LED Third Brake Light, My Newest Design Options

[Special_Edy]

So I originally built a 58 Red LED third brake light and was dissatisfied with the result-








It was only about as bright as the OEM incandescent so it was back to the drawingboard.

I finally had time today to solder this together, it uses 97 5mm White LEDs(the maximum amount I could cram in). The current draw is apx. 9 watts and the service life is apx. 100,000 hours. It is bright like headlight bright.





First Layer of 57 LEDs-







Second layer of 40 LEDs, Finished!!!!!!-











And finally Video-
http://www.youtube.com/watch?v=eh44hn_EBz4


If there is enough interest I may make some of these for 6gc members as well as some of the other exterior lights.

This post has been edited by Special_Edy: Nov 24, 2012 - 3:01 AM

[broderp]

Interesting idea. Did you calculate the current flow thru each LED to utilize the proper size current limiting resiztor and optimize the output of the LED? I've seen many circuits that use the wrong sized resistors, this leads to dim LED or worse, overdriving the LED's and damaging them. (Will dim or just not work)

Also, based on the picture of the side marker light on your Celica, your not in the USA, do you have any restrictions on how bright a light can be? Seems to me that here in the USA, if I have a rear tail lamp as bright as a headlight, I'd probably get a ticket! lol So one like your first design with 50+ LEDS may be a better alternative.


Nice job.

[Special_Edy]

Interesting idea. Did you calculate the current flow thru each LED to utilize the proper size current limiting resiztor and optimize the output of the LED? I've seen many circuits that use the wrong sized resistors, this leads to dim LED or worse, overdriving the LED's and damaging them. (Will dim or just not work)

Also, based on the picture of the side marker light on your Celica, your not in the USA, do you have any restrictions on how bright a light can be? Seems to me that here in the USA, if I have a rear tail lamp as bright as a headlight, I'd probably get a ticket! lol So one like your first design with 50+ LEDS may be a better alternative.


Nice job.

Well, Ive learned alot about LEDs to say the least.
The LEDs are transistored for 14 volts and I lowered the forward voltage a tad so they should never have any problems.(even a whopping 50% power reduction would only drop light output by 10%)
As for the beam of the LEDs, they really do project most of the light in a tight cone. Anyone 1-2 car-lengths directly behind you will see it much more brilliantly(in the video it glitched my camera at about 5 feet) but its still far brighter than stock from any angle.
The only applicable laws that Ive read specify the maximum luminosity of a bulb mounted anywhere on the vehicle(except headlights and brakelights) can be no more than 300 lumens(in my state). This definately falls below 300 lumens and you could even argue that each of the 97 bulbs counts individually. The aim, shape, housing, lens, color and height of the brake light will be unchanged the only thing you are doing is replacing the barbaric incandescent bulb with a more enviromently friendly(and badass) light source. It also uses nearly half the energy and produces about twice the light of the incandescent.

Oh, and I am in the US, I just have JDM fenders and tails.



Now why I havent made much progress. A week and a half ago I did this-



I was in a turn lane and thought I saw the car in front of me go, so I turned and watched three cars go by before I could go. I let out the clutch and nailed the car in front of me(he had stopped ahead) . Guess I should of double-checked.


And of course the LED turn signal I was working on at the time was installed inside that turn signal housing. I had to run out into traffic to save it from getting run over(it flew out when the housing disintegrated).

Video of my turn signal functioning after the wreck

I think only 3 leds total stopped working, which were just the wire bending and shorting out(no repairs needed). But the board was cracked into many pieces, held together only by the LEDs and solder.





Here is my progress on the controller for the sequential turn.




Ive finished the 555 timer, it adjusts from 14hz-58hz.
Working on the three 4017 decade counters which do the sequencing.
The 4081 is just AND gates to make the 4017s count from 1-24 instead of 1-1000


Ive still got to wire in the resistors and some sort of mosfet or transistor to drive each of the 24 channels. I also want to utilize capacitors to fade the LEDs in the sequence out instead of them flashing off.





Finally, Im looking to get some clear LED's that produce red light. I found some that are half the brightness than the white ones I have now but have twice the beam width, so they are approximately 2 times the the lumen output.
I also found some wider angle clears that are apx. 5 times the output I want to order which are about the same price as my current bulbs, along with some 3Watt LEDs(they could probably damage your retinas:D) on heatsinks but those badboys are a $1.25 a piece.
Let me know guys-
would there be interest in a 400 lumen white LED third brake light?
And a 200 lumen red LED version(with clear bulbs)?

This post has been edited by Special_Edy: Dec 10, 2012 - 3:29 AM