#22 gauge magnet wire

[charlie_ruizpr]

 will be building a VAWT that is 32 inches wide and 24 inches high, THE 3 blades will be 3 inches by 24 inches. The neo magnets will be 2x 1 x 1/2 on a 10 inch metal disk with 12 on each disk and nine coils in between.

How many turns would I need with a #22 gauge wire for a 12 volt application and can I use 2, 3, or 4 strands per coil?

[tecker]

  6' X 36  with four blades is Good  Four strands of 22 . 200 turns per phase . Bring out all strands and switch them in series parallel to handle the Rpm range .

[charlie_ruizpr]

  6' X 36  with four blades is Good  Four strands of 22 . 200 turns per phase . Bring out all strands and switch them in series parallel to handle the Rpm range .

200 turns per phase or per coil?

[wooferhound]

If it was me . . .
I would build the machine without the coils, then put it out in the wind and let it spin. Determine the RPMs that it spins and take note. Take the machine down and make a single Test Coil and put it where the stator is going to be. Spin it up to your noted RPM and do measurements on your test coil. If needed make another test coil and repeat your measurements. When you get a coil that performs like you want it, duplicate that coil 8 times so you end up with 9 coils to build your stator. You can be very confident that your machine will perform as planned.

Good luck with your VAWT, most of us have not had great experiences with them. Put it up real high so it can catch some wind that is not turbulent for best results. Let us know about your progress, we love to hear about new projects.

[charlie_ruizpr]

Thanks for the info.  I am just asking how many turns I would need for reference only for my test, but I will put my VAWT up soon to check rpm and then make a test coil hopefully next week or the other.  This is the type of vawt that I am making only a 3 bladed one.

[tecker]

Do a one coil test

[electrondady1]

 your milll will have a free wheeling speed of rotation in a given wind.
when you put a load on it it will slow down.
pick an rpm you want to use as a cut in speed .
build your test coil for that speed.

the little drag mills i build rotate at over 120 rpm.
at first i would turn coils so that cut in was at 60 rpm.
now i use 30 rpm.

[charlie_ruizpr]

your milll will have a free wheeling speed of rotation in a given wind.
when you put a load on it it will slow down.
pick an rpm you want to use as a cut in speed .
build your test coil for that speed.

the little drag mills i build rotate at over 120 rpm.
at first i would turn coils so that cut in was at 60 rpm.
now i use 30 rpm.

wow what type of wind turbine do you build, do you have any pics?

[charlie_ruizpr]

your milll will have a free wheeling speed of rotation in a given wind.
when you put a load on it it will slow down.
pick an rpm you want to use as a cut in speed .
build your test coil for that speed.

the little drag mills i build rotate at over 120 rpm.
at first i would turn coils so that cut in was at 60 rpm.
now i use 30 rpm.

SO the test coil should have 1.8Vac?

[wooferhound]

On a 3 phase machine you will have 3 coils per phase. After you rectify a phase you will get about 1.4 times the AC voltage of each phase. so you will want 3 to 4 volts per coil.

[electrondady1]

i'm using single phase .

[charlie_ruizpr]

On a 3 phase machine you will have 3 coils per phase. After you rectify a phase you will get about 1.4 times the AC voltage of each phase. so you will want 3 to 4 volts per coil.

Is this good for a 12Vdc application.

[wooferhound]

The neo magnets will be 2x 1 x 1/2 on a 10 inch metal disk with 12 on each disk and nine coils in between.
How many turns would I need with a #22 gauge wire for a 12 volt application and can I use 2, 3, or 4 strands per coil?

Yes that is for 12 vdc 3 Phase.

electrondaddy is confusing me with his comment above.

You say you plan on 12 sets of magnets with 9 coils in between, That is not a single phase machine so I was referring to 3 phase information. If you want to build a Single phase machine then you will need to have the same number of coils as magnets.

[electrondady1]

sorry, i didn't mean to cause any confusion.
in woofs post it implied using the freewheeling speed as a reference point in building a test coil.
i am simply suggesting that the top speed of the mill is not an ideal point for cut in.

placing 12, 1"x 2" mags on a 10" rotor is very tight spacing at the inside .
10"- 4"=6"x 3.14=18.84 -12" =6.84/12=.57" between mags. at the centre.
that will limit coil leg width ,the number of coil turns that can be placed in there before cancellation.
i think 12"dia. is the standard.

i only mentioned that i was using single phase to clarify that i would  have a different cut in speed than
Charlie

[wooferhound]

Electrondady1 is correct.
 I was talking about letting the VAWT freespin to get a reference RPM, you would want to determine for yourself what speed your mill should cut-in at and it will be well below full speed.

[Ungrounded Lightning Rod]

Electrondady1 is correct.
 I was talking about letting the VAWT freespin to get a reference RPM, you would want to determine for yourself what speed your mill should cut-in at and it will be well below full speed.

A rule of thumb often quoted here is to expect the optimally loaded RPM on a fixed-pitch HAWT to be roughly half the freewheeling RPM.

No idea if this is right but seems to me it's a good starting point.

[charlie_ruizpr]

sorry, i didn't mean to cause any confusion.
in woofs post it implied using the freewheeling speed as a reference point in building a test coil.
i am simply suggesting that the top speed of the mill is not an ideal point for cut in.

placing 12, 1"x 2" mags on a 10" rotor is very tight spacing at the inside .
10"- 4"=6"x 3.14=18.84 -12" =6.84/12=.57" between mags. at the centre.
that will limit coil leg width ,the number of coil turns that can be placed in there before cancellation.
i think 12"dia. is the standard.

i only mentioned that i was using single phase to clarify that i would  have a different cut in speed than
Charlie

I do not that I will be using those size magnets1" X 1/2" round magnets with round coils of course

[electrondady1]

windstuff ed posted a theory on the old board that 60% of wind speed was the idea loadedl speed for vertical mills
if i recall correctly he was referring to both drag and lift mills but i could be wrong about that .

[charlie_ruizpr]

After I experiment with this, I will be building a horizontal axis wind turbine may 5' or 10' it depends on the 15' or so tower I will make first.  If the stator that I am making for the vawt does not work well (wich I think it won't) I will use it on the hawt.


Still getting the pieces together for the vawt, trying to build it before saturday, so that my brother and I can test it w/o a load first

[Ungrounded Lightning Rod]

windstuff ed posted a theory on the old board that 60% of wind speed was the idea loadedl speed for vertical mills
if i recall correctly he was referring to both drag and lift mills but i could be wrong about that .

I understand Savonius style mills peak at a TSR of about 0.8, i.e. 80% of wind speed.

http://dspace.library.iitb.ac.in/jspui/bitstream/10054/1598/1/5683.pdf is a paper giving research results on a number of Savonius-style rotors, including Benesh variants, and how it varies with adjustments of rotor geometry.  Looks like they found the power peak around 0.8 for most of 'em, down as low as 0.7 in some cases.  The TORQUE peak seems to be about 0.6 - but it's the power peak that matters.  (It happens higher because, in the 0.6 to 0.8 range, raising the RPM gives you more of a HP gain from the faster spinning than you lose from the lower torque.)

[electrondady1]

link saved to favourites, thanks u.l.r.

80% is better.

[charlie_ruizpr]

Well it's up but I need to change the bearings and give the blades a 9 degree angle to see if I can get more rpm. When the wind blows it tends to try to turn backwards and also with gust winds it does not turn anymore, I beleive it is do to the bearing being that they are old and were submerged in water. Also the turbine does not try to turn backwards it trys to turn at low wind speed and sort of returns slightly but turns backwards like 2 or 3 degrees. I turned it by hand this morning and then it started turning a couple of minutes later but slowly.



http://s237.photobucket.com/albums/ff290/3gd16/Charlies%20wind%20turbine/?action=view&current=MyVAWTsfirstrun922101.mp4

[electrondady1]

congratulations.
it looks nice , hope you can tune it up to get it to work for you.

[charlie_ruizpr]

thanks