Hmm, that’d work? I was concerned that the µC would have more “control” over the boost circuit. That’d be great if I could do that. Might just give it a try, and if it doesn’t work, sell it or give it away to someone who actually wants modes.
Yep. When I’m running down my bobofett light, it’ll keep going just fine with barely firefly levels of light, but if I turn it off, there’s no way I’m turning it back on again unless I let the cell “rest”.
Yeah, I got only unprotected cells. Need to make sure I just don’t run it down too much so it doesn’t go supernova on me.
While it is not a high current cell, the only available purple 26350 does fairly good. It delivers close to twice the capacity of the Aspire cell if you don't push the load too much and while the output voltage is slightly lower, let's say it at least delivers close to 180% energy output of the Aspire cell, the current 18350 champion.
Yep, pin 5 is just a simple PWM output, with >99% duty in high mode, my suggestion would just pull this pin high, so 100% duty. Pin 6 is the Boost IC enable pin, so just pulling that high again.
Writing custom software for the PIC onboard that is simple one mode with LVP should be no problem though now that we have the pinout.
Mmm, I’m always sarcastic.
The one-size-fits-all philosophy…
Goes right along with “Let’s throw in all manners of blinkies. If you don’t want them, don’t use them” admonition.
Exactly. I got bobofett that eats dead AAs and is pretty much moonlight- or firefly-only. My EDC is a 1-mode ’502. I got a WK50 and BLF348-219 in my bag. My F1 is for varied nighttime use, and pretty much the only one where I use multiple modes (and only because I can doubleclick to turbo). My F13 is for nighttime snooping outside.
All my other lights, I “retired” from disuse. Even my VG10, I keep it around for some nighttime use, but only if I preset it to moonlight and have the luxury to switch to other modes before needing it for anything else.
Hmm, just realised now that even all my C8s are semi-retired. Nice throwers,
pretty much all my modded ones are 1-mode, but I’m just not using them all, less and less, and now are kinda unused.
Hey, that happens when you have more lights than you know what to do with.
But yeah, I’m not about to take a dedicated thrower like the C8 and use moonlight mode on it. Makes no sense. It’s not a general-purpose light, not an EDC light I can just stuff into a jeans pocket, so yeah, it’s a dedicated thrower, and I want it to go full-tilt when I pull the trigger.
The most important feature of any tool is that it should never ever get in the way. Doesn’t matter if it’s a computer/OS (you listening, Monkey$oft??), guitar, car, drill, or flashlight. The operation of said tool should be seamless and organic. It shouldn’t require you to “think” before using it. The tool should become an extension of yourself.
If your tool doesn’t fit that description, then it’s a lousy tool.
Back to flashlights… If you have a doubleclick for strobe function in the UI, then you have to remember to not step through the modes too quickly, unless you want to lapse into an epileptic fit when you hit strobe accidentally. It’s a lousy tool when it makes you consciously slow-step through modes to avoid that.
I get your point, but it kinda defeats the purpose. I want to be able to drop in any cell and just have it work, and not have to cherrypick brands and colors for a specific light.
Same way like in a DD light, brand X will drive it nicely but brand Y will only push half the amps, or conversely, brand Y will drive the light nicely, but brand X will fry the emitters. I want to get fairly repeatable performance from any cell.
Right now, my choices here are either panny-Bs or 30Qs (or generic powerbank pulls, mainly pretty decent LG cells). That’s all I want to deal with in 18650-land, capacity or current (or “who-cares?”).
I got some LK 26650s to last me a while. I really don’t want have to get a bunch of very specific 26350s for each light I mod.
So, yeah, I admit there are some cells out there that buck the trend, but I don’t want to have to go shop around for them. In general, 26es are just not as energy-dense as 18s.
To me, it’s like having a car that only gets decent performance from brand X gasoline, and just lacks something if using any other brand (mileage, power, etc.). I really don’t want to get locked into a particular brand.
Hmm, PWM-output for a boost driver? Is that just a control-voltage (say, 0.00V-1.25V for scaled output)?
Got any schematics on this driver? Sounds interesting. Might be some other tricks to use. Eg, no need to change a sense-resistor (desolder, resolder, piggyback, etc.) if the output could be scaled by tweaking that control-voltage pin.
Yeah, the LiitoKala INR26650-50A is the 26650 cell of the year 2016 in every aspect. Buena, bonita y barata: good, beautiful and cheap. :-)
Besides 18650 and 21700s, the remaining formats are under-developed in some or another way. God of the li-ion cells, please go spank the big brothers, they deserve it.
26650s may not be as energy dense, but they're not that far at this moment and, anyway, even for a 5' 5" slighty like me, 26 gauge tubes feel more comfortable. :THUMBS-UP:
Any extension tube available for the UltraFire F13?
Original post date: Mon, 07/31/2017 - 10:39. Typo fixed.
Lightbringer, the F13 should make a nice thrower with an H2-C + XHP35, doesn't it?
Of course, this means going 2 × 26350s or longer cells with extension tube but, what extension tube? Yezl Y3 maybe?
The PWM signal is filtered and biased before being sent to the IN- pin of the op-amp. So it is just a control voltage, but without an MCU it would be difficult to change that control voltage, so swapping sense resistors is just easier. Schematic is posted over here.
I also have the H2-C driver schematic, and a similar MCU bypass could be done with that, but you’d either have to run the emitter in 12V mode, or you have to swap around the FB resistors for the MP3428 to drop the output voltage. H1-A is the superior driver anyway IMO. The addition of reverse input protection MOSFETs on H2-C thermally insulates the ground planes from the ground ring, which means the driver can’t dump heat to the host as easily.
You mean these ones?
I'll make sure to desolder or turn them into a fine powder with my milling bit if I am to get an H2-C.
Yep, those are the ones. 2x Si2300DS MOSFETs in parallel. Probably the biggest limiting factor of the H2-C driver. Unfortunately even bypassing them won’t create an ideal scenario for heat transfer, it will take some input resistance out though.
Maybe scratch off a bit of solder mask and add a thin layer of solder all the way around the grounding ring?
That would help to be sure, a lot of work though.
That might help a bit but it won’t be like having a solid copper pour all the way to the edge. Solder is a terrible heat conductor, and copper is an exceptional one.
It throws pretty nicely as-is. I’m getting (guessing by ceiling-bounce tests vs other lights) about 1klm in a decent-sized hotspot, so it reaches out pretty nicely. That’s with just an XM-L2, not XHPanything. Would need to change the reflector for a ’35, else use an adapter ring.
Nah, not for me. It has a nice feel and balance with just 1 cell. Don’t want to turn it into an L2 because I already got an L2.
And I’m really not a fan of dual-cells, period, even ’350s. Bad enough if I’d lobotomise a driver I’d lose regular LVP, but with series cells, that’s just begging for trouble.
Okay, just goggled the .pdf for the XM-L2. At 2.8A it’ll have a 3.3V forward-voltage, so with 7135s that means it’ll hold that current down to about 3.4V at the cell (with sag). A 26650 should be able to laff at “only” 3A or so, and not sag all that much at all, so that corresponds to flat regulation down to… what?… 40% SOC?
I can live with that.
The buck driver I got probably will just crowbar at 100% when it starts pulling out of regulation and go DD the rest of the way down. So either this driver or shoehorning in a lobotomised 2.8A 105C/105D will get me decent current (and light) for most of the battery’s life.
It just happens to me that I have some spare 0.1mm² copper sheet.
Take a look at these graphs:
That driver was tested with a well cooled (?) XM-L2 emitter.
Keeping an eye over the 3A curves? Not looking very good, but install a Nichia 219C emitter (Vf ≈–0.2V) and you can definitively enjoy close to 80% regulated time, better throw, better throw and better throw (die size, lower temperature and higher CRI).
Okay, so 3.5V would be my cutoff, and that’s still 3.0AH out of the cell, or 60% life. 1hr solid runtime? The light would probably be uncomfortably warm at that point, so it’s “self-regulating”.
Unless I were at sea searching for an overturned boat or something, I can’t think of anything I’d be doing that I’d need that much light for that long. I’m picturing more of an intermittent-use light.
Caving, though, that might be interesting with a nice bright light, but you won’t catch me down there anytime soon.
At this point, I’m thinking of just sticking with the buck regs I have now.