This is a simple method to make a flashlight that will last forever.
It uses a small stepper motor to generate energy and many capacitors for keep it stored for several seconds.
Ps: I'm from Argentina so let me know any grammar mistake.
Step 1: Materials
Most materials are recycled from the trash.
You will need:
- Two LEDs, with their silver led holdres.
- An unipolar stepper motor with its reduction gear.
- One or two broken PC motherboards, to remove the capacitors.
- Two 220 ohm resistors.
- A sheet of cardboard.
- A small piece of plastic.
- Plastic spacers.
- Four rectifier diodes.
- Spray paint.
Step 2: Prepare the Capacitors
The key to the lantern is to put capacitors in parallel to be interpreted as one large-capacity capacitor.
I use 40 capacitors of 1000uf 10v.
If you use more capacitors the torch will stay lit longer.
Solder four rows of 10 capacitors each one.
Then solder the rows together.
Step 3: Make the Carboard Case
Draw the box on the cardboard.
Trim the excess parts and fold by the lines.
Paste a strengthening in the areas where the motor will be attached.
Use double-sided tape to close the box.
If your cardboardis very hard use scotch tape to keep it closed.
Use the pdf file attached as a guide.
Step 4: Paint the Cardboard
Paint the cardboard to make it look better and be more resistant to moisture.
Step 5: Prepare the Motor Connector
Solder the four diodes to the contacts of the individual coils of the motor in the male connector and a small piece of wire to pin cable which connects the common of the four coils.
Step 6: Finishing the Inside
Solder the output of the four diodes to the positive of the capacitors and the wire to the negative.
Solder two pieces of wire on the opposite side of the capacitors.
Then insert it into the box.
Step 7: Leds
Cut the plastic about the size of the top.
Drill two holes for the led holders and paste.
Inset leds, solder two resistors in the positive terminals of the LEDs. Solder the negative together.
Then solder the wires coming out of the box and paste the plastic to the cardboard.
Step 8: Attach the Motor
Use a zip tie to attach the motor to the cardboard box, remember to connet it to the capacitors.
Step 9: The Handle
Use a small piece of plastic and hte spacers to make a handle and paste it strongly to the motor gear.
Runner Up in the
Flashlight Contest
Participated in the
Krylon Summer Projects Contest













87 Discussions
Question 3 months ago on Step 6
What voltage do the diodes need to be?
Reply 1 year ago
awesome
2 years ago
Tenia pensado en hacer algo asi yo tmb. Nunca sabes cuando necesitas una para alumbrar a un demonio que es debil a la luz y que te ha destruido toda la iluminacion de la casa :P..
jaja..
Creo que tengo un motor chiquito de continua(no paso a paso), capaz que pueda servir igual. Y concuerdo con que un envase de plastico ignifugo seria mas conveniente. Por lo demas, muy buen trabajo!.
3 years ago
Look up laser hacker.com he had some joule looper circuit that relly conserve the power to run an led from a super capacitor.
8 years ago on Step 9
can we use a charging circuit to charge some rechargable AAA batteries and use them in place of capacitors . They can turn the lights on for a long time.
IF WE CAN THEN PLEASE POST THE CIRCUIT THAT CAN BE USED......
Reply 3 years ago
The name of of the project is "Flashlight with no batteries" If you want a flashlight with batteries, there are millions out there in the store.
Reply 8 years ago on Step 9
Rechargeable AAA batteries, depending on the type, will need a complex charger to prevent overcharging and it has to be at a certain voltage.
Those circuits are very complex, its not easy.
3 years ago
what type of capacitors did you used
4 years ago
Can I use a bipolar stepper motor instead?
5 years ago on Introduction
Great looking diy no battery light, I agree with crumpton that pvc or something would look better and be easier to carry.
5 years ago on Introduction
Great project, but for a project this nice I think you might do better to put the body in a plastic box like a tupperware, or maybe a piece of PVC pipe rather than cardboard.
5 years ago
got all the parts but don't have time
7 years ago on Step 2
Could you just use several larger caps?
Reply 7 years ago on Step 2
yep
Reply 7 years ago on Introduction
what size would you recommend if i just wanted to use about 3 caps?
7 years ago on Introduction
Maybe not the prettiest flashlight in the world.....but VERY cool!!
7 years ago on Introduction
Thank you, your 'ible and biotele's 'ible have inspired me. I am trying to make something similar using an old hand cranked torch. I used 4x 1500uf 6.3 volt. It seems very dim unless I crank it continually. biotele used a joule thief to brighten his but I was wondering does more voltage make it brighter? So you have used 10 volt capacitors if the capacitors were lower say 6.3 volt would the led be less bright. Or is your torch dim too?
7 years ago on Introduction
oh, this is a really good idea! Now to figure out, how would I do this with a battery pig of a camera.
7 years ago on Introduction
What can we do with the processors?
7 years ago on Step 9
Very nice instructable. Your idea is brilliant of using capacitors and stepper motor.Thanks.