Many LED light

I was considering trying to make or modify a light into an LED light. I was thinking about some kind of array of at least 25 and probably between 30 and 40 LEDs (if not more), probably white and in the 5000+ mcd range.

How well would that work, I mean how bright would it be? I realize that it'll be fairly power hungry, but that can be dealt with by more powerful batteries. Beyond that, is there anything I should be on the lookout for?

I've seen it done, so I know it CAN be done. Just don't know if it would be worth it.

Why not just 1 or 2 White Luxeon Stars? Each is as bright as a 15-20 nichias..

I'd second the suggestion for using the Luxeon devices; they are more efficient and more compact than a sufficient number of 5mm LEDs needed to produce the same amount of light.

However there are good reasons for using the 5mm LEDs, including redundancy and distribution of the light source (so that you don't produce a single small glare spot for someone looking _at_ the light source.

Should you decide to go with the large array of small LEDs, a _very_ important thing to watch out for is heat sinking. People think of LEDs as tremendously efficient, but they are not really so. LEDs convert something like 5-10% of the input electricity into photons; everything else goes into heat. With a single 5mm LED, you don't even notice this heat. But with 30 or 40 of them, you need to deal with carrying this heat away.

I'd suggest reading through CPF for ideas. I'd also suggest looking at this site for suggestions: http://www.resurgentsoftware.com/perfect_led_light.html

Good Luck!

-Jon

1 LS is as bright as 15-20 Nichias as mentioned before, if you use the 1W units.

And there are 5 watt LSes available, but white 5Ws are almost impossible to obtain. (The ElektroLumens group buy took months of lead time before it was actually shipped to EL.)

If you just want a bright LED light with a minimum of fuss, dat2zip sells very nice "drop-in" pills for MiniMags/Brinkmann Legend 2AAs with a 1W Luxeon. Very easy mod with VERY good results. Many people here have BadBoys and love them.

BTW, has anyone done anything to a Brinkmann 2AA NexStar? I know there are a few 2C mods, I'm wondering if the BB pill will drop in to a 2AA Nex.

Edit: Another advantage to LSes is that they have a built in slug for attaching the emitter to a heatsink.

Any suggestions for heat sinking 20 5mm white leds? Nothing was stated in the provided link to the perfect led light. And what power source would anyone suggest? I'm thinking about trying it with a 9 volt.

Originally posted by webley445:
Any suggestions for heat sinking 20 5mm white leds?

Click to expand...

<font size="2" face="Verdana, Arial">Make board as large as possible, make copper on board thick as possible [2 or even 4oz clad thickness], use double sided clading, and maximize the copper area connected to the cathode leads. Almost all of the heat is transmitted from the LEDs via the cathode lead.

What torch do you intend modding?
You need something large and made of metal, preferrably D cell powered.
Cyan LED's give much better efficiency than whites, as there is no phosphor coating on the dice.
I'm hoping to put a very large array of LED's on the front of a large torch. I shall replace the lens with a stout piece of metal, and connect all the LED cathodes to it.
My torch will have a mixture of cyan and white LED's to provide brightness and color rendering.

I haven't decided yet. But yes, it would be probably a 3 or 4D light. I want something that's gonna be BRIGHT and give me good run time. Actually, I'd love to find my old diving light and be able to use it.

Hi Avatar,
I believe that the more LED's you can get into the torch head, the better. More LED's running at a lower current are more efficient than fewer LEDs each running a high current.
I'm hoping to convert a 4D plastic torch, but I'm going to add a lot more metal.
Maybe you might find the ideal candidate for conversion at the outdoor shop in Opry Mills... I had a brief look at the torches there when I visited Opry Mills last Sep.
The cyan Nichia's I use in my torches are very bright as 5mm LED's go. I was camped over at Elm Hill Recreation Ground for nearly three weeks and my 2LED 3D was my primary light source for the whole time! The battery life was incredible and even with only 2 LED's the torch was bright enough to illuminate the forestry. 10 or 11 of these in a suitable torch would be very bright indeed! Even with 10 LED's, you should get 100's of hours out of a set of duracells!

As much as I really like th Luxeon Stars, I think there is room for the multi-led Nichias.

Look at the Streamlight 3C. 10 LED's. I will take that light any day over a Reactor.

And look at the KL2. 19 LED's. Maybe not as much as a beam as the KL1 and KL3, but a wider, area light.

Thanks, empower. I'll try that. My friend's wanting to head out to opry mills to go shopping this weekend. I'll see what I can find while I'm there.