The driver’s not the limiting factor its the dedomed XM-L2, I have several and I’ve built quite a few more lights with a BLF17 and 20 dd’s that do well over 8A with other emitters (MT’s @ 8.4v, SST-90’s, multiple parallel XP-G2 & XM-L2 setups), my EDC runs at 8.4A and will do 13+ off a 25R (but the triple XP-G2 doesnt like that very much lol, anyway point being the BLF drivers can do well over 8A).
If he found a better way to keep it cool than a noctigon/sinkpad (like when people etch / mill a flat piece of copper down) I’m certain the BLFxxDD would be more than capable for the light.
You said it. With other emitters... You can get a BLF DD to supply 20A++ with the right emitters/battery combo, its irrelevant. But this is a TK61 thread. It uses an XM-L2. Vinh`s light uses an XM-L2. At 8A, 4,2V is required to the emitter. A BLF xxDD wont get near 8A peak even with freshly charged cells due to the voltage requirement.
Personally id rather have around 4,7A regulated with the stock UI (or 5,75A), than peak at 6A+ and output that will drop well below 4,7A in time (with BLF xxDD). No doubt that the BLF xxDD is capable, but I dont see it as an optimal solution for a TK61. Unless you want it to throw or have a pencil beam with other emitters.
Around 8A regulated to a single XM-L2, that is where the magic is IMO. I don't see how you can get close to that with a BLF xxDD driver.
hmmm im far from expert, but doesn’t Fenix battery configuration put much less strain on the cells? i think 8A is not problem at all. I was told, even at 4.7A its like 2.2A per cell, so 8A should be around 4A per cell?
With multiple cells and higher voltage and a buck driver 8 amps or more isn't a problem. Well, if the driver is built to allow that kind of current. A buck driver converts the excess voltage into amperage.
The limitation with a direct drive driver isn't anything to do with the driver, but rather the lack of headroom between the input voltage and output voltage.
Carried my TK61 doing 406.25Kcd and that was enough to shine across the Mississippi River at Vicksburg.
Found new drivers had arrived while I was gone, so will be looking at bumping power…
Sorting things, will be back with a pic or 2
The old gent that was hanging out at the lookout, watching barges slide down the river as he’d done most of his life first told me it was impossible “Son, that there River is a MILE wide!”, then shook his head in disbelief at what he was seeing. (It’s not a mile wide at this point “only 1072M”, but is in other places) When told this power level would end up nearly doubled, he was incredulous. Love playing with lights like these around non-flashaholics.
Finished up my first mod on my tk-61 did a gasoline de-dome and resistor mod. Everything went great super bright and an amazing throw. Never would have known about modding this light if it wasnt for blf. Just want to say thanks to everybody wo shared information with me.
Hi guys, some tips how to center the emitter/reflector on the TK61? i heard its very hard, and if the led is not perfectly centered you could lose like 15% of the CD, is this true? Sad
It’s a wonderful feeling when you amaze someone like this. Showing someone who’s used to Energizer lights which have one LED and a little aspheric lens a light pushing 1km in throw always blows people’s minds.
Yeah around 600 meters. Below 1 lux with the naked eye it’d be almost impossible to see that far out. Also a thing to remember is 4x the candela = 2x the throw due to the inverse square law. Eg. a 100kcd light will only throw twice as far as a 25kcd light.
Do you have a specific reason for trying the 70N02? A quick look at the datasheet reveals that it is not designed for low logic levels on the gate (I don’t know what the logic level on the TK61 is). It will not be the optimal choise if the logic level is under 5 V, as it will not open fully. Also, wiring out transistors like that from a DC/DC converter may result in some crazy EMC/functional issues…
EDIT:
For a good N-MOSFET, you could try this one. It seems to have a very good price/performance ratio, and it will fit into the PCBs standard footprint (sot-23). http://www.mouser.com/ds/2/115/ds31946-65244.pdf
I had it available in front of me and was curious. Wanted to help RMM to push the stock driver. Unless the stock driver could do extreme amps I was moving on. And it seems it could not nearly as many amps as I had plans for.
Ive finally got my HX-1175B drivers yesterday (only 64 days after I first ordered them), so Ill put one of those in my TK61 like I had planned ages ago. Seems like others have already beaten me too it.
Currently got some other projects that's been moved higher on my to do list. I think you guys might like one of them, ill share if if successful. But this time I want to finish my own project before sharing details.
Ill update this thread later on with how I did my TK61. Might compare with Supbeam K50 too.
Thanks for the tip Samppa. Welcome to the forum btw! :) Always nice to have people with some electronics knowledge helping with mods!
Gotta tell. Just got in from playing with the TK61 and my latest psycho bright light. (Similar size as TK61). Awesome stuff! Regular car headlights look like old incandesent Maglies in comparison. :D
