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

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

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

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

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

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

Comments

[iskazorilla]

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]

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]

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

[steveastrouk]

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

Steve

[ilpug]

Hmm...

[robotkid249]

Nice job.

[john2010]

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]

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.
-flashj

[Kiteman]

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

[Tool Using Animal]

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.....

[Kiteman]

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.

[Tool Using Animal]

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....

[Kiteman]

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

[duk30ne]

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]

I did also moving magnet windbelt :http://www.youtube.com/watch?v=8ulPtmmVelI
Hard disk coil i tried have less voltage output

[FeedTheGrid]

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

[DeanC993]

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]

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

[lr10cent]

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]

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