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XPE Single + Triples with lenses

Rob's picture

By Rob - Posted on 25 February 2009

These things are tiny!

A sheet of single XPE emitters, with one 16 degree Carlco lens. Then some triples with 18 degree lenses.

The triples fit really nicely, the lenses slotting into the MCPCB. Ideally the singles should have come supplied on square boards so the tiny square lens did the same. It would be nice to get them exchanged but one could make do with rounds with care.

Gary's picture

The photo does not convey just how tiny these leds and lenses really are, received my order from cutter today and having seen them in the flesh am not looking forward to soldering them up.

LadyToast's picture

what are the specs? How bright?

Rob's picture

These are R2 bin LEDs, just as bright as the XRE only much, smaller. OK - not quiet as you can drive an XRE to 1000mA and XPE to only 700mA. The efficiency curve tails off at that end of the scale so it's not as if they are 30% brighter though.

You can fit 4 XPE in the space a single XRE would take. Sadly they also generate the same heat so cooling is the only thing stopping a matchbox size light being a reality.

Carlgroover's picture

1000mA ia 42.86% increase over 700mA so may be worth the extra light, how quickly does the efficiency drop off?

Rob's picture

Good grief, OK. According to the latest data sheets.

R2 XPE @350mA 114-122lm @700mA about 175% output.
R2 XRE @350mA 114-122lm[1] @1000mA about 225% output.

So taking the best possible output from both, an XPE@700mA is 214lm and an XRE@1000mA is 275lm. So the XRE is 28% brighter, but you have to pump through 42% more current to get that brightness. Given current is proportional to power, if you're going to improve on an XPE design by throwing more power into it you might as well add more emitters. Say you turn a 4 emitter design into a 6 emitter. That's 50% more power usage, but 33% more light. Ok, it's close on those numbers. But 6 XPEs (even with all the cooling) are smaller and lighter than 4 XRE.

Plus they are new and cool - this counts a lot! Eye-wink

[1] OK - the R2 isn't on the XRE sheet, but seeing as the other bins are identical I assume this is too.

Carlgroover's picture

Can you tell me the approximate output difference of your new lights compared to the Ay-ups and could the new bulbs be fitted into an Ay-up housing as it is so convenient to use. (I realise this may involve a hacksaw) Smiling

Gary's picture

Going from memory the ay up set give about 600 lumens, 6 xpe's should give about 1100.

kiwiboy's picture

And when does the production line start Eye-wink

Gary's picture

The cost of the led, lenses, driver, thermal adhesive and delivery was around $170, then you have to factor in the cost of a battery and charger, switch and leads.

Production line will begin after I have finished machining up the housing for it and it all fits properly and works.

Rob's picture

Cutter do a special 'Troutie Kit' which is for a housing some dude on MTBR forums designed. Here's a classified for said ad housing:

Nice as that is think it's a bit 'spensive. The only housing cost I have is for Jaycar heatsinks that will cover some aluminium box section I found on the street (yup - another free score!).

Anyhow, the cutter kit is 140+GST and includes driver/LED/lenses so you just add housing above or make your own. If you look at the above classified there is a coupon code to get a small discount. Mark swapped out the Carlco lenses for some Khatod at no extra cost (well - they might have been marginally cheaper to be honest but wasn't going to quibble over a few bucks).

LadyToast's picture

I love this thread, and I barely understand any of it. Smiling

If talk of a production line is to be believed though I would like to put my hand up, and I'm sure others would be interested as well. I'm certainly keen to see a lamp over 1000 lumens.

Have you had a chance to check out the focal properties of those lenses? Can you mix and match (narrow/wide beam)?

Flynny's picture

Yep it's a commercial production job but nightflux are claiming their Proton Max Extreme pumps out 1350 lumens

Rob's picture

As part of this design process I came up with one idea that would fit in 80x20mm housing (you'd probably make it 60-70mm deep) that would pump out over 1600lm. Involved 8 XPEs, 2 XREs and a MaxFlex Smiling

You could fit 16 XPEs in the same space if you were mental! Although a single MaxFlex couldn't drive them - you can master/slave a bFlex though. Eye-wink

kiwiboy's picture

I understand about 20% but I sure would like a set - you folks thought about productionising a few sets? Might save some $$ going to Ayup or similar with the Mont and others on the horizon...

Buck's picture

It's quite time consuming to make these things. I spent a few hours last night filing down the housing similar to Rob's. I need more powertools Smiling

Either that or talk to a machinist like Gary!

lozza6's picture

nope, just a dremel Smiling

Stuart M's picture

then I think my triple MC-E wins coming in at over 1800 real lumens.

I say real lumens because I am not claiming theoretical lumens. Most manufacturers conveniently claim output at the upper range of the led they are using and then forget to deduct for efficency of the optics in front of the light source.

3 MC-E, min 430 lumens each = 1290
multiply for current supply as 600 mA 1290 x 1.55 = 1999.5
allow for efficiency > 90% 1799.55 minimum lumens Eye-wink

Now if only someone could come up with a decent lense for it

Let there be light

Nic's picture

All those calculations seem a bit theoretical to me...


Buck's picture

Well the spec sheets state lumens at 350mA. Stuart then multiplies by the factor on the graph to get the theoretical output at 600mA.

The problem with the MC-Es is that there are 4 emitters on the one die. This leads to a funny patterned light output that is hard to focus using lenses. Therefore the "real" output is not that impressive.

Paul's picture

I also love this thread because it's so nerdy and I can pretend I understand what they are saying.

The joy/thrill of night riding (besides having more opportunities to ride) is that the play of light and shadow put a different perspective on the trails and peripheral vision, so a trail you know well in the day is completely different at night.

Am I the only one who thinks that by building more and more powerful lights you are also reducing the joy/thrill of night riding. Maybe we should go back to a dolphin and gaffer tape or a full moon no light ride.

Stuart M's picture

They are minimum figures that have been tested. In theory the led output could be alot higher if I did things like ignored the efficiency of the optic and assumed that all the light produced actually passed through the lense where you want it and if I do things like use the max output of the led, not the certified minimum.

Let there be light

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