Zak.wilson ordered one of these domeless high CRI Crees which sparked some interest on the freenode ##flashlight IRC channel. Coherent-rambling bought some too and sent me one for testing.
The emitter is compatible with XHP70 solder pads so it’s possibly a plug’n’play replacement for some lights. The forward voltage is nominally 9V but ranges from about 8 to 11 volts at rated currents. So a 12V compatible driver is probably a safer bet.
Test was done on an Al heatsink using some old copper MCPCB I found from my stash (didn’t check if it was DTP). The emitter is only rated up to 1400mA current and will probably break if swapped in place of an XHP70 in a high power light (zak.wilson already destroyed his). As this is my only sample I will test the LED to death at a later time when I have finished playing with it.
Typical for a domeless emitter, the tint shift within the beam angle is very small. This will probably play nice with a wide range of optics and reflectors. Works fine for general lighting as a bare emitter as well.
Measured integrated in a 50cm sphere, the tint starts off just a bit on the green side and reaches BBL at 2A.
That may not look too bad in a reflector. The 12V is a barrier for using it but it may have a use for a high CRI flooder flashlight. On the other hand the optical performance may mostly be worse than a high CRI Samsung LH351D
The efficiency is interesting, because there seems to be a pretty narrow sweet spot where this outperforms other options. Assuming you compare good bins at the same CRI, an LH351D is more efficient below about 800 lumens. Above 1300 lumens, an XHP70 is more efficient, and based on zak.wilson’s experience can probably also take more abuse. Now, both of those would lose efficiency if you dedomed them to get similar tint shift, but they’d also decrease Duv at the same time, which would require a filter on the MHD-E… So I suspect it’s a wash.
I think I’m going to end up using them at just around 1,000 lumens, even in a big chunky host like the L6. Basically keep things efficient and aim for high sustainable output, rather than the monster turbo power most people would use an XHP70 for.
For anyone who’s interested, these came from Arrow. They’re certainly cheaper than XHP70.
Definitely not. The ft03 is a high power flashlight, its driver will kill the led if running same power of xhp70.2. Also this led has quite bad efficiency, so not suitable for something runs on battery
That’s not really being fair to the LED - remember, this one has a very high CRI, which always limits efficiency. If this were a 70 CRI model it could be 4 output bins higher and produce 33% more light on the same power. 100-125 lumens per watt at 5-10 watts is a very normal and acceptable performance for 90 CRI, and many of us have no problem using LEDs like that in battery-powered lights.
If, on the other hand you like 5000K, Mouser has them. What Mouser doesn’t have is Arrow’s amazing shipping deal, so it’s $8 to the US and more to most anywhere else.
