Introduction: Windbelt Redux 21st Century Micro Power Generation

Picture of Windbelt Redux  21st Century Micro Power Generation
This is my second iteration of Shawn Frayne's Windbelt generator, my first can be found here. This version is designed to utilise cross ventilation in a house. A Windbelt is an oscillatory wind generator working on the principal of aeroelastic flutter.

Here's a link if you're not familiar with Shawn Frayne's

Watch out VIDEO!!!! There's a better looking video available on Revver, but here's the youtube. I'll state that the frequency is much higher than it appears in the video, it must be a consequence of the frame rate.

Step 1: The Frame

Picture of The Frame

I started by measuring the widest window in my house, then I cut a board 52 inches long to fit and ripped it down to six inches wide. Then measuring in 4 inches from each end I drilled a 2 1/4 inch hole at either end and cut out the middle between them.

Step 2: Mount the Voice Coil and Magnets

Picture of Mount the Voice Coil and Magnets

This is pretty easy, pick an arbitrary spot on the center line at one end and use a nail through the bearing to mount the Hard Drive voice coil, a nut was threaded up the nail to hold the coil in place, the magnets are secured around the coil with wood screws.

Step 3: We Need a Way to Attach the Belt

Picture of We Need a Way to Attach the Belt

I reshaped the heads on the voice coil by filing down and gluing on a couple of pieces of wood and then a half of a razor blade to give an attachment point for the belt, not elegant but it works for now.

Step 4: At the Other End

Picture of At the Other End

we make a bridge for the belt to go over and mount it to the frame. tensioning is accomplished by means of a tuning peg. The tuning peg is a pencil crammed into a hole ;-).

Step 5: The Belt

Picture of The Belt

I grabbed the first thing available, a video tape. The belt is attached to the head with scotch tape, and at the other end to the "tuning peg" by scotch tape.

Step 6: Stick It in Your...

window and open a window on the opposite side of the house, the video shows it in operation, careful tuning of the belt tension causes the the voice coil to resonate, that's a good thing. Measured power output is 1.5 Volts AC with a short circuit current of 20 ma. The leads from the coil are attached to two LEDs wired in parallel with reverse polarities as suggested by Kiteman.

Suggested areas for exploration, personal and general.

I didn't rebalance the voice coil, I'd also like to try paring one down to reduce it's mass.

Hand wind (or stack multiples of) the coil to increase voltage output.

Try various belt materials.

Acquire some schottky diodes and make a voltage multiplying rectifier.

perhaps follow that with a blocking oscillator for battery charging.

Just thoughts.

And finally a Thank You to Alan Parekh for the LED's


iskazorilla (author)2017-11-30

Hi Sir! Where can I found the full list of materials used and where to purchase it? I'm having a hard time finding the materials because of the availability here in our country. Thanks so much!

MBAustin (author)2010-02-20

I took apart a hard drive to get a voice coil, but it is much smaller than the one in this video. Will it still work?

chip207 (author)MBAustin2014-08-14

hey dude do i have to add tha voltage multiplyer circuit to get a out put voltage thanks

steveastrouk (author)2011-01-24

What about feeding the twist of the blade into the voice coil axially ?


ilpug (author)steveastrouk2013-04-02


robotkid249 (author)2010-07-16

Nice job.

john2010 (author)2010-02-28

when i solder the magnet wire to the circuit board, where do i solder the wires? and which wire foes onto which side of the led connection?? please helppp thanks

flashj (author)2009-12-15

I took apart a Iomega zip drive recently and it had all sorts of interesting parts that could be used in this project, including two coils and several spring loaded arms. The plastic case makes it easier to work with for me and I don't feel as bad for taking apart a hard drive. All I was after was the quiet motor. :)

Will post a pic if anyone's interested.

Kiteman (author)2009-12-06

Did you ever get as far as generating useful power with this, maybe charging a battery?

Honestly i've had no time for any project over the last 8 months, but I've been thinking of revisiting this project recently using the voice coil from a laptop HD, hoping it would have lower inertia.  Need low voltage drop diodes as well.....

I had an idea for a vaguely-useful application;
Build the coil, magnets and LEDs (and maybe a charge-store, like a battery or supercapacitor) into a single unit that pegs to the ground, and the ribbon gets strung up to the guy-points of a tent.
The ribbon flutters away through the night, illuminating the LEDs and stopping people tripping over your guy ropes.

Ideal for festivals, I thought.

That' pretty cool, a quick google shows solarbotics sells some nice low voltage drop diodes  (.22 V @ 20ma).    Hmm, winter break is just around the corner....

Can't have you sitting around and twiddling your thumbs, now can we?

duk30ne (author)2009-11-16

What an amazing concept!.. Maybe it could be also used in cars, in front where the radiator is, while the car is moving it could generate power to light all the little lights or even battery charger..

alessiof76 (author)2009-05-13

I did also moving magnet windbelt :
Hard disk coil i tried have less voltage output

FeedTheGrid (author)2009-04-14

Very cool. Aeroelastic flutter is new to me. I like it!

DeanC993 (author)2009-02-17

Hi that is so cool very nice way of wind power! i am wondering if you could put the wind belt horziontal? ***** Great Job!!

Betonov (author)DeanC9932009-03-19

I believe you could. It shouldnt make a noticable difference in power output

lr10cent (author)2009-03-05

On some other Windbelt thread, they were talking about how to use this. If there's an easy way to increase the voltage, one thing that comes to mind is charging batteries to run your doorbell. I read recently that doorbell transformers use 3 watts. That's 26kw hours per year. So maybe a couple of bucks year. If you could build one for $5 it would pay off (although not for your time). I don't know how much juice thermostats use, but that might be a good use too, for the same reason, since I bet they use a transformer as well. The tricky part is where can you get a really cheap small, 24V battery bank. Another, outdoor use for a scaled up device might be to charge batteries for a fence charger. Convenient because you've already got a frame to mount it on, and I'm sure that fence chargers are often found well away from the grid. I'm wondering if there isn't some coil that has a lot more turns on it that could be used to get a higher voltage in the first place. Alternatively, if your coil or magnet was really light you could mount it on a longer arm. (Opposite side of pivot from the ribbon.) And maybe there's a way to use the brushless motors from the computer for the same thing, although the radius may be too small. I suspect the usual voice coil mechanics are heavier than they have to be, although I haven't looked at any for a while, so perhaps a bit of judicious grinding might help?

lr10cent (author)lr10cent2009-03-05

Oh, more stuff I thought of: -You could maybe build something light and floppy like a tuna tail to run this. If you got the oscillation right I'll bet it would put out a lot more power. Or a cantilevered airplane wing shaped gadget, which maybe could stick up a long ways. You'd just have to tune the flutter right. Details left to the reader. :-p

Dr.Bill (author)2009-02-28

Looks like it might even have its own frequency too. Ya know like 60 cycle current has.

Dr.Bill (author)2009-02-28

Pretty Cool Stuff. I've Never seen that Before.

mcnnowak (author)2009-01-21

Oh wow.. Before i started the video it looked like it was powering a laser pointer pointing straight down. >.< Nice

fabrivassa (author)mcnnowak2009-02-17

yeah, I thought it was cutting something out from a paper sheet with a laser

roo2 (author)2008-04-18

Great Instructable! I was wanting to build the Frayne-style windbelt, but I'm glad I found this one. Much easier, and the results were better than I expected. I made one for class and was able to get a pretty consistent 1.5-2.0 volts (peak of 2.9) in pretty good Oklahoma wind (sustained 20mph gusts to 35). I also soldered up a full wave rectifier and ran it to a 1000uf 3.5v capacitor and was able to charge it to 3.44 volts in about 50 seconds. Awesome! Some observations while creating my windbelt: 1. Not all HDDs are the same, some have bigger magnets or better wiring. If i remember correctly, I think Western Digital had the best combination of thick magnets, protective plating for the wire, and easy-to-solder leads. 2. To prevent rubbing, I found it was easier to align the actuator arm and magnets if I just cut the HDD frame around the magnet and bearing screw hole locations. Then I simply zip-tied the whole assembly to the wood frame. 3. To increase the amplitude (swing arc) of the coil side, I cut the reader arms to about a 1/4" long and attached the tape there. 4. Because of the size limit (2ft.) for this project, I found that a loose tuning worked best. 5. Whatever tuning created the longest swing arc seemed to be the best solution, but with the VCR tape this created a lot of noise. I stumbled upon some 1" wide nylon-reinforced packing tape and I think the combination of the weight and thickness kept the noise down without slowing the fluttering action too much. 6. The looser tuning (and therefore lower switching rate) also worked better with my plain-jane silicon diodes, as Schottky diodes -while better- seemed hard to come by. In summary, this was my first time building an instructable (and soldering for that matter), and it came out great! Thanks TUA!

Tool Using Animal (author)roo22008-04-18

Thank you roo2, that's the nicest compliment, and I l like your mods.

second, thanks for that

zeroKelvin71493 (author)2008-12-29


Rossiroller (author)2008-09-14

Is there any way you could make a couple and use them to power a fan that blows through them? This probably violates the laws of something, but useful idea.

It does violate the laws of thermodynamics.

It breaks the law of Conservation. But who says we can rewrite the laws of physics.

Rossiroller (author)Rossiroller2008-09-16

that could work then you could make a self sustaining fan.

wiley coyote (author)2008-10-01

Excellent work. Living in a high rise I should be able to get good results on my balcony. This technology, from "junk", has incredible potential in my humble opinion. I can see clothes lines generating power while drying your clothes or certain types of trees becoming power plants on a blustery day. The possibilities are endless. Any repetitive tugging action could be utilized and you are not restricted to wind only or any particular set up. I love it!!!

Please ignore some of the previous comment. It is still very exciting, but I see now that the tuning is somewhat critical, limiting or at least changing the possibilities.

tjandrata (author)2008-09-17

Where i have to conect a wire to the voice coil? do you have a close-up pic...

FullyInvolvedScientist (author)2008-05-29

This is a great instructable! Is there a way to figure how many amps can be produced with this setup? Great job again!

No_Where_Fast (author)2008-04-24

Really Really cool.

basheer (author)2008-04-12

i still cant understand how the electricity is produced can any1 help.can i have the do it yourself step to build one as i am an electronic enthusiast.thanks this project appears to be worth built

In general, or in this specific case? If you move a wire through a magnetic field a current is produced (of course the motion is relative so the case can be reversed). The HD magnet has one north face and one south face on each side half the coil is over the north, half over the south, when the coil moves a current is induced in either side of the coil, viola, electricity. Since it's oscillating back and forth AC current is the output.

hickler (author)2008-03-10

I was just wondering how you connect the wires to the voice coil. Thanks

There are two very small solder joints on the mini circuit board attached to the voice coil, I carefully used them.

JOEDUPONT (author)2008-02-23

Very, very nice. perhaps putting such a thing across the roof of your house might be nice. try getting energy from a flapping flag.. they are not illegal yet! thanks for sharing with us.. good for you! joe

Badluckguy (author)2008-02-15

Have you thought much about making an automatic "tuner" for this? I'm thinking a balanced bar on a pivot, each end of the bar being a weight. The weight facing the window could be made into a shape (scoop or sail maybe?) that would catch the wind. Coming off the side of the pivot bar at a 90deg angle could be another bar with a gear on it. Add a gear to the pencil "tuner" you already have here, and you could maybe get the balanced bar system to cause the belt to tighten or loosen as the wind speed increases/decreases. If you could gear it right you might be able to get the belt tuned to the correct frequency for a given wind speed, and so wouldn't have to adjust it manually.

messyworkbench (author)2008-02-12

Made one in a few hours and managed 0.9 volts. I used a much shorter length of tape and my assembly alignment left much to be desired so I am sure that I could get more. I have a picture showing 0.6volts on my multimeter. I tried a Compaq coil as they are huge and the tape was not able to move it. It could be my lack of assembly skill or it just may be that there is a critical mass where the tape cannot move the coil. Lots of things to check out.

alcurb (author)2008-02-11

Brilliant idea (no pun intended). I hope you win the LED contest. Is this invention applied in large scale somewhere else? I think that in the eve of a huge energy crisis, any idea that leads to the development of a device to create usable energy rather than to waste it is extremely valuable. Cheers!

insomartin (author)2008-02-08

i heard a noise... the flutter noise. is there a way to silence it?

liam2317 (author)insomartin2008-02-10

If you read the thread here the guy that actually came up with the idea - Shawn Frayne has left a post talking about it, one of the things he points out is;

"-After experimenting with several generations of the small, 45.5 cm long windbelts, I've figured out how to reliably make them run quietly. Really quiet, like a leaf in the breeze quiet. So it's possible on those scale for sure....on the larger scales, well, let's say that's a work in progress."

Sounds promising...

insomartin (author)liam23172008-02-11

thanks, done that, it works great now. XD i learned that accidentally while creating the wind chime, the longer i create the belts the quieter it is. thanks alot.

srilyk (author)insomartin2008-02-08

I doubt you're going to be able to silence it... at least completely. As far as I can tell - this is generated by the "wobbling" of the band. But then again, most generators have excess energy given off as noise... Hmmmm I wonder how much noise you would have to get to build up a significant charge in say, a condenser type mic :P

insomartin (author)srilyk2008-02-08

callmeshane was also right! it is the resonance that makes the belt flutter. (see resonance) i hate wind chimes... maybe i could tune the flutter to make a led wind flutter thingamajig. i we have a big open space and it's windy here at manila at night. hope this would work. another thing... could this charge a 1farad supercap? thanks!

About This Instructable




Bio: Working my dream job in the Telecom industry, so chances are, i'll never have time to respond to comments or messages, nothing personal.
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