now there’s a bright idea

1st pun :D

Posted at 4:23 pm on Sep 3rd, 2009 by sly

Meh… Someone built a 2800 lumen light already. http://forums.mtbr.com/showthread.php?t=487467

Posted at 5:06 pm on Sep 3rd, 2009 by epicness

Before instructables whiners start, here is the direct-NO-LOGIN-REQUIRED-pdf-link;

http://www.instructables.com/pdf/700-Lumen-LED-Bike-Light/700-Lumen-LED-Bike-Light.pdf

I submitted instructions in obtaining PDF URL just from the article URL for any Instructables articles to Hack-a-day, I guess they didn’t like it.

Posted at 5:11 pm on Sep 3rd, 2009 by PDF

http://www.dealextreme.com/details.dx/sku.14413

Brighter and easier. Remove the reflector if you want a flood.

8.4v works, like 2 LiPos, or a Nimh “9v” (1.2 x 7).

Actually anything from just under 5 to 8.4 volts works, but it requires enough current, and will deplete batteries very quickly.

Posted at 6:06 pm on Sep 3rd, 2009 by tz

I used that same LED tz, and built a custom current driver using an lm3401. the thing will project a beam 300 yards. need to get a proper lens on it, but i’m good with electronics, not optics.

http://i533.photobucket.com/albums/ee334/ajm8127/DIY%20Bike%20Light/00001-640×480.jpg

Posted at 7:33 pm on Sep 3rd, 2009 by tony

i thought leds didnt get hot

Posted at 8:31 pm on Sep 3rd, 2009 by roy

@roy:
power leds get really hot, but out the “back” side. some high-power led designs use some thermal feedback to keep the operating point sane, others just throw a big heat sink on it and let ‘em go.

Posted at 9:08 pm on Sep 3rd, 2009 by dielectric

that’s not really a potentiometer, looks like he’s using a pre-packaged PWM module.

/at least i hope he is.

Posted at 9:52 pm on Sep 3rd, 2009 by Man On Fire

With only R2’s, that’s only marginally better than my 3x Q5 setup – but I would suspect that the use of just lenses with no reflector backing means the cast and fullbrights aren’t as useful with much of the energy wasted – especially given the existing lens on the bulbs. Brute force instead of finesse.

Though I’m planning on my next build using R2’s, but I’m going with this reflector:
http://www.dealextreme.com/details.dx/sku.18842

Probably go with the same pucks I did for my existing unit:
http://www.dealextreme.com/details.dx/sku.3256

Just like my existing unit I’ll do one puck per bulb and put copper VGA ramsinks directly on the base of each bulb. I like the 14mm base DX has for the Q5’s.
http://www.dealextreme.com/details.dx/sku.11023

I’ve looked at the R2 on a premium star, but my parkinsons ridden hands aren’t up for cutting things down anymore – and really I don’t consider the 2-3% brightness difference to be worth the 20% price hike.

Posted at 11:11 pm on Sep 3rd, 2009 by Jason Knight

@dielectric:
I’m not disagreeing at all with what you’re saying I just wanted to note that with enough output you can actually feel some heat from LEDs out the front as well. I built a custom light a year or so ago that puts out around 800 emitter-lumens and you can feel some heat from that radiating out the front. Nothing even remotely close to an incandescent though (I managed to burn a hole in my TV with a custom incandescent I built which turned itself on when I wasn’t around, whooops)

Posted at 3:45 am on Sep 4th, 2009 by Rob

Looks like Instructables closed down no login pdf link access. You may resume whining.

Posted at 7:43 am on Sep 4th, 2009 by pdf

I’ve wondered why I haven’t seen more bright LED projects on hackaday. Check out candlepowerforums.com for some good info.

My light setup for my bike is a Marwi P7 conversion that puts out around 700 lumens. I don’t need an external heatsink, the one inside moves all the heat to the body. While stopped it gets hot quick, I have to dim it until I get moving.

Posted at 8:36 am on Sep 4th, 2009 by Xiejol

If one was to take a microcontroller and create a stobing circuit with this set up, one could find out the frequency of the stop lights around town with a few adjustments. :-) However, I hear it’s not highly suggested.

Posted at 8:52 am on Sep 4th, 2009 by JD

Intructables has really gone down in my view with all their forcing people to sign up and log in for more and more functions (although I understand the PDF being users only).
I used to have that site in my quicklinks but no more, you can’t even see the secondary small pictures without logging in.
It’s a pity, and an affront to people that submitted articles when he were more reasonable, but it shows that you should never put too much money on a single horse eh.

Posted at 8:02 am on Sep 6th, 2009 by Wwhat

Quite nicely put together, although i’m not sure that using a heatsink is anything new with high power LED’s. I’e been seeing cheep 20w modules floating around on ebay quite a lot recently. Has anyone had any luck with these?

Posted at 9:50 am on Sep 6th, 2009 by TalkingJazz