# Couple of LED lights using Joule Thief circuits ...



## wquiles (Mar 27, 2012)

You would think that given how many flashlight projects I do that I actually own a lot of lights. Actually, I own very few lights (well, to a non-flashaholic I own an "arsenal" - but in reality I only own a few lights - most are customer lights that I photograph before sending them out to their respective owners). A couple of weeks ago we lost power here where I live and it happened right at 6AM - right when we wake up to get ready for work and take the kids to school. Still pitch black, and with no power, I scramble to get several LED lights scatered throughout the house so that we can all get ready. Problem was that I did not have that many lights to start with, so I started thinking about the "need" to make more emergency lights to keep around - specially/mostly indoors, where you only need a little bit of illumination, specially lights that can stand on their tail to light up a room, bath, kitchen, etc..

I already had two "big" output lights: two of my own custom 1xD's, direct driving a P7, from a 3xAA adapter. But those are way, way too bright for a small room indoors, so I needed something with less output, and that would run for a LONG time as well. Since I recently have been playing with my own Joule Thief circuit, I decided to build a couple of lights to take advantage of the abundance of used AA cells and LOTS of new D cells (that come free with most D Mag's that I buy from Fry's, HomeDepot, etc.). I also though about making my own P60 drop-in with a super low output, for night adjusted vision, so I started working on these.

First is the P60 drop-in. I bought a "kit" from Asia for the P60, so I started looking at what emiter would work well with the smooth reflector. I started with an older P4:







But decided to use a more efficient LED instead. Looking at my parts bin revealed a neutral white XM-L, so I reflowed it into a datiLED 8mm board:






When I tried it on the smooth reflector, I was able to get a great beam 






So I soldered and epoxied the Joule Circuit on the back:






And tried it with a few cells:











I soldered a wire to the spring (Bat +) that comes with the kit:











And simply (although not "pretty) used hot glue to keep everything in place - very solid, firm setup:






The fit of the base to the reflector in these kits is horrible, so I used a thin piece of copper tape to set the focus to the right spot in a press-fit:






And this is how it looks in the Solar Force host:






Home made P60 drop in:






Nice tint:






I can use new or used CR123 cells, but since my circuit can operate down to 0.8 volts I decided to make an adapter/sleeve so that I can also use AA cells in this host:









































With an AA cell it was a tad shorter than an 18650 cell, but the springs more than make up for the difference:


















The next light uses some really old 3W LED's that I got many years ago, but that were vf-matched to 3.5-3.6 volts), so I decided to build a floody light using 3x of these LED's, each driven by its own Joule Thief circuit, everything feed from 3xAA cells (using another of my own custom 1xD's as a host). Since I wanted to re-use parts I already had, and I did not have any reflectors for these weird looking LED's, I decided to modify a home-made Mag D P7 reflector and make a sort of "dish" reflector out of it.

I started with the P7 heatsink to hollow it:











It is hard to see in this picture, but I cut a lot of "facets" in the heatsink, going from outside towards the inside, using my very sharp PCD insert to achieve a polished effect on the Aluminum:






Then drill and chamfer the hole for the wires on both sides:
















I then did a dry fit to see how I can place the 3x "weird" emiters. Note that I had to cut/trim their wires to give me clearance:






In this photo you can see a little bit better the facets in the heatsink - nothing too fancy but seems effective:






I then proceeded to glue them:











I then carefully solder the wires:






And since this is going to be floody and very open, I put a good dose of glow in the dark powder with 2-part slow cure (30-min) epoxy:






I then solder each of the 3x Joule Thief circuits:






And test it:






Here it is running:






Ready in the host (heatsink is a press-fit):







I carefully cut/fitted the reflector so that it would line up over the heatsink, to provide additional "focusing" on the sides:






Here is how it looks from the front after being turned off - notice how the heatsink reflects some of the light, as well as the cut Mag reflector:






Of course, in raw form the image is fairly "ugly", so I planned on using a diffusing film to even out things:






Here it is OFF:






Here it is ON:






And although not quite focused, here is the afterglow:








OK, now for the last "emergency" light. I already had the floody light, so I decided I wanted one with more throw. So I decided in a neutral white MC-E, using another of my own custom 1xD's as a host, so it can be driven from a single D cell or a 3xAA adapter. First, I had to once again modify the P7 heatsink in order to facilitate installing the MC-E. Fairly easy on the mill thanks to the DRO:
















I am using a left over metal reflector for P7's that I had handy:






So I prepared everything:






And used the reflector to position/center the LED by eye as best as I could:











I then solder wires:






Wired a single Joule Thief circuit:






Prepared the stock switch:






Here is the finished product:






And although not in focus, here is the afterglow:







That is for now. By the way, guess which of these 3x my kids LOVED? Of course, the weird one with the 3x LED's and the massive afterglow of the glow powder 

Will


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## TriggerHappy (Mar 28, 2012)

Awesome - I love the 3 LED glowing one especially!

Where did you get the joule thief pcbs? 

Thanks
Pete


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## wquiles (Mar 28, 2012)

TriggerHappy said:


> Where did you get the joule thief pcbs?



I designed and made them myself. I still have some left but this is not a sales thread, so contact me by email (in my signature) if interested.

Will


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## Mike S (Mar 28, 2012)

Very nice. Those turned out great. 

Do you use the same components in all of your joule thief circuits regardless of which emitter is being used? Also, which power LED's perform the best?

It's interesting to see how few components are needed to boost voltage from a 1.5V cell. I have a few cheap lights which only have a transistor and an inductor, and that's it.


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## wquiles (Mar 28, 2012)

Yes, same circuit. I made my own boards to use this specific Zetex part (ZXLD383):






I can change the inductor to adjust the current setpoint, but the overall current varies with the battery supply - as the battery drains the current lowers as well, down to 0.8 volts - lower than this the circuit will not work. Right now I am using the 4.7uH to 5.6 uH size of inductors to get a fairly high current level, as the max recommended value per the data sheet is 4.7uH, but the larger the core of the inductor the less saturation at the higher current levels. Still, it is all relative - this is not a high power boost circuit 

Will


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## TriggerHappy (Mar 28, 2012)

Hi
Thanks for posting the circuit - all the Joule Thieves I have seen have required winding a little transformer etc - that little chip makes it so much neater!

Pete


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## jabe1 (Mar 28, 2012)

I'm certain you could sell alot of those circuits. I would certainly buy a few; price dependent of course!


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## wquiles (Mar 28, 2012)

TriggerHappy said:


> Hi
> Thanks for posting the circuit - all the Joule Thieves I have seen have required winding a little transformer etc - that little chip makes it so much neater!
> 
> Pete


Yup - the tradeoff is having to deal with surface mount parts, which could be a pain if you don't have experience with them. Pretty much everything I do is surface mount now-a-days, so it is not too bad once you have boards made.




jabe1 said:


> I'm certain you could sell alot of those circuits. I would certainly buy a few; price dependent of course!


If there were enough interest I could start a proper sales thread. Email me if interested.

Will


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## ^^Nova^^ (Mar 29, 2012)

Those pcb's look good Will. What diameter are they, they look very close to a AA battery?

DatiLED made and sold some JouleTheifs a while back and they didn't last long, I am sure you could sell many of these boards.

Cheers,
Nova


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## wquiles (Mar 29, 2012)

^^Nova^^ said:


> Those pcb's look good Will. What diameter are they, they look very close to a AA battery?
> 
> DatiLED made and sold some JouleTheifs a while back and they didn't last long, I am sure you could sell many of these boards.
> 
> ...




Thanks. I got enough emails to justify opening a formal sales thread for these. As to size and other details, I put all of that in the sales thread.

For now we can keep this thread focused on lights/projects that use these circuit boards.



Admins - I am linking to the sales thread - I hope it is allowed/permitted: Link to sales thread



Will


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## Kestrel (Apr 4, 2012)

I'm very interested in trying a P60 joule thief with *2x*AA in a three-cell SF body. Taking an excerpt of the data you posted in the 'hurricane lamp' thread:

Vin = 1.0v, Iout = 0.016A, eff = 27%
Vin = 2.0v, Iout = 0.120A, eff = 78%
Therefore, using two depleted AA's rather than one will be an excellent configuration IMO. There seems to be a lot of potential here. I love doing this kind of stuff with my C3's. :thumbsup:

Edit: The above data is outdated, see Will's post below.


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## wquiles (Apr 4, 2012)

Kestrel,

Yes, the 2xAA configuration (or 2x D in a Mag 2D body) is awesome. I took one of my 4x CR123 bodies and used to of my home-made AA to 18650 cells and built a 2xAA equivalent, and it works great.

The only thing to note is that those higher current levels were achieved with those HUGE inductors I used in my first evaluation since that was what I was able to get my hands on. Unfortunately wiring those large inductors is a royal pain and on top of that using the large inductors leave you very little room for a P60 module, so I am now using the surface mount inductors which give me a little bit less current. 






With the much smaller surface mount 4uH inductors I am now using I am getting about 50-60mA at 1.5volts and 100-120mA at 3.0 volts, which is still very decent/effective in sucking whatever life is left out of primary cells 

Will


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## Kestrel (Apr 4, 2012)

wquiles said:


> [...] With the much smaller surface mount 4uH inductors I am now using I am getting about 50-60mA at 1.5volts and 100-120mA at 3.0 volts, which is still very decent/effective in sucking whatever life is left out of primary cells.


Ah, good, thanks for the clarification.


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## Darvis (Apr 4, 2012)

Will... :rock:

You truly possess some mad skills my man!!! 

I have to admit, I'm super jealous of the whole machining aspect you bring to the table whilst I'm relegated to plumbing parts and tupperware for my lights...

This is great stuff! 

BTW, the AVR programming is a hoot!! A few days into it and I've gotten all kinds of blinking LED madness going on here... which brings me to a question for you: I see Atmel sells some chips that have boost circuits built in, have you played with these and the PWM outputs? I wonder if they can be JT-ish if programmed right?


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## wquiles (Apr 5, 2012)

Thank you 

Glad to hear you are enjoying the AVR stuff. It is very neat to be able to get things working fairly quickly - it is a great platform. I have not seen the Atmel chip you mention, but would love to take a look. Got a link/URL?


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## Darvis (Apr 6, 2012)

I was looking at the Attiny25v, but misread the min voltage requirement to be .8v when instead it's 1.8v... too many late night learning sessions on the net for me!!


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## wquiles (Apr 11, 2012)

This was completed recently by *Drywolf*




Drywolf said:


> Hey Will,
> Got my package today. Very professional. I'll post a pic or two of my completed thief later today.
> 
> 
> ...




I really like that!


Will


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## wquiles (Apr 11, 2012)

By the way, I am planning on perhaps offering a "kit" for the next wave of boards, so that folks can have a "project" - perhaps something like a "father and son" (or daughter!) Saturday project. Or perhaps something that could/would be a good project for boy scouts, for camping, etc..

Will


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## Kestrel (Apr 11, 2012)

wquiles said:


> [...] perhaps something like a "father and son" (or daughter!) Saturday project. Or perhaps something that could/would be a good project for boy scouts, for camping, etc..


Hi Dad! :wave:


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## sassaquin (Apr 11, 2012)

wquiles said:


> By the way, I am planning on perhaps offering a "kit" for the next wave of boards, so that folks can have a "project" - perhaps something like a "father and son" (or daughter!) Saturday project. Or perhaps something that could/would be a good project for boy scouts, for camping, etc..
> 
> Will



I am very interested in a kit.


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## Illum (Apr 11, 2012)

TriggerHappy said:


> Hi
> Thanks for posting the circuit - all the Joule Thieves I have seen have required winding a little transformer etc - that little chip makes it so much neater!
> 
> Pete



well, you could work around the flyback it by using two discrete transistors for switching and an inductor.
My "Joule thief's" have always wind up looking like this:






Even with thru-hole parts this one is about the size of a dime





They're fun to make... but gee, operating LEDs beyond the 5mm arena is something I never considered, mainly because it is simply not cost effective.


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## wquiles (Apr 11, 2012)

Those are very cool!

The discrete version of the circuit is a great project indeed. If folks search for "Joule Thief circuits" you will find plenty of examples 

Will


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## wquiles (Apr 11, 2012)

sassaquin said:


> I am very interested in a kit.



As soon as I get the new boards (about 2 more weeks is my guess at this point), I will discuss various kit ideas 

Will


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## Illum (Apr 11, 2012)

the ZXLD chips looks more professional though, discrete transistors strain the height limit of your driver bay and it could be tempermental if your enclosure is metal. 

A couple threads to start those off who wants to diy, the schematic of my little dingy is on post 17: http://www.candlepowerforums.com/vb...t-to-power-a-5-mm-LED-from-1.5V-alkaline-cell
http://www.candlepowerforums.com/vb/showthread.php?226903-ZXLD381-3Cuts-DIY-1.5v-Driver

Just like you wquiles, DatiLED made a couple of these SMT driver boards too:
Incredibly, he used the winded coils: http://www.candlepowerforums.com/vb/showthread.php?279042-5mm-LED-battery-drainer

Is the XML really that efficient at ~100ma? I want to give it a try. 5mms are fun but difficult to collimate. Your spot looked pretty good!


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## wquiles (Apr 12, 2012)

Excellent - thanks much for the links 




Illum said:


> Is the XML really that efficient at ~100ma?


Yes, the XML, and similar high power LED's are most efficient (lumens per watt) at very low currents. The XML in particular is most efficient in the range of 100-200mA. If you go to this thread you can see the actual experiments/measurements 

Will


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## fyrstormer (Apr 21, 2012)

*Re: Joule Thief Circuit boards for sale ...*

Are the V2 boards large enough to serve as the anode board on the back of a P60 drop-in? The V1 boards were much too small for that, though they did fit _inside_ a P60 drop-in rather nicely.


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## wquiles (Apr 21, 2012)

*Re: Joule Thief Circuit boards for sale ...*



fyrstormer said:


> Are the V2 boards large enough to serve as the anode board on the back of a P60 drop-in? The V1 boards were much too small for that, though they did fit _inside_ a P60 drop-in rather nicely.



Not large enough. My V2 boards are about 13.2mm, and the the boards that fit on the bottom of a P60 drop-in need to be 17mm diameter. I have toyed with the idea of making a larger V3 board precisely so that it can be used directly with a P60 drop-in, but of course I would have to have enough interest to justify making another production variant to recover the investment (or at the very least try to break even!).

Will


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## Bimmerboy (Apr 21, 2012)

*Re: Joule Thief Circuit boards for sale ...*

Soldering in a proper size washer, or some similar solution on the V2 should do the trick for P60's!

BTW... thanks for the answer, Will. Figured I was missing something.


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## wquiles (Apr 22, 2012)

*Re: Joule Thief Circuit boards for sale ...*

No worries man. Please do post some pictures of the project(s) 

Will


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## fyrstormer (Apr 23, 2012)

*Re: Joule Thief Circuit boards for sale ...*



wquiles said:


> Not large enough. My V2 boards are about 13.2mm, and the the boards that fit on the bottom of a P60 drop-in need to be 17mm diameter. I have toyed with the idea of making a larger V3 board precisely so that it can be used directly with a P60 drop-in, but of course I would have to have enough interest to justify making another production variant to recover the investment (or at the very least try to break even!).
> 
> Will


It would be a nice option. I'd be up for at least two more boards big enough to serve as combo anode+driver boards for P60 drop-ins. It wouldn't be an issue if I could find suitable anode boards _anywhere_, but for whatever reason they're hiding from me, and I'd really like a clean solution.


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## wquiles (Apr 23, 2012)

*Re: Joule Thief Circuit boards for sale ...*



fyrstormer said:


> It would be a nice option. I'd be up for at least two more boards big enough to serve as combo anode+driver boards for P60 drop-ins. It wouldn't be an issue if I could find suitable anode boards _anywhere_, but for whatever reason they're hiding from me, and I'd really like a clean solution.


I know the "blank" boards are available (somebody is of course making them!), but I have not tried to find them myself so I don't know where to start if I were looking to get some.

As to the 17mm version of the Joule Thief - I would have to have both in stock, as the smaller size is good for AA/CR123 lights/small projects, etc..

I will definitely keep it under consideration (never say never, right?), but I need to make 100+ production boards to get "reasonable" costs  , so I don't want to be stuck with 98 boards nobody else wants 

Will


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## fyrstormer (Apr 23, 2012)

*Re: Joule Thief Circuit boards for sale ...*

I know I can remove components from another driver board, but that seems awfully wasteful. I'd really rather not have to destroy something that would be useful otherwise.

Will, here's an idea: add a poll to this thread so people can "vote" on whether they would buy a 17mm version of the Battery Vampire driver. It wouldn't be an official pre-order, but it would at least give you a clear idea of whether there is enough demand to justify ordering the larger board.


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## Kestrel (Apr 23, 2012)

I have moved this "17mm 'joule thief' board" discussion from the Joule Thief Circuit boards for sale thread to the current thread so as to keep the sale thread on-topic. Please feel free to discuss this topic here.
Thanks folks,


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## wquiles (Apr 28, 2012)

GeoBruin said:


> Yes please! Have you made any more attempts to get these to run at a lower current suitable for a 5 mm LED?


Yes, more on this below ...




GeoBruin said:


> I've done a couple run time tests using both a fully charged 123 primary and 2 L91s. I get about 12 hours of useful light, starting out around 75 lumens and tapering off to less than 1. As Will said, if I let it go until I can barely see the glow of the LED anymore, I measure about .8 volts left in the cell(s).


Awesome - thanks much for actual usage data 




Moses Mok said:


> Hey Will, got my V2 board today! Thanks!


Excellent - thanks!



TranquillityBase said:


> It's alive!
> 
> XR-E 2800K


Very cool application :devil:





psychbeat said:


> Hey Will-keep us/me posted on the possible host or turnkey options.
> Besides the P60 option- I'm looking for something smaller.
> 
> Not tryin to pester u


I am trying to offer some AA options - running a little bit behind on these. I hope to have something soon 


Will


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## psychbeat (Apr 28, 2012)

Ooops- didn't know about this thread- thanks!


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## wquiles (Apr 28, 2012)

OK, so now that I am caught-up from my sales thread on custom Delrin parts for the V10R/V11R, I have been able to spend some time on the my Joule Thief's characterization on very low currents 

I started by building 6x test boards with various inductor values - here are 4x of them:






And then I tested with my normal target (3Watt Luxeon), but also with a 5mm and 3mm white LED (both 20mA rated):






My standard Joule Thief has a default inductor value of 4.7uH, so I tried inductors values of: 22uH, 33uF, 47uH, 100uF, 220uH, 470uH, and 1000uH (1mH), at voltages in between 1.5 and 3.5 volts (to simulate 1xAA, 2xAA, and 1xCR123, and a little above 3V to know some more - I am always curious like most of you!). Out of these tests today:

- for single AA cell, the 22uH gives between 14-15mA for the 5/3mm LED's, so a value of about of slightly less than 22uH will give you the 20mA, but with 22uH you have some headroom, so this is about perfect to account for part to part variability.

- for 2xAA cells, or 1x CR123 cell (3.0 volts), the 1000uH (1mH) gave 9-10mA, but at 3.4 volts (like with two Energizer Lithium AA's) I got 19mA, so it looks like 1mH is the ideal value for two AA cells (of any type), or a single CR123. 

Will


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## wquiles (Apr 28, 2012)

OK guys, this is the first kit that I had in mind - something really simple to get started with a Battery Vampire (Joule Thief) circuit:






It is a 2xAA kit, driving a 3mm white LED, and using a V2 circuit board with a 1mH inductor to keep the current to the LED at just under 20mA with fresh cells, but that will keep sucking the life out of the AA cells for a long time:






On the inside, I made everything super simple to do:











All I need here is a drop of epoxy to keep everything in place for long term stability (in case it gets dropped, etc.):






Since this battery carrier even has a built-in clip, it can act as a marker, hang from a tent while camping, in your pocket (of wife's purse) for EDC duty, etc..

Is there is enough interest in these, I can do a step-by-step short tutorial, and I can see what type of pricing I can get on the components (not that many) to make it an attractive project.

Interested?

Will


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## psychbeat (Apr 28, 2012)

Would a Nichia 219 or xpg fit in there?

or are you thinking of offering anything smaller or metal?

I'm semi clumsy @soldering but could probably manage one of these


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## wquiles (Apr 28, 2012)

psychbeat said:


> Would a Nichia 219 or xpg fit in there?
> 
> or are you thinking of offering anything smaller or metal?
> 
> I'm semi clumsy @soldering but could probably manage one of these



This particular kit can't be all things to all people, so the 3mm LED fits the original intent of something simple and low cost. Given the extremely low power, there is no advantage on a metal case for this particular project. For folks who are interested in the kit but don't want to mess with doing/completing the kit themselves, I will be also offer turn-key kits, but of course those will be higher priced to cover my hand assembly labor charges.

With enough time and money you can fit anything anywhere, so yes, if you modify/cut this battery carrier I am sure there is a way to fit a Nichia 219 or XP-G in there somehow, but now you got more cost and labor on the project. With a Nichia 219/XP-G (or any 3W+ LED) you would not need the low-power version of my V2 board with the 1mH inductor, but if you are after longer runtimes, then of course you could use this low current version of the V2 driver to power the higher power LED's at the same very low currents of the 3mm LED.

Will


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## ^^Nova^^ (Apr 28, 2012)

Hi Will,

One of these for 2xAA with a 5mm as a kit would be wonderful. What 5mm led options do you have? IIRC you said something about some CREE ones you had?

These should run for ages and still suck the last juice out of AA's and the holder is great.

Cheers,
Nova


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## wquiles (Apr 28, 2012)

^^Nova^^ said:


> Hi Will,
> 
> One of these for 2xAA with a 5mm as a kit would be wonderful. What 5mm led options do you have? IIRC you said something about some CREE ones you had?
> 
> ...


You can fit an 5mm but only after enlarging the hole - only the 3mm is a direct fit (no tools needed). I decided to start with the simplest project possible.

Other LED's could be used, but unlike 5/3mm that have a built-in "optic", other LED's would be a pure flood without an optic, so yes, possible, but more work/time/cost. It all depends how much time/money you want to spend on a project. I can't come up with a project that will please everyones needs, so I had to start somewhere, and I started with the simplest, most basic kit.

Will


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## wquiles (Apr 30, 2012)

Disclaimer: These kits are the ones I have available for sale in my Joule Circuit sales thread, but you can certainly use this tutorial to came up with your own kit/project.


Tutorial for AA Kit (3mm and 5mm)
Start by opening the case by removing the small crew:







Here is the open case:






Start by removing the positive wire (the black cable without the white stripe):






Then remove the dual battery connector and discard it - we are not going to use it all:
















We then push the cable all the way through the small hole:











Then separate the two conductors (one is solid black - which is the positive wire, and one black with a white stripe which is the negative wire):






Now note the anode (+ leg on the LED) and the cathode (- leg on the LED). The anode is the slightly longer leg, which in this photo is above/on top:











Then align the LED to the Battery Vampire (Joule Thief) board by slightly spreading the legs. In this particular photo, the anode (slightly longer leg) goes towards the inductor - this is the LED+ on the board, and the cathode goes into one of the two small holes side-by-side - that is the LED-:






Here in this photo, the board and LED are backwards in order to solder them, but you can clearly see the longer leg (anode) inserted in the LED+ hole:











Then solder the two legs in place:






This is the 3mm LED holder - it fits on the stock wire opening (a little tight with the LED in place, but it does fit):











In order the align the board and LED with the LED holder, slightly bend the LED legs as shown here:






Here is a test fit to show you how it would look like. Note that the anode (LED+) sits down, closer to the edge of the case:
















Measure the ground wire (black wire with white stripe) and cut it:






Then expose the wire to make ready for soldering:






Rake the positive wire and carefully bend the wire backwards and then on a 90 degree turn as shown:











Insert positive wire into case as shown:






Measure and cut the positive wire as shown:






Then expose the wire to make ready for soldering:






This is how things should look like prior to soldering. It is much easier to solder with the LED outside of the box:
Then expose the wire to make ready for soldering:






Align the negative wire (the one with the white stripe) with the hole in the board marked GND and solder it in place:











Now align the positive wire with the hole in the board labeled Bat+, and solder it in place:











Before we go any further, we need to test it - it should be fully functional right now:
















I test each driver before shipping, so if it does not work, and you have not kill the driver with static electricity (you should be grounded while working on this or any other circuit boards), then it must be a wiring problem, cold solder joint, etc.. Check your steps and re-wire/touch-up solder points as appropriate.


Now, in order to close the cover, we need to tuck in the negative wire back in its original position:





















Another quick test:






You should have cut off the extra wire/legs sticking out earlier, but if not, do it now (make sure the small pieces don't fall inside the case and short something!):






Here I have two of them ready for the hot glue:






We need to make sure that positive metal contact and wire don't move and don't come off its alignment, so we start there:






Then we add hot glue over the LED legs and wires to keep everything from moving and prevent shorts from external debris:






Finally apply hot glue to the back/bottom side of the driver to cover the electrical connections and prevent short from external debris:






Another quick test (I know, it sounds paranoid, but that is how I do all projects) - the rechargeables are not fully charged and the Energizer cells are new, so there is a brightness difference:






Put the screw back in, and you are done!:






**********************************************************************
The 5mm version needs more work, so here are a few more pictures/steps for the 5mm version

Note the 5mm LED and holder are of course larger. The hole in the case which worked well for the 3mm will not do - it will have to be enlarged by using a 1/4" diameter drill bit:











As before, align the anode/cathode, and solder in place. It is best to trim the excess here:






As before, measure the negative wire (black with white stripe) and cut it, then same for the positive wire (solid black):











As before, align wires with the matching holes in the board and solder in place:











Time for a quick test. Yes, as expected, the 5mm LED is brighter than the 3mm LED:











Tuck the negative wire in the case, and test again:






As before make sure before applying the hot glue that the positive battery contact is aligned and centered in the case:






And use hot glue as before to keep everything in place and safe for external debris:






Note that the circuit board should sit slightly below than the top of the AA cells, so that the cover can be put back in:






When putting the case back, note that there is a little bit of interference from the 5mm holder and the edge of the case at this point (you can trip it or leave it "as is"):






Here are 3x completed units: 3mm, 5mm, and 3mm:







Will


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## GeoBruin (May 2, 2012)

Looks great Will. 

Will these ship with the boards that have been optimized for a 20mA 5mm LED (1mA inductor value)? Also, will you be selling just the boards in this configuration? 

Thanks for all the great work! 

BJ


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## wquiles (May 2, 2012)

GeoBruin said:


> Looks great Will.
> 
> Will these ship with the boards that have been optimized for a 20mA 5mm LED (1mA inductor value)? Also, will you be selling just the boards in this configuration?
> 
> ...



BJ,

Oh yes, my bad. Sorry for not clarifying that. I will offer boards optimized for the 20mA 5mm LED (1mH inductor) separately from the kit - same price as regular boards, same shipping options. I will go right now and update the first post on my sales thread to clarify that 

Will


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## RI Chevy (May 3, 2012)

These look like a 3 volt paklight.  Very cool.


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## ^^Nova^^ (May 3, 2012)

Next challenge for you Will - drop-in with JT driver for a 2AA minimag with 5mm led and reflector. Sounds like the perfect long running backup light.

BTW, love these converted 3AA battery boxes, going to have to get one (or 2) next time I order something from you.:thumbsup:

Cheers,
Nova


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## wquiles (May 3, 2012)

^^Nova^^ said:


> Next challenge for you Will - drop-in with JT driver for a 2AA minimag with 5mm led and reflector. Sounds like the perfect long running backup light.
> 
> BTW, love these converted 3AA battery boxes, going to have to get one (or 2) next time I order something from you.:thumbsup:
> 
> ...



I will be keeping parts in stock for these 2xAA kits, so you can order them any time 

I also have been working on a 1xAA and 2xAA Minimag "package", but I don't have all of the parts ready. I hope to have something to share soon 

Will


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## GeoBruin (Jul 9, 2012)

Will, any updates on the mini mag package? I tried to put my own together with your 1mH board, a Nichia 5mm LED (like the ones I sent you) and a mini mag but I just couldn't come up with something sturdy.


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## wquiles (Jul 9, 2012)

I actually have spend some time on it, and have one working unit, but what I came up with so far is too expensive to make time-wise, and it is not quite fully baked to my satisfaction. 

Here is what I have so far:
































Will


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## psychbeat (Jul 10, 2012)

Hey Will-
Are you still thinking of doing a turn key 123 light?


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## wquiles (Jul 10, 2012)

psychbeat said:


> Hey Will-
> Are you still thinking of doing a turn key 123 light?



No plans for a turn-key 123 light at this time.

Will


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## tobrien (Jul 14, 2012)

wquiles said:


> Kestrel,
> 
> Yes, the 2xAA configuration (or 2x D in a Mag 2D body) is awesome. I took one of my 4x CR123 bodies and used to of my home-made AA to 18650 cells and built a 2xAA equivalent, and it works great.
> 
> ...



what is that thingamajig you have the pill on (with all the holes on it)? I've seen those in Nailbenders threads and so on, what is it?


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## nein166 (Jul 14, 2012)

tobrien said:


> what is that thingamajig you have the pill on (with all the holes on it)? I've seen those in Nailbenders threads and so on, what is it?


aren't they great I went and bought one after seeing a picture like this.
Its called a hand vise or a work holder. They come with a wooden handle that screws onto the bottom. I unscrewed the handle and bolted mine to my bench
I also made a more mobile base out of black iron pipe fittings, nice and heavy to hold the work steady. ebay, harbour frieght, Micro-mark and mcmaster sell them


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## wquiles (Jul 14, 2012)

tobrien said:


> what is that thingamajig you have the pill on (with all the holes on it)? I've seen those in Nailbenders threads and so on, what is it?



Do a Google search on "*WORK HOLDER PEG CLAMP VISE*"

Will


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## wquiles (Jul 15, 2012)

Alright! I finally got a solid working 1xAA Minimag working with the Joule Thief circuit 

The biggest problem I was having is achieving a truly solid GND connection, since soldering to Al is not trivial. I recently got a small tapping head, and with that I was able to drill/tap 1-64 screws (very small!). Here I already have drilled and counter sunk the two holding holes:






Here I am using my tapping head on the Yuasa indexer to get both holes 180 degrees apart:







Here is a mock-up with non populated boards to show how the pill looks like:







Here I am using a populated board, with the solder "blob" for the AA cell's positive contact, and wired for the LED's - so to use the board in this configuration, only two wires need to be used: only for the LED. And if the LED is at ground potential, then you would only need ONE wire 











Then glue the LED, and solder in place:












Drop the pill in the modified head and body with the 20mm optic and o-rings, and voila!:

















Will


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## sassaquin (Jul 15, 2012)

Nice job on the baby minimag, it is very cute and looks to be a perfect emergency light. 
Thanks for sharing the photos.


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## Illum (Jul 16, 2012)

The only problem I've encountered using joulethief's to drain Alkalines is the tendency to leak. Any battery holder that has enclosed walls and stamped steel contacts are ruined fairly quickly by a single [or pair, or trio] of leaking [but functioning] batteries sitting in it for about a week or so. I have resorted to using duct tape to seal leads soldered to gold plated magnets to battery contacts. They don't look pretty, but they work. Now... they work beautifully draining cr123as:naughty:


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## JimmyM (Jul 20, 2012)

Will,
I'm sorry I just came across this. This is awesome. Sometimes you just need a light that ISN'T a blaster. Have you done any runtime tests on a fresh cell?
I built my daughter's a couple of "camping night lights". Using Yellow LEDs (buglite) and a switched mode buck converter running on 4D cells in a cheap-o plastic lantern body. It will pull the cells down to 0.5V each and is current regulated. One has 4 LEDs the other has 6. They're pretty bright and last forever. They have gone to girlscout camp for 2 weeks, then a week of family camping and another weekender camping trip all on the same set of D cells.

EDIT- Do you reflow these? or hand solder?


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## wquiles (Jul 21, 2012)

JimmyM said:


> Will,
> I'm sorry I just came across this. This is awesome. Sometimes you just need a light that ISN'T a blaster. Have you done any runtime tests on a fresh cell?
> I built my daughter's a couple of "camping night lights". Using Yellow LEDs (buglite) and a switched mode buck converter running on 4D cells in a cheap-o plastic lantern body. It will pull the cells down to 0.5V each and is current regulated. One has 4 LEDs the other has 6. They're pretty bright and last forever. They have gone to girlscout camp for 2 weeks, then a week of family camping and another weekender camping trip all on the same set of D cells.
> 
> EDIT- Do you reflow these? or hand solder?



I have not yet done a long term runtime since I use my lights with "depleted" cells. Even AA's are plenty bright at night, even more so with a depleted CR123 cell.

Now-a-days, and thanks in good part from what I learned from you and from George (taskled), I reflow "everything" that is surface mount. I only do hand solder for wires, touching up something, changing a value/part, etc.

Like you said, with good equipment and practice, reflowing becomes second nature 

Will


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## JimmyM (Jul 21, 2012)

wquiles said:


> I have not yet done a long term runtime since I use my lights with "depleted" cells. Even AA's are plenty bright at night, even more so with a depleted CR123 cell.
> 
> Now-a-days, and thanks in good part from what I learned from you and from George (taskled), I reflow "everything" that is surface mount. I only do hand solder for wires, touching up something, changing a value/part, etc.
> 
> ...


I guess i should have asked if you used a reflow oven or a hot air pencil. I'm building my D1s again and I use a reflow oven to do 10 at a time. those joints are too good for a conventional soldering pencil.


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## wquiles (Jul 22, 2012)

JimmyM said:


> I guess i should have asked if you used a reflow oven or a hot air pencil. I'm building my D1s again and I use a reflow oven to do 10 at a time. those joints are too good for a conventional soldering pencil.



I am using the same equipment/techniques as before, as I show here in my web site - using the pre-heater, and then the hot air pencil to reflow parts once they are at temperature.

When you say the joints are too good in your case, do you mean you have so much copper in the traces that it takes forever using the hot air pencil?

Will


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## JimmyM (Jul 22, 2012)

wquiles said:


> I am using the same equipment/techniques as before, as I show here in my web site - using the pre-heater, and then the hot air pencil to reflow parts once they are at temperature.
> 
> When you say the joints are too good in your case, do you mean you have so much copper in the traces that it takes forever using the hot air pencil?
> 
> Will


No, no, no. YOUR joints look too good to have been done with a conventional iron. In any case your preheat then reflow approach is perect for high mass boards. I just use my oven to do several at a time. Your tools are doing the exact same thing my oven is doing.

edit- I just looked at your site. Did I aleady know we had the same equipment? What paste do you use? I use Shenmao water soluble leaded paste.


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## wquiles (Jul 23, 2012)

Ahh, thanks Jimmy 

Yes, I have the same equipment since it was "you" who recommended those to me. It has been working flawlessly for the last couple of years. Like you said, practice, practice, practice 

I am using Kester Easy Profile 256 solder paste. Like with most of these, you need to keep in the fridge to prolong its useful life.

Will


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## JimmyM (Jul 23, 2012)

wquiles said:


> Ahh, thanks Jimmy
> 
> Yes, I have the same equipment since it was "you" who recommended those to me. It has been working flawlessly for the last couple of years. Like you said, practice, practice, practice
> 
> ...


I have a small fridge in my basement shop that I keep my paste in. Along with some refreshment.  of course. I work best when lightly lubricated. heh heh.


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## Mr Floppy (Jul 23, 2012)

wquiles said:


> Alright! I finally got a solid working 1xAA Minimag working with the Joule Thief circuit



That is excellent! I've been looking at your joule thief circuits and thinking of ways of putting them in a 2AA mag but always dreaming about a 1AA version.
The picture says it all! No way I'll be able to that myself. If you ever offer this as a service, I'll be in line to get one.


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## tobrien (Jul 24, 2012)

would one of yall be down to make me a nice neutral white battery vampire for CR123 primaries?

edit: I will pay for this


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## PCC (Jul 24, 2012)

If you look at the very first post in this thread you'll see that Will had made a P60 drop-in using this driver. One of those in a L2M would be a nice little battery drainer unless you are looking for something custom made.


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## tobrien (Jul 24, 2012)

PCC said:


> If you look at the very first post in this thread you'll see that Will had made a P60 drop-in using this driver. One of those in a L2M would be a nice little battery drainer unless you are looking for something custom made.



if I had the time and tools I'd do it myself but alas, I do not


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## wquiles (Jul 24, 2012)

Mr Floppy said:


> That is excellent! I've been looking at your joule thief circuits and thinking of ways of putting them in a 2AA mag but always dreaming about a 1AA version.
> The picture says it all! No way I'll be able to that myself. If you ever offer this as a service, I'll be in line to get one.


Thank you 

Right now it is very labor intensive, and you can get 1x AA LED lights far cheaper than what I would need to charge for this one. Here are the basic operations/steps: Cut & re-thread body), cut threaded part on head shorter, and clean up edge on threads, bore head for pill, create a new pill from scratch, drill and tap pill's screws for ground contact, solder/assembly pill, and do final assembly. Lots of labor, all done on manual machinery. I would have to charge upwards of $100+ to even come close to breaking even 





tobrien said:


> would one of yall be down to make me a nice neutral white battery vampire for CR123 primaries?
> 
> edit: I will pay for this


The cheapest way to go is to simply have Nailbender (Dave) make you a P60 drop-in using one of my Joule Thief V2 boards. 

This is not a sales thread, so if interested, contact me privately by email.

Will


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## Mr Floppy (Jul 25, 2012)

wquiles said:


> Lots of labor, all done on manual machinery. I would have to charge upwards of $100+ to even come close to breaking even



Ouch, then again, I'm sure some collectors would hand over the cash. At times, the frustration of working with the size Zetec380 (don't know how similar it is to the 382), I've often felt like paying $100 for it. I've made some of the ugliest dead bugs


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## tobrien (Jul 31, 2012)

wquiles said:


> Thank you
> 
> Right now it is very labor intensive, and you can get 1x AA LED lights far cheaper than what I would need to charge for this one. Here are the basic operations/steps: Cut & re-thread body), cut threaded part on head shorter, and clean up edge on threads, bore head for pill, create a new pill from scratch, drill and tap pill's screws for ground contact, solder/assembly pill, and do final assembly. Lots of labor, all done on manual machinery. I would have to charge upwards of $100+ to even come close to breaking even
> 
> ...



,I'll hit you up in an email


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## fyrstormer (Aug 2, 2012)

Hey Will, remember those AA adaptors you posted on the first page of this thread? I was thinking, an AA-to-2x123 adaptor and a matching 2x123-to-18650 shim sleeve would be a great accessory for your Joule Thief boards. I already have a Joule Thief that I've turned into a P60 drop-in, hosted in a Solarforce L2M shell, and the ability to run it on 1x18650, 1x123, 2x123, or 1xAA using various combinations of adaptors would be awesome. (I know some of those voltages are impractical with the Joule Thief, but a set of adaptors might as well be as flexible as possible.) I tried to talk Oveready into making a set like this, but nothing ever came of it. If you're willing to make a set of adaptors like what I described, I'm interesting in buying a set.


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## wquiles (Aug 3, 2012)

If I had a CNC setup where I could create the design, program the CNC, and then make several of them (10+) then I could offer them cheaply enough. As it stands today with my manual setup, it takes me 30-60 minutes to make each one, and at a cost/labor of about $1/min, there is no way I can sell them to even come close to break even.

Will


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## tobrien (Sep 30, 2012)

*Re: Joule Thief Circuit boards for sale ...*

i've decided to ultimately order a joule thief from you (at some point, not right now though) and a Nailbender module (shipped to NB of course) and I just wanna check: due to the efficiency of the XM-L it makes more sense to use _that_ emitter with the joule thiefs instead of the XP-G, correct?

edit: but as voltage from the cell goes down, you get closer to the VF of the XP-G though, right? not sure what emitter to go to


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## Kestrel (Sep 30, 2012)

*Re: Joule Thief Circuit boards for sale ...*



tobrien said:


> i've decided to ultimately order a joule thief from you (at some point, not right now though) and a Nailbender module (shipped to NB of course) and I just wanna check: due to the efficiency of the XM-L it makes more sense to use _that_ emitter with the joule thiefs instead of the XP-G, correct?
> 
> edit: but as voltage from the cell goes down, you get closer to the VF of the XP-G though, right? not sure what emitter to go to


NB has compared the XP-G to the XM-L with the JT driver, he recommends the XP-G BTW.
Check the beginning of NB's latest P60 thread for more info, post # 2 IIRC? :thinking:


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## tobrien (Oct 1, 2012)

*Re: Joule Thief Circuit boards for sale ...*



Kestrel said:


> NB has compared the XP-G to the XM-L with the JT driver, he recommends the XP-G BTW.
> Check the beginning of NB's latest P60 thread for more info, post # 2 IIRC? :thinking:



thanks bud, I didn't notice it haha. 


you're a big help


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## wquiles (Oct 1, 2012)

*Re: Joule Thief Circuit boards for sale ...*

Thanks *Kestrel* 

NB has the most hands-on experience with my JT boards, so I defer to him 

Will


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## CMAG (Apr 5, 2013)

*Re: Joule Thief Circuit boards for sale ...*

Will, would you know if your newer JT will fit a Aleph can


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## wquiles (Apr 7, 2013)

*Re: Joule Thief Circuit boards for sale ...*



CMAG said:


> Will, would you know if your newer JT will fit a Aleph can



I have not tried building yet an Aleph can, but here is the size of the board:
http://www.atdms.com/battery_vampires.html

How big are these?
The new V2 boards are slightly larger in diameter than V1 boards, but 100% functionally identical. The V2 production boards have a diameter of approx. 0.53" - 0.54" (approx 13.5mm to 13.6mm).


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