Luminus LED are 3-4v and use 30A+ current.
Take a look at some of the datasheets, it’s insane.
As with most LEDs you can drive them at even higher currents for more output as long as you give them enough cooling.
Let’s assume one wants to drive it at max allowed Tj (150C)
They rate Vf vs temp up to 120 degrees, let’s use that.
27A (this is the max, not 28) * 3.52 V = 95W.
Thermal resistance between PCB and junction is 0.45 C/W.
Let’s assume 30 degrees max ambient temperature. You need your host to have under 0.8 C/W. So even stock output will not be thermally sustainable in a passively cooled flashlight. Which is not always a problem.
The LED has a build in thermal resistor, so you can ramp down when it gets too hot
you can do it smart so that the ramp down also calculates the thermal difference to Tj which gets lower with less current
there are no thermally sustainable flashlights in that power range so far, the X9 might get 100W thermally stable
Not with that U.I.
I want all the nice features some of the BLF drivers have ;).
Regarding CFT-90:
When you a driving an LED with 95W you can add a fan. It makes no difference in the runtime in practical terms. The light needs to be big anyhow. You need lots of batteries, a big heatsink, large driver, large reflector or optic (only a thrower makes sense).
Boost driver for xhp and mt-g emitters with firmware adjustment of current limit and pwm for fan speed control so the higher the output the faster the fan spins. Sized for 3p or 4p 18650 or 26650.
I maybe look into building a buck-boost driver with the TPS63027, so 2A max output.
Another topic: looking at multiple posts about fans for cooling, I can’t quite get it. Where should the fan get air from to cool the components?
Air could be ducted from outside the light and blown across the fins of a heatsink allowing the emitter to be cooled in a manner similar to a computer cpu or gpu.
I probably don’t know what I’m talking about but here goes
9v MT-G2 to 3S
we all hate pwm and we all want the efficiency I love ramping but it seem like the D4 is (dear I say it) too much of a hot rod for getting more lumens for longer time. (yup most lumens its great) but I keep waiting (and I think some lights can do it now) but 3k-4k continuous in a nice tint. Yes I know that the heat dissipation of the material is/can be a bottleneck even in lights larger then the D4.
Love the BIG floody MT-G2 when can we make them in triples?
XHP to me has too many artifact issues and unpleasant tint (never heard of a 4C tint in an XHP 35, 50, 70)
Again not up on the latest but what about progress for us guys who want say the smallest light possible that will run three MT-G2 at 3000 lumens continuously with out getting too warm. don’t care if turbo is 5k or 6k or ?k the peak numbers are almost a game because they don’t address what it take to keep belting out big lumens.
Love the D4, but its a case in point, it can run over 4k lumens but struggles to constantly run over 400-600 depending on emitter. again not an expert and not up on the “latest” but it seems like something is missing in the “improvement” trend over time of technology.
And yes I am thinking every day use (not necessarily carry but at least use) the BIG MONSTERS just don’t seem to get actually used.
I know its a jumble and thanks for listening
P.S.
There also a 36v MT-G2 that we never get to use.
6v
9v
36v
If we were starting from scratch with would be the smartest voltage to run?
I so badly want a 2S current controlled buck driver that will output 5 to 6 amps at 6 volts! And then, a single cell boost driver for use with good 18650’s or 26650’s that will run the XHP50.2 as it should be.
right now, a driver that can drive the 6 and 12v xhp70s to 6000 lumens so i can put 3 of them into my chunky monkey. that should be about 8-10A an LED…
Personally I don’t see much use for the voltage references that the 1616 and 1617 offer. You still need voltage dividers to utilize them to measure the full range of voltage levels a cell can have. To use the 4.3V internal reference, VCC has to be at least 4.3V anyway.
The size of the 1616 interests me though, but other than that it won’t do much more for me than the easily available and widely supported 1634.
Maybe, I did not say that correctly. I would like to deliver 6 volts to the led, not something around 8 volts falling off to 6.something volts. And I would like to do it at a constant current as long as possible. The big thing for me would be regulation and not direct drive. Gives battery life stability if all of the modes are regulated. Currently I am using 2S FETs and a very old constant current from the BTU Super Shocker (I think) but it only delivers around 3 amps to an XHP50.2.
My understanding is that if it regulates current and voltage, from a voltage source above the rated LED voltage that it would be a buck driver? Correct me if that is wrong, have been building 1S lights for a good while, but 2S+ are more recent builds for me.