i think you guys will like my brake light prototype

[rox]

this is just the running light portion, at half power (12v) in a fully lit room

each circle consists of 24 lumileds superflux leds. the center is going to have a single luxeon star for the brake portion.

 

[highlandsun]

It looks interesting. How does it compare to the original incandescent brake light?

Hmm... 24 red-orange SuperFlux LEDs driven normally should produce about 100 lumens, so you've got 200 lumens if both of those circles light up full. Adding a red-orange Star to each, 55 lumens each, not bad. Should be very close to the output of an 1157 behind a red filter/lens, may be slightly dimmer if these things will also be behind a filter.

A clear 1157 only provides 38 lumens on the low filament, and 402 lumens on the high filament. I think your ring of SuperFlux LEDs will be much brighter than you need for running lights unless you drop their drive current some more. The brake light might be a bit dimmer than you need, unless you allow the LEDs to all be overdriven.

Gives me some ideas though, I've been thinking about putting some LEDs behind the blank center reflector on the tail of my car.

 

[rox]

each circle replaces 1 1157, so 2 per side on the car. dont forget that a red lens over a white bulb blocks a significant part of the light, but blocks virtually none of the red led light. i might turn down the drive current on the rings, it will have to wait till i get it on the car to see. there is also a provision on the board for running the rings at dual brightness for running/brake. also i saw another persons car using only a single luxeon and it seemed plenty bright.

 

[lambda]

I'm not sure officer, we were approaching a stop sign, then everything just went red!

Very nice!

Please show us some pics when you get those bad boys mounted on your car.

 

[highlandsun]

Yeah, sounds OK but you won't know for sure until it's actually on the car. It may be bright enough or even too bright in a couple directions, and not enough at some other angles. The actual minimum brightness specs are pretty low, so I think you'll be in good shape overall. Have you already read the Lumileds app note on designing automotive signal lamps with SuperFlux LEDs? It goes into the illumination requirements in pretty good detail.

I'm rigging up 4 amber Luxeons for a front corner lamp - running light/turn signal. The big kicker here is that a signal flash is supposed to be >5x brighter than the running light mode. I may actually need 5 Luxeons to meet this requirement. Right now I'm betting that overdriving the Luxeons for the flash will be enough.

 

[Rothrandir]

wow, that sure is impressive. what kind of vehicle will you put these on?

also, is there a limit to brightness? i would like to eventually spend $$$ and make super bright turn signals because...well...i don't know why...i just want to...

 

[flash....]

I agree... Nice work...
Look like Corvette style rear lights.
What kind of car? I have allways wanted to do that, only as a complete fill for the entire behind the lens area.
Are those LEDs fairly affordable?

 

[evan9162]

Where'd you get the superflux LEDs?

-Darin

 

[rox]

here is the car its for

this is what the lights look like now

if youre curious about the car go to http://www.fearme.com/cars/rx7/

howard: i went with the wide angle superflux which have a 70 degree viewing angle at 1/2 intensity so hopefully that should be good. 4 luxeons sounds like one bright turn signal man. oh yeah im also working on a version using the snapleds round array, which is designed for automotive purposes. and yeah i read through the lumileds technical docs

flash: they are semi affordable, i think they are $25 or so for a rail of 60 from futureactive. probly cheaper if you call them.

darin: i got them from futureactive which is the only retailer for lumileds i think.

 

[highlandsun]

I was looking into the SuperFlux and SnapLEDs too but I decided that it was easier (less soldering, less aiming) to use a handful of Luxeons instead. The High Domes look really good on the data sheet. They're pretty bright in person too, definitely. But they need to be, otherwise they'd be totally masked by my HID headlights.

Nice RX7... Check my pix on this other thread, you'll see why I need them bright. http://www.candlepowerforums.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=15&t=000090&p=1