearance of being penetrated by a LEGO antenna or pin, which you'll see later when assembling the whole shebang.
  4. - at this point I'll make the assumption that you're a highly skilled master LEGO craftsman, thus this link is pretty self-explanatory. For those of you out of the loop, Brick Link is a huge online "candy store" for new and used LEGO pieces. My LDD file for the traffic light contains a full list of parts; just to give you a fair warning, this project -- according the LDD file -- contains exactly 1,779 LEGO pieces. If you're a novice builder and lack the patience and ability to sit through assembling a titanic model of this caliber, I would not recommend trying this. Also keep in mind that more LEGO bricks also equals more spending. Albeit this structure is pretty straightforward and requires a lot of simple masonry and engineering techniques, as opposed to something crazy elaborate like my LEGO Nintendo 64 Transformer. The LEGO portion of this traffic light is basically one really big yellow box with a door on the back, to be blunt.
  5. Model Railroad Traffic Light Control Circuit - I personally chose a pre-assembled DC version of this item, to save time, and so that it could easily be modified to potentially become portable and run on batteries. The AC version is slightly more expensive but can use larger 120V light bulbs with a greater amperage rating. The DC version is cheaper, but is limited to smaller bulbs like LEDs -- hence why I chose them; also because lower-voltage bulbs tend to have lower output power and would have less a chance at melting my LEGO bricks. The DC controller required an AC adapter (12VDC output) to be spliced into the screw terminals you'll read about that on step 2).
  6. Radio Shack - you'll need the following things to mimic my design verbatim: on/off toggle switch, 22 or 20 gauge wire, soldering iron/gear, 12VDC output 120VAC input adapter, and small spade and ring terminals.
If you're capable of purchasing/downloading all of the above items, then proceed to obtaining the whole lot and then moving onto the next steps for information on assembly! Just to give you an estimate, you'll probably spend over $100 on one of these suckers; more than half of that is the electronic portion alone; I was lucky enough to have a bunch of old AC adapters in my closet, and the soldering iron, spade terminals, and wires were leftover from my giant LEGO NES controller. Again, this is not an easy nor cheap project to build, if you're unskilled with LEGO construction as well as basic electrical work. Some of the initial failures with lighting and LEGO construction may even seem rather frustrating.

I'll keep the assembly steps pretty straightforward, with some notes on the LEGO construction portion and a very basic schematic to go along with.
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Mielameri6 months ago
Love it! LEGO-ise the world!
How do you come up with this epicness?!?
A lot of my blood, sweat, and tears go into these projects -- as well as money and beer.
Here's a traffic light in wpg, canada.
2014, 10:22 AM.jpg
astondb96 months ago

You weren't the only one to have an unhealthy obsession with traffic lights and road signs.. I too had a room full of road signs and still dream of a working traffic light on my wall... Which just makes this project even more amazing.

DarkStarPDX6 months ago

Is there a way to import the BOM into BrickLink and have it figure out a way to buy all the bricks? Seems like it's going to take quite a while to source all 115 different bricks... You would think LEGO would make it convenient to buy the bricks out of their design software...

Baron von Brunk (author)  DarkStarPDX6 months ago
Unfortunately, I believe LEGO Group removed the order function with uploading LDD models to their site -- so I also think that means you can't order an entire list of pieces directly from their catalog (I think). I'm more of a maverick, sloppy artist -- hence my process involves ordering a ton of pieces of a certain color that I've determined necessary (from Bricklink), then building my creation organically from the pile!
create man6 months ago
I am really impressed
zack_man8886 months ago
I too shared your childhood obsession with all things having to do with construction. This brought back some good memories. Thanks for sharing!
The Fig6 months ago
Nice work, Baron. I think a couple of black ones of these (in Australia our traffic lights are black - pretty boring I know) will be making a presence at our next LEGO Fan Expo. Thanks for sharing the designs and all the tech details. Keep on building!
Baron von Brunk (author)  The Fig6 months ago
Thank you! Again, you can make your final design bigger or smaller or even a different color if you'd like, with my frame as more of a general suggestion. If the microchip I've used isn't sold internationally, you could also use an Adurino circuit and have several lamps rigged together!
arempel6 months ago
Quite innovative indeed!
arempel arempel6 months ago
Myson loves trucks, stop signs, etc so it's not weird at all. My son likes this so I might be investing into some Legos soon. Nice work here!
Wow I could never do that probably because I'm very impatient