Anybody tried this yet?
I’m all ears. Please tell.
Be nice to see some Vf numbers at >1.5A on copper. Match, you listening?
I reflowed one on copper yesterday, used a qlite driver with 2 7135's removed, so current should have been ~2200mA (on one 18650), but I measured just 1.3A (OTF output was 247 lumen with no dimming at all). Two possibilities: the driver is faulty, or the Vf of the Nichia is too high for that current with one Li-ion. I have another go with a different driver one of these days.
try two li ion in parallel (safely of course)
One guy measured 3.7V at 1.5A, 3.9V at 2A (not on copper, but on a fan cooled heatsink).
^^I assume this would mean an even higher Vf for the 219 if it was on copper.
Has there been any testing on 219 burn-in to lower the Vf?
Something like 24hr burn in @1000mA
I would expect the Vf to be the same or a bit lower on copper.
Burning in should make very little real difference on Vf.
Hi bdiddle,
I have a small light that I put a nichia on a 16mm copper sinkpad in. I kept the 2.8A driver that was in use for the XML. On a fresh li-ion the emitter sees 2.17A. On an IMR about 2.37. Once the over voltage wears off your pobly looking at about 1.5-1.7 ish I would guess.
That is nice, I will try the 2.8A driver as well, and do some lumen measurements as I go (that is: djozz-lumens = ceiling bounce estimate)
From my understanding, heat lowers Vf so with copper reducing heat then Vf would go up.
I can’t the find the link but Match’s test on XML2 showed higher Vf on copper vs aluminum.
As for burn-in, here is an old thread from CPF which shows the affect of 24hrs burn in on an older LED and Vf did permanently go down.
Since I haven’t seen any testing on 219 its just wishful hoping that burn-in might help.
A copper direct bond TRIPLE star would be awesome for the nichia. Help combat the issue of high VF.
Like THE_day said, copper wont combat the high vf issue, but it may allow for better output numbers at a given current, and hopefully higher max drive current.
I have question about the Nichia 219 and linear drivers.
Has anyone tested the approximate runtime to ~50% for a 219 running at 1.5A from a linear driver?
I have a light modded with a similar LED, the Nichia 119 and a 1.14A driver and I get about 2hrs runtime and it’s still just over 50% brightness (eyeballing estimate)
Also, would I be able to run a light say the size of the Convoy S2 with adequate heat sinking continuously at 1.5A?
Any user experiences appreciated, Thanks!
Running an XP-G/Nichia at 1.5A will be just fine. They shouldn’t give you any problems at all running continuously, and heat shouldn’t be a factor. 1.5A is their sweet spot.
Thanks, my Nichia at 1.14A gets pretty hot after 15-20 minutes if not held continuously so I assumed 1.5A would get it burning.
inch, thanks for the link, I actually considered posting my question in that thread
There is little benefit to running a 219 at over 1.2 amps. It is mostly heat after that. 10% more lumens for %25 more power. It may do better on copper though. LINK
Hoop, that was one of the graphs that made me choose 1.14A in the first place and it’s been great with long runtime.
Now with copper pads available I’ve reconsidered the option of driving it higher but if it’s still little gain or greatly reduced runtime on high then I might just pass.
I appreciate all the help, thanks!