So i bought myself a “SKY RAY 9 x CREE XM-L T6 13500LM”
While being brighter than any flashlight i’ve ever seen there’s no way in the world it’s 13500LM that would require about 100watts.
I bypassed the driver and applied power directly to the leds and i couldn’t get it to pull more than 1.5amps total.
I assume these LEDS are thus fake.
I’ve also tested the driver and at 1.7amps it’s about to catch fire.
So i intend to toss the driver and replace it with 3 16mm drivers in parallel for 5.6 amps total (25watts)
Im also going to replace the LEDs with CREE XML2 white U2 1A
Now it would seem that the limiting factor with flashlights is their ability to remove the heat. Im intending on mounting a 10-15mm heat sink to the leds with an internal fan to help move the heat from the heat sink to the inside of flash light so it can be radiated to the air. However one would think that this flash light would get very hot, to hot to hold.
My thoughts are there seems to be very little on this forum that deals with heat removal to the point where i assume people overheat their lights and or only use them long enough to show their mates how bright they are for 1 minute.
One thing i have considered was to drill holes in the flash light to allow cool air in and hot out and thus not requiring the flash light to pass all the heat via its body. BUT that wouldn’t look that great And you could then hear the fan. It might not be a big deal though.
Another fresh Kiwi ! Dude that amp reading is low - extremely low. Once its all driven properly, you’ll find an internal fan wont do J.S. without vent holes anyway. If the holes are small enough to fit between the fins, then why not ? Although don’t rely on that alone a huge copper heatsink will help cooling.
Yeah i have another sky ray SR5 single LED which is branded as cree and is more powerful but still all i can get out of her is an amp and a bit (so this led is much more powerful). Im also replacing this.
I have a 8watt LED and it gets very hot with heat sink and fan which is why im asking about this cos 25 watts is a lot more !
Also I was concerned that the A meter was wrong but after more testing it’s right. !
Maybe i will drill holes in it. it will be fine if the holes are perfect but if not it might look home jobbed
If you’re using a fan I think you’ll need to have openings for air intake and exhaust. A completely internal fan in a sealed light won’t have any cooling effect.
If the holes are between the fins, they’ll be deep enough ( from the outter edge of the fin ) that you won’t see them. They’ll only be ~2mm wide, shove a black sharpie into the hole and colour the exposed aluminium black - they’ll be invisible.
Ahhhhh I see. Not what I pictured you had. Flag my prior comments. The fins aren’t that deep. Drill by all means, but the holes will be more visible than I pictured. As for sharpie, nope I’m a kiwi, just the sharpie brand has a thin pointed tip perfect for small holes. I was gonna say vivid, but they have all different tip shapes.
Cripes. I just watched the entire clip. What a rough dude. I hope that isn’t a blf member that shelf the LEDs sit on is veeeeery thin with minimal thermal path to the external body. It really does need something done to cool it - Crickey.
Don’t you have some old computers? You will find all kinds of heatsinks inside.
The block of alu that makes up the housing must be the heatsink, behind the led with a fan, is not only tricky, but you need holes (making it no longer usable in rain), shorten battery lifespan, create a noise flashlight.
Decent warmth bridging from LED shelf to the housing is key here.
But hey, using active cooling sounds like a very cool (pun intended) project.
(I think we will try a SRK with oil to transfer the heat from LEDshelf to the housing.)
(and am also a SRK buyr from AE, in dispute over 2, money back for 1 and preparing pics for 2 more. I go for the 3 or 4 led ones, saves a lot on LEDs)
Hi yeah it wont be water proof but i never go out in the rain with my light and if i do it would take a lot to actually get down the hole and to start building up.
The problem still remains that if you transfer the heat into the body this will get hot and soon it gets to hot to use. I see the only way around this is to active cool. Also since this has a large diameter and a big space to the driver board it’s just screaming for a fan.
Lastly active cooling is soooooo much more effective than passive cooling.
Based on the running time and thermal management system of real-time temperature detection. When the flashlight is on high brightness mode, the first 5 minutes the output will keep full brightness. In the subsequent 5 minutes, the output will gradually drop to 50% of the initial brightness.
The emitters and essentially anything else inside the light can tolerate much higher temperatures than you can. Hold on to it tightly as well. As it turns out, your hand (or rather the blood flowing through your hand) works pretty effectively as a radiator, helping move heat out of the light. Good thermal mass inide the tube is the first line of defense against the heat, and should be prioritized as such. Those thin walls aren’t the best.
[quote=Lightgecko]
Hold on to it tightly as well. As it turns out, your hand (or rather the blood flowing through your hand) works pretty effectively as a radiator, helping move heat out of the light. /quote]
I must disagree with that I’m afraid. The surrounding air will dissipate the heat faster than essentially insulating the light with your hand. I sure as buggery wouldn’t grasp the fins tightly to try and cool a torch. I do the complete opposite and hold as far away as practical from the head.
I must disagree with that I’m afraid. The surrounding air will dissipate the heat faster than essentially insulating the light with your hand. I sure as buggery wouldn’t grasp the fins tightly to try and cool a torch. I do the complete opposite and hold as far away as practical from the head.
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Look up the thermal conductivity of air. It’s a much better insulator than your hand is. I completely agree with you that fins allow air to cool the light due to the increased surface area, however on the rest of it where there aren’t any fins holding it will help pump out some more heat. I don’t mean that it’s better than a good solid heatsink, but it does help.
In the massively overdriven tiny lights like an XHP-50 in a AA light with two 14250s in direct drive, there’s just not enough thermal mass avuailable, and you have to really hold on to it tight. The coolig effect is much more noticeable.
Remove as much alu from the LED shelf as possible to let air pass
cut away material in two lines, the ones marked with red just seem the only ones possible
this creates holes for cool air to be sucked in (bottom) and hot air to be pushed out (top)
that shelf the LEDs sit on is veeeeery thin with minimal thermal path to the external body. It really does need something done to cool it - Crickey.