New version DRY driver info thread goes here (note: specs shown there are still for the previous version)

New listing:

1.260"/32mm. Supposedly this one is no longer direct drive in 'turbo', but still in buck mode. Which probably gives more flexibility in using it for stuff other than 3 series LEDs with 3S cells.

The six-legged thing marked '5241a' is a gate driver for (at least one of) the FETs.


Definitely subscribed to this one.

Cool thread. This one may get quite long.

When did you order yours? I ordered 3 from Ric back in September. He keeps promising to send them, but they never arrive.

Top pair looks like they short pin 7 to ground if jumpered. The others look to do the same thing with other pins on the IC. No idea really but try 2, 3, and 6. Pin 8 looks like ground.

Mmmm, without looking, I think it was ordered the very end of December. Took a long time to finally ship, I think this driver was the holdup. I ordered only a day or two before the pics of the old version were replaced with pics of this one.

Thanks Comfy. I just PM'd Ric, again.

subscribed :slight_smile:

The stars are for different mode groups selection, like the Nanjg 105C driver? :smiley:

Have you hooked it up to a XM-L2? MT-G2? Any idea what it puts out on a single cell? Double cell? Need information! :slight_smile:

Thanks Comfy, appreciate you looking into this one, will probably be using it in the near future…

I think RMM has already done some testing and found it to be pretty constant as a buck driver over a range of cells. As with all dd drivers once parasitic resistance is accounted for, output depends mostly on the cells and arrangement.

Edit - :stuck_out_tongue: What am I thinking? A buck driver is anything but DD.

Next-mode memory?? Man! Well, it does reset back to low but it takes way too long, around 6-8 seconds. I'll have to poke around, which of the two pairs of capacitors are controlling the reset time isn't obvious yet; anybody else see something I'm overlooking?

As far as I can tell the stars don't do anything at all.

I did just a quick temporary test to see if it worked, didn't measure anything. But with 8.4v and a single XML2 the LED wasn't destroyed, so it's definitely not direct drive like the old version was.

It is not direct drive, it is definitely a buck driver. In stock form my pulls about 1.8 amps from two cells going into an XM-L2, also works with three cells (reduced current draw by approximately 1/3 as expected). I haven't tried four. It also works with an MT-G2 with both two and three cells but I haven't tried cranking it up yet with that one (too expensive to waste!).

I tried to jumper over the sense resistors and in about half a second it burned out my XM-L (was half expecting it to). Hooked up a trimpot and cranked it up to 2.65A at the input with two cells going into an XM-L2... held it there for three minutes and nothing burned up. The current stayed fairly stable the whole way through, rising up to around 2.69A by the end of the test. I was still able to hold onto the driver board the whole way through, although it was getting warm. At right around three minutes the driver stepped back down to high from turbo.

This looks very promising! I don't have more time tonight to play with it but I am going to try for 3A at the input side with two cells... around 6 amps going into an XM-L2 with some regulation is a thing of beauty.

Indeed RMM! A thing of beauty for sure, and thanks for putting this through the ringer. Watching diligently…

zeremefico has tried to do resistor mod on the new DRY driver and get good direct drive result. Think I am going to post the link over here to concentrate all the related threads together.

Single XML2

1 cell = NO WORKY! :(

2S (8.27v)
L = 0.19A
M = 1.07A
H = 2.47A
T = 3.49A

3S (12.41v)
L = 0.19A
M = 1.06A
H = 2.46A
T = 3.48A

4S (16.60v)
L = 0.20A
M = 1.07A
H = 2.47A
T = 3.50A

It really needs resistor mod. Since when 3.50A is “low” for us? :bigsmile:

Sure, 3.5A is low for a single LED, but if it does the same 3.5A into 2 LEDs in series it's not bad. And if it still does 3.5A into 3 LEDs in series...

In this thread, an MT-G2 was run with 3S by one member and half fried. Another did the same, but for only like 20 seconds and his emitter survived. So is the verdict that this driver does not buck well with the sensor bank shorted?

Buck drivers that freak out and connect the full input voltage to the outputs when the sense resistors are shorted isn't uncommon.

It's likely that the MTG2 can survive 12v in the lower modes, when the switching frequency is high and duty cycle (on time vs. off time) is low (~30-40%). LEDs with little bond wires that just act like fast-blow fuses are less tolerant. MTG2s are tough SOBs.