Please tell me what lights you used, i am planning to use the X6 for some LD-2 triples and i hope it will take the heat fine.
I have done 2 blf titaniums in 18350 and upgraded my electrolumens EDC with xpl triples and ld-2 driver complete with NTC thermal regulation. The EDC is a fantastic host for the triple. The blf titanium is a bit small for a triple as titanium does not conduct well and it regulates down to medium pretty quick (about 20sec from cold) due to heat buildup, but makes a great showoff light and medium still throws an insane amount of light for this sized light.
Thanks Bribo 
good to know some stats on other triple build for comparison.
Kenjii asked me the same question yesterday,and here is the answer:
"For 3x nichias 219C,(theoretical) power dissipation on high(12Amps):
Pd=(Vbatt-Vled)*I=(4-3.3)*12= 8.4Watts
On medium(2.4A):
Pd=(Vbatt-Vled)*I=(4.15-2.9)*2.4= 3Watts
3Watts with some silicone cubes isn’t a problem,but 8.4Watts on high is very high. That’s maybe possible with piece of alu/copper cube/sheet glued with Arctic alumina directly to top of the mosfet,and more copper/alu/good thermal paste to connect that to flashlight body.
Note that this is worst case scenario,without voltage drops on springs,switch,wires;if you got 12-14Amps with DD driver,then there is a significant voltage drop on those parts,so dissipation in driver wouldn’t be that high.
This is where experimentation is only way to find out. But the sure thing is that regular mounting of driver isn’t good enough."
Thanks. I’ll give it a try with a heat sink and let you know.
1st question (likely rhetorical): to set a 2S 4.5A max, I would source a 200kOhm and the other 2S mods ?
Will drive this NUBM44 450nm diode
Will give 3 primary modes:
- 120mA - will surely be “dead” mode as it will be below the lasing threshold of approx 400mA
- 900mA - ~1W OTF
- 4.5A - ~6.5W OTF
2nd question (the real question): if I wanted to mod the driver for a 2S 2.4A max, I would have to change the current-sense resistor and adjust some other components (I have not yet researched the exact values required). Do you feel that a 2.4A max is even possible, given the design of the driver ?
Goal is to drive this NDG7475 520nm diode
Will give 3 primary modes:
- 48mA - will surely be “dead” mode as it will be below the lasing threshold of approx 200mA
- 480mA - 150mW OTF (perfect)
- 2.4A - ~1.5W OTF
The allure of your driver, above all others, is that with these extremely powerful lasers, running any multi-mode PWM driver does almost nothing to increase “safety” and in fact likely decreases it, because the PWM max pulse energy is still max, while the human perception is that the output is “low”, which leads to the situation where it may not be treated with the same “respect” as if it were at 100% duty cycle. For this reason, mutlimode, while a nice idea, is not useful for these high-powered laser diodes. Your driver is a game-changer in that regard because it actually decreases the max power output (!)
The low-mode will surely not be enough to exceed the lasing current threshold of either of these diodes but I’m willing to deal with having to cycle through the “dead” mode in order to get the other linear lower outputs.
If the answer to these questions is “yes, you understand these correctly” then I think I can swing the 5x since i’m sure once some of my friends see it, they’ll want the same 8)
You can see the hosts and beam shots of these diodes in this post on LaserPointerForums.
Honestly, if you wanted to work together to come up with a high-med-low set that worked for the bulk of these high-powered diodes that are available, I suspect it’s the laser market that would eat this driver up. The laser community would also probably not even blink a concern at a $15 driver cost if it gave us a safe and multi-mode alternative, but that’s just my speculation.
H/T to “RMM” user on LaserPointerForums for turning me onto this driver in this post on LPF.
Thanks !
-=dave
.
[ps- please let me know if I should post so the info thread instead]
Hi dave,
so what you basically want is to drive those high power Laser diodes with two cells?
Which hosts do you usually use for those setup?
Current can be set to practically any value,that's not problem(200kohm for 4.5A is correct);for <4A shunt needs to be changed first,and then current can be fine tuned with small resistor.
Problem is very large amount of heat generated in driver,because LD-2 is linear driver and linear drivers burn extra voltage into heat;in this case with two 3500mAh batteries in series (MJ1,GA) Voltage drop over driver would be ~3.9*2-4.7=3.1V and dissipated power would be 3.1V*4.5A=13.95Watts,this is a lot of heat,much more than LD-2 can handle(which is 3-5W,depends on how good thermal contact between driver-pill is).
Situation is a little bit better with green diode;max. power dissipation is ~6.5W,still too much for LD-2.
There is a possible solution to overcome this problem,and that is to add high power dissipating element (resistor/diode/zener diode/active zener) in series with laser diode;this way part of the dissipation would be on that element,so dissipation on LD-2 is reduced. For example adding high power(5W+ power dissipation capability) rectifier diode or 0.4Ohm resistor(also 5W+)in series with that green laser diode would reduce dissipation in driver by ~1V*2.4A=2.4W,so dissipation in driver would reduce to ~4Watts,and this is the worst case scenario with fresh batteries,so with good thermal path this is possible. Note that rectifier diode or resistor also needs to be mounted inside of host for cooling,but that's usually easier to do (there are diodes available in TO220 and similar packages).
Since removing low mode isn't that complicated,and if other LPF-ers wants similar driver,I can do that.
Regards
Thanks for the thorough response. Yes, the Vf and power levels of these diodes places them in a difficult position for linear drivers to manage. I will do some experiments and see if a parasitic load in series makes sense.
-=dave
With the ld-2m the led plus is ditectly wired to the battery plus. Is this possible and recommended by the ld-2 too?
If you're using LD-2 in flashlight with >17mm pill,then yes,you can connect LED+ directly to batt+(spring) with thick wire,and connect driver Vcc to batt+ with thin wire for driver supply.
Thank you, I will do that if there is an advantage.
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I have been following this for a while. I am now thinking that I might put one in a POP lite P32 converted to 18650. I would attach it to a 17 mm. to 20 mm. adapter board or ring filed to 19 mm. I would use a Nichia 219C with its low forward voltage, so it would stay in regulation at maybe 4 A., low enough that the un-finned stainless steel bodied zoomy host could dissipate the heat. The brass ring would be better for driver heat dissipation than the board.
An XP-L would also be interesting, but it wouldn’t stay in regulation as long and would generate a bit more heat at the same current with its higher forward voltage.
My first P32 has a Nichia and a BLF A6 FET+1x7135 driver. That is right with 3xAAA but would over drive with a good 18650. Qlite drivers work well with Nichia and 18650 but fall out of regulation sooner.
Hi, can this driver work with 4 cells and 12v leds in low amps (2.5a)?
Hi,
XHP35?
Yes,there is an option for 4S operation,few members used 4S setup at 2.5A for xhp35 successfully.
Hi,
Is this driver still available for purchase? I didn’t see any $$ info in the OP.
Thanks
Sales thread link is in his sig so I presume so.
What he said
I’ve read through this entire thread before asking this, I didn’t see any other question/answer that looked directly applicable. So here goes…
I recently built a Jaxman Z1 with an FET+1 driver and Luminus SBT-70 emitter. Amp draw is a ridicuous 17.97A from a single 26650 cell. With this kind of draw, the non-efficient SBT-70 is making a LOT of heat! Enough to kill mode switching as the driver heats up and affects the off-time capacitor.
So I’m wondering if I can use the LD-2 at 12A to give some better control on this light? The light has a brass pill, I’m thinking about making a duplicate in copper, would it be necessary to mount the FET on a separate board/mcpcb or just use good potting/additional heat sinking?
Yes, it’s a single emitter pulling 18A in direct drive from a single cell. Nuts, right? So would 12A be a better solution or a further reduction to 9A?
It doesn’t make many lumens for all the draw, doesn’t throw all that far for the nice AR coated aspheric, but the round die under a fisheye is just awesome to me so I want to continue using it like this.
Appreciate the help, I seem to be running into the ceiling more and more these days with some of my builds. lol
OH, and for the record, with the proper modifications on the LD-2, my MaxToch Shooter 2X is making 2300 lumens and 335.75Kcd at 2.87A at the emitter through an XHP-35 from 4 LG HE-2 button top cells. Almost the same throw, double the lumens as the stock potent thrower. Sweet! (yes, I made a 2 cell extension for this light)
Thanks again for your help in guiding me on the proper modifications to the LD-2 in this application, working perfectly and loving it.