After seeing information on Joule Thief LED drivers on the internet I decided to try making them. After getting some working units I started experimenting ( as I usually do ) with different sources of parts from objects I can recycle.
I found that the Kodak Max disposable camera had a transistor that worked in this circuit and a 1k resistor also required. So the idea was born to try and modify the circuit in such a way I can get my daughter involved ( and hopefully interested in electronics and recycling and away from Nintendo DS and TV )...
Her response to the finished torch.... " This is sooooo cool "...
Then I saw the Get the LED out comp and decided to share. So here is my first attempt at an Instructable.. I hope someone finds it interesting or even maybe useful.

Step 1: Get Your Bits..

Ok so now you know I am an electronics packrat, so here is what you will need if you wish to give it a try.

A Kodak disposable camera is required, mine was free from a photo lab that usually throws them away.

A switch that I rescued from a broken phone.

Some enamelled wire also rescued but from a microwave oven. If you are not exeprienced with high voltage then I do not reccomend you pulling apart a microwave as there is a high voltage capacitor in microwaves that can possibly kill you. The wire I used was from the microwave fan motor, you can source wire from most electronics shops or salvage from many other places like dead motors etc.

The last thing needed was a white LED, the more light output it has the better. This was the only thing I bought so this project only cost a little in money but more in time.

Oh absolute last thing that is required is lots of paper under the project with all my scribblings on it. Without this the project will never work. hehehe..

Feel free to reproduce your own paper with scribblings on it to get better results.
<p>I got shocked 4 times...ouch.</p>
<p>If you don't want to wait, just short the capacitor with an insulated screwdriver. </p>
I got shocked by one of those things!<br /> NOT&nbsp;FUN!!!!<br />
lol im the same thing
reallly coollll :D
Thanks, I'm glad you liked it... Catch ya.. David....
get any transistors from this??
Hello TXTCLA55, In this circuit there is only 1 transistor which gets reused. Most of these camera circuits have 1 or more transistors, either surface mount or the usual small switching transistors with 3 legs like the one contained in this circuit. Most I have seen ( and been able to find data on ) are low voltage low current switching transistors so no good for most circuits other than small switching low current devices ( like this Joule Theif ).. These circuits are cheap ( or free ) so if you can get a few then its worth playing with the transistors but be warned they are easy to destroy, I have destroyed at least a dozen playing around with them... Catch ya.. David...
Thanks alot!
No probs...
This is a nice instructable. The only problem I have with it is that in MY cameras, the transformer has this hideous gunk on the tape around the windings which glues it to the ferrite loop thing. I tried scraping it off, but it's about as hard as a rock, and even with a utility knife, I'm only able to remove teensy flakes at a time. I'm have both a Kodak Power Flash, and a Kodak Fun Saver, and they both have this stuff. You're lucky you got a camera that just had some tape holding the ferrite E things together. Maybe yours is older than mine or something. If you do it again, pray you don't get this epoxy crap that's on all my cameras' transformers.
Hello, Glad you liked my Instructable, I have not noticed epoxy on the transformers before so I dug out a Kodak Funsaver and your right, nasty little critter isn't it. I have always used the older kodak Max type cameras for this hack so never knew about the epoxy. If you can get a Max camera it will be no probs otherwise there are no easy ways of softening( dissolving ) epoxy. Sorry if I have not been of much help. David..
I got a camera without the outer case from a nearby store (the people said it was Fuji) but the inner case took me 10 minutes to remove. Found a 1F cap inside, it was on the edge of the board and I think I shocked myself with it while trying to pry the case open with a screwdriver. Finger on the positive battery thing. Ouch. More parts than in a Kodak one. Should I just wait and try again next week?
Good Morning knight2067 If you can wait and get a Kodak it would be easier. If you can't get a Kodak then if you post a photo of your camera and circuit you do have I will see if I have any and maybe create a updated instrutable for you for the camera you have. Just be careful with the bits that bite.... hehehe.
I think I'll wait. Can't get good pics right now... It has 5M ohm, 15 ohm and 220 ohm resistors; a transformer and something that looks like a little transformer, (The big one has no tape, both are in your photos) a transistor (D2687) and some other little thing in your photo, which you removed. Also has two switches, one for the flash and one to complete the circuit between the battery and cap. you must press a button on the original casing to charge it. Thanks for replying.
I've just ed started going to my local camera store and getting all the old disposable flash cameras. They just chuck them. Anyway, these camera have either AA or AAA batteries in them. and akaline. so FREE BATTERIES. not bad. also if you turn the front viewfinder plastic lensy thing around you get a fish eyed lense. MEGA COOL!!! love fish eyed lenses. have yet done the mount on to a digital yet. but all i good time.
Hello altomic, I get quite a lot of cameras which is nice. I test the batteries and I put the best ones aside, most of these batteries I give to some pensioners I know, they are very happy to get free batteries. I have noticed though quite a few of the batteries are not what I would call "top of the line" and start to leak after a couple months storage. If they are kept in a big bag together then this ruins the whole bunch. Otherwise the batteries that are a bit run down go into my joule thief lights before disposal. Actually hoping to make a LOT more joule thief lights and put in the hothouse, make it a lot easier to see when watering in there early mornings.. Have fun, bye..
the first thing your should do after opening the case is short the legs of the capacitor with a plastic handled screwdriver. that will discharge the capacitor making it safe to work with. expect lots of sparks and melted spots on the screwdriver.
Instead of leaving the capacitor to discharge, couldn't you just remove the battery and activate the flash a few times? I work in a camera shop and we have great fun throwing charged capacitors to each other. very stupid.
Hello Acidmoxy, Sorry for the late reply.. You can activate the flash when the capacitor is fully or near fully charged but it rarely discharges the capacitor completely. Also if the capacitor is not charged to over about 90% or so charge, the flash will not work anyway, leaving over 250v sitting in the capacitor. It is always best to discharge the cap with a lump of metal at the end of some plastic or rubber, even when you "know" the cap is discharged.. Hands up all those that have been bitten by a "I was sure it was discharged" cap before... Hehehe.. Even I have been bitten a few times.. Not a lot of fun. Have a great day. David.
you can bang the camera on something to discharge the flash; it knocks together the two plates attached to the shutter and sets off the flash. or be an idiot and touch your finger to the plates...
do you actually need that pnp or npn?
Hello Alex, I assume you mean the npn transistor. Yes it is required as the circuit will not work without it. The LED will not work at the 1.5 volts or less which is being supplied by the single AA battery, most white LEDs require approx 3.2 volts to work. The transistor is being switched on and off rapidly which lets current pass through the transistor to ground when switched on but when it switches off the current has no where to go so would normally nothing would happen but the magnetic field induced in the coil while current was flowing will collapse when current stops flowing, when a magnetic field collapses in a coil it usually creates a spike voltage greater than the original voltage supplied. The magical thing about this circuit ( and why I am so impressed with it ) is that the spike voltage is high enough ( ie: greater than 3 volts ) to "turn on" the LED for a very short period of time and so make light. The circuit is switching on and off so fast we cannot see any flickering in the light produced by the LED. It also means that a battery that is too "flat" to run another circuit can be put in this device and still run continuously for weeks. There are better discriptions of how this circuit works if you look around the internet for Joule Thief.. David.. BD
thanks!, i have another question, its in no way related to your project, lets say i have a 1000ma batterry, how long would it take it to charge it with 100ma of current? can you give me the formula?
Hello Alex,<br/><br/>There is no simple answer to this question, especially from the info you have given. Factors such as charge voltage, constant current or not, residual charge left in battery, type of battery etc. etc. all come into play. As I understand it IF the battery is fully depleted then usually you can use the formula charging time (h) = battery capacity (in mAh) x 1.4 / charging current (in mA).. As shown at <a rel="nofollow" href="http://jeltsch.org/node/262">http://jeltsch.org/node/262</a> <br/><br/>If there is residual charge left in the battery then the charge time will be shortened. The best way to charge batteries is a little difficult and involves measuring the battery charge and temperature during the charging and stopping the charge at the required voltage and/or more importantly before the temperature of the battery rises too much and starts damaging the battery being charged.<br/><br/>All these factors are different depending on type of battery being charged.<br/><br/>Sorry I cannot be of more help.<br/><br/>( If anyone has more idea than I please don't hesitate to add a reply as I am no electronics guru.)<br/><br/>David.. BD<br/>
Thanks again!
Awesome! and its featured. I like the way it uses all the old parts and the old board. CONGRATS
Thanks, I was trying to reuse as much as possible to show Rachel what can be done with a bit of careful thought and using what most people these days consider "junk".
that's awesome! I really like how you stuck the joule thief back in the camera at the end
Thank you,<br/>I found the original web site that got me interested in making a Joule Thief..<br/><a rel="nofollow" href="http://www.emanator.demon.co.uk/bigclive/joule.htm">http://www.emanator.demon.co.uk/bigclive/joule.htm</a><br/>Could not find it when making this instructable.<br/>

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