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Discussion Starter · #1 ·
Quick question I was curious about. If I am running 3w Luxeon III bulbs, they would be running @ 3W 1000ma. So if I was to replace them with Kree P4 led and if everything is made to kit ok with new optics and all, Could I use the same driver to run run it? For question sake, heat is not an issue.
Thanks
 

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Providing it’s a constant current style driver you’ll be just fine. Out of interest what driver are you using, and have you made a decision between the Cree XR-E and the Seoul Semiconductor P4?

Both emitters have their positive and negative aspects; basically it comes down to which emitter will suit your optic or reflector choice, and how you’re going to physically mount the emitter. You say heat is not an issue and while these emitters produce a lot less heat then previously available emitters, thermal consideration is still important for lumen maintenance, particularly at higher drive currents like this.

And by the way, an average Luxeon III emitter would be consuming a little bit more then 3 watts if driven at 1000mA, unless you’ve got an emitter with an extremely low forward voltage! ;)

Let us know what you’re thinking! :thumbsup:

Cheers, Dave.
 

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p97z said:
From what I understand the Seoul Semiconductor P4 is supposed to be more compatible with the Luxeon optics. Give it a try it should work.
The Lumiled Luxeon and SSC P4 have different sized domes, although I have noticed a few manufacturers claiming that their optics are compatible. It would just be a matter of experimenting to see what works and what doesn't.

Luxeon style reflectors seem to be pretty compatible, and most only require a little material being removed from the back of the reflector to get things focussed properly. Particularly with the SSC P4, I would be looking at reflectors with a rougher orange peel style surface rather then flat and shiny reflectors.

Dave.
 

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Yeah let us know how you go with the SSC P4’s.

I still haven’t got around to buying any to play with yet. I may eventually buy a few to replace some Luxeon III emitters in one of my lights, but for the time being I think I’ll stick to the Cree XR-E for my next build.
 

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I'm planning to replace the Luxeon in my Exposure Joystick with a P4. Not sure if I'll need to replace the optic too, but you can get SSC optics in the right size if necessary - though I'd be quite happy if I got a bit more flood with the beam, as it is very focussed as standard.
 

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I will get in 2/3 weeks Seoul P4's and also the new Edison led's. The edison's have the same shape as the P4's, so the dome is a bit lower than the dome from a luxeon. I will try and test them with some luxeon optics. I also want to try the Ledil optics, but I can't find a shop that carries them. Cutter has them only for Cree's.
 

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Discussion Starter · #9 · (Edited)
thoughts

First off, I would like to thank Dave (and all others) for the input on this forum. The sharing of minds here has been positive and greatly informative to the point that I have now caught another OCD nuerotic behavior to add to the rest of my problems. Seriously, thanks. For respect to the light manufacture that built my lights (I do love them for they gave me back the night to ride) I will keep the name of light I intend to upgrade out of it.
My thoughts are to either the following:
Replace existing LED (lux III) driven with 7.2 lith ion batteries with either of the newer LEDs mentioned.
The limitation will be space for led and optic. The light housng is basically a billet rod of Al bored out to18.45+-.05mm with depth of 11.9mm to a inner circular seat where the now MCPCB board with a hole in it to seat against the Lux LED bolts down (two hole approx 12.21mm on board). Depth of bore is 11.9mm to seat ( 6-7mm diameter) and 14.37mm to bottom.
I would also need an optic or reflector that it in these dimensions and throw more flood than spot. I use my same bike to commute to work every day along with cardio training on way home (I am a RN and work some whacky hours).
Secondly: a new driver (Bflex?) that if works out on first light, I would then modify second light in parrellel, to be run from the same driver using a jumper. Space for driver is 19mm wide and 31mm depth with a momentary switch mounted on back of CB.
Not afraid to mod housing.

Any help or thoughts with thisis greatly appreciated and also places to purchase(like the P4 and optics (Cree I found @cutter) will be greatly useful.

Edit: as the kree is rated @700mA, what is expected if used @1000mA? thanks
 

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Comments I've seen over at http://www.candlepowerforums.com/vb/forumdisplay.php?f=45 suggest you can run a Cree at 1A provided your heatsinking is adequate. In fact the heatsinking requirements aren't really any different to those required for a P4 if you want to run that at 1A. The only real difference is that SSC do rate theirs for 1A (or at least quote a lumen output at that current), whilst Cree are a little more conservative. Of course the question then is whether given the choice of drive current the 25% of extra light is worth the 50% extra power - particularly given that with the eye's logarithmic response that will only look 10-15% brighter!
 

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Here is something to think about. You can buy a DiNotte 3W on their web site for $99.00 (without batteries). Buy the DiNotte and replace the existing LED with a SSC P4 or a CREE. You can then experiment with optics and swap in a flood or spot. You can get a cree or p4 for under $13.00, use the existing DiNotte driver to get low, high and flash. Just a thought...

$110-$120 for 220+ lumens of light not a bad price if you ask me.
 

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Apart from the fact that if you're going to all that trouble you might as well build one from scratch - you could build a version of my triple Cree (or other similar designs which have been posted), for about that much money. 500 to 600lm for $110!
 

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p97z said:
Here is something to think about. You can buy a DiNotte 3W on their web site for $99.00 (without batteries). Buy the DiNotte and replace the existing LED with a SSC P4 or a CREE. You can then experiment with optics and swap in a flood or spot. You can get a cree or p4 for under $13.00, use the existing DiNotte driver to get low, high and flash. Just a thought...

$110-$120 for 220+ lumens of light not a bad price if you ask me.
220 lm?
Don't think so. I've got a triple Cree, and I'll eat my shorts if that thing puts out 660lm @1A. I'd say 160 out the front is a very reasonable figure.
 

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brum said:
220 lm?
Don't think so. I've got a triple Cree, and I'll eat my shorts if that thing puts out 660lm @1A. I'd say 160 out the front is a very reasonable figure.
Yeah, but then you've got P3 bin (I assume) Crees, which are rated at about 130lm at 700mA, which is I presume what you're running them at. He's talking about running the top spec U bin P4s (equivalent to a Q3 bin Cree, but unlike those, available to buy) at 1A, at which point they are rated at ~220lm as he says. The two issue being that the U bin P4s have a nominally higher output (they should give at least 150lm at 700mA), and they are being run at a higher current. Of course he is also talking theoretical lumens - but then given that's how everybody rates LED lights that isn't unreasonable - still at least 2.5 times as bright as the nominal 80lm LED it's replacing. I reckon a derating of ~15% for optic losses and higher temp than spec is reasonable, so he will still get ~190lm out the front.
 

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Keep in mind that some lumens are not useable. A lot depends on the optic or reflector and what you are going to use it for. A good example is a triple luxeon at 3W using 20 mm IMS reflectors. Sure it's got a lot of throw but how good are lumens for commuting? The lumens are focused in a narrow spot.

Lumens and bike lights in general depend on what you are using them for. You don’t want a spot light on your handle bars and you probably wouldn’t want a flood light on your head. The original topic of this thread was replacing LED’s with newer LED’s. When rjpstoked started talking about machining and a bFlex… I just had the idea to take a DiNotte (an incredible design I may add) and put a Cree or SSC P4 in it.

I agree that a brighter light can be made for that amount of $$$... but to come up with a design that is practical and bright is hard to do.
 

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True... there are a bunch of nice designs here. Half the fun though is coming up with your own.

Right now i'm working on a triple cree made from a cigarette lighter adapter. :)
 

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p97z said:
True... there are a bunch of nice designs here. Half the fun though is coming up with your own.

Right now i'm working on a triple cree made from a cigarette lighter adapter. :)
You are so right... coming up with a design is half the fun!
And building it is the other half. ;)

Cigarette lighter adapter huh?

Back to the original thread:
rjpstoked - definitely go for the upgrade! Sounds like you've got the homebuilt LED bikelight bug!
 
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