Picture of Flashlight with no batteries

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.
Remove these adsRemove these ads by Signing Up

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.
linterna.pdf(595x841) 3 KB

Step 4: Paint the cardboard

Picture of Paint the cardboard

Paint the cardboard to make it look better and be more resistant to moisture.

Step 5: Prepare the motor connector

Picture of 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.
1-40 of 81Next »
Can I use a bipolar stepper motor instead?
michaelgc9 months ago

Great looking diy no battery light, I agree with crumpton that pvc or something would look better and be easier to carry.

macrumpton1 year ago

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.

PONG1231 year ago
got all the parts but don't have time
Could you just use several larger caps?
brunoip (author)  Adambowker982 years ago
what size would you recommend if i just wanted to use about 3 caps?
chipper353 years ago
Maybe not the prettiest flashlight in the world.....but VERY cool!!
putty1cat3 years ago
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?
putty1cat3 years ago
oh, this is a really good idea! Now to figure out, how would I do this with a battery pig of a camera.
zapper0673 years ago
What can we do with the processors?
Very nice instructable. Your idea is brilliant of using capacitors and stepper motor.Thanks.
sharktooth3 years ago
That's Excellent...

If you don't mind, I have some suggestions for you.....

You can add some more gears (you can find them in toy cars), so that,

when you complete a round of hand-crank, the motor will complete its 20 - 25 rounds...
arikyeo4 years ago
I think it would be more advisable to use just 2-3 supercaps in series... They can last for minutes. Just my 2 cents ;)
brunoip (author)  arikyeo4 years ago
that was my first idea, but they are harder to get than regular capacitors.
n410gangwar4 years ago
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.

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.
11rex114 years ago
i used some capacitors form a disposable camera the big one for the flash worked great
brunoip (author)  11rex114 years ago
Post a pic :)
11rex11 brunoip4 years ago
I made this several years ago But ill look for it i think i know where it is
does it necessary to use the same kind of stepper motor?
brunoip (author)  johnbertquirabo4 years ago
any unipolar stepper motor would be fine
zorba020084 years ago
can i use a stepper motor from dvd writer or hard drive ? but these motors i have has 12 pin output what can we do ?
awhh sorry the spaces didnt stay. You just have i diode leading into a pin and one leading outside.
where could i get the same kind of stepper motor used?
Well these types of motors are used in allot of things but probably the easiest would be a stepper motor inside a printer. You purchase larger motors but the printer stepper motors work very good.
the trick to find a good stepper motor is low rpm soo a hardrive would not work too well.... to get the most power from a stepper motor is to wire it up like this Stepper input o----||| |----o----||| |----o o----||| |----o----||| |----o o----||| |----o----||| |----o o----||| |----o----||| |----o Negative Positive this takes 2 diodes per pin, the pin is connected in the center and the diodes filter the power to give you a + and - output. The ||| represents the orientation of the diode.
brunoip (author)  zorba020084 years ago
Maybe it has two motors inside, try to get the datasheet.
Regards, Bruno
where can i get a recycled stepper motor?
does these capacitors cost much?
does it really last forever?
good day!!

how long will the light last if i will be using unrecycled capacitors?
brunoip (author)  noeroldansiabox4 years ago
the same ¬¬
good day!!

how long will thelight if i will going to use unrecycled capacitors?
matstermind4 years ago
what if you add a switch, them charge the caps for 10-30ish seconds. how long would the light last?
antling4 years ago
Nice and 2 thumbs up!
D5quar34 years ago
Just get like three super capacitors.
Just remember, they have to have low enough ESR.
Why do they need low ESR?
1-40 of 81Next »