Could you put a cree in an Arc AAA and not change regulator

[jason9987]

I don't have an Arc AAA but I will probaly get one, my question is could you swap a cree for the 5mm in the arc and leave the same regulation circuit to get a brighter light with the same runtime? I know that it wouldnt compare to the brightness of a cree driven closer to its max current but aren't leds more efficient the less current you put through them? Maybe theres negitive effects of underdriveing LEDs but I've never heard of any. Just seems like everyone that puts a high efficiency LED in a small flashlight drive it higher than what the orignal design was. Wouldn't it work the same as putting a cree in place of a lux to double the brightness and have the same runtime just on a smaller scale? I dont know that much about the differences between the way 5mm leds work and high power LEDs work so don't flame me if its a ridiculous idea:shrug:

 

[matrixshaman]

Millermods is doing something like that but I think he uses something beside the stock driver. I have wondered too if it would be brighter and I'll guess it might be a little but probably not a lot since it would be very low current input. I don't know what the driver in the Arc AAA is putting out so maybe some others here more familiar with it will chime in. I've got a brand new Arc AAA still sitting in the package that I really don't know what to do with since I paid way too much for it back when they were getting $120 for them on eBay (got mine for $60 then) - still have my old one too that I bought when they first came out so I'd probably mod one of these if I could easily get a Cree or Seoul P4 in there.

 

[TorchBoy]

The basic idea seems OK, lots of variables aside. But aren't the brightest 5mm LEDs as good as a Cree anyway? How about getting a better 5mm to put in there?

 

[jason9987]

Does anyone know the difference in efficiency between a cree and the 5mm in the Arc AAA or how much more light you would get in a direct swap?

 

[TorchBoy]

A 16,0000mcd 5mm LED has a similar efficiency to a halogen bulb, at about 24 lumens/watt. 5mm LEDs are now available with three times that, or 50,000mcd and 72 lm/W, which is about the same as the Cree efficiency at 1W. The Cree gains a little bit in efficiency under 350mA but drops again at very low current (from the XR-E datasheet).

It probably comes down to other considerations, like a 5mm LED is smaller, cheaper and more predictable.

If anyone tries the Cree let us know what result you get.

 

[Greta]

Replies copied from HERE.

Pax et Lux07-14-2007 03:48 PM
Re: Could you put a cree in an Arc AAA and not change regulator

Am I reading this thread correctly - that there would be no real point to putting a Cree into a low-output light?

If there is no efficiency gain at present Arc AAA-P levels, the only point in using a Cree would be to make a substantially brighter light.

I have to declare an interest and say I'm someone who tends to prefer smaller lights to run at lower levels for close work, like reading, and have larger, brighter lights for outdoors tasks. Does this make me the only person here starting to think that maybe the Arc should not get a Cree?

I mean, the switch to SSC over at Peak seems to have created lights with slightly brighter spill at the cost of losing that famed snow-white tint (sorry to mention what I consider to be Arc's only serious competitior).

Unless, of course, the Cree would produce a better beam or something like that.

kitelights07-16-2007 12:19 AMRe: Could you put a cree in an Arc AAA and not change regulator

I believe that all all of the high power LEDs have been modded into the ARC AAA. Aside from the drive current issue, the major issue is the beam. The 5mm LED has its own lens that focuses the light. The Lux I, III and the Cree will produce all flood - kinda like holding an incan bulb in your hand, not very practical, unless you create some type of reflector or lens.

The Miller Mods version cuts and polishes a parabolic reflector into the head to focus and direct the Cree. It's a wonderful mod from reports and I'm on the long waiting list for one, but it's not the light that ARC developed for the masses.

Some complain about the current price of a standard ARC and the MM is 2-4 times the price. The mod is a compliment to the timeless, can't be improved upon, ARC form factor, but I don't see 200-300 orders for the mod justifying that major a change in manufacturing.

I agree that small lights ARC sized that are brighter than ARC output are too bright for close work and tasks. The MM mod has a low enough level for close work and enough high power to be impressive for it's size. That high output level comes at a sacrifice of runtime, which defeats one of the basic utilitarian goals of the ARC AAA. The other "weakness" in the MM ARC is the exceptional job that he does cutting the reflector, reduces the "meat" in the head and makes it more susceptible to damage from drops - something else that just isn't practical for a company that offers a lifetime warranty on its products.

The ARC AAA as it was designed stills covers the vast majority of my needs - if I've got pants on, one is in my pocket. I'm fond of the new AA Cree imports, but I don't always have one on me - not as convenient as the ARC.

Gransee07-16-2007 12:02 PMRe: Could you put a cree in an Arc AAA and not change regulator

McGizmo made a mod for me that has a Arc-AAA battery compartment and PCB with an enlarged head/reflector and Seoul 1/2 watt. Since it uses the stock AAA pcb, the run time is similiar (~5hrs). I tested this at LSI and it produced ~10 lumens. The beam is nicely focused. The only downside? The head OD is .860". For that size in the pocket, I want more than 10 lumens.

In my opininon, the current design provides a useful balance of runtime/size/brightness, etc. Nichia is continueing to improve the 5mm part. And we will continue to upgrade the Arc-AAA each time they release a brighter part.

peter

Daekar07-16-2007 01:31 PMRe: Could you put a cree in an Arc AAA and not change regulator

Quote:
Originally Posted by Gransee (Post 2044353)
In my opininon, the current design provides a useful balance of runtime/size/brightness, etc. Nichia is continueing to improve the 5mm part. And we will continue to upgrade the Arc-AAA each time they release a brighter part.

peter

I'm glad to see you say this! I've bought three Arc AAA-P lights now, one for myself, and two for loved-ones, and have nothing but positive comments. While I appreciate my high-power Cree lights, I like the performance and form factor of the Arc. I think you're doing the right thing by sticking with the Nichea parts, they'll keep getting better just like everything else... and when they do I'll be right there to buy another Arc AAA, whether you decide to go with greater runtime at the same output or more light for the same runtime. I'm sold. 😀

cy07-16-2007 02:10 PMRe: Could you put a cree in an Arc AAA and not change regulator

Peter, I'd love to have a stock ARC AAA w/cree that runs five hours and puts out 10 lumens. a very useful amount of light.

I've got a Miller mods Arc AAA two stage cree that's absolutely the best in form factor with stunning performance and long runtime too.

uses std Akl AAA cell, can't say enough good things about this design. sure wish it would be possible to put miller mods design into production. it would be a smash hit!

Quote:
Originally Posted by Gransee;
McGizmo made a mod for me that has a Arc-AAA battery compartment and PCB with an enlarged head/reflector and Seoul 1/2 watt. Since it uses the stock AAA pcb, the run time is similiar (~5hrs). I tested this at LSI and it produced ~10 lumens. The beam is nicely focused. The only downside? The head OD is .860". For that size in the pocket, I want more than 10 lumens.

In my opininon, the current design provides a useful balance of runtime/size/brightness, etc. Nichia is continueing to improve the 5mm part. And we will continue to upgrade the Arc-AAA each time they release a brighter part.

peter



THE_dAY07-16-2007 02:38 PMRe: Could you put a cree in an Arc AAA and not change regulator

i have to agree with cy,

MillerMod's arc aaa xr-e mod is incredible and would be a smash hit if mass produced through Arc!

just look at all the other aaa cree/seoul lights coming about and selling well.

iirc, the fenix lod-ce Q2 was the first of the special editions to sell out.

i'm not saying stop the regular Arc aaa production, just add a cree version to the mix.

in the end, it's Peter's company and his decision but you must see the MillerMod's Arc aaa version before you dismiss it.🙂

paulr07-22-2007 08:11 PMRe: Could you put a cree in an Arc AAA and not change regulator

Stay with the existing form factor and the low powered 5mm led is fine, but pleeease go to a led with neutral white tint even if it costs a few % in lumen efficiency. The Nichia blue cast is just really harsh. It was maybe ok a few years ago, but today we're just too accustomed to white leds that are actually white.