Phew! I almost ordered three. I’m still hopeful though. Perhaps ImA4Wheelr got a faulty one. I’ll be keeping my eye on this thread.
Edit: did you remove the built in switch to connect it? I’m wondering if the switch can’t handle 6A.
Ouchyfoot wrote:
Edit: did you remove the built in switch to connect it? I’m wondering if the switch can’t handle 6A.
I did not remove the switch. The switch is quite small and may be an electronic switch for sending a signal. It certainly doesn't look like it can flow 60watts (rated output of 10 volt x 6 amps).
This is a shame because the driver looks real good. Lots of components. All nicely soldered (by machine, I would guess). Makes me wonder why they are selling it so cheap. I was hoping it was due to the awkward layout.
Maybe if I would have better heat sinked it, but I doubt it would have made a difference. I think it is just designed for 3+ volts. Comfy has one on the way and he is knows much more than me about this stuff.
Just saying what the specs say : Output Voltage : 2.6-3.9V Best for SST50 or SST90 Led
RaceR86 wrote:
I'm sorry to hear about the driver failing ImA4Wheelr. Hope you get it up running again. And thanks for taking one for the team!
Thank you for the sentiment and recognition. I tried a couple times to find the thread where this driver was first brought up, but it eludes me. If you happen to know it, please post it so I can update it. I think I have a link to it at work.
I'm hoping I'm missing something and Comfy figures out how to make this work with MT-G2. It would be nice to have a low cost 3S option for it.
ImA4Wheelr
You have that big driver that is rated 2.6-3.9V output?
Is It the one from post #101 Driver for the MT-G2 thread?
that driver is meant for using in a bike lights and almost all (99% of them) bike lights use 2S2P configured battery packs so 3S NCR’s was a bit too much for that driver, other than kinda-not-liking modes that driver should work nicely with MT-G2!
P.S. I have a similar driver in my bike light, I thought to thinker a bit with it but it turns out that it pushes the leds pretty hard already (led’s get hot fast) so I wouldn’t gain anything except the heat. LEDs are connected in series and if I recall correctly I measured about 12V ~ 1.68A on high. Again, batery pack is 2S2P…
O, and the switch is electronic, so called momentary switch, not a clasic clicky, it only sends a signal to MCU and doesn’t have to handle big A…
@Sirius9 - this driver should put out 1.6A. If it is regulated with QX5241/SM5241 chip then output current is calculated 0.2/R. Resistance of two parallel 0.25ohm resistors is 0.125, so 0.2/0.125 = 1.6. You can add another resistor to get higher current. Another 0.25ohm (R250) would give you 2.4A.
I’ve somehow got http://dx.com/p/5v-8-4v-2000ma-3-mode-led-driver-board-162787 which is very similar to yours and one guy (desolder) told me how to calculate current for it - see product discussions.
a bit different regulator but the math is the same but it’s not worth pushing it further
because there is not enough thermal mass to dissipate all that heat as is, if I add another
R250 it would start cooking in matter of seconds…
That's not an ic in your photo it is a mosfet.
Oh, I thought that ledoman, by sayng “f it is regulated with QX5241/SM5241 chip” is referring to a mosfet!, sory I am not EE, just a hobbyist 
Hikelite wrote:
ImA4Wheelr
You have that big driver that is rated 2.6-3.9V output?
Not sure what driver you are talking about.
the 38mm one
Sirius9 wrote:
Is It the one from post #101 Driver for the MT-G2 thread?
that driver is meant for using in a bike lights and almost all (99% of them) bike lights use 2S2P configured battery packs so 3S NCR’s was a bit too much for that driver, other than kinda-not-liking modes that driver should work nicely with MT-G2!
The driver we are discussing is linked in the OP. It says it is rated for 7 to 18 volts input. Here is a pic:
Photos of both sides of the driver in the OP.
There's also two more like that
http://dx.com/p/smart-led-driver-board-for-bicycle-flashlight-blue-236160
I notice in the descriptions in the other two, it does not state "parallel".
I see.
I got this one and output as high as 4.7A to the MT-G2, a bit more than it does to an XM-L which is around 4.5A.
yes that’s the one, guess OL didn’t pay attention on that other thread already dedicated to MT-G2 drivers…
DX isn’t quite known by their accuracy in product description, accidentally I pay attention to those drivers because i am into bike lights (also ) but I always tend to start from lower voltage margin, it’s safer that way… Anyway I hope that you will manage to fix it but if it’s fried for good, better $5 driver than $20 emitter 
Sounds like good advice Sirius9. I'll try to follow it going forward.
On a side-note.. That driver seems to be the same is this driver from lightscastle. Cheaper from LightsCastle.
Ok, where are all these drivers of this form factor being used? Bike lights I'm guessing, but I never seen or had one with this type driver.