Double Joule Solar Thief All Contained in a Mint Tin




Charger of electronic gadgets, using AA rechargeable batteries, photovoltaic panels, and two thieves, two joule thieves that is.
All parts and components are recycled from old electronics broken yard solar lights. Only new parts are rechargeable batteries and thin coated wire for toroids.

This is my first Instructable so forgive me if it's rough, I will make every attempt to improve it, so questions comments and all constructive criticism is welcome and expected.

Step 1: What You Need

photovoltaic panels- I got mine from old solar garden lights, that got run over by a car and wear only thing that did not crack
toroid-from old PC I got from garbage
L7805 voltage regulator, 1N4001 diodes, 2N3904 NPN Transistor- all from broken enlarger timer
miscellaneous wires from many broken things I horded

The only thing I buy is enameled wire, but you can reuse old CAT5 wire too.

And some sort of an enclosure for whole thing to fit in I used Altoids tin but I also wanted to use Apple USB Power Adapter box, Its clear so its awesome, maybe next project.

So My green twist is two twists. All parts wear, and can be for you, re purposed from broken, discarded electronic waist, And second twist It uses solar power to use however you like or want.

Step 2: Toroid Makeing

Toroid making is not too complicated, winding two wires in pair through a toroid. At the end of winding there are 2 pairs of wires. twist together one of each of different colors and solder them together, other 2 wires are left loose

Step 3: Assembly of Joule Thieves

i used 1N4001 and 2N3904 and have about 25 turns on my toroid

Step 4: Separating the Thieves

one joule thief gets attached to photovoltaics other to usb

Step 5: Drilling and Glueing

drill through both top and bottom of a tin, use drill bit bigger then gauge of your wire, lace wire through and glue solar panels on tap and bottom of the tin I used double stick foam

Step 6: Rejoining of the Thieves

solder solar thief in to battery holder and battery holder to usb thief
solar thief is used to charge batteries, and USB thief to charge whatever your hart desire,

Step 7: Regulator You Mast Have a Regulations

L7805 voltage regulator and some creative soldering, and now I have 5V not 30+

Step 8: Compact It All

insulate all the connections and stuff it all in the tin, use double stick tape to hold battery holder in place

Step 9: All Must End

last step insert rechargeable and wait for the sun to come up, Open tin for charging



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    48 Discussions

    karlpinturrGhost Wolf

    Reply 8 years ago on Introduction

    Folding the tin WON'T break the solar cell, as they are on the OUTSIDE - one on the top, one on the bottom.

    In theory, you could charge the batteries with the tin closed, but unless you stood it on its end, you'd basically only get half the power.

    The only thing you'd have to worry about breaking is the connecting wire between them - but just make certain it's long enough.

    Ghost Wolfkarlpinturr

    Reply 8 years ago on Introduction

    Yeah I see that's smart to have it that way I just thought it had to be folded out like that all the time.


    7 years ago on Introduction

    From where did the regulator come in and do you join it and how come a cap ... whats all this. I mean please have a step by step instructor... 1stu copy some ones else diagram.. and u wantsus to follow... 2nd the regulator was required but how do u fit it in what abt the cap... Look dude iam a novoice to all this things till the time there is a step by step thing and clear diagram I cannot even think of statring it... please re do ur instructions and reload as its totally of no use atleast to me... Please help


    8 years ago on Step 3

    I know NOTHING about circuits and diodes and all that shocky ouchy stuff... But is this page meant to be in another write-up? Completely ignoring this page I, and by "I" I mean my electrician brother, was able to build the charger and it works.
    Someone pointed out that the voltage regulator you cited was wrong, indeed it was, the correct one is LM 7805 Voltage Regulator.
    Also, could the author just clear up something for me, why are the USB parts sticking out of your tin the male parts? Things needing charging already have the male part, the charger should have the girly goods.
    I am not knocking, please do not think that, I just think this article needs A LOT of cleaning up.

    2 replies

    Reply 8 years ago on Introduction

    From a fairly brisk skim-through, it appears to me that the usb is actually an alternative method for charging the batteries IN the Altoids Tin, not for charging anything outside it...


    they is a big problem with this unit that i see and have teasted
    the solar panels to the joule thief dose sound a good idea but dose not work as expected.
    yes it ups the voltage but in doing so you lose the ampage needed to charge the batterys.
    i found i had to leave the batterys to charge for longer due to the little ampage comming out of the jt unit.
    now connecting the solar panels direct to the battery with a diode inline to stop discharge thru the panels would be better.
    also haveing the panels in parrale for more ampage and a single battery would be better that is if the usb jt unit will work correctly from the 1.5 volt to up it to the 5 volt needed.
    now the joule thief from the battery to the usb seems a good idea if it works correctly.
    running a secondary coil on the jt connected to the voltage regulator would be better if it works as this will draw less power from the bettery then if it would wired to the led output of the standerd jt


    8 years ago on Step 7

    what is the cap there for also have you checked the aa batterys in a device to see if they do fully charge or not ?


    8 years ago on Step 3

    you should use a schottky diode at the output instead of the 1n4001
    a schottky has a lower voltage drop


    Reply 9 years ago on Introduction

    5V. he used a voltage regulator. the second joule theif, if made correctly, can output well over 100 volts.


    Reply 9 years ago on Introduction

    You can easily get over 2,000 volts from a well designed JT circuit using only a single AA battery.  I have been able to run over 400 leds from a "dead" AA battery.  Check out my videos on youtube for more on the joule thief circuit.

    Great project, well done.



    Reply 9 years ago on Introduction


    It is:


    If you have any questions, jet let me know.  Check out the Joule Thief topic over at and you will see many great variations on this circuit.  I thought I was doing some nice things with it but these folks really have gone beyond anything I would have thought of.  I am still learning and also I like to share what I have learned, which is how I learned.



    9 years ago on Step 3

    Funny how your schematic drawing does not match you work, but looks a lot like mine! You can draw your own schematics by downloading ExpressPCB schematic for free at

    1 reply