So few important notes added that I've not mentioned before:
1.When driver is configured for 2s-2s configuration,reverse polarity protection won't work properly (opamp itself doesn't have protection),so be careful with battery polarity in those cases!
2.For 4s configuration stock opamp(MCP6H01) has too low maximum voltage rating(tested one with 4 fully charged HE2 - 16.8V,and it didn't survive,even if maximum rating in datasheet is 17V),so it should be replaced by higher voltage ratings opamps mentioned in OP under "3s-4s cell operation"(very hard to find in SC70 package,and pretty expensive).
You connected switch wrong,try to connect it exactly like in picture(there is a possibility that small pmos on driver pcb is burned in case that you connected it the wrong way).
Upgraded Roche F8 flashlight(built this for my friend almost a year ago with LD-1),replaced driver LD-1->LD-2,17->20mm driver brass adapter,NTC connected(glued on noctigon).This is probably the best small 1x18650 host if you want maximum run time on high,until flashlight overheats. It takes considerably more time to overtemp. protection trip,compared to similarly sized hosts,like Convoy M1,with same setup.Large surface area of fins works great. Lumen(lux) increase is ~16%,very consistent to my other LD-1->LD-2 upgrades.
I must be doing wrong, but I have two of the LD-2 drivers and I can’t either one to work (light). I have a triple XP-L (in parallel) connected to the emitter leads on the driver, and I am using my bench power supply for now, and actually, it looks like a complete open between the battery + pad and the ground ring (edge) and as I said, i get no light.
What am I doing wrong? Or did I get two dead LD-2s?
Did you solder jumper one? You need to do that when using a single cell. I didn’t realise this, thought there was an issue with the driver, and then accidentally ruined it when I tried to pull it out to inspect. I was pretty annoyed as it was a perfectly good brand new driver that was in the bin before it even lit up an LED…
Yes, I just realized (found) about that jumper when reading through the thread (again). That seems like an odd way of saying to add the solder bridge if you use a single battery though :(.
But, that wasn’t the only problem: I was trying to use the driver in the triple pill that came with the BLF TI, and that pill has a small retaining ring (screw in). I tested without the ring and the driver worked (after adding the jumper also), so looking more closely, I noticed that when the ring was screwed down, it was touching the small solder blobs where the emitter leads poked through the board.
So, I used my Dremel to grind around the inside edge of the ring a bit (in other words, I increased the inner diameter), to make it “narrower” ledge, and also ground a kind of bevel so that it wouldn’t touch those points, when the ring was screwed down, and now it works.
Can I also suggest that you add a note about not shorting the emitter contacts on the battery side of the driver?
As I mentioned, in my case, I had put the wires in from the component side and soldered from the battery side, the way that you would solder a pin on a “normal” PCB. So that left a small lump of the bare wire+solder exposed on the battery side of the board which was what was contacting the retaining ring. I’m not sure which wire was contacting the ring, or maybe both were, or which one should not contact the retaining ring (or maybe both shouldn’t), so it’s probably best to just make sure neither one contacts the body.
