Well, if you can call it that! It's so much more, though:





This is a custom tail light I built for my trike. It is made of 120 super-bright red LEDs, and two 1W Luxeon LEDs. The two Luxeons are in the middle, they shine hotter than the rest of the bar. The 120 red LEDs are separated into two groups of 60, which alternately flash (you just can't tell from the picture). The flash rate is about 2.5Hz.





As you can see, the lights brightly illuminate the road, walls and everything behind the trike for at least 25 feet. The lights are visible from much further away than that, though. They are also easily visible in daylight.



The case is a 19" long piece of PVC conduit, 1" inside diameter. The PVC was later painted black with Krylon paint. Inside of the PVC tube is a clear acrylic tube, 1" ouside diameter, 0.875" inside diameter. The LED light bars are sealed inside the acrylic tube. The flasher circuit for the LED light bars is also contained in the tube. The ends are closed off with some metal caps I found at an electronics store.



The control box is mounted on the boom of the trike. It contains two Luxeon drivers, a 1000mA BuckPuck for the two 3W white LEDs on the front, and a 350mA BuckToot for the two 1W rear red LEDs. There is a single power switch, and a potentiometer that I can use to vary the brightness of the headlights. One wire goes to the headlights, one to the tail light, and one to the battery. I used a 11.1V, 7200mA Lithium Ion battery from batteryspace.com to power the whole thing.

So how well does it work in traffic? Well, cars actually give me more space. As I hypothesized, the extreme width of the tail light causes cars to pass with a wider margin than ever before. The light is easily visible from hundreds of feet away, even during daylight. The flash rate is roughly equivalent to that of a train crossing light or school bus, so it's something drivers are used to slowing or stopping for.

The total cost? Ummm, expensive. The biggest expense was the battery, actually. Darned import fees. I'll be posting more detailed pictures and instructions on my website soon...

That is the most amazing thing.
This has got to get on the make blog.

Instructions/schems/more pix plz?

Expect to see it here soon.
Specifically the bike section.
After you get the instructions up, aim for Hack-a-Day.

Good god that thing is bright. That thing must draw like, a full amp if not more.
It'll look a lot better if you outlined the last 1" with amber LED's.

Also, I'd imagine you got the Stars and drivers off Luxeon/lumileds. Where'd you get the other stuff? What was the approximate cost to build?

Edit... NM on the cost... "Expensive"

Here are schematics for just the 120LED blinkie portion, in jpg format:

300k download

Here are the original Eagle CAD drawings. Note that I created these using the Lite version of Eagle, which limits you to 4" long board. I needed 8" long boards for the LED light bars, so I modified the light bar artwork in photoshop to create an 8" long board. I have included it in PDF format.

120LED blinkie driver schematic - note this file is for reference only, it has no matching board file.

blinkie driver schematic, including dual Luxeon emitters

blinkie driver board artwork, including dual Luxeon emitters

blinkie driver schematic, with no Luxeon emitters

blinkie driver board artwork, with no Luxeon emitters

blinkie segment schematic (30 LEDs)

blinkie segment board artwork (30 LEDs)

8" blinkie segment board artwork (60 LEDs, pdf file)

Don't even bother looking at these files unless you know how to make printed circuit boards. Obviously, building this thing will take some training in electronics, a decent amount of equipment, etc. etc. Also note that the design has been optimized for 11V, but it should run just as well at 12V. It will not run on anything lower than 10V.

I don't have all of my assembly pictures sorted and edited yet, but will soon.....

Ah, right, the parts...

I bought the Luxeon emitters from Future Electronics.

I bought the 120 red LEDs from eBay, the seller was "Light of Victory LED company"

The LED drivers were from www.luxeonstar.com

The PVC conduit was from a local hardware store.

The acrylic tubing was from www.rplastics.com

The other misc. electronics were from my local electronics store.

And, as mentioned before, the battery (and matching charger) were from www.batteryspace.com.

Doesn't the headlight shining on the inside of the front fairing make it impossible to see through in the dark and reflect a lot into your eyes?

I actually look over top of the fairing. Even without the light, the fairing slightly distorts the light going through it, so it's not really suitable to look through anyway. Having the fairing illuminated makes it look like I have a 1 square foot wide headlight, though!

That is awesome... .what kind of life do you get out of that thing? Hw heavy is the whole assembly with the battery and all?

On a normal bike, i think half of that would still be sufficiently bright.

What, no turn signal????
j/k

Have you had any airplanes try to make an approach with that thing...!?!? You may have more light-power on your bike than I have on my ambulance at work. Very cool!

Nice!

Turn signals were planned, actually. Maybe if/when I build a velomobile.

Now *THAT'S* a light!

So, how much is "expensive" in dollars, and is that Cdn$ or US$? Could you have built it for less if you'd done some design differences?

Kick Ass Jello-J!


If 2manybikes is the Emperor of taillights (Deathstar), you would be the Darth Maul withthat dual lightsaber

Does that mean I'm gonna be cut in half?

Katzenjammer, the estimated cost was about $200. Nearly 3/4 of the cost was the battery!

dang, that's a tail-light. With all the blinky nuts here, you could make it a part time job making these for folks

It looks like it maybe in the Plans for Rebel Cycles

Hmmm, maybe, but only in kit form. I'm considering 60 and 120LED versions, without the Luxeon emitters (since they add about $25 to the cost)

you're a madman.

So what's the battery life?

In a week of commuting I haven't drained the battery yet. The battery has a life of 80 Watt-hours, and I calculate the front and rear lights draw 9W total, so that would be 8.9 hours. It'll probably be less than that, though.

Nice, longer than I would have expected.