Hi there - not new to the hobby, but new to this forum :D
I have been participating on CPF for many years, and you can see a lot of my projects here in my website (www.atdms.com).
In particular, this mini mag mod could also benefit from one of the Battery Vampire (Joule Thief) circuits that I came up with recently. It is not a high current/high power circuit, but it works down to 0.8 volts, so it works great on a single AA cell, and up to 2x AA cells. It is a great circuit from sucking the life out of cells, and even cells that are considered "depleted" will still provide useful light.
I don't want to feel like I am pushing my board/product here, so I will stop now. Do let me know if you have more questions about these circuits.
The Battery Vampire (Joule Thief) circuit boards don't provide amps of current - quite the contrary, these are very low power LED circuits. These circuits allow draining cells down to 0.8Volts - to get the last remaining energy possible out of primary cells. The idea most of us have for using these is to make a small LED light that will use "spent" AA or CR123 primary cells after they no longer work in their original/respective host. This allows you to continue to get use of those cells that are supposed to be thrown away/recycled.
The other neat thing about these circuit boards is that they drive the XP-G and XM-L LED's at their near optimum level for lumens/watt, right around 100-120mA (with a 3Volt input). So not only you are getting useful light output from "used" cells, but you are also driving the LED's very, very efficiently.
You can easily make your own Joule Thief boards by buying transistors, resistor, capacitors, perforated board, and winding your own inductor. But these circuits came out of interest by members of CPF's for something easier to use - folks did not wanted to figure out all of the details, find/make parts, so the boards I made simply take all of the guesswork out, as these are ready to use "as is". Myself and others are using these for P60 drop-ins to provide an extremely long running option to a P60 host.
Again, my intent was to offer the original poster another alternative for a 1xAA or 2xAA host - my apologies if my post was considered self-serving. Most everything I do is custom work, so I don't have much for sale, but if you let me know the appropriate subforum I will gladly follow your advice and put a quick sales thread.
You offer a decent suggestion with the Joule Thief. What is the diameter of the boards you make? I'm just thinking of some other projects they might fit in...
Btw, you do great machine work and I like the magneto drive project you're working on.
Thanks man. I created a sales thread which has all of the details, but I am too new to link to it. But the boards are slightly smaller than an AA cell at 0.54" OD.
The MagnetoDrive has been a fun and exciting project indeed. I hope to be able to move that along this year, as I got some great feedback at the DFW flashaholics meeting in April.
Thank you. I created the sales thread, but I can't link to it yet (I am too new).
I have the 3xAA kits ready to go with both 3mm and 5mm LED's using a special version of my circuit with a matching inductor for even lower currents :)
welcome aboard Will. I read all your post over at CPF. You are one of the ones that keep me going back there. I have been interested in the joule thief but not able to completely figure all of it"s applications. I"ll hopefully figure it out. Could/would you by chance sell them turn-key with a host? Sorry if this had been answered. Thanks.
Guys, I have been trying to get a 20mm optic in the AA head, but if I bore the head deep enough to get the P60 (well, the threaded part only) and the optic, I then have way too little thread engagement with the body.
Anyone else playing with the 20mm optics?
I am also trying with the longer head in the LED version of the AA mag, and that one "does" have plenty of room for the P60, optic, and a good thread engagement.
Finally, to improve the thermal path, I am also playing with threading the inside of the head to match the threads in the P60 module, but I ran out of "donor" AA LED hosts before I finished, so I need to see if I can find some "cheap" - here is a photo of my messy machining work bench with work-in-progress:
Are you using Carlico or Cree cute optics? I thought (memory going bad), that one was shorter overall, but I think you’ve found out, you can’t stuff it all into the incans, only the LED maglites.
You could possibly gain a little by giving up on the P60 drop in and just make your own copper heat sink and flow the LED directly to the copper, but it would probably be negligible anyhow.
Will, the Carclo optics work great in the Incan minis. The trick is to remove a portion of the threads from the end of the battery tube. You need to bore at least 18mm into the head. There won't be a lot of threads remaining but there are plenty. Trim off the tapered tip of the threads to where the o-ring just disappears into the head when the threads start to engage. ;)
I tried several 20mm optics - they are all too long if one is to have any decent amount of threads left (a quarter turn on the head is in my humble opinion not enough). Of course, this is not a problem with the shallow OEM plastic reflector.
I am missing something here, as the problem with not having enough thread engagement has nothing to do with the body. The problem is that when boring the head, you remove a significant portion of the threads in the head. If you bore deep enough to get the pill + 20mm optic to fit inside the head, there is about only 1/4 to a 1/3 of a turn left - way too little for me.
Yes, I have found that there’s not a lot of threads left. You should get more threads as JohnnyMac stated in a previous post, at least to where the O ring will be up under the head, but that is about it. If I had a lathe, I would just make a custom heat sink out of aluminum or copper and make it thinner, as there really isn’t any mass to the thing in the first place and the P60 pill is not good at thermal transfer anyhow. Brass, Bronze, etc., are all a lot worse than Aluminum is. A smaller heat sink out of Aluminum that was a “press fit” into the aluminum head would transfer heat better, to the head, than the larger P60 pill.
Just my thought on it and Y'all know what that's worth.
How much is the depth of the Carclo inserts below the lip of the head? (My Nite Ize reflector is only 8.9mm inside the lip but 10.7 total, so 1.8 +0.8 for the lens sits above the lip and under the bezel's o-ring)
Does the carclo lens fit entirely inside the head, or does part of the depth rest over the lip of the head like the reflector? If it all fits inside, is a shim needed to replace the reflector depth to hold the lens to the o-ring correctly?
Do you use or omit the mag clear lens (leaving o-ring between lens and bezel) with the Carclo optic?
How long is the head on your mag with bezel off?
I have a couple drop-ins that should arrive in the next couple days, but the one I have now is 10.7mm deep with the LED base recessed at least 1mm, so the reflector + pill depth would only be about 19.6mm below the lip.
I know the lenses are cheap (before shipping anyway), but I estimate only 3 threads if I have to go 22mm deep, so the answers to the above will be very helpful.
Sounds like cutting down the battery tube helps to get the body o-ring up inside the bottom of the head for friction and sealing (and maybe better spring contact) rather than for more turns of the head.
It doesnt sit below the lip but about 2mm above. Actually I modded 2 Mags, one one I bored to deep, so in one I use the lens, in this silver one, no lens needed. But the lens could disappear completely because its OD is smaller than the heads ID after boring. I left all the O-rings in place, just removed them for working. ;)
Head is 38,1mm. Pill is 10,6mm.
As you can see, I've got more than 3 threads left. But as I used a counterbore, the pill might slip in about 1mm more due to the more tilted bore hole.
22mm is the distance from the heads bottom to the pills bottom, not how deep I bored! I bored about 16-17mm. I only made very small steps and checked how it fits a few times.
Cutting the body is important when using optics because the threaded part is a cone. So you enter a few mm in the threads before you actually start threading.
Thank you so much, I wasn't understanding the 22mm was amount left from the back of the head. Rough guess that leaves about half of the threads.
My incan head is the same dimension and I have been guessing I would get to about 18mm bore depth for it to work. Sounds like the reflector might be fine to start with, but that I can swap to the optic later.
Looks like the optic would seat on the o-ring inside of the bezel as long as it stays centered in the head.
Yes, I can see where thread engagement is quicker by cutting the top of the body off. I'll need a way to clean up the threads if I do that to be sure I get it all back together.
