(picture of the led after testing, so some superficial damage can be seen)
This is one output test in a small series of tests of new Nichia’s, with led samples provided by BLF-member clemence. These leds were first analysed for colour spectrum by maukka, his thread about that: Nichia NV4L144/W144 AME/ARE CRI and output testing
I have very little time at the moment, for testing and for posting, so this post will be very brief, I may extend it when I have time again.
The output test is of a 6V version of a 6500K 70CRI E1200 output bin Nichia 144A led. I did the test on the custom made board by clemence (‘VirEnce’) which is DTP on the cathode side (the led has no central thermal pad), and I repeated the test with the same led reflowed on a custom non-DTP board that I have had made (see my sigline for a link), the solder pads widened by scraping off some solder mask. The VirEnce board was too big for the hole in my integrating sphere so I made it smaller for the test.
Here are the results, compared to older tests of mine of a Cree XHP50 led and Cree MT-G2 led, which are both also 6V leds. The bin of the XHP50 is unknown because it was one of the first sample leds that was sent to me by Hank of intl-outdoor at the time.
What can be seen (in short):
-the led has good output up to 6A, comparable to the XHP50 test led (but note that there will be better bins available of the XHP50 since this test led), but on both boards it can not handle the same high currents of the Cree leds.
-the cathod-DTP ‘VirEnce’ board performs clearly better at high currents than the non-DTP ’djozz’board, but under 4A (±25W) the difference is not spectacular.
Conclusion: the Nichia 144A does not beat the Cree leds in output, but they still produce a lot of light, and as these 144A leds probably come in some great tints, I can see them having a niche in flashlights that are not occupied by the 6V Cree leds. For modding they form a challenge because of the (for flashlight boards) non-common solder pad lay-out.
As said more testing to come later, but for the next two weeks I have zero hobby time.
Edit, nov 7th 2016:
I wanted to test another 144A leds, this time a 90CRI one because the main attraction of this 144A series will be the high CRI versions. From the limited leds I got from clemence I chose a 6V 5700K R9050 led and test it on a ‘VirEnce’ DTP board, because a 6V led is more likely to be used in flashlights than a 12V led, and because the 5700K version was the only R9050 led in 6V present in the collection.
The output bin of this led is E1000, which should on average have about 17% less output than the 6500K 70CRI led tested above (which is E1200).
You can immediately see the difference of the dies of the two leds, the left high CRI 5700K, the right low CRI 6500K. The high CRI led appears to have a thicker phosfor layer, with a more ‘egg-yolky’ colour, typical of high CRI Nichia leds, while the 70CRI led has a more pale-greenish yellow colour.
After I reflowed the led on the test-board I discovered that I reflowed the wrong 5700K R9050 led, namely the 12V version. Should be no different from the 6V one except for the internal wiring of the 4 dies, but I wanted to test the 6V one, so off the board it went again. Before doing that I took this picture at very low current, to show the phosfor layer well:
I reflowed the correct 6V led, but that same picture on low current with this led looks strikingly different now:
It looks like the phosfor layer is very unevenly distributed in this particular led, I doubt that was on purpose. And it may not even be out of specs like this, the average tint and CRI may be perfectly correct, and so can the output be. But you do not want that in your aspheric flashlight, I checked with an aspheric flashlight lens and the hotspot looks like this:
I checked with a small OP reflector as well, those are usually quite forgiving. But no:
Ok, I did not have another specimen of this led, or any other 6V R9050 one, so I did the output test on this one, standard method as described above as well. I compare it with the low CRI 144A led from above.
What can be seen?
*as expected, the 90CRI version has considerably lower output than the 70CRI led from above, about 25%
*from the voltage and output performance you can not see that this led would be faulty. It does do clearly worse than the expected average difference between E1200 and E1000, but if you take the maxiumum output of the E1200 bin, and the minimum performance of the E1000 bin, at the Nichia test current of 1400mA, this difference is (only just) within specs.
*the maximum output is reached at almost the same current as the 70CRI variant, that current is slightly lower, voltage is a bit lower too, maybe all this because it runs a bit hotter, maybe it is just a voltage difference between the leds (well within specs).
Conclusion: I do not know if the tested led is a rarity, I hope so because you do not want a led like that in a flashlight, at least the other 5700K R9050 led has a proper looking phosfor layer. It performs well enough though, no surprises in output and voltage behaviour. I have had no chance to judge the tint and colour reproduction inside a flashlight, but maukka has already covered that.
It was fun to see and test such an odd led! :party: