No problem… 5000k is a little to cool for my liking. I really like between 4500k and about 3750k. Thus the mix of the 2 leds.
I highly doubt that the LD-3 will handle a quad build.
At 12A it will have to dissipate roughly 6W+. It is only rated for 3W with thermal cubes IIRC. Same issue I have ran into with the Texas commander.
Although you should be able to get away with a normal FET driver in a quad. I have an S41 quad 219C 4000k and it works fine. It pulls around 21-22A in turbo but that is ok as it is around 5A per LED which is about perfect.
Although it gets VERY hot. If you use long thin wires you could drop that down a bit. 24AWG is about the thinnest I would go.
Isn’t that a bit too high for 219C?
Nope, they make peak lumens at around 6A, so 5-6A is perfect. I tested them to 12A and they lived just fine, they just put out the same lumens at 12A as they do at 2.5A except with a ton more heat.
Just curious, are there any multi output (3-4 outlet) drivers small enough for flashlight applications? That would be a good option.
How about RGBW drivers? We can use 1/2/3/4 output or even combine them all.
There are some great branded multi colour flashlights, right?
Interesting.
So why does Nichia state the max current at 1.8A?
https://www.nichia.co.jp/specification/products/led/NVSW219C-E.pdf
For the same reason the Cree says that an XP-L2 max is 3A but we run them at 8A+. They rate them first off for non-DTP mcpcb which makes a massive difference. Then they also need a safety factor built in.
Heck I tested the XP-L2 to 15A and it still worked! These latest gen LED’s without bond wires are super tough when mounted on a DTP star and have a good heat path.
What driver are you using in your S41?
I think it is.
Efficiency suffers considerably.
Up to some 2 Amperes they’re 100 Lumen per Watt though (iirc)
Using a TA driver in almost all of my lights.
It is perfectly fine, it produces more heat naturally but that is the only drawback.
Sheer output vs efficiency, it is a matter of perspective. Generally over here at BLF the perspective is: sheer output :smiling_imp:
Yes, they can handle it.
It’s a matter of opinion and preferences etcetera.
I just don’t like the idea of a modern LED doing less than 100 Lumen per Watt.
By moving to any higher CRI LEDs,we already sacrifice efficiency. There are always compromises
5 Amperes is excessive i.m.o.
3 Amperes is still okay for a 219C, maybe 3.5 Amperes.
But with a linear driver you run into problems when the battery can not provide the Vf at such currents.
The party is over pretty soon, even with modern low Vf LEDs.
DD FET drivers and how they’re usually implemented makes matters even worse.
Folks are limiting the current by means of thin wires and what not…
Sure, that’s what you would want when the battery is fully charged, but that’s only a short while…
The battery has to drop REALLY low in order to get down to your “ideal” 3A, so that is not an issue.
Plus with the TA drivers you get a regulated 2.5A output + the FET for max power. Best of both worlds.
True of course.
We all want it both ways… 
High CRI AND high efficiency.
True, but i was thinking of a triple @ 6 Amperes or more.
Yes please.
I don’t mind if it can produce high lumens for more than seconds too (it heats up to unhealthy temperatures darn fast when you drive it hard).
For streetlightings 100 lumen/watt is pretty standard in 2016. Manufacturer are moving to 120 lumen/watt total SYSTEM lumen this year.
To get the most efficient yet as high as possible CRI to the end user, most manufacturers (including Nichia) have been decreasing chip size. Some goes to small chips meant to reduce intensity and better spread of lighting spots, some forms big COB with much higher voltage at very low current.
For example the 757, E17A, and E21A is Nichia flagship at the moment for it’s (own) record breaking efficiency while maintaining one of the highest efficiency AND CRI in the class. AFAIK, Yuji LED still has the best colour quality but suffers with it’s poor efficiency (60-70 lumen/watt is typical).