By the way, this is just to comment that if there is one led emitter which could benefit from a 4040 footprint, that is the 2mm² white flat or CULPM1.TG. Its about power density.
Hello, with Convoy l21a original driver at 6A the heat will be the same as the sst40? Or the osram 2mm produce more heat than sst40 at the same amps? I saw your charts and there is a Vf difference and of course the emitter area. Thanks
You will not see much heat difference betwern the leds if they are driven by the same driver at 6A. The power/heat at the led will be somewhat different but with the driver being lineair, the overal power/heat by led+driver combined will still be the same.
my concerns are about the temperature control using the 2mm and how it will be affected. the idea is to keep the ntc for extended periods on turbo/high without risk of malfunction, but at the same time, prevent a shut down by the ntc. Reliable flashlights for sale to regular / inexperienced customers, with better throw.
I removed the NTC and did stack the sense resistor to crank up the current to about 7,3 A
It gets nice and warm after about 5 minutes, but i havent used it for very long extended/continuous times, so cant say something about that.
I would avoid buying from Kaidomain for the moment until I get a successful reflow myself for testing. The 2mm has a slight purple tint even at 4.5A. djozz is thinking it may have been a bad reflow. It could be an entire batch as all 6pcs have the same issue.
My 30pcs 1mm do the same thing at 4.3A so I’m selling at 3.5A (650 lumens) with stacked 7135 chips
So do you think whoever is doing white flat reflows at Kaidomain is doing a botchy work? @#$%, I have a couple lying around.
Will mount them on an old PC heatsink, set a small narrow beam TIR lens on top of the emitters, and proceed with some testing with my power supply and smartphone as ceilingbounce luxmeter.
I’m not 100% since this is the first time using white flats. I did attempt a reflow, a terrible one, and it was instant purple. It was the same tint but much worse, which feels like that confirmed it for me. It would have been a different story if it was blue but it was exactly the same tint
Ordered some lead solder paste to try again once it arrives.
I believe it is normal. It is quite purple-ish, but the output is close to other pure white WFs I got from mouser. IMO the tint worked pretty good outdoors.