I don’t have a single-7135 driver at the moment, but the moon level depends on both that and on the specific LED used. Like, for an XM-L2 it can probably run at about 6 or 7, but an original XM-L may need 9 or 10.
This driver looks like it should do almost everything for almost everyone. The only thing missing is a zener, and there are other drivers available for that. I’m not really into multi-serial-cell lights anyway; my only MT-G2 light was pretty disappointing so I’m not eager to make more.
It seems that we are having some problems with Zener builds. I thought I’d tested one out on a little PSU at least, but now I’m not so sure: both DBCstm and RMM have reported [by PM] being unable to build a Zener configuration with v024 and have it work!
RMM reports that placing the cap which normally goes at C1 on the Zener pads and then stacking the Zener on top of that works. That’s pretty doable and a great way to salvage existing boards if needed.
We know the schematic to be good, the same schematic works for other designs. RMM reports that his new 17mm & 20mm drivers of similar design are functioning, so it seems clear that this is a layout issue on mine. I’ll re-test with the Zener pretty soon.
In the meantime, here’s an UNTESTED revision intended to address RMM’s suggestion of moving the C1 closer to the MCU. C1 is now fed through a single thin trace, R1 has been moved so that it is no longer between C1 and D1/R3, and C1 and D1/R3 are connected through a massive trace, and all of this is happening right next to the MCU’s Vcc pin. I also increased the size of LED+ slightly and doubled down on the GND vias. EDIT: and no, LED+ and MCU Vcc do not actually touch. It’s just OSH Park’s rending system that displays it that way.
Since I’d been playing with the layout again for this driver it struck me that what I’d really always wanted was LED+/- pads that were across from each other. IMO that’s a key aspect when it comes to very,very, tight builds. I set about shuffling things around, but they wouldn’t play nicely. Then I recalled that the LFPAK56 footprint I was using sucked. Switching to a normal Power-SO8 footprint helped, but it took me a long time to achieve the level of symmetry I was looking for. Without the OTC it’s actually really easy to do all kinds of great symmetrical patterns (ask me how I know, oops!). In the end this was the best I could do. Now that the signature look of the original driver is entirely gone, I’m not sure whether to call it something else or what.
Also note that I didn’t spruce up the Power-SO8 footprint any for LFPAK56 use. While it should function fine I’ll probably do that at some point.
As far as functioning with the Zener, this should be very similar to v030. (so in theory they both should work fine :p)
Oops, don’t use this one. I made a minor error with the vias & GND ring on top. While this one should work, I recommend v024, v030, or wait for v042.
Now moron’s like me can stack the MCU on the MOSFET footprint.
That looks nice Wight, dont’ think you should change the name as the Revision number suffices. That’s just me though. I’ll have to get some of these, and solder paste stencils, and give em a go. (starting to get more than I can remember what goes where) I need to use up the ones I have and switch over to these… my memory doesn’t multi-task well.
Yeah I read about that, but the C1 is half the length of the pads for the zener. Anyway I assume the layout will get fix without the need to make-shift.
I didn’t know if it needed to be there for continuity or if the pads should be jumpered or what. Thought it might be necessary to continue the lineage for the LVP.
Oops, another minor mistake. The WIP v041 version has a problem with the GND vias and GND rings. I’d hold off on that one until I can release v042, although it should function. In the meantime v024 is still fine for single cell builds or Zener w/ the workaround described above and v030 should be OK for Zener builds w/out a workaround.
No, it should be fine with C1 completely unpopulated as long as you’re doing a Zener build and have place the cap for C1 over on the Zener pads with the Zener.
Correct, C1 is not a great fit there. You may also place C1 right next to R2. There is plenty of space to put C1 Against the right-hand end of the Zener and either solder the other end to the GND ring (scrape first) or solder it to the GND side of R2. I’ve just checked to make sure it would work, I was able to solder the cap in there without an issue with the Zener already in place. Adding some extra solder will help. EDIT: be sure not to solder to the other end of R2 (the end pointed towards the middle of the PCB).
Let me ask this then, if I already have the driver built (I’ve got 9 sitting waiting to be used) and I have need for a Zener modded version…can I add a second capacitor with the Zener? Do I need to remove the C1 from it’s original location?
I think it’s different. When I set a cap on those pads it looks a bit tricky to solder in place. The cap can’t touch both pads at once - the SOD123 pads are too far apart. Your Qlite builds had a 0805 cap sitting on a 0805 pad which is longer than the cap itself. The SOD123 Zener will actually just barely fit on long 0805 pads by itself…
Good question! The answer should be no problem. Add the cap, leave C1 in place, and you should be fine IMO. I’d bench test to be sure though.
I wasn’t going to do it tonight, but my curiosity made me look at it, and from there I was a goner.
Piece of cake. Took a built A17DD-S08, removed the diode, stuck a 200 ohm resistor in it’s place, held the small capacitor between the pads with needle pointed tweezers and touched solder to the pad then the cap, same on the other side… cap in place. Located the Zener for position, laid it on it’s side cupping the cap, badda bing badda boom done!
Soldered on 2 20ga leads, stuck those to a 20mm Noctigon with an MT-G2 on it, soldered by ground lead from my test cell that has a switch soldered to the negative, taped a second cell to it. Fired it up! 5 modes, presto! :bigsmile:
Thanks Guys! Really appreciate it, that was kinda driving me nuts! My last 2 Zener mods I went back to the very first BLF FET boards from matt, out of retaliation. lol
Looks good. Thanks for posting the pic showing how it’s done!
I think making that joint is probably fine for those with enough soldering experience (and a pair of tweezers ;)), but some might find it difficult. The alternative placement I mentioned above also works best with a pair of tweezers, so I don’t know if it’s any easier.
I’ve only been soldering since I got the Hakko 888 station. I used to butcher stuff horribly with a 25 watt Weller iron or an old Sears dual power gun. I sucked, in very ugly ways with cold joints that broke.
So I’ve only really been successful for about 6 or 8 months. Might be close to a year now, don’t remember for sure. I DO remember that switching to the .031 solder helped tremendously even before the Hakko, then getting the right tool made all the difference in the world.
I’ve used a small variety of soldering tools. For years I used a 100W gun for everything (do not do that). I’ve had a 25W and a 40W iron IIRC. I also have an 80W iron for use on big, stubborn things. Eventually I got OK with the 40W I think. Then I got a knock-off temp controlled station. That was an improvement, but after 6 months or so it started having problems and within a year of purchasing the knockoff station I got a Hakko FX-888. I’ve been very pleased with the FX-888.
