skyray king to blf q8 transformation

Hi people

after a long break from the flashlight/led related hobby I was drawn back a couple of weeks ago.
After a buddy of mine I gave a skyray king years ago and recently got some replacement 18650 flat tops he complained that they wouldnt make contact so I soldered some beads and he was ready to go.
well that was it for me and I got hooked again after messing around with induction heating for a while.
had a srk sitting around that had 3 cree xml2 and decided to give it a go after I accidently supplied 24v from my power supply that was switched to soldering iron
modded it to 3 sst-40 flashed Anduril, did a quick tail amp measure of 18amps with 2 used but charged LG HB6 so not to burn multimeter rated at 10amp
waiting on a Aluminum Reflector for 4 x Cree XM-L and a couple of xhp50.2 3v from Kaidomain to mod another I have lying around

as for FET replacement for Q8 drivers mentioned somewhere and sourcing them I love these NXP PSMN0R9-25YLC due to
drain current rated 100amp pulsed 1563amp 10μs
RDSon lowish enough close to Vishay SIRA20DP
min 0.95 max 1.25 mΩ at Vgs 4.5v
min 0.75 max 0.99 mΩ at Vgs 10v
and really cool at total power dissipation 272W

for comparison
Vishay SIRA20DP
drain current rated 100amp pulsed 500amp 100μs
RDS (on) min/max. (Ω) at VGS = 10 V 0.00048/0.00058 or 0.45/0.58mΩ
RDS (on) min/max. (Ω) at VGS = 4.5 V 0.00065 0.00082 or 0.65/0.85mΩ
total power dissipation 104W
specs from datasheets after a lot of searching/sourcing/pricing FETS
anyway some pics of mod

used quite a bit of copper especially the pill

That’s quite the mod nmbusa - impressive!

Nice mod! Oh boy - The SIRA20DP has been my favorites FET lately...

Interesting you went with 2 FET's in parallel (I think), and located off board - guess to keep them cool?


cooler yee,was curious if there would be any increase in tail amps.
as for SIRA20DP I’m more a nxp guy as I like the big drain tab for soldering led -wire in modded drivers with no pad from back in the time of “comfychair-inspired quick+cheap+lazy single-sided 17DD FET-driver”
had a bunch of Nanjg AK-47A from then that were real easy to make fet+1 with LFPAK56s the right side up lol.
as for sourcing fets

had some bummers with fakes from china in my induction mods and cant find SIRA20DP to give a try.
the PSMN0R9-25YLC i mentioned is great, even has a lower total gate charge
QG (tot) at 51nC compaired to SIRA20DP 134nC.

there is also this
N-channel 30 V, 0.87 mΩ, 300 A which I cant source which I think is overkill even has a high gate charge at 109nC

if shipping from the likes of mouser/digikey and others was cheaper to Greece I wouldnt bother with Chinaland, the link I posted has thousand of followers and probably no fakes at $7.55 +3.67 shipping for 10 fets i’m happy

c :beer: heers

cool mod! SIRA20DP are nice, have used them a few times on wights DD FET board.

Are those mcpcbs DTP?

Nice work btw! Good to see some true-to-roots BLF action :+1:

actually I dont think they are.
the old copper ones had a dielectric layer

they had the Cree XM-L2 U2-1A I fried and since they were ok copper mcpcbs I reflowed sst-40

The level you are driving those emitters, and with all the work you’ve done for minimizing resistance, I think DTPs are in order for this mod.

your right Jared.
after a shorty s2+ triple XP-L V6 and C8 xhp50.2 3v with blf A6 firmware had to fix the srk 1 with anduril and 1 with narsil
it was basically a trial mod if I still had the patience lol.
all the copper is waiting for the xhp50.2s with DTP I have on order for a swap and these sst-40 are going in another srk sitting on my bench

Sorry for doubting you! Clearly this isn’t your first rodeo. Just couldn’t help but notice those boards were out of place. Blame my OCD lol

Cheers indeed!

Hi Jared

never passed my mind.
dont know if you jinxed me though! lol
as stt-40s blew all at once this morning.
took it apart and found the culprit was the bolt under copper heatsink to lens went loose so leds were airborne bearly touching thermal paste.
have to find that damn locktite
che :beer: ers

so the dont go to waste I did a djozz job

with my dremel removing dielectric layer exposing the copper underneath

Nice work nmbusa. Dont see many mods like this anymore. :beer: