XHP 35.2 HI Released

[adam7027]

@agnelucio

I’m still waiting for the automotive industry to start using proper LED solutions. All these cars I see, even 30k+ cars, with cold, low CRI lights, awkwardly focused and PWMed at ~200Hz.

Maybe then Cree/Nichia/Luminus will have to make decent “XHP”-class emitters.

+1. It is ridiculous, how bad headlights even the so called “luxury” cars have. For me, luxury is at 98CRI 4500K (or 3500K, if I want to be gentle to my (and other traffic participants’) eyes). And yes, I can also easily pick up those lights’ low freq PWM - it’s a shame.

[Aviator]

Do you have an idea when an XHP35.2HI will be available mounted in a starboard? I should need a dozen of LED in the 3525 format but can’t even find the old XHP35HI.
Thanks

Leo

[djozz]

@Barkuti

@Sirstinky

… Maybe IDEAL Industries will pick up on the enthusiast market and develop LEDs that are good for flashlights rather than street lighting!

We’ll see. Pray for it / ask the Creator if you will (psst! Always in present tense), it is best to use our powers rather than just looking forward.

At this point, though, I am not very thrilled with the present led technology. With this I mean leds whose spectral power distribution is a mixture of directly pumped visible radiation plus phosphor converted radiation, i.e. the typical blue pump phosphor converted led emitter used nowadays. The wrong thing about this not only are the usual issues with their spectral power distribution curves (low CRI and such), but the absolute crap which you end up with when the emitters are used in conjunction with an RLT collar, which is a consequence of the limited frequency band spectral emission of the parts which receive the recycled light, i.e. only the phosphor emitted frecuencies get the boost and thus both tint and color rendering ability are destroyed (even more).

The solution for the above problem is to migrate to a new type of led, which would be using a pump of frecuency outside the human visual range (UV pump, for example), a pump of course to be used fully in stimulating the emission by the phosphor layer, or using another pump technology (an electron emission pump, like CRTs in the good old days, or whatever) for such duty. What I mean with this is that the phosphor layer must emit all of the expected spectral power distribution. This way RLT collars would operate normally with such led, preserving tint and color rendering ability.

How about a thread for a discussion about this?

The disadvantage will likely be that a violet pump led will make an RTL collar less efficient in boosting the illuminance of a led, which is the main reason to use a collar in the first place.

An important reason that RTL collars boost the illuminance of leds so well is that the workings is not limited to light reflected back into the die that is scattered back into the main beam, but especially that the unconverted blue 450nm part of the spectrum, which your eyes are very insensitive for, by directing it back to the die has an extra opportunity to be converted to much more visible longer wavelengths. If you use a violet pump that is completely converted by the die so that the pump wavelength is no part of the beam, then this extra boost effect of the illuminance of the die no longer takes place and and I expect that the collar becomes less efficient at boosting the illuminance.

[JaredM]

LEP seems like the answer honestly. I’ve not seen a spectral output curve for one but I presume the blue component may be less that an equivalent CCT LED. Any ‘pump’ wavelength in the output would be from reflection off the phosphor. This may be an application where we see something like what Barkuti suggests with a near UV laser and full visible spectrum phosphors.

It appears that a limitation in most LEDs output is the phosphor layers thermal limit being reached and conversion efficiency plummeting. Remote phosphor designs then are the next logical step, and then that basically brings you immediately to lasers for high intensity / directed applications. Omni directional lighting will prefer LED pump sources.

[mountainair26]

I wonder when the HI version of the XHP35.2 is going to be available for sale at places like digikey? Anyone have a guess? I have an HD XHP35.2 installed in a convoy L2 clone host I got with the convoy 2+ amp driver off a 26650 and like it a lot other than the normal cree beam color issues when used indoors, but want to try for the most throw possible when the HI version is finally available