I mainly don’t want to sacrifice the factory beam pattern just to get a slightly warmer tint. That’s what happens when you move to an xhp50, xhp70 or XML size emitter. Good beam pattern with a sharp cutoff line is my highest priority. The second highest priority is being noticeably brighter than the stock incandescent bulb. Then a lowly third is a good enough color temperature.
The first two can be accomplished with a little hunting around and maybe small modifications. Then you’re stuck with whatever color they give you. Usually that’s cool white.
My first set of car LED headlights were cool white with a tiny bit of blue, but my current set of headlights are actually a more pure white without any traces of blue. Color reproduction is quite nice.
That looks easy enough, heatgun or hotplate will desolder the LED without ruining the rest of the components.
If it’s MCPCB then hotplate is the easiest way, at 240C bed temp all 60/40, 63/37 lead and SAC305 leadfree solder will melt completely without excessive yellowing of the solder mask. Don’t let the board stayed too long on it, you’ll yellow the masking ink.
- If it’s FR4 board preheat slowly no more than 120C for 5 minutes on hot plate followed with heatgun ontop. Make sure you put a thermocouple fixed on the board so you can monitor the temp (240-260C) is max reflow temp according to many component’s specs. Place your heatgun gradually closer as the blower could blew the components off the board. When you start to smell burnt epoxy shut the heatgun off or move it farther away from the board.
The better way for FR4 boards is Infra Red top heater oven such as found in your toaster. The resin-fiberglass matrix has very low thermal conductivity making hotplate technique harder and requires longer preheat time.
Haikelight wrote somewhere they fixed the green tint shift, any idea how?
Am I correct when I say:
4 x XHP50.2 driven at 6A each (so in a Q8 like configuration 24A from the driver) produce 16K lumens
?
I have an idea for the future Q16 and 16K lumens would be so awesome but I would not want a green tint shift.
Remember that the xhp runs at 6v so 24A at 6V would be the same as 48A at 3V. AKA, it would get VERY VERY hot. You will really need a buck driver to drive these as well due to the super low Vf they have. 4 of them together could pull as much as 72A of current on a low resistance FET driver based on other peoples results.
That is a whopping 425W of power! Or over 5 times the amount of heat that the Q8 produces right now. Also I would not trust the LED’s to survive that long term.
That said, the xhp50.2 should be capable of about 5k lumens each maxed out although 3.5-4k each is a more reasonable goal IMHO. It also keeps the heat a bit more reasonable.
As I have said before, a quad xhp50.2 Q8 should be able to make around 15k lumens without much trouble and more if you push it. Or drop it down to ~10k lumens and it should have about the same amount of heat and battery life as the XP-L’s at ~6k lumens. If you just really want to hit 16k lumens for the numbers to match up, then yes, that should be possible.
Now for the green tint, this is not really an issue I have noticed unless you get a funky tint LED from above the black body line (like a 3C vs the good 3D for example).
The newer LED’s do have some yellow tint shift but that is largely reflector dependent from what I have seen. Larger and deeper reflectors with OP don’t have an issue.
Optics like the cute-3 work great and removing all the tint shift but that would not really work for the Q8.
The only practical way of doing this is to use a buck driver with the cells in 4s and the LED’s in 2s2p. By upping the voltage to 12V you drop the current needs down to around 12A. This is doable with repetitively cheap buck drivers like a beefed up version of the GT driver.
Wired in 6V they would need twice the current and the driver would cost a fair amount more as well.
Basically a Q16 is possible and would work for sure but would also cost more for sure.
Stormrider, I suggest you to create a new thread in Headlight section. We’ll continue there, for the sake of better indexing. So people will get what they “googled” for in BLF.
We’re already too far off the original topic here. This is a very interesting topic indeed and I think we better share it in the matching section so people can easily find it when they need related information.
Running them in 6v in series or in 12V in parallel will net you the same results. Each LED will get 2.4A in series but they will only be at 6V, so the same amount of light at 1.2A at 12V.
I never really like triples or quads (except for tint mixing) as long as I can use bigger dies LED in a single optics. Smaller TIR will eats up efficiency and make beam control somewhat limited. If you have 4 XPGs and 1 XHP50 and you only want one beam profile pattern then go for XHP50 paired to a single bigger optics. For multi beam pattern try assymetric optics. If it’s unavailable then 4 different unique optics would be the next choice. FYI the output/efficacy of 4 x XPG3 setup is almost equal to a single XHP50.2.
Hey, coming in on the backside of this, I’m cooking up a build with an XHP50 (not the .2 version).
-First tried a 2A driver from mtnelectronics. On 3 CR123’s or 2 17500’s, I think it tried to fry my fingerprints off. Pretty sure that was too much current. Depending on the physical arrangements of the components it would actually run on high but I think I was nearing the limits of the components and it would go low. Did some math and realized the 6V led times 2A was 12w of power pulling way too hard on the batteries. I know there’s an XHP50 in the Lumens Factory mini-turbohead so it must be possible. There’s a sweet-spot for the current in there somewhere.
- I scaled back to a 1A driver currently and it’s calmed down. I have a 1.2A driver from Kaido on the way which I think should be a pretty good sweet spot. Going to try that out later. It’s an unbored 3-cell Surefire M3, so not a ton of power I can cram into it. My goal is a plug and play head that doesn’t require li-ion batteries. Either 2 17500’s or the option to run primaries in a pinch.
(going to transplant an SST-40 onto the 2A driver and see what that does. A 3V LED should play nice® in that configuration.)
Just want to thank djozz for putting this together! This post and the info herein, especially the output/lumens chart brought me to BLF.
Hmmm, I seem to recall someone seeing that on either the 50.2 or the 70.2 but I haven’t heard of Cree actually releasing it.
This might also be a case where some big company special ordered a large batch of 3v versions to retro fit a cities worth of street lamps or something. I don’t think it necessarily means they will be selling a 3v version to the public.
It was mentioned in another thread as well but to date I have not heard of any spotted in the wild yet. I am also very interested in these. If someone finds some please let me know.
