Hi, everyone. I love making projects out of Altoids tins specially the Altoids smalls tins, they're so small and very cute and they fit perfectly in your pocket so you can take them with you anywhere and anytime.

I've seen a couple of Instructables on how to turn these small tins into flashlights, but I want to challenge myself to see if I could fit a joule thief in it. For those of you who don't know, the Joule Thief is an easy little circuit that allows you to drive a white or blue LED from voltages as low as 0.5 volts. So with this project you can squeeze every last drop of energy out of your dead batteries and you will have a fully functional and very useful flashlight in your daily activities or to use in a survival situation.

This DIY project is great for beginners in electronics. It´s not complex, It´s very cheap, it´s useful and it´s fun to use!

If you like this please vote for me in the “Survival Contest” Thanks!!

Step 1: Materials

1 Clear 5mm LED – (Color of
your choice)

1 5mm LED Holder - Chrome or plastic.

1 1KiloOhm resistor (Brown-Black-Red)

1 AA battery holder or you could go AAA.

1 AA or AAA Battery

1 button or toggle switch.

1 Altoids Smalls Tin - Flavor of your choice.

1 Blue or White LED (Other colors are fine, too)

1 2N2222A Transistor

1 Ferrite Toroid (You can get the toroid and transistor from a dead CFL)

Thin wire, two colors (magnet wire works)

Step 2: Tools

Soldering Iron



Hot Glue Gun (Melt glue)

Wire Strippers

Electrical Tape

Extra Wire

Safety Goggles

Helping Hand (Optional but very useful)

You can pick up these parts most anywhere and they´re low cost.

Step 3: Prepare the Tin

Ok, so this step is probably the hardest part. Take your time and do it carefully if you succeed in this step, you´re halfway gone in this project. I separate the lid of the tin to make it easier to drill and don´t bend the tin in the process.

Grab your drill bits. Find one that is as close to the size of your LED as possible. I found out that a 9/11ths sized drill bit works perfectly. But try to run on just smaller, because as you know, you can make the hole bigger but you can never make it smaller.

I decided to use a scrap block of wood to prevent the tin from caving in and denting.

You may want to mark where you want each hole, use a nail or a push pin to leave a little dent this will help you to place your drill in the exact point you want yor hole. Now lightly press as you start drilling let the drill bit do the work for you. If you press hard against the tin you will mangle it.

After you drill your holes pop in the LED holders to make sure they fit and do the same with the switch in the lid of the tin.

Step 4: Making the Joule Thief – Winding the Toroid

The first step is to wind the toroid. I found mine in a dead CFL, and it works fine.

Take your two strands of wire and thread them through the toroid, then take the other two ends and wind it once around the toroid. Don't twist the wires and make sure that two wires of the same color are not right next to each other.

Keep winding, making sure you wind the coils tight. You want about 8-11 turns on your toroid, in my case 7 works fine for me. Make sure the turns are spaced evenly around the toroid.

Once you wind around the whole toroid, cut off the extra wire, leave a couple of inches for soldering. Strip some insulation off the wires and then take a wire from each side, making sure they are of the opposite color. Twist them together, and you're done with the toroid.

Step 5: Solder It All Together

Now we are going to solder everything together. You could mount it on a small piece of wood or cardboard if you like. You can follow these written instructions, or take a look at the diagram.

First, take the two outer leads of the transistor and bend them outwards a little ways, and bend the middle lead backwards. Take one of the wires coming from the toroid that is alone; that is, not twisted together with another wire. Solder it to one side of the resistor. Solder the other end of the resistor to the middle lead of the transistor.

Take the other single wire from the toroid, and solder it to the collector of the transistor. Solder the positive side of the LED to the collector as well, and solder the negative side to the emitter.

All that's left to do now is solder an extension wire to the negative side of the LED. Take a piece of that wire you had earlier and solder it to the transistor's emitter.

Step 6: Final Assemble

It´s time to do the final assemble, to reduce the chance that we get a short, use some electrical tape or like me you can cut a piece of felt and tape it to the bottom of the tin with some double sided tape this will make things appear classy.

Before we close up you need to put a bit of tape again. Put a layer of tape between the resistors/ positive legs and the negative legs. This prevents any shorts from happening when you close the lid.

Carefully bend the two legs of the switch down a bit. Take some wire and solder it to one of the switch tabs. Solder the other end of the wire around the positive side of the battery case.

Solder another wire to the second switch tab and the other end to the wires coming from the toroid that are twisted together.

At this point you can test to see if everything is working. So, is it?

Step 7: We're Done!

We're done. Just make sure you don't have any shorts (you shouldn't if you used electrical tape) and that your button is screwed in tight. I decided to use a AAA rechargable battery instead of the AA battery but this is up to you.

You now have a fully functional flashlight.

I highly recommend this project for all starting DIY people. It works for both kids and adults. It gives you a practical gadget that you can actually use or give as a gift to someone.

This is a project that is great for beginners and kids, and teaches a lot of electrical basics in the process.

If you decided to give it a try post a picture in the comments.


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    24 Discussions

    Bobby Dean

    3 years ago

    will this work with a fully charged LED or would the battery have too much charge for the LED


    3 years ago on Introduction

    Its much better to use "Boost" converter, since they are smaller and much more efficient.

    Gomi no Sensei

    3 years ago

    The switch placement totally ruins it for me. How can you slip it in your pocket like that ? Why didn't you put it on the top next to the led or use a glued on micro switch on top ?


    3 years ago on Introduction

    I have a few questions.

    1. My torroid from a CFL seems too small. It has 6mm OD and 3-4 mm ID. I can't get 3 turns of wires (from a telephone cord) to fit. Is the torroid too small?

    2. Can a steel washer work instead of a torroid? Transformers use steel cores.

    3. CFL contain transistors, too. Would they work? There is a long wait for transistors ordered on Ebay.

    4. Wonder why torroids are relatively expensive even on Ebay!

    1 reply

    Reply 3 years ago on Introduction

    Hi! Well to make the Joule Thief you need a piece of ferrite not necessary in a toroid form. Toroids are often used because the ring shape is more effective at generating or creating an electromagnetic field, but a simple coil with two windings around a central
    core will work just fine. You can get it from an old CFL like I did but some CFL have smaller toroids so probably you should open another one and see if you can find a bigger toroid also you can find them in old computer motherboards, computer power
    supplies, or you could buy them in any electronics store.

    - About the winding ideally, you want about 8-11 turns on your toroid but It could work even if you have less turns about 5 or 6 will do the job.

    - You can use the transistors you find in dead CFL some are labeled C2611 or 13002 just make sure they are NPN, but sometimes when you use these transistors your LED won´t light up in this case just change the resistor instead of using a 1KOhm resitor try with a lower value 240 Ohms will work fine.

    The transistor could be a 2N3904, BC547B, 2SC2500, BC337, 2N2222, 2N4401 but any NPN transistor will do the job.

    I´m not an expert in electronics but I hope I helped you, Thanks!!


    3 years ago on Introduction

    Clever. Altoid tin projects are back! Nice work.

    Some suggestions for the contest. Follow the advice of comments from others. Show the underside of the board and if you don't plan on showing a schematic, put up a link to an instructable that has it. Also, in the photographs it's clever they way you improvised a battery holder. Show how you made it. It adds value to your instructable.

    1 reply

    Reply 3 years ago on Introduction

    Thank you so much for your suggestions I'll edit my instructable as soon as I can to make it more clear and complete!



    3 years ago on Introduction

    Now I know what to do with all those "smalls" tins I have been saving, very fun idea, you got my vote!

    1 reply

    Reply 3 years ago

    Thanks! I hope you give it a try and share a picture!!

    I've got plenty of half dead batteries from my electric toothbrush.
    Now i fill suck all left energy from them.

    Can you add a photo with a button being pressed?

    2 replies

    can you please add a photo of the underside of your circuit board, to show the soldering points. I think I've got an understanding of circuit but a visual confirmation would really help. Thanks

    2 replies

    He made a standard JT, the schematic is in my instructable or you can try a even better shematic as in my low power consumption JT.


    3 years ago on Introduction

    There's a bunch of Joule thief Instructables but I like the style you gave to yours with the altoid box. I also like the cardboard circuit board!