LED Taillights, Custom Made for the 914 Options

[Harpo]

Looks good. I'm inclined to believe that they can't be bright enough. Our tail lamps are lower than most cars and if those following us are indeed one car length per 10 MPH then the brightness should not be a problem. IMO

Thanks for the great work! I can't wait to get a set.

DAvid

[CptTripps]

David: That may be true, but there comes a point where you can flash peoples eyes and cause spots where they CAN'T see. That's REAL bad when they're driving behind you. ;-)

[Spoke]

Looks good. I'm inclined to believe that they can't be bright enough.

I thought the same thing when I started this design. High power LEDs nowadays can put out ridiculous amounts of light.

To compare output levels, I have one board with 63 of the standard 5mm LEDs running about 50mA in each LED. This board with 20 Cree's running 35mA puts out more light than the 63 5mm LEDs.

The test I did today with 200mA produced so much light that was painful to look at. I stood 20 feet away from the board installed in a 914 housing and I couldn't look at it. The shadow produced on the wall looked like a powerful red spotlight.

I will adjust these to be as bright or brighter than any vehicle brake lights I see. The main idea as you point out is to make our 914's be seen under braking.

[Harpo]

Obviously you have first hand experience with how bright these are and therefore trust your judgment. Looking forward to having this upgrade in my car.

Thanks again

David

[McMark]

Could you do a few milliseconds of bright flash and then step down to a safe level? (IMG:style_emoticons/default/idea.gif)

[r_towle]

Looks good. I'm inclined to believe that they can't be bright enough.

I thought the same thing when I started this design. High power LEDs nowadays can put out ridiculous amounts of light.

To compare output levels, I have one board with 63 of the standard 5mm LEDs running about 50mA in each LED. This board with 20 Cree's running 35mA puts out more light than the 63 5mm LEDs.

The test I did today with 200mA produced so much light that was painful to look at. I stood 20 feet away from the board installed in a 914 housing and I couldn't look at it. The shadow produced on the wall looked like a powerful red spotlight.

I will adjust these to be as bright or brighter than any vehicle brake lights I see. The main idea as you point out is to make our 914's be seen under braking.

Are you doing something for the 911?
Having pulled up behind a few I am concerned the taillights are far to dim

[Spoke]

Could you do a few milliseconds of bright flash and then step down to a safe level? (IMG:style_emoticons/default/idea.gif)

Neat idea. Yes, this would be easy to do. How long of brighter flash would be good? 1/10 sec? 2/10 sec?

[Spoke]

Are you doing something for the 911?
Having pulled up behind a few I am concerned the taillights are far to dim

I plan to do one for the 911. They have really small brake lights.

Here's the latest 914 brake light. I stretched the board vertically to fill the brake light cavity and moved the LEDs to the edges of the board to get a larger light footprint. LEDs shine in the direction you point them. The lenses don't have a very wide dispersion so these will look larger especially at night.

I added the leading edge bright flash when the brakes are applied like Mark suggested.

The circuitry on the back really shrunk since I didn't need all the current the first circuit was designed for. I still use a big ass DPAK FET where I think I could have used a converter with a built-in FET.

Plus I changed from a boost converter to a buck converter. Buck converters are more suitable to handle transients on the brake/taillight wires than a boost converter.

[Harpo]

Looking good

[Cairo94507]

I really like the idea of a brighter flash for a couple milliseconds and then stepping it down to just bright.

[jcd914]

Looks good. I'm inclined to believe that they can't be bright enough.

I thought the same thing when I started this design. High power LEDs nowadays can put out ridiculous amounts of light.

To compare output levels, I have one board with 63 of the standard 5mm LEDs running about 50mA in each LED. This board with 20 Cree's running 35mA puts out more light than the 63 5mm LEDs.

The test I did today with 200mA produced so much light that was painful to look at. I stood 20 feet away from the board installed in a 914 housing and I couldn't look at it. The shadow produced on the wall looked like a powerful red spotlight.

I will adjust these to be as bright or brighter than any vehicle brake lights I see. The main idea as you point out is to make our 914's be seen under braking.

There are legal limits on the light output from both brake and running lights, something in the range of 100-300 candela for brake lights in the US.

Jim

[Speedmster]

Looks good. I'm inclined to believe that they can't be bright enough.

I thought the same thing when I started this design. High power LEDs nowadays can put out ridiculous amounts of light.

To compare output levels, I have one board with 63 of the standard 5mm LEDs running about 50mA in each LED. This board with 20 Cree's running 35mA puts out more light than the 63 5mm LEDs.

The test I did today with 200mA produced so much light that was painful to look at. I stood 20 feet away from the board installed in a 914 housing and I couldn't look at it. The shadow produced on the wall looked like a powerful red spotlight.

I will adjust these to be as bright or brighter than any vehicle brake lights I see. The main idea as you point out is to make our 914's be seen under braking.

There are legal limits on the light output from both brake and running lights, something in the range of 100-300 candela for brake lights in the US.

Jim

I'm not seeing a maximum limit. I see a minimum limit. I'm looking a NHTSA Table IV-a—Effective Projected Luminous Lens Area Requirements. Then again I'm not even near expert on reading regulations. Anybody know how to read this stuff? (IMG:style_emoticons/default/WTF.gif)

Easier version:
http://books.google.com/books?id=K7OqEdViZ...nts&f=false

NHTSA version:
http://www.fmcsa.dot.gov/rules-regulations...spx?reg=571.108

Maybe that's why the "NOT FOR ROAD USE" printed on the board. (IMG:style_emoticons/default/lol-2.gif)

[Spoke]

Been contemplating (IMG:style_emoticons/default/idea.gif) a way to secure the board to the housing with minimal effort.

Mikesmith suggested a clip that would be held in place by the taillight lens and would just clip onto the divider on the housing and the board and thus hold the board in place.

So I used some sheet brass to mock up such a connection.

Here are the pieces. Looks like it will work just fine. I will look into getting these made in plastic or metal.



Just insert the clips into the holes in the board.



And slide the clips onto the plastic dividers.

[CptTripps]

Great work man. That's a seriously great project...expertly executed.

[monkeyboy]

Beautiful!

[Spoke]

Here's a comparison of the Cree LED board and the 1157 bulb. The first two flashes are the taillights and the last 3 are brake lights. Quite an improvement over the 1157 bulb.

For braking, the 1157 bulb is burning 21W while the Cree LED board is burning only 1.4W. One can also see the immediate light of the LED vs the 1157 when the brakes are pressed.

I had put in a circuit to flash the brake lights 4 times the intensity for about 1/4 second but it's not working in the car. Worked nicely in the lab with short wires to the power supply. The longer wiring of the vehicle must be slowing the rising edge of the voltage to the lights.


https://www.youtube.com/watch?v=qyFzq9C1hxM

[Spoke]

This set of LED brake lights is now for sale. This is the only set available with these 5mm LEDs.

I wanted to try these out before I had the Cree LED board going. I've been running these in my car for the last several weeks.

These work well and put out a lot of light. See posts 186 through 196 for the light results.

This is the only set. Just looking to cover my cost at $55 + shipping. Includes 2 boards with pigtails and light bulb bases as shown, and 6 clips.

Real simple installation: pull bulb, insert bulb base, insert clips into boards, clip onto existing enclosure frame.

Respond to this thread if interested in purchase.

[Jeffs9146]

I am in for a set! (IMG:style_emoticons/default/beerchug.gif)

[Speedmster]

This set of LED brake lights is now for sale. This is the only set available with these 5mm LEDs.

I wanted to try these out before I had the Cree LED board going. I've been running these in my car for the last several weeks.

These work well and put out a lot of light. See posts 186 through 196 for the light results.

This is the only set. Just looking to cover my cost at $55 + shipping. Includes 2 boards with pigtails and light bulb bases as shown, and 6 clips.

Real simple installation: pull bulb, insert bulb base, insert clips into boards, clip onto existing enclosure frame.

Respond to this thread if interested in purchase.

Spoke, is there a chance you could shoot a video or take a photo in broad daylight about 20-30 feet behind the car? Interested in how the LEDs preform in the daytime also. Similar to the photo in post #196 that was at night from the rear of your car.

[Cairo94507]

Wow- this project is moving forward very nicely. That is looking nice. I too would like to see some video from behind during the daytime. Thanks for the hard work and dedication.