Not really mod. Today I found 3 pcbs for TA fet+1 in my box with junk and decided to solder them. Actually don’t know what to use them for ¯\/¯ Suggestions?
In a flashlight? Unno.
Wow! very nice and clean job! Awesome drivers
Naw, too obvious. What else needs a driver… a car? A printer?
Wellp, I like the pretty purple… earrings for the missus? :laughing:
Convoy 17mm 5A lineair driver
With temp protection 
remove the NTC to get rid of it.
Swapping/stacking sense resistors allows you to play with current output
Wow, those where darn good pics, thanks! 
Sorry I can’t help you with the memory issue.
It looks like it has two Alpha & Omega AON7520 “AlphaMOS” mosfets. I might be wrong on the precise model but that symbol on them is definitely Alpha & Omega.
It would be nice to know what that SVA11 / SVAII thingy is.
At the risk of exposing my lack of electronics knowledge: could those all be FETS? In which case, together with the two big ones, for each power setting a separate channel with FET is used (so no PWM) ?
The two large squares in the center are the primary FETs running in parallel for redundancy / heat spreading / etc. The medium sized three legged chip is the smaller FET that Mike mentioned, usually used for signal control or power under 2 amps. The 10 legged chip is a PIC-style MCU. It’s that 5 legged (SOT23-5 footprint) that runs the FET control show. It’s got to either be a current controller/regulator or op amp. I’m still mildly new to those. I’ve searched for hours to try and identify it, but no luck yet.
I did a lot of mods, upgrades, etc. this last weekend. One of my favorites is to this SK98 I've had sitting around for a while.
I 'helped' TA get rid of some LEDs and I used this 219C, 5000K on a 20mm DTP MCPCB to replace the XM-L.
I replaced an UltraFire 5 mode (H,M,L,Flash,SOS w/memory), 17mm FET driver in a C2 with a Convoy SST40 5A and used the old C2 driver in this 98. Sorry, no picture of that driver but I opened up the hole on a Nanj 20mm contact board, extended the driver's cheap spring, added another (from a bad SP32A driver) as a spacer, soldered the negative outer rings and then by-passed all that resistance. It can pull 6.7A with a Molicel P26A, ouch!
I found out that an S2+, lit switch fits and works fine with the Ultrafire driver. I don't want to burn it all out so I'm using 35Es (~5A).
And the 90+ CRI, 5000K tint is beautiful! with an 'almost' sharp-focused projection of the die.
Correction: I didn’t mention the three legged chip, I only mentioned the two primary FETs (Alpha & Omega AON7520) and the SOT23-5 chip (SVA11/SVAII).
A couple Surefire 6P mods… (I got bored)
. 6P machined for 18650, kiriba-ru copper triple/quad hand fit to press fit pills, Lexel aux board/Mtn/Dragon board both with Dragon drivers…
Left 5Mega/Surefire Defender head, red/orange Lexel board…
Right Surefire 6P fully loaded…
Fully Loaded 6 Tritium tubes…
Fully Loaded Glow Tape…
Fully Loaded Dragon Secndary/Aux LED’s Low…
Fully Loaded Dragon Secondary/Aux High…
Red/Orange Dragon Sec/Aux on High…
I love reading about one member helping out another. Nice work Nachtfeuerzeug. 
Convoy m21a xhp50.2 6500k 18.5 amps with a Samsung 30t 5,000lm cold 4,800lm at 30 secs 
Sometimes I find myself, with a mini mag host…
I’ve tried some reflectors, and at least two TIRs,
some 3mil. some 5mil. XPL2,
some beers,
well today it’s aspheric, lens scratched up the most,
it’s not bright, wont reach far,
but still I must post….
3000k 5mm LED ground and polished plus some silver marker sloppily applied to kill an artifact
Head [dis]assembly.
Took me a while to realize how to make it turn on and off the original way, but it does.
retro?
Cool.
A narrow-beam 5mm variant could be quite efficient in this setup.
Which lens is that? I wanna upgrade my minimag like that
22mm should do it.
Agro, true direct drive any inefficiencies are to blame on the LED, abused optic, or host itself. 
id30209, with regular batteries or NiMh it’s pretty much a moonlight mode that lasts a very long time.
I’m feeding this one one LiFePo4 cell with a dummy cell, 
3.2v 400mah but starting with 40ma draw it lasts long enough for me.