why are people always thinking too much?
a LDO is just a thing that puts out a constant voltage it is not a magical 2S or 4S conversion part
on 2S/4S builds the cell voltage would be above 6V absolute maximum voltage rating of an Attiny MCU, so you need to bring the voltage down (z-diode or LDO)
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totally different story here it remains 1S—>3V driver(could be as well used for 2S—>6V LED)
the LDO is there because it is needed on a CC build
reason:
Attiny MCU puts out a PWM signal, the operation amp needs a DC level
so this PWM signal gets filtered to a DC signal using a low pass
if the MCU voltage is not stabilized then the CC set voltage would vary depending on battery charge(like 2.5A with emtpy battery and 4A with full)
You mean the 2mm WF?
Does it hit ~9A on a low drain (10A rated) 21700?
A local modder here offers FT03’s with the 2mm white flat so I assumed it’s safe for the 2mm.
It is not that simple. A fet driver max output current depends on led forward voltage a lot. An XP-L HI draws like 5A but a 3V XHP50.2 can draw 14A from the same driver. in my L6 a White flat 2mm hit 10A with Liitokala 26650.
Definitely agree - finding the best regulated output (4.5A?) as a maximum is a good idea. I figure you know what you’re doing, so I’ll just wait patiently
My tries of white flat 1mm version showed that 4,5A is good for this emitter. Worth the bump from 4A but over that nothing significant output increase happening. Just more heat and turning angry blue over 5A
I think that the need for the driver should not be based upon the 1mm flat white plenty of linear drivers for that, but for the 2mm flat white hopfully to get the full potential from the emitter
For people who want to push the WF2 to its limit, I suggest considering that at the very upper level of output, the difference between say 1400 and 1500 lumens, which wouldn’t be noticeable, requires something like 3.5 extra watts to achieve. It is almost pure heat. This effectively causes reduced output due to the light heating up faster and the driver engaging its thermal controls if it has that feature, the cell being depleted faster, and also it is bad for the LED. This is why people who do LED testing often recommend a “sweet spot,” where the output and efficiency are at a reasonable compromise. For me, I’d want to run a WF2 at 5A for something like 1300 lumens. It’s an extra 3W for ~120 lumens from 5 to 6A. I definitely wouldn’t want to go beyond 6A. It’s something like 7 extra watts for ~220 lumens going from 5 to 7 amps. ~30 lumens per watt.
you are absolutely right especially on commercial lights 6A for WF2 should be the maximum
put people want to push them hard, if it dies or degrades replacement is cheap
Its like NOS in a car to boost power for a short amount of time, everyone knows its not healthy, but they still do it
I’m open to whatever people have tested as a good mix of output/heat, so as you’ve both mentioned, there hits a point where the returns just don’t make sense (low lumens/W).
But I know you’ll pick the right level; I have faith
My C8 WF1 with L4P LD-A4 driver is set to 4,5A and does 160kCd. I tried all current settings, from 3A up to 6A and the sweet spot is at 4,5A. A bit below, you don't lose that much I mean that wouldn't be noticeable by naked eye. A bit above, you don't gain anyhing but heat.
My L2 WF2 with L4P LD-A4 driver is set to 7A and does 330kCd. Same history than the C8, nothing to gain with higher current.
I also have a WF2 in my Amutorch JM70 with a TA FET driver. On turbo with a black LK 26650 , it doesn't turn blue but I think the current is a bit too high. Thus, I'm not using it for extended time on Turbo. It does 470kCd, I should measure the current drain...
I’m super interested but only if the light came built with the driver and white flat emitter. Hopefully you can sell your drivers to astrolux and they can sell the ft03 with flat white.
I thought you were selling blank driver boards… not fully built just wire it up boards!