Diy VAWT Alternator

[DFIII]

I am in the process of building an alternator for a 6' by 2' helix vawt.

It has 28 neo's and 21 coils.  I am trying to figure out what to use for the coils.  On hand I mostly have 22 awg some 20awg and some 16 awg (not much)

I am planning on 3 phase with 7 coils per phase.  I am wondering if any one could help me with the wire size and number of coils.  I am a disabled person who can't work and can't get ssi so I am Broke and have a passion for recycling.  So buying the wire is not much of an option but know where I can get more wire (from scrap)

[Stonebrain]

Difficult to say.

It depends on the tsr/rpm of your vawt.

To find out what you need,you must determinate the rpm to windspeed relationship under load.

The problem is that without a alt you don't have a load,so you have to estimate it.

You can estimate it very roughly by determining the rpm to windspeed without load('freewheeling')and multiply the rpm's by an estimated value(maybe 2/3 or 3/4 ??)

If you know at what windspeed you want reach cut-in(that's when it starts charging the battery,basicly 12v)now you know at what rpm you want 12v.

Then with a testcoil,taking in account the numbers of coils,how they are connected(typicily series/star),and the diode drop, you can find out the number off turns you need.Then you look what wire that you have that fits that number of turns.

Don't know if I'm very clear,

so don't hesitate to ask more.

cheers,

stonebrain

[tecker]

First you have to determine your power zone . That zone is from the highest rpm to the to the lowest rpm with torque . From this point you determine the cut in that will decrease the rpm to what will be the stall point . You have some options with the stator that has been miscalculated (adding resistance or pwm adjustments and some mechanical design etc)  .Use a torque wrench and a slip ring ( I use Two teflon washers and a bolt washer set)  match the slip ring to a drill motor and get a ball park figure to test the getset with. Form there you assume  the cut will be 40% higher to be in the power range of a useable design. You may have to lean on a resistance or a pwm but you can get your winding in there .I use Quad fillar windings and bring out all windings to a box at the stator to match with you can't really charge with anything less that awg 22 that gives 4 to 7 amps   (machine winding )for 100 feet of wire and good bending radius.

[TomW]

Lots of folks pull degaussing coils out of dead boob tubes [TV]. Problem then is here at least you gotta pay to get rid of the CRT in the TV.

Note. LCD and other non CRT type TVs do not have them.

Just an idea thats been used here before.

Tom

[electrondady1]

got a photo of your rotor?

is it a single rotor radial?

 if you have access to electronic scrap.

consider rectifying each coil separately.

consider using multi conductor coils .

 

[DFIII]

Thanks to all of you for your help.  I have started taking pictures but so far only have a picture of the 16" car rim and my paper patterns for placing the mags and coils.  Waiting for my stator material (2 layers of 3/4 inch plywood).  I just started this whole message board thing so I have alittle bit of a learning to be able to upload what I have.

I'm really not sure if I mentioned that I am building a helix Vawt either 2 blade but am leaning towards 3.  I will have a 2' sweep and 6' tall.  Thinner and taller for more RPMs.  Not sure my RPMs yet because I only have builot a miney version for an I dea on how to put it together and I am Waiting for cad drawings that my neighbor is drawing up for me.

[DFIII]

http://www.otherpower.com/images/scimages/12958/

Here are the pics I have so far.

The magnets are ones that I scraped from really old hard drives (the really big ones)

Not sure of their strength but can tell you that they exploded my thumb a while back when 6 on one side and 4 on the other made a sandwhich with my thumb.  I don't have pics of that and I doubt that many would have liked to see it. (my thumb is fine now after a trip to the dr.

[hiker]

is it going to be like a brake drum alt??

plywood cutout slots for coils-no metal backing??

 where did you find the hds at? nice mags..

yeah..thumbs are always a target.....hope it heals up fine..

[willib]

Hi DFIII,

Some nice #17 wire can be found at your local alternator shop , the guy i know has solonoids that he regulary throws out in the trash.

i've gotten real good at dissembling them with a dremmel and cutting wheel attachment.

its not easy but after all the wire is FREE.

The larger ones have even thicker wire in them..

hope this helps

Bill

[wooferhound]

Could you make your pictures at a resolution of 640 x 480 before you upload them? Those Pictures don't even fit on my 20 inch monitor. It makes things faster for our Remote users that are connecting to the internet on Dial-Up or slower, plus it saves harddrive space on the server that is provided free by our hosts.

[DFIII]

I apologize for the big pics.  I will convert them from now on

[DFIII]

I believe I asked the wrong question about the coils.

What I am looking for is a place to start.  I am really building the alternator and then build a vawt to spin it.  I'm immagining that with this many magnets it's going to take a decent size vawt but this is my first and only know what I have gathered.  I'm a hands on person and learn more from getting my hands dirty.

[DFIII]

I was also wondering if I can wind 2 or 3 in hand of a smaller size wire to increase current.  I've seen some alternators coils wound two in hand to make it easier to wind than the lower gauge equivalent, but not with higher gauge wire for those of us that have a bunch of say... 22 awg.

[Ungrounded Lightning Rod]

You're building a Savonius or a Lenz rather than one of the Darrius types, right?

A Savonius has a power curve with a peak near a TSR of 0.8 (and I'd presume it's similar for a Lenz.)  A regular darrieus has a broad peak near TSR of 6.  Not sure about a cyclogyro type but it should be in that ballpark.

From the TSR under load and the circumference you can figure out RPM vs. wind speed.

[electrondady1]

winding two or three in hand is not a problem with finer wire .

in fact the coils seem denser.

when you have your mag rotor wheel on a bearing and can spin it

do a test coil and let us know the  results.

the rpm range is important to the coil turn count.

 will your mill be a lift based design or drag ?

[DFIII]

I have added a stsotr mount out of 2 disks of 3'4" bc plywood (sanded).  I just need to figue out a starting point for my coils.  I wound a coil last night of 16awg with 30 turns and I'm going to run some test.  atleast try cause I found that after cleaning a salvage wheel bearing that it will not do.  it has pits on the bearing surface and it wobbles.  I have a couple more but will have to take a trip to my storage unit.  I'm thinking of using one of my tread mill motors for testing.  With the controls from the treadmill i should be able to controll the rpms some what acuratly.  I will post new pics as they come and test results.  

Oh yeah about the laminates.  If I decide to use them, would it be ok if they are not connected together (like a stator on a motor) and just inside each indavidual coil.  I'm using laminates from scraped T-formers.

[DFIII]

That is 3/4" plywood

[DFIII]

My vawt will be drag based I think.  It's a helictical and I might add a outer cage in the future to decrease drag on the backside of the blades.

I got the HD's from a house that I cleaned out for a woman that Hired me.  Her ex husband was a computer tech and had left behind alot of equipment. I also have 18 wedge type mags that are not ass strong but I stacked them 3 high and used a laminted back.  This mill took some damage in a wind storm and was dimantled to provide materials for my current project.  Still have the rotors and am planing on making a dual rotor axial.

My car rim alt will be air coil for now.  Not sure where I will find laminates that are atleast 12" dia.  I have chosen to change my stator design a bit and go with the coil setup from the brakedrum stator.  Three coils sets which is going to increase my coil count to 42.  That is alot of coils but I am looking for a very low cut in speed if possible.  I want it to produce at least a little charge current a really low wind speeds.

My thumb is fine but I know have one nail growing under the other.  I can not be removed (well it can but will grow back)

[DFIII]

I have added more pics at a smaller size.  and will update ass I move forward.

Can I increase the number of phases since the stator will be a work in progress as materials present themselves.  IE.  say instead of 14 coils / phase making three phases, use 7 coils at 6 phase