Introduction: Windbelt From Hard Drive Voice Coil and Magnets

Picture of Windbelt From Hard Drive Voice Coil and Magnets

This is a Proof of Concept version of Shawn Frayne's Windbelt built from hard drive parts. I knocked it out in a couple of minutes because I got tired of waiting for someone else to do it ;-)

This is a quick and dirty instructable.

Step 1: You Will Need ..

A hard drive
magnet wire

Step 2: Salvage the Voice Coil and Magnets From a Hard Drive

Picture of Salvage the Voice Coil and Magnets From a Hard Drive

We'll skip the disassembly step, it's simple enough.

Step 3: Assembly and Operation

Picture of Assembly and Operation

Use a nail through the ball bearing in the voice coil to attach the coil to a piece of wood.

Mount the magnets around the coil just as they were in the HD.

Tie a long length of ribbon to the heads on the voice coil.

Solder a couple of pieces of magnet wire to the contacts of the voice coil.

Solder the other ends of the magnet wire to a LED.

To operate, hold the wind belt in front of a fan with one hand and dynamically tighten the belt with the other, to light the led takes a fairly low frequency ( And consequently high amplitude).

Future steps, frame, rectification


john2010 (author)2010-02-28

where on the voice coil do i solder the magnet wire ?

When you look closely you should see two fine wires coming from the coil to the circuit board, where they are attached to the board is where you need to solder too.

bloodyjoe (author)2009-09-30

hey are all these parts from a hard drive ?

vigtigper (author)2008-10-29

I just found this cool instruction video on how to construct the windbelt

electronic boy (author)2008-08-12

you could add a 5 volt capacitor at 1 f to store the power then you will have longer bursts of light

stonehenge360 (author)2008-06-03

In the video it looks like the ribbon is not at its most efficient length. From what I remember from Physics, there should be an optimum length for any given wind speed that creates a standing wave harmonic in the ribbon which would be the most efficient power generator. Also, theoretically there is an optimum tension the ribbon should be at.

medievalbiscuits (author)2008-05-05

What are the other two wires coming out going toward the left? (The ones that are not connected to the LED)

That's just the connection cable from the HD, I couldn't remove it without tearing up the contacts. I'd suggest you check out my more current windbelt instructable.

windbelt redux

jongscx (author)2007-11-10

What if you made added a full-wave bridge rectifier before the LED, since I'm assuming the coil creates an AC current since it oscillates.

carpespasm (author)jongscx2007-11-11

then it would probably stay lit pretty continuously I would imagine. I've got a box of old dead hard drives that are waiting to have their magnets pulled, now I have a use for the coils if i can convince them to leave the casing without the need of a pair of pliers. I'd like to set up several of these in series to see what kind of output would be practical with something like this.

guyfrom7up (author)carpespasm2007-11-11

it's a bit more complex than that, a proper power condition unit is more than just any old bridge rectfier.

static (author)guyfrom7up2008-02-10

But not that complex either. Micro power generation generally has low expectations, like charging the batteries that power the devices. Not directly power devices that would be upset by the ripple of rectified AC of a varying frequency. A battery is an effective power conditioner it's own right, nothing simpler than a battery. Perhaps a MOV to clamp down spikes.

nil0lab (author)jongscx2008-01-27

You'd obviously lose some of the voltage since you get .6V loss per std diode (.2V for germanium). You'd maybe best step-up the AC voltage with an old transformer.

At low powers like this, every loss counts

dentsinger (author)2008-02-05

This is cool. I can imagine wind flag farms might be even more efficient than turbines (without having looked it up yet.)

nil0lab (author)2008-01-27

Kudos! This is exactly what an instructable should be! What voltages did you get? Peak-to-peak or RMS? Anyone else replicate this? Can you tell us what your voltmeter said? And what hard drive you used? (make and model?) And what ribbon or string materials worked best for you?

Thank you. Honestly, I'm a dilettante, I got bored after I saw it worked. The ribbon was whatever I pulled out of the xmas supplies that vibrated best, the hard drive was either a maxtor or western digital, under 20 gig size. I was hoping to inspire some others to try this and improve upon it, there had been lots of talk but........

Exactly what I meant. Before the internet, people like us invented something and then wandered off bored and it was forgotten till someone else reinvented and published! Now we can do our little bit and spin it off for others to build on. You did say you got a voltmeter, though. Did you never measure?

Doctor What (author)2007-11-12

does it produce AC or DC power, and could i shock people with it??

AC and no, the power output is measured in milliamps.


nil0lab (author)Doctor What2008-01-27

Well, actually, the LED is a Light Emitting *Diode*. Diodes only let current through one way. I.e. what's actually going though the diode is DC, but pulsed.

Not that it matters much- to get DC from AC, all you need to do is add a bridge rectifier (four diodes). Or if you only want have the wave, use a half-wave rectifier (two diodes). See

Alternatively, if you want DC at a particular voltage (e.g. to charge a device), you can run the AC through a transformer to get a higher AC voltage. See The idea would be to let the capacitor charge up till it exceeds the charging voltage and then release it to the device to be charged (I'd use a Power FET for that since they are very efficient). Something like an arduino or freeduino would control the flyback and the charge pulses quite well, I think.

bofthem (author)2007-11-20

Would you consider submitting this to the Mashup contest?

Why not? I need another Tee ;-)

eight (author)2007-11-17

They wrote a song about this didn't they...? "Tie a Yellow ribbon round the old oak tree..." Nice POC. Thanks for the post!

HYRYSC (author)2007-11-15

I love this because it takes materials that would normally end up in a landfill somewhere and is used to produce energy. There are probably things that you learned from this and could improve on, but you did it and I applaud you for that!

shooby (author)2007-11-14

Good job, this is cool. Any plans on using many of these to, for example, charge a cell phone?

shooby (author)shooby2007-11-14

After DC conversion of course.

Tool Using Animal (author)shooby2007-11-14

The plan next is to make some measurements regarding frequency, voltage and current, then plan the best way to convert it into DC

Fortunately Harborfreight had their better multimeter on sale half price, so I picked one up tonight. Project due tomorrow, test friday and four chapters worth of HW dur next tuesday, so it won't be soon.

Also wanted to add that I did some magnetic flux modeling with vizimag software and want to try a couple of different magnet arraignments.

dglp (author)2007-11-11

I don't have any spare voice coils, nor do I have the tools and workspace to make one of these, so I'm proposing it and hoping that someone will do it and send me the video. In addition, I never heard of a windbelt til now, so maybe everyone else has already thought of this. Since the principle is based on a vibrating ribbon, it should work almost as well with a string. more specifically, a string several metres long. Several strings of differing thickness (gauge) strung between poles should make a nice self-powered electric air guitar or harp. The guitar would need a fretboard and frets, the harp could just play itself in the breeze, like an electronic windchime. The problem of frets could be solved with a slider on each string and a series of peg holes in a 'fret' board - like a cribbage board; or by putting posts in the ground at tuned intervals, exactly like frets. This would be a good one for installation on the High Plains. Miles of fence wire tuned and ready to be played by the wind and passers-by.

bofthem (author)dglp2007-11-11

Some wind harps, or aeolian harps aren't too hard to make. You could probably make one using tools you can borrow from anyone with a garage shop.

dglp (author)bofthem2007-11-11

Agreed - but the point of the windbelt is to generate electricity, so I'm thinking of ways to use that electricity. LED's are a nice idea, but using the electricity to power an electric guitar pickup (as one way of feeding the electrical output back into the device) seems like a cool thing to do. A self-powered, self-playing instrument could be entertaining.

!Andrew_Modder! (author)2007-11-10

:-\ so it just flaps?..

It generates electricity from the vibration of the tape in the wind.

oh ok :-)

i think it makes electricity or something

Kiteman (author)2007-11-11

Removed? Why?

frickelkram (author)2007-11-11

Ok ... you where faster than I .. :-) I was too busy with the Helloween contest. I have an instructable at work but I am not finished yet. My design is nearly the same than yours. I also use old hard disc drive parts. I use two of them to get more power out of the construction. The main difference is that I try to build a device that can be used. I don't want to build just the proof of concept. I know that it works. But I try to find out how effective the design is and if it is really usable. At the moment I still experiment with belts and I am working on the design of the power electronics. Powering a led is nice but I try to get a clean voltage out of the system and maybe stack some of the generators to get even more power ... I think it will still take some time until I get a working device.

guyfrom7up (author)2007-11-10

good concept, but I think you delivered it poorely. this instructable seemed rushed, I've been working with the windbelt concept for a while now, fine tuning the electronics and parts and such. Even though yours did work, it did present the windbelt to it's full potential. Couple of things that would have made it better: 1) Proper tensioning of the belt 2) Proper power conditioning unit 3) better belt material to make it more open to different angles and velocitiecs of wind my rant is over now

Kiteman (author)guyfrom7up2007-11-11

Quote from the intro: A quick and dirty Instructable.

Don't forget "Proof of concept" & "couple of minutes" ;-)

Kiteman (author)2007-11-10

... dynamically tighten the belt ...

You mean "pull", don't you?

Nice job, though. Have you contacted Shawn to let him know?

Kiteman (author)Kiteman2007-11-10

I forgot to add - why not wire up two LEDs in parallel, but with opposite polarities? The flickering AC should light them alternately.

Duh, because I didn't think about that !!! I have a fairly sensitive meter, if I can get it working, an old Avo Mk8II. to use for measurements in the future. I PM'ed Shawn just to check on the IP issues, He's cool with it.

Further thoughts - it's hard to see on the video, but I'm not sure that the voic coil is "keeping up" with the tape - sometimes the tape seems to vibrate from the voic coil pivot (good, it's moving the coil), but sometimes it seems to vibrate from the tip of the voice coil's arm (not good - that's wasted energy). It would be incredibly hard to make the ribbon harmonics match the voice-coil's harmonics, so I think it's probably best to go with Shawn's original idea of attaching the magnets to the ribbon - they're easier to fix, and their lower mass means they are more likely to "follow" the ribbon. That also means, long-term, that there would be less strain on the wires connecting the coil to the outside world.

At the lower frequencies required to demonstrate the led lighting there were "skips" in the motion of the head, but when the ribbon was tightened to get a flutter like shawn's original the head followed along fine, I just did not have a means of measuring, or indicating, energy production. It bears further exploration, I think. One reason I do think this would be superior is that it keeps the coil as close to the magnet as possible, where as moving the magnet away and toward the coil the flux drops of with the inverse cube of the distance. Proper ribbon attachment would help too ;-) When winter break comes, if my interests haven't changed.

robbtoberfest (author)2007-11-11


mrmath (author)2007-11-10

It would have been nice if you had explained what it was you're trying to build.

Kiteman (author)mrmath2007-11-10

It was a fairly prominent thread for a while.

mrmath (author)Kiteman2007-11-11

Not all of us read the boards. I, for one, would have gotten something from the link you just provided bing in the intro of the instructable.

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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