Ni MH have about the same energy storage as 14500s, so with a good boost driver there is really no advantage to taking Li ion cells. It needs room for a large induction coil, and it should shut off at more than 2 V. But see below.
A boost driver has intermittent output current. Unless the frequency is so high that that can be smoothed out with a capacitor, one can’t ask for truly constant current. Modes should work by increasing the fraction of the time it outputs, to reduce the average current.
I still think that ideally, one would use clay, but I agree that would be too ambition for this discussion. I think clay is better than CAD because one has more direct control and can feel what one is doing. It matters as much how the finished light feels as how it looks. Maybe more important, the designer should look at, and preferably feel, pottery. When designing for an NC lathe, one should not ignore the thousands of years that people have been searching for more pleasing bodies of revolution with pottery wheels.
With a larger coil & cap it can get to 1Amp out from 2AA. (input current must stay below 2 Amps)
I use the DX SKU 25505 single mode with modest output for 1 & 2AA. Within spec it will do 80-90% efficiency. (for my use here, run time is more important; top bin Cree LED’s will now get to 500 lumens at 1 Amp.)
For sure there are better higher current 2AA drivers out there from Fenix, Olight, Eagletac, etc.
As stated earlier, the key is to get the driver.
Happy Hunting.
Hmmm, give every person a lump of clay to put over a dummy battery tube, and hold in a comfortable grip — then laser scan that and use it to make a perfect hand-fit flashlight?
Nah, that’d be over budget …
I have a weak spot for a good AA/2AA light. I’m actually tracking down a 2AA host to mod with some older AA drivers I had apparently stashed away for a rainy day. I’m anxious to see where this goes since I’m already looking at other AA options to my EA11 and Thrunite 1A. The Manker T01 is certainly promising, but i would MUCH rather support this build than a production light. I’m not too particular about the shape, but the usability and programming is key. Oh yeah - the “wow” factor is important to.
I’m also curious to see what CalvinIS has in store…
I think after reading through this thread and digesting much of what has been said I would like to see the BLF X5 (In type 3 black aluminium) with a longer 2 AA cell body as light for this GB. The X5 seems to tick all the boxes and size and looks wise it would kind of be what the Mini maglite should be if they kept up with the latest technology. I would presume it would be doable in the $20-25 level too which always seems to get a lot of interest in GB’s.
I have one in 2AA, but have been unable to purchase a single AA tube for it. I would love to find a single AA tube, used with a 14500 it would be a great little light. They are very well made, I like it better than the Solarforce L2r.
The other issue is that there do not seem to be any really good driver out there. I have a couple of older AA lights that could use a bump, but really need a driver with the new LED.
There are more new members every day and some have EE knowledge so keep asking and sooner or later it will happen. Remember it took several years to get a programmable 17mm buck driver. If someone were paid to do it then it would get done sooner but as it is you have to wait for someone with a hobby interest to take it up and run with it. Testing, boards, and parts costs money so setting up a way for people to pitch in could accelerate the process but you first need to find your EE. Then there’s always the DIY method and you might find lots of help where you might not find volunteers.
One of those (kinda) new members here, although I’m not an EE. Sorry. Just wondering, how did the other drivers get designed? Obviously some smart folks have put in the effort here before, folks like Wight or Alex Wells, maybe. Those are names I’ve seen but know nothing about. Are they not up to this job? Do they just not want it? Have they left the community?
Welcome to BLF :-) That is one heck of a first post calipsoii ! That sounds and looks like a great driver, both the hardware and the software! So what's the story? You designed it and kept it a secret till now?
edit: I should check CPF a bit more often ;-) http://www.candlepowerforums.com/vb/showthread.php?373167-Build-Log-The-1-5V-Project
That is a great build log, I'm enjoying reading it :-)
Hey calipsoii, thanks for sharing the teaser with us, now how about some details and a sales thread?
Some things I’d like to know:
1) With your circuit design, is the 420mA output the most that a single Eneloop can do, or is it set at that level for safety, or efficiency, or parts are cheap, or what?
2) You said maybe 2xAA or 1xCR123A might do higher current. Any way we could get testing done on that? If you don’t have the time or the means to test, could you send a sample to one of the guys here that do testing, like djozz?
3) Will you be selling this driver? And, if so, when, where, and how much?
4) Is the design open? Will you be sharing your board layout? Could someone here legally make PCB changes in order to improve the design, make different sized boards, or change components?