Looking for diode suggestions. Building high power led flashlight

[EliteFunk]

I've built a few lasers but never a flashlight. I know my around the electronics but I'm not well versed in leds. I was hoping someone could recommend an extremely high powered diode and driver that will still work in a small handheld. I can make a custom aluminium heatsink at work though. It will be going into a Cree housing. Can't remember the exact model. Will check when I get home. Any advice is appreciated. Thanks.

 

[Alaskan]

I guess you are looking for a white LED, if you would consider a colored one, here is a thread with some information:

http://laserpointerforums.com/f39/wtb-green-phlatlight-96226.html - this thread also has information about the higher power multi-diode LED arrays which can be purchased fairly cheaply on ebay.

I thought I saw a thread some time back where a member showed either a 50W or 100W white LED they built into a host, maybe it was Pman. Look for that, if not, you can easily find high power 50-100W white LED's on ebay along with drivers for them, only thing is although they are extremely powerful, if you are looking for "throw", they are not ideal for that because the size of the multiple emitter area is fairly large, when running in series parallel next to one another as they do in those packages, difficult to get a great amount of throw from them when that wide but they have a lot of brute force with so much light. The smaller the emitter, the tighter the beam you will have with a proper reflector, or lens. You can find a lot of projects on CandlePowerForums showing high power flashlight builds, if I recall the forum name correctly.

Item : 50W LED chip
Emitted Color : Warm White / White
DC Power Input: 30-32V
Current: 750-900MA
Color Temperature:
Warm white : 3000-3200K
White: 6000-6500K
Intensity Luminous: 3000-3500LM
Size :4.2*4cm
degree :120 degree
Lifetime : > 50,000 hours

Edit, I went looking and look what I found, a you tube video showing someone building a flashlight out of a multi-LED array, much like shown in the above diagram, but using a 100W LED unit and perhaps a larger package. I thought the 50W and 100W units were different sizes, but one ebay seller shows them the same size. If so, there are more emitters in the higher power package which are spaced closer together inside the mount:



Item : 100W LED chip
Emitted Color : Warm White/ White
DC Power Input: 30-32V
Current: 1500-1700MA
Color Temperature:
Warm white : 3000-3200K
White: 6000-6500K
Intensity Luminous: 6000-7000LM
degree :120 degree
Lifetime : > 50,000 hours

I think this is the same thing Pman built (above) using this as inspiration, or... maybe this is the same one in the video, for all I know.​

Edit again: I kept searching for Pman's project, but not finding it, arrrg! Maybe I remembered wrong. Anyway, while searching I found RHD built one and here's the link:

http://laserpointerforums.com/f66/ginormous-bug-eye-100w-led-build-72191.html

Photo from the above link. Search the forum, you might find more.
​

 

[Benm]

That puts out of a lot of light, but i have my doubts for practial use: when would you need a very bright wide output beam that has batteries that run out in minutes?

A single emitter led with good optics would give you a beam with much more 'throw', but their power is limited. I think the most powerful chips are still 5 watts which they have been for years. Cree seems to make some 10 watt models outputting over 1000 lm, though i've never seen one in the wild.

 

[Alaskan]

I'm not a fan of short run times either, better have a large battery pack if using the 50 or 100 watt LED. With such a large spread of emitters trying to focus into a nice beam won't happen, only brute lumens. Unless you just want to build something unique, I would look at an SST-90 emitter flashlight, or perhsps the TK75.

 

[94Z28]

For small CREE handheld you need to check out mountain electronics website or ebay.

They have bargain XM-Ls for cheap.

I use XML2 on Noctigon 16mm copper mcpcb with the MTN FET + 7135 driver for about 30$ I make 1800lms

 

[Seoul_lasers]

I suppose you haven't seen these yet
Cree XLamp CXA3590 LED Array

the XLED series are among the brightest LEDs on the market.


The 50W chip emitters from China quite often are damaged with more than 10% of the individual emitters burnt out on the chip. This is why the price is usually pretty low.
I'd presonally stay away from these and go with an LED direct from Cree.

 

[dubious speculation]

It will be going into a Cree housing. Can't remember the exact model.

You need to tell us that first, the size and type of host you have will dictate what LED configuration you should use.

I think the most powerful chips are still 5 watts which they have been for years. Cree seems to make some 10 watt models outputting over 1000 lm, though i've never seen one in the wild.

CREE makes single emitter LED's capable of much more than 'just' 1000 lumens. Search XPL V6 2C, XP-G3 S5 3A, MT-G2 (capable of over 3500 lumens). They also manufacture multi-die emitters mounted onto a single substrate, search XHP-70. I think you'll find that LED's have come a long way from what you may remember.

I would look at an SST-90 emitter flashlight

Old, outdated and expensive. SST-90 @30W only produces 2300 lumens compared to an XHP-70 N2 that emits over 3000 lumens at the same power consumption and with a smaller light emission area (7mm^2 compared to 9mm^2). EDIT: Real world SST-90 test results indicate 1600 lumens at over 15A (link). I am a bit skeptical of that number so take it for what you will. But there's no doubt there are way better options out there.

I suppose you haven't seen these yet
Cree XLamp CXA3590 LED Array

the XLED series are among the brightest LEDs on the market.

Far too impractical to drive in a handheld format. With a forward voltage of over 38v it's not something that's ideal for whatever flashlight host the OP has in mind. Also, take note of the emission surface area, it's over 34mm^2, which is next to useless in a handheld format.

It will be going into a Cree housing. Can't remember the exact model. Will check when I get home. Any advice is appreciated. Thanks.

Regardless of what flashlight host you have in mind I would forget about using those 50-100w multiple led arrays. The thermal management of the substrate they are mounted on is very poor and the efficiency is low compared to newer LED's. Not to mention the mounting issues you will have and the problem of finding a suitable way of driving a 30V LED.

 

[Benm]

Far too impractical to drive in a handheld format. With a forward voltage of over 38v it's not something that's ideal for whatever flashlight host the OP has in mind. Also, take note of the emission surface area, it's over 34mm^2, which is next to useless in a handheld format.

It's mostly the emitter area that is the problem though. You could supply the required voltage with a boost converter without much of a problem.

Then again the supply voltage is indicative of the unit consisting of multiple diodes in series (probably 9 to 12 at 38 volts).

As for the XHP-70 led: Isn't that actually a package containing 4 dies?

Given how compact it is focussing would probably not be that big of an issue, but still, it's technically not a single chip device?

 

[Alaskan]

I am behind on my LED flashlight research, the last one I bought was the SST-90 and at the time, it as the best you could buy. Probably cheap now, but a smaller emitter would be better, if you can find one, especially if more output power.

 

[grainde]

Ive built a few MT-G2 flashlights and I can highly recommend this emitter. Generally it will give over 3000 lumens at 8.4 V input to driver and 6 A out. In my case I just added extra chips to a Njang 3 A board and did the Zener diode mod. I also used a section of copper rod to mount the copper star and help cool the emitter. More info here if interested. :beer: