Ultrafire 15XT6 teardown and mod

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BryanTM
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Ultrafire 15XT6 teardown and mod

 

15 X XML-T6 head PCA.

 

 

 

Edited by: BryanTM on 01/05/2015 - 08:40
BryanTM
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Dirver PCA

 

 

 

 

 

 

BryanTM
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Driver PCA Layout Bottom

 

 

 

 

 

 

BryanTM
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 LED's arranged in 3 groups of 5 in series. As received, Low = 0.15A, Middle = 0.35A, High =1.0A.

I-V measurements for Head assembly

 

 

 

 

 

 

 

 

 

Sirius9
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With this links no one will see your images, they are on your local computer and no one else have access to them…
file:///C:\Users\BRYANM~1\AppData\Local\Temp\msohtml1\01\clip_image002.jpg
You need to read this tutorial first:
HowTo: Adding pictures to posts
or you can give me your IP and I can hack your PC and extract those images for you Silly

 

BryanTM
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These lights use 2X or 4× 26650 batteries under many trade names including Trustfire, Ultrafire…. *Fire15XT6

Driver current is controlled and measured using a shunt resistor which was 0.10 Ohm as delivered. This gives:

Total draw from batteries ~10V to 18V approximately constant current (maybe 5-10% sag at low end)
Low= 0.15A
Middle=0.35A
High =1.0A

The shunt resistor is not shown in image above but resides in the lower left relative to the picture and is marked R100 (0.100Ohm)
For convenience I simply paralleled across the existing R100 resistor a number (3) of R220 (0.22Ohm) resistors until I got to from the battery stack 3.0A on the high setting. 1/(1/.1+ 1/3×.22)=0.08684Ohms (approx)

This yields Low =~0.50A, Middle= ~1.0A, and High =~3A. The head gets warm to the touch on high, but not excessive. On middle setting the head is barely warm after many minutes of operation.

Notes:

Red-Black wires are 22Ga and have high temp insulation. No issue with Ga as this is a constant current drive, there is minor IR loss in short wires.
PCB material of the LED array appears to be high thermal conductivity. TBD Rtheta to the LED junctions.
The array PCB is attached with a flexible thermal RTV, the LED’s appear to be well centered in the reflectors.
The PCB bracket is at least 0.25” thick, so a decent heat pipe to body.
At 3A the driver does warm quickly if not in the head assembly. Grease would be a good idea at the interface.
There does not appear to be any low voltage cut-off as the controller works down to ~8.4V.
The controller may be of the buck-boost variety as the LED voltage range is in the middle of the battery operating range.

BryanTM
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I think this will do it.

Thanks for the info.

Sirius9
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Well, close enough… You should use relative image size html tag so they (images) would not hang over/out of the screen.

 

Dru_dragon
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Welcome to BLF! :bigsmile: Great first post, I’m assuming that’s tail cap amps on 4×26650? Sounds horribly under driven, glad you could improve it.

Andrew