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New LED Flashlights
By RobD, Section Homebrewed Electricity Posted on Fri Jun 20th, 2003 at 09:41:07 AM MST
New Flashlights

Hi All,
After several designs and LEDs I have finally come up with an LED flashlight that is equal to a good Maglite flashlight with about 1/5 the power or less.
The LEDs are from Lumileds and are the most powerful in the industry. They are their Stars and the output is very high. I have used a special switching circuit and chip to drive the Flashlight and keep the efficiency high.
If any one has any questions or wants the power supply info I'll be happy to give it out. I'll put a more detailed circuit on my site in the next few days.
This flashlight is really good and powerful. I built several before this that just didn't have the color or intensity and it seemed they just sat in the corner when a 'real' flashlight was needed, not these. The photo is of the large one . There is a smaller one one but I haven't photographed it yet.
RobD
http://www.dsgnspec.0catch.com/LEDS.htm

New LED Flashlights | 8 comments (8 topical, 0 editorial)

Re: New LED Flashlights (none / 0) (#1)
by ADMIN (info74 at otherpower.com) on Fri Jun 20th, 2003 at 10:24:58 AM MST
(User Info)

Nice! I'll build one when you can supply the the driver circuit info!

I just started looking into the Luxeon Stars -- very bright; we are looking into carrying them.

Cheers

DANF

Re: New LED Flashlights (none / 0) (#2)
by Anonymous Hero on Fri Jun 20th, 2003 at 01:22:58 PM MST

I found out about these leds last winter and made a headlamp with three in series to fun off a nmh 12 volt pack. Plenty bright and last for days. I used a potentiometer on the lever that was for the close and far light focus to be able to dim the light when the full output wasn't needed. Not as efficient as a pwm circuit but these things are efficient enough. The only trouble I had was getting the right glue to keep the lens on each led. without them the light spreads out to much. I also made a headlamp using 4 AAAA batteries and limit resistor for someone else. I bought the headlamp at Wallymart and it had a switch to go from some ordinary white leds to a incandencent lamp. I replaced the energy hog with the luxeon star with good results. Chris

[ Parent ]

Re: New LED Flashlights (none / 0) (#4)
by RobD on Fri Jun 20th, 2003 at 03:06:49 PM MST
(User Info) http://www.dsgnspec.com

Hi Dan,
I can make a kit up pretty cheap. Circuit board sizing might be a problem because I contoured these especially from the flashlights I bought at Wallymart.
Also I want to burn these circuits in awhile and make sure there are no bugs.
If you want the parts let me know and I'll get them out to you so you can do some experimenting.
By the way I got these LEDs from a buyer who bought 100 at a time and they ran me about $5.00 each. I'd love to get more since I'm down to 5 pieces. If you want to carry them I'll let you have the circuit design which looks quite good. It starts with 6.15 volts and runs it down to 3.1 volts at a current limit of about 250ma. 100ma below the peak advised for the Luxeons. I did some experimenting and came up with 250ma. as a compromise between brightness and current drain.
RobD

[ Parent ]

Re: New LED Flashlights (none / 0) (#6)
by Anonymous Hero on Sat Jun 21st, 2003 at 01:53:28 AM MST

The Luxeon stars LED are some of the best, and we have used them in off grid lighting projects. We also support a world development project that uses thease LED's you can find it here. http://www.lightuptheworld.org/index.html Great job on the flashlight, for heavy use you will need to make sure that you have a good thermal heat sink for long life. Jenni Bryce www.pineridgeproducts.com

[ Parent ]

Re: New LED Flashlights (none / 0) (#7)
by RobD on Sat Jun 21st, 2003 at 08:27:38 AM MST
(User Info) http://www.dsgnspec.com

Thanks,
On the flashlight pictured the small pedestal that holds the Star acts as a heatsink and since I'm only running it at 250ma. the heat created is much lower than the 360ma that this LED is capable of. On the smaller flashlight (not pictured) the reflector is aluminum and acts as the heatsink. Both give off very low heat. I did make sure that the switching power suppy had an extra choke on the output to keep the AC ripple under 200 mv. (Spikes in the output can cause problems and over heating in the device driven)
RobD

[ Parent ]

Re: New LED Flashlights (none / 0) (#8)
by jubalearly on Mon Jun 23rd, 2003 at 03:56:12 PM MST
(User Info)

You might want to check out the LED flashlight & circuit designs on http://www.candlepowerforums.com

I'd be interested in buying Luxion stars if you decide to carry them. 1w for now, 5w is a bit much for a flashlight. Heck, I'll need a good heatsink for a fixture with that.

[ Parent ]

Re: New LED Flashlights (none / 0) (#3)
by RobD on Fri Jun 20th, 2003 at 02:51:10 PM MST
(User Info) http://www.dsgnspec.com

Hi Chris,
I didn't post a photo of the second flashlight. I had to make my own reflector for it. I used my lathe and made a cutter that would cut a curved shape inside aluminum bar stock (1-1/2") and polished it with 500 paper and other polishes until it was almost mirror perfect. The aluminum also aided in heat dissapation. I think you lose a lot of power in the resistors but if your not concerned about loss it makes a much simpler light.
Regards,
RobD

Cool idea (none / 0) (#5)
by TomW on Fri Jun 20th, 2003 at 05:01:36 PM MST
(User Info)

RobD;

And may I suggest an upgrade? Make it a shake light and it would be even more useful. My wife got one of those shakelites and while its a whole lot better than no light it hardly qualifies as a flashlight.

Yours is a very nice unit regardless and thanks for sharing.

Cheers.

TomW

"Education consists mainly of what we have unlearned."--Mark Twain

New LED Flashlights | 8 comments (8 topical, 0 editorial)

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