So to go along with my XHP70.2 test Lumintop also provided me with some XHP50.2 to play with.
The results are about what you would expect from 4x XP-G3’s. Although it looks like they are not the highest bin dies where the XHP70.2 gets the highest bin dies. I suppose that makes some sense, the xhp70 should be more popular, the xhp50 is mostly for retrofit installations and the XP-G3 is a very popular LED in itself.
So it makes right at 5000 lumens hot and a bit more from a cold start. Pretty good for some situations. It also should provide more throw then the xhp70 as well.
Only other thing to note about the test is that the test rig got bumped about half way through and the readings dropped slightly after that (didn’t notice until I was graphing it out afterwards). You can see the drop around the 6.5A mark (dog was very excited and I didn’t notice the test rig shifted). The difference was not enough to re-run the test. Just add a few lumens to the numbers after that.
When the XHP50.2 J4-5A 4000K finally arrives, should be any day now, and the resisters arrive, only ordered today, problem one will be it is on a 20mm star so some fancy wiring to be done, hopefully I can do the same as my Courui D01
problem two, it is on a 1.6mm board and the GT’s board is 2mm, maybe use a rubber spacer at the bezel??
Cheers David,
. . . . . . who has just had his two solder stations burn out within a week of each other :UGHH:
I thought about trying something like that but after my own D01 experience, that is something I prefer not repeat lol. I ended up having to use a mill to shave down the solder joints for the D01 to get the reflector properly positioned.
By 13A you would be loosing lumens but the XHP series is pretty tough, they generally don’t burn until you drive them REALLY hard if you have a good thermal path.
10A is about the most I would try to run them at, personally I think around 8A is a good number before the diminishing returns.
For me this is the optimal configuration. I would drive it at around 12V and 4.5A. A shaved XHP50.2 K2 would be similar to the Luminus CFT-90, but with the stock U.I. and much, much cheaper.
These second generation XHP LEDs are very power-dense, but I don’t think you will get close to an effective luminance of 200cd/mm^2 in a reflector light with the shaved XHP50.2. The actual die luminance will be less than one would think just considering the total output and the die area because there is light coming from the cross and phosphor to the sides of the die, as I showed with the XPG3. Also, in a reflector light, focused at the center, the beam center lux results from an average of the luminance from the die and cross, so the effective luminance will be less, i.e. If you look into the reflector it will be filled with reflections from the bright die but some area will be filled with reflections from the less bright cross.
Yes I realize they aren’t perfectly suited. But take a look at Texas_ace’s masurements with the shaved XHP70.2. With these we can determine the throw with the XHP50.2. It should be similar to the XHP-35 HI, but with a 30% larger hotspot (8mm^2 vs 6mm^2) and 50% more lumens.
