I got an old Mag-Lite 2D just laying around. It was time to jump on the LED flashlight bandwagon and upgrade the old Mag-Lite Torch incandescent bulb flashlight. There are many Mag-Lite LED upgrade kits on the market, but just for fun, I was tempted to create my own DC-DC converter and squeeze all the components to fit in the old bulb socket.
DC-DC converter diagram:
Cree XM-L2 LEDs details
DC-DC converter details
…
Initially I was intimidated by their small size, it still doesn’t look too easy to solder, but perhaps some practice would help. :bigsmile:
So far, the circuit has performed well.
Thermal images of the DC-DC converter
Thermal images of the LED
This converted my light, big-time. It’s rated at 280 lumens, and transformed my 2D, completely. I didn’t have to make any modification to the reflector cone. The best part about a Mag-Lite LED conversion is you get to keep the old anodized aluminum flashlight casing. You’ll enjoy the same high strength water resistant case you’ve come to love after the Mag-Lite LED upgrade is complete.
Howdy. I’m quite sure the ‘modders’ on this Forum will appreciate this thread! Only 2 posts here in the Forum? Stick around, you will be family in no time. I wish I had your electronic know how. I chuckled when I watched the video at the end as I saw the beam of my (3) D cell Maglite (if I can call it a beam).
thanks for your thread and pictures.
patrick
Impressive soldering skills. Love the imagination, and stackup concept of the driver, who needs a pcb?
What a terrific mod. Hi and welcome by the way. I admire your skill and imagination used in modding the light and building the circuit board.
Just an idea, what about putting the driver in the tailcap since there is more room and put the led on a solid piece of copper.
Thank you all for your kindness and warm welcome. 
I was tempted not to do any irreversible modification to the torch. In this way we can keep the focusing system up and running. If there’s a need I can change back to the original bulb.
In a modding project like this, the mechanical design problems are challenging because of limited space to accommodate the necessary LEDs sinkpad. If you want to keep the initial design there’s no way to install a large heat sink in order to push LEDs power up to the real value. For this project I kept the power level at minimum and luckily it was enough to improvise with such small copper plate to do the job. My initial sink pad design was like this:
and maybe I will use it for the next challenge that I have in mind, modding a big 6D Mag-Lite torch I have in my collection. 
I love gorilla mods. This one takes the cake. :party:
Looks like it's going to be a boy.
Seriously though, really nice work. I'm already a fan. If there is a scratch build contest this year, you will be a serious competitor. Welcome to the forum.
Very nice! And welcome to BLF! The LM3410 is good choice for this mod. You may also want to look into the LTC3490 from Linear Tech. It is a bit more expensive, but it has synchronous rectification and a lower internal feedback resistor and reference. These should make it more efficient.
I love the point to point wiring, its the only way to get things really small!
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@ ImA4Wheelr
Thanks for making my day
@Crux
Thanks for the suggestion. Next time I’ll try the LTC3490 series circuits. It seems that’s very good for 1W LED applications.
Keep in mind that the LTC3490 will NOT tolerate more than 3.2V battery, so Lithium cells are out.
The saga continues…
I have decided to give it a try in order to do the same modification to a 6D Mag-Lite flashlight.
Due to the fact the power supply exceeds the maximum input voltage range required by the LM3410, I had to modify the diagram. Here there are some pictures as details of the flash light modding.
The old 6D Mag-Lite
The new diagram
CREE MCE4WT LEDs series
The DC-DC converter
testing the DC-DC converter
and finally the converter was mounted
The two flashlights
You performed open-brain surgery on the insides of a PR bulb base — TWICE — “just for fun”??
In the immortal words of the great Bill Murray: “I wanna party with this guy!!”
I think if I were the same size as your avatar (1:1) I’d still have a hard time putting all those parts in such a small space.
NICE mod!! (puts on entrepreneur cap) You surely must realize that the people who make vastly less interesting ones of these, charge more for their bulbs than what your MagLight costs new, yes? I’d wager there would be thousands (at least) of Sheriff’s Deputies who’d love one of these in their issue Mags…
PS: WELCOME to BLF! You’re definitely among friends here!
Dimbo