Microwind Generator - any one up for the job?

That is a very nice idea, I will give it a go sometimes soon!

BTW I made one and it works very very well.

I put one together, using gorilla tape.  see full details here:

http://buildingstuffinthebasement.blogspot.com/2009/11/diy-windbelt-with-wood-and-duct-tape.html

nothing like the nail-breaking power of mylar, but this seems to work well enough to light up led's in ~ 7mph wind

This is one of those seemingly simple projects which has HUGE devils in the details. For me and my daughter as we do (try to do) this for her science fair, the killer part is the belt and its movement. Pretty much like S Frayne suggests in his post here. Right now, from my frustrated Dad point of view, if I can't get this working in a fairly controlled environment with a steady wind source from a known direction, I really can't see how this could ever be made robustly enough to handle the myriad of environmental conditions that a commercial unit, deployed in Haiti, would encounter. We can get some movement of the belt, but still not (apparently) quite right, as there is a bit of sideways motion in addition to the vertical movement of our magnet as it rides up and down on the belt itself. All the basics are unknowns or at least "unproved" - 1. how long to make the belt, 2. how wide to make the belt, 3. the tension on the belt, 4. one magnet or two (both riding the magnet, one above and one below the belt), this does change how the belt moves of course..... 5. distance of fan from belt 6. angle of moving air onto the belt 7. does a craft store magnet lack the strength of a rare earth magnet and so is wrecking our project because it lacks the required strength? 8. how close do the coils need to be from the magnet? 9. If I attach the coil to the bracket with plastic and a cable tie does that somehow detract from the generation? I don't think so, but I've never worked with such tiny amounts of juice before either. However, each one of these does provide a teachable moment so all is not lost. But my kid is still pissed that the project I convinced her to do is not yet working :( Notice how I really haven't even mentioned the electronics part? Solely because the belt apparatus is so touchy and sensitive. I love the idea. I love what he has done with a so-called educational policy. To my chagrin though, even acknowledging the elementary level I am at, I find this device is just too sensitive to too many parameters to ever be able to handle a real world setting. Frustrated but still intrigued by it - Jeff

hello all, i noticed this thread has been dead for quite awhile and I was wondering about, Steve how the project has been coming? In-peticular I was wondering if you could provide me with the electrical frequency of the output of the 45.5cm wind belt, as I am attempting to test one of my own however I could not find any specific specs on your website. I wish to work backwards mathematically to find the frequency at which the band must oscillate to produce the same results as you.... Is this indeed practical? Or would it be more beneficial to just begin from scratch?

What a brilliant idea!

I'm not sure it's a solution to many actual problems (as one comment said, a hand-generator will provide much more power, much more quickly), but I would like to see this as a fence or screen - say, strung between the railings around a balcony or roof-garden and running a small sonne et lumiere installation, maybe with the music changing with the wind-speed.

yeah, you have to get the perfect angle of wind and just the right tensions. If you add a fin though it would add to the cost because then you need ball bearings

gyromild says: "Just curious, is there any particular reason that the coils are placed on only one end of the belt instead of both?" I'd also like to know the answer to this but I can't find it above. sfrayne??

. Does anyone know where I can find info on local wind speeds? Something similar to an insolation chart, but for wind. I'd like to know how often the wind is >5MPH around here.

I read where someone wanted the url for Mylar Taffeta. Here it is:http://ecom.citystar.com/hang-em-high/ushop/index.cgi?ID=FZPHD4&task=show&cat=FABRIC&pgidx=23
I think you better cut and paste this for it to work.
I've been reading, and studying this issue since I found about it, so please let me know what you learn. I am completely ignorant about how to determine values for any of the generating or transfer equipment.
I feel kind of lost because I can build just about anything with plans, but this 'flutter wind' generator is busting my b***.
If you find out anything, anything at all, please let me know.
I could wait until it's posted at Shawn's site, but I really don't want to.
They only want $.50 and $.65 for a 1 yard roll of 2.5 or 3".

Ok......had to join just for this....not the sharpest guy in the drawer, but FAR from the dullest....very bad on typos...for those who have a problem with it, look like you'll miss out on lots of good stuf!<<

(removed by author or community request)

hey, I'm the windbelt guy, Shawn, and I have to say, I'm sort of honored that this thread has started on Instructables. I don't want to contaminate your re-creation efforts with the specifics of what I did for those prototypes in the PM video, but I did want to point out a few hints: -The Windbelt, even the crude protos in the videos, can take airflow from a variety of attack angles and still pump out juice. Something like 60 degrees of variability works out surprisingly well (of course, power drops with the reduction in exposed cross-section of the vibrating belt). Also, unlike with most turbines, the Windbelt can take airflows that are either turbulent (e.g., from a ventilation fan, or around buildings) or laminar. -While on the topic of turbines, a nuance that I'm getting some heat for: In the PopMech article, I say that the Windbelt technology is 10X more efficient than micro-turbines. Micro! Not big turbines. You can crunch the numbers -- the most well-known micro-turbine work was published in Nature a few years ago...just do a search for 'wind-powered WiFi' and you'll find it. Also, you can find the refs on the "Windbelt" section of the Humdinger Wind website. So, that's the benchmark that we'd compared ourselves to there, just for clarification... -The windbelt embodiment in those videos can take airflows of between 4-14 mph without any adjustment, and the power output increases accordingly (not quite to the cube of the windspeed, but close). Above 14 mph, the reported-on protos sort of hiccup, and maintain a constant power output. Which is totally not good enough for a real, rural lighting app. So, I am working on expanding this "bandwidth" to about 4-24mph for larger belts, without resorting to a dynamic tensioning system (which of course is festering in my mind too, for really large installations) -You can use a whole lot of different materials for the belt and get some output, but it's easy to get a few orders of magnitude less output than you can with better materials -- I've used Mylar-coated tafetta, after trying a few dozen other materials, and that works pretty well -- super thin polyester tape (used to repair film reels) works OK, but is loud (but is available from McMaster, so a plus) -- also, the dimensioning of the belt and its balancing is key. Super key. But I'll be curious to hear about what you all discover... -The protos shown in the video run at around 90-100hz in 10mph wind. The AC output before conditioning is pretty much a perfect sine wave, as you might expect. -You have to balance your system so that the magnets oscillate up-and-down, without much torsion. The magnets should feel like they will break your fingernail when they're moving (um, slight exaggeration, but when you get it, you'll know what I mean). This is a much, much more substantial mode than a simple torsional mode. This is the wizard behind the curtain. -That coil setup shown is not the most efficient, at all. But it works at low windspeeds. Other configurations are much more efficient at higher speeds. -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. I'm super excited to see if some folks in the Instructables community can recreate my results (or better) without any more clues than that. I'm treating this like an experiment for how ideas spread, but if that annoys you, of course shoot me an email and I will give you more details if I can. I will say that I am preparing a formal tech brief/Instructable, for a slightly larger Windbelt -- I'm working to make it failure-proof in random reproduction, which the current design certainly is not, so I'm telling folks I'll have it posted on my website and/or here by mid-January. Thanks again for the interest, really -- and like I said, feel free to email me with questions -- I am under a flood of emails now, but I'll get to them all. Email's on my site. -Shawn

I am trying to build the wind belt device for a project at school but i have a few issues i cant get over before i start. I am trying to maximize the induced current in the coil. Hopefully doing so will give me a guideline as to the tension, width, amplitude, and desired frequency. Though i realize that the device may have to work at different wind speeds. Given that the coil is fixed and its area is constant the change in magnetic flux is proportional to the change in magnetic field. eg. Mag flux Phi=BAcos(theta), Emf (V)= -N(the number of coils in the solenoid) x d(phi)/dt. If i am trying to maximize power P=I^{2R, since power is related to the current, and Emf is related to the current as well b/c Emf is voltage, V=IR. SO maximizing the current and/or voltage should get me the most power output i.e. My ultimate goal. I know my magnets strength is about 7 micro Teslas. If i can figure out a way to maximize the change is magnetic field i.e. the second derivative of magnetic flux (i am assuming in this case that the second derivative of the magnetic field [interjection= i dont know if that's possible?] is porportional to the change in Emf and/or the second derivative of the magnetic flux.) Then i can find a maximum change in magnetic field, which hopefully will allow to me to relate magnetic field to the Amplitude, frequency, and period needed to create such a change in magnetic field.}

I dont know if this is possible to do mathematically. And i have one major question which is if I passed the magnet through the coil with a cycle period of lets say .001 seconds, supposing the magnetic field still passes through all the wire loops of the solenoid would that guarantee me a greater Emf produced (which in turn i think would mean greater power produced) than a magnet of the same field strength with a cycle period of .01 seconds.

Basically, in order to produce the most power am I just trying to make this thing vibrate as fast as possible. And if so does anyone know of some way to relate all the variables b/c at the moment im strugglin to do so.

Thanks

Bump!

Tool Using Animal is at it again.

Also I can't seem to find any sources for Mylar coated Taffeta.
Any help would be appreciated

So I am actually making a windbelt for a research project. I am changing the width of the belt and the tension. However, I need to make a contraption that is set up on one end of the frame that helps me change the tension of the belt. I am thinking of using a screw and wrapping the taffeta around the screw. Then having some type of "U" shaped mechanism attached to the screw. The "U" Shaped device would have a knob of some sort that you could turn to adjust the tension. I don't know if this makes sense. But I need help finding materials or idea. Oh and I am attaching a torq wrench to the end of the screw, so I can tell how much tension there is on the belt.

I built one and it works ... a little box made of 1x4's 24 inches on a side then cut 2 cm deep notches every 2 cms on two of the sides to slide the mylar strips through(varying sizes) I made some little wooden wedges to lock the mylar and coils in place .... I am using two niobium 8mm x 3mm disk magnets one on each side of the mylar with just one coil at the moment .... if I can find my usb card reader I'll put pics and video up .. I went by radio shack yesterday and bought a bridge rectifier .. see if i can trickle charge a battery --- anyhow back to coding

I think it might be fake, or I'm doing somthing wrong. I just tested it and while the ribbon does move up and down with a rare earth magnet on it it will not produce that much electricity. Using my volt meter I recified it and found that only about .005 volts were flowing. Do I have to make a bigger coil? even with a small coil there should be some electricity.

Much like playing with ribbons, they whizz only in certain angle of attack, at a certain speed. Ribbon length, width, and thickness, also come into play for it to vibrate at maximum amplitude. IMHO it is an amazing idea, but it would still require a lot of tweaking to adapt to unpredictable wind condition and direction when placed outdoor. For one it certainly need to be attached to a fin, to get that perfect angle everytime the wind changes direction.

there is a windbelt group, please direct all of forums into their.

Something bothers me about this...I can't put my finger on it just yet.....but something seems....wrong, once it is done on a grander scale....*sigh*

In the words of the Guiness guys; Brilliant! I would say this is one of the best things I have ever seen! And it is small too. I am going to try and make one of these.

sure i'm making one right now, but what is this "microwind" you speak of?

What a simple, elegant concept. You should make one!

Favorite quote from the comments:
He's essentially taken an established string instrument and gone from acoustic to electric.

Sounds awesome to me!

Either placed where there was constant wind, or used to charge batteries, this would be idea for "places that do not use tremendously large amounts of current". It seems well suited for the purpose it was originally made for, in underdeveloped countries.

I just did a test using packaging ribbon (for like birthdays) holding it with my hand and it started to sound like an engine! Only two bad things that I can point out: The magnet weighs it down, reducing the frequncy (I have lighter ones coming in the mail, so that's fixable) And the wind has to be htting it just att the right angle, but it still kinda works.