New 3V XHP releases + Overcurrent Guide

Overcurrent Guide

Fresnel Lens Spotlight Reference Design

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I’m glad that Cree is finally releasing 3v XHP emitters, especially the 70.3 and 35.2, but unfortunately they’re all domed and low-CRI (and presumably CW-only)

One step forward and another step back, what a shame. An XHP70.3 HI in 3v could be a real contender with the SBT90 for FET-driven hotrods, in terms of sheer output and decent throw.

Edit: I have just checked, looks like HI is gonna be available, though only CW

Even the old-reliable 70.2 is getting a 3v version, that’s gonna be some insane power draw for peak output, like 40A or so.

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Now Cree also realized that enthusiasts overdrive LEDs (sometimes to insane amounts) :smiley: (And likely it also serves for the purpose of evaluating new thresholds or key selling points)

I don’t know how the impact is from LED tests here in BLF to LED and flashlight manufacturers, but it seems that at least Cree is aware of this trend. There are some interesting points of Crees testing method though:

  • Cree tested the light flux in conjunction with Tsp, not only for max light flux I do.
  • only 100 W thermal capacity of cooling plate (likely based on peltier elements). From my experience with peltiers, above this threshold the temperature rises sharply because the peltier has no thermal mass and is not able to maintain a low temperature any longer. Basically, a simple large and heavy heat sink seems to be better for the XHP50/70 LEDs at least.
  • the wire gauge is unknown.
  • stabilizing for 60 sec could be too long depending on the cooling solution. For lower power (30-60 Watts or so) this is not a huge deal, but if the thermal capacity is exceeded the light flux will go down rapidly due to rising temps inside the LED.

There is a table of maximum overcurrent of widely used Cree emitters. The XP-G4 (my test here) is given with 6 A, the XM-L2 new gen (my test here) is given with 10.25 A. The XHP70.3 HI has a max current of 4.65 A(12V, so for 6V it’s roughly doubled, at around 9.3 A or so), what is way beyond the theoretical maximum I achieved in my test.

So still relatively conservative, since they only tested to 85 °C Tsp. But still it could be possible that their cooling solution limits the maximum performance but I think they already considered that while designing the testing process. Keep in mind, that the Tj is somewhat higher due to thermal resistance of the board. So 85 °C Tsp are safe conditions for sufficient service life.

Unfortunately Cree does not give any light flux chart like I use for their testing…

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Here go the last useful drivers in Sofirn lights, as soon as they notice there is 3V XHPs, they gonna swap them over from boost to FET lol

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To be fair, everyone will still be asking for R9050 as usual, meaning it needs to be 6v

Not sure. In the end they make lights for the masses, not for us enthusiasts. It’s everything about cost, as cheap as possible. And I also fear that they dump all boost drivers as soon as 3 V emitters are widely available (also the chinese manufacturers are develop and release also 3 V emitters for sure)

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On the other hand, I can’t wait for Sofirn to release an XHP70.3HI version of the Q8, it would be insanely bright and hopefully affordable.

Maybe 30k lumens at $100 (as a triple)? Who knows, but the performance will blow way past the competition.

@Sofirn please

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I’m not too excited about the 3 v xhp70’s for two reasons: At 3 volts the current draw goes very high and you need to dissipate as heat, so putting it in a small host like a C8 is impractical. Also, less efficiency, since we’ve eliminted the benefit of a boost/buck driver with series batteries. Also, 1S requires stronger batteries of you plan on going direct drive. The only benefit is you don’t need a boost driver or 2/3S to run it anymore.

So, Cree with the 3v xhp70 has basically emulated San’an SFQ aka ‘p’ series 7070 LEDs and we know those are basically power hungry LEDs designed to be bright as poaaible and not much else. Only time and testing will refute or confirm that.

They could be good for modding lights that come with the high power Chinese 3V LED’s. Especially if they give better colour temps and CRI options.

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And also a straightforward upgrade to lights with outdated 5050 emitters (XM-L2, SST-40) and standard mcpcb sizes, especially those with FET drivers. Hopefully Cree releases 3v versions in high-CRI or NW as well.

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I think my wallet just screamed in pain.

…well, here come more lights.

Cheaper SBT90 alternative. Multiple near-SBT90 emitters more cheaply and easily.

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Yes, I’ve got an Astrolux FT03S with a SFH55 in it, the earlier versions apparently had the SBT90.2 fitted? I’m always keen to experiment -provided the emitter costs aren’t sky high (like for the SBT90.2.)

Yeah, that’s already a better emitter than the SBT90 though in terms of pure output, but is the same footprint size while XHP70s are smaller.

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Whoaaaa. I saw the title and skimmed over cuz assumed it was more 50.3’s. But 3V 70.3’s is very interesting. Sad that CCT and CRI will be limited but still very interesting. I like these flashlight related resources cree releases too, they’re the only one that do that.

Except whats the deal with “LumFlux”? That’s not a commonly used word lol. Stop trying to make LumFlux happen

Also is that megalumen box thing real? What’s up with that

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