Language: 
To browser these website, it's necessary to store cookies on your computer.
The cookies contain no personal information, they are required for program control.
  the storage of cookies while browsing this website, on Login and Register.

GDPR and DSGVO law

Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding.
Amazon Warehouse Deals ! Now even more Deep Discounts ! Check out these great prices on slightly used or just opened once only items.I always buy my gadgets via these great Warehouse deals ! Highly recommended ! Many thanks for supporting OverUnity.com this way.

User Menu

A-Ads

Powerbox

Smartbox

3D Solar

3D Solar Panels

DC2DC converter

Micro JouleThief

FireMatch

FireMatch

CCKnife

CCKnife

CCTool

CCTool

Magpi Magazine

Magpi Magazine Free Rasberry Pi Magazine

Battery Recondition

Battery Recondition

Arduino

Ultracaps

YT Subscribe

Gravity Machines

Tesla-Ebook

Magnet Secrets

Lindemann Video

Navigation

Products

Products

WaterMotor kit

Statistics


  • *Total Posts: 514018
  • *Total Topics: 15297
  • *Online Today: 44
  • *Most Online: 103
(December 19, 2006, 11:27:19 PM)
  • *Users: 4
  • *Guests: 6
  • *Total: 10

Author Topic: Finding the right generator  (Read 27167 times)

Offline khabe

  • Hero Member
  • *****
  • Posts: 526
Re: Finding the right generator
« Reply #15 on: November 29, 2008, 01:28:58 AM »
For a small wind genny you could use a brushless outrunner motor.

They are small motors for model cars and planes that have moving neo mags and stationary coils. They are VERY efficient motors and make quite efficient gennys.

They come in all sorts of sizes from tiny to large so you should find one to match your turbine. They are also quite cheap on ebay:

http://shop.ebay.com/?&_nkw=brushless+outrunner

They will generate 3 phase AC when cranked. With three bridge rectifiers feeding a cap you get rough DC, can then use efficient regulator for proper DC.

Yes, but even low cogging outerrunner brushless RC motors  (12 tooth/10 or 14 pole and 9/8 ... 9/10 ... 18/16 ... 18/20 ...)  have cogging too much for small windmill - it will not self-start. And those motors are cheap but not very cheap ---. $30 for tiny ones and up to $300 for larges. Tiny ones has tiny bearings and thin shaft as well. At that kV of these motors is at 500 to 3500.  When kV is 1000 then you need 1000 rpm for get one Volt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! And this is NO LOAD VOLT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  :o  :'(  >:(
regards,
khabe
« Last Edit: November 29, 2008, 01:49:06 AM by khabe »

Free Energy | searching for free energy and discussing free energy

Re: Finding the right generator
« Reply #15 on: November 29, 2008, 01:28:58 AM »

Offline Yucca

  • Hero Member
  • *****
  • Posts: 884
Re: Finding the right generator
« Reply #16 on: November 29, 2008, 01:53:07 AM »
Yes, but even low cogging outerrunner brushless RC motors  (12 tooth/10 or 14 pole and 9/8 ... 9/10 ... 18/16 ... 18/20 ...)  have cogging too much for small windmill - it will not self-start. And those motors are cheap but not very cheap ---. $30 for tiny ones and up to $300 for larges. Tiny ones has tiny bearings and thin shaft as well. At that kV of these motors is at 500 to 3500.  When kV is 1000 then you need 1000 rpm for get one Volt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
regards,
khabe

I have a small outrunner from Hong Kong about $15 on ebay and yes I notice it has noticable no load cogging even though it has different number of poles to mags? I think a wind turbine of a couple feet diam would start one running though.

You´re right the kV on the normal model motors is too high for direct to turbine and cogging will amplify through gearing. :(

I suppose a rewind with finer wire for lower kV would help but then that´s a fiddly long winded job.

Yucca.

Offline khabe

  • Hero Member
  • *****
  • Posts: 526
Re: Finding the right generator
« Reply #17 on: November 29, 2008, 02:13:55 AM »
My bread-and-butter comes from generators Im developing and building past 10 years, even longer,
Those are very specifics, but el.machines anyway, at that sui generis and ... devilishly good (they are speaking, the customers ;)
As more specific - as higher price :)
regards,
khabe

Free Energy | searching for free energy and discussing free energy

Re: Finding the right generator
« Reply #17 on: November 29, 2008, 02:13:55 AM »
Sponsored links:




Offline TinselKoala

  • Hero Member
  • *****
  • Posts: 13971
Re: Finding the right generator
« Reply #18 on: November 29, 2008, 05:16:57 AM »
I guess I paid about 2 dollars for this little motor that makes a pretty good demonstrator generator.
We're not trying to save the world from the tyranny of oil, here, we're just trying to help a kid do a science fair project, and I have a hunch he's not (yet) attending MIT, so it doesn't have to be too complicated.
Neither does it have to be the most efficient generator, or the fanciest technology.
A mechanically commutated DC motor won't require rectification, and if the right type of motor is chosen it won't exhibit "cogging" or excessive bearing drag, and so will be easy to turn with a wind turbine or water wheel or even a hamster in a cage, without complicated transmissions or gearing.
And a demonstration using this kind of motor will give the presenter ample opportunity to discuss issues of overall efficiency, ease of construction and maintenance, environmental impact, not to mention the physics of electromagnetism.
http://www.youtube.com/watch?v=kFavcqNWF5I

Offline Thaelin

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 955
Re: Finding the right generator
« Reply #19 on: December 04, 2008, 11:26:49 PM »
   Very simple setup would be to take the 12 mag 9 coil and make it smaller. Use grade 8 magnets from the hardware shop and smaller wire. Since its a concept show and not a off the grid system, many options. Not to mention he will learn the ins and outs of construction.

   And now, Uber thanks to all here that have posted as you have given me the final piece to my long sought puzzle of the coil make up. I have yet to find out the turns or ohm rateing  for a standard system. All I could find was let us sell you a kit or a video of how they made them but no specs. So now I build. I have to have 12v @ 25A output at a fairly low speed and this will do it. Less than 300rpm.

thaelin

Free Energy | searching for free energy and discussing free energy

Re: Finding the right generator
« Reply #19 on: December 04, 2008, 11:26:49 PM »
Sponsored links:




Offline pese

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 1598
    • Freie Energie und mehr ... Free energy and more ...
Re: Finding the right generator
« Reply #20 on: December 04, 2008, 11:32:38 PM »
make instead electricity compressed air.
and drive your car with this

http://www.brasschecktv.com/page/456.html
Source BBC-News Car 120km/h speed !

Gustav Pese


Offline khabe

  • Hero Member
  • *****
  • Posts: 526
Re: Finding the right generator
« Reply #21 on: December 05, 2008, 08:48:07 AM »
I have seen one compressed air car - was surprisingly noisy.
cheers,
khabe

Free Energy | searching for free energy and discussing free energy

Re: Finding the right generator
« Reply #21 on: December 05, 2008, 08:48:07 AM »
Sponsored links:




Offline pese

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 1598
    • Freie Energie und mehr ... Free energy and more ...
Re: Finding the right generator
« Reply #22 on: December 05, 2008, 09:38:01 AM »
All energy that make noise, have to mutch losses. Regardless of whether piston or turbine propulsion. Similarly, it is certainly possible with a  sound insulation to build. Some Honda generators show the possibility as there is. Certainly, it is possible to progress. Pese

P.S. I  womder that nobody have think about to reduce the coists and losses -for- compression the air. I look for contact to figure that out.
 

Offline khabe

  • Hero Member
  • *****
  • Posts: 526
Re: Finding the right generator
« Reply #23 on: December 05, 2008, 12:32:01 PM »
Perhaps take up with compressed air is not prestige enough - there is no orotund sounding therms and words - no ether ... fusion ... scalar ... essential ...  >:(
Is it too commonplace, cheap and bathetic ??? At that it needs attend school ...  and it needs much more precise work - no fluttering wheels, no crooked shafts  ::)
when making compressed air. And pressure is dangerous ... especially when education has been poor 8)
gruss,
khabe

Free Energy | searching for free energy and discussing free energy

Re: Finding the right generator
« Reply #23 on: December 05, 2008, 12:32:01 PM »
3D Solar Panels

Offline pese

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 1598
    • Freie Energie und mehr ... Free energy and more ...
Re: Finding the right generator
« Reply #24 on: December 05, 2008, 06:29:01 PM »
Perhaps take up with compressed air is not prestige enough - there is no orotund sounding therms and words - no ether ... fusion ... scalar ... essential ...  >:(
Is it too commonplace, cheap and bathetic ??? At that it needs attend school ...  and it needs much more precise work - no fluttering wheels, no crooked shafts  ::)
when making compressed air. And pressure is dangerous ... especially when education has been poor 8)
gruss,
khabe

education for poor folks
google make it possibel

http://www.google.de/search?hl=de&q=turbine+compressed+air+generator&meta=

GP


And here some adds.
from my link collection:

http://rexresearch.com/negre/negre.htm


PS.
If you can handle
butan/propan camping gas (12 bar)
than you can handle , lower pressured air....


Offline Thaelin

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 955
Re: Finding the right generator
« Reply #25 on: December 21, 2008, 09:02:11 PM »
   Concerning Gen heads for wind, there are many makeups to choose from. I have settled
in on the 12mag/9 coil setup. To reach fair output, it seems to be necessary to hit 700 rpm
with it.
   Now what would happen if you had a wheel with 24 magnets on it and two sets of 9 coils
in two arcs on both sides? If both sets were wired seperate but outputs together for double
the amps, still mean the wheel would have to only travel one half the speed?
   That would make the wheel bigger, but it would only have to go 350 instead. I have a bike
wheel that had 48 slots between the spokes I am thinking of mounting two metal rings on
so as to put 24 magnets on both sides for a total of 48 and run the coils in a half circle mounted
on both sides and running in the middle of the mags.

   Any comments here?

thaelin

Free Energy | searching for free energy and discussing free energy

Re: Finding the right generator
« Reply #25 on: December 21, 2008, 09:02:11 PM »
3D Solar Panels

Offline capthook

  • Sr. Member
  • ****
  • Posts: 469
Re: Finding the right generator
« Reply #26 on: December 21, 2008, 09:57:55 PM »
Hi Thaelin -

One implementation of the  12mag - 9 coil setup is in the axial flux dual rotor design.
The idea of the dual rotor is eliminate iron in the stator and then maximize the flux in the airgap between two rotors of magnets.
If iron is used (should always be so) as a backing for each rotor, the 'magnetic circuit' is completed - boosting flux.  (the flux from the backside of each magnet is 'channeled' to flow back through the adjacent magnet and back through the stator)

The problem with a single rotor/dual stator design is the incomplete magnetic circuit.
One would think that putting coils next to BOTH faces of the magnet would offer superior performance - but that is not the case.

I have just completed my first axial flux dual rotor build. (Hugh Piggot style design)
1. 12 mags 9 coils
2. .75" x .5" N42 mags  :  1/4" steel rotors
3. 500 turns #24 AWG coils .75" ID x 2" OD x 7/16"
4. airgap from each rotor to stator 1/8"

The magnets were taken from a build I did 2 months ago of a single rotor/dual stator design like you describe.  The coils had an iron core.

Comparing the two:
1. The dual ROTOR generated TWICE the power
2. The dual ROTOR resulted in around FOUR TIMES (or more) LESS drag. (no iron in coils)
(so at least 8x better performance)

For a long time I was of the notion that putting coils on BOTH sides of the magnets would be best - even though I'd been told it was not so as the 'magnetic circuit' was incomplete and thus inefficient.

Having now built BOTH designs - I can say that a DUAL ROTOR is SUPERIOR in many ways over the dual stator.

My next build of this design will use larger magnets (2" x 1" x 1/2") , 16 mags 12 coils with larger wire (#18 AWG?) and 1/2" steel rotors.

Offline Thaelin

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 955
Re: Finding the right generator
« Reply #27 on: December 22, 2008, 10:14:09 AM »
    I see I was incomplete with what I was trying to say. I am looking to put
two metal rings, one for both sides of the stator. The magnets will be placed
on the inside of both rings so that they face the stator.
    I see tho that the two rings will have to be joined somewhere for the flow
to happen. Guess I could put small metal pieces across the back of the rings
so to complete it.

    As I am not going to be powering this by wind prop, I need to maximize the
low speed output as much as I can. That is the reason I am considering this. I
just wished I had drawing software that I could put down what I see in the head.
It frustrates me to no end when I cant put my thoughts to action.

The beat goes on.

thaelin

Offline terry1094

  • Newbie
  • *
  • Posts: 25
Re: Finding the right generator
« Reply #28 on: December 22, 2008, 04:56:17 PM »
The Fisher Paykel washing machine motor makes a good generator.  Here is a complete detail plan for a windmill from downunder:

http://www.thebackshed.com/windmill/fp2a.asp

Elsewhere,

http://www.watchtv.net/~rburmeister/smart.html

others recommend grinding the edges of the cores of the electromagnets to reduce cogging.

Terry

Offline Thaelin

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 955
Re: Finding the right generator
« Reply #29 on: December 22, 2008, 05:48:55 PM »
  Thanks Terry:
   I believe I saw that vid of one hooked up. I must stress again tho that this will not be
a windmill setup. It will be a Gravity Wheel that is running it. The only kick back I have
is it must be a low speed unit. My latest test shows I have ample torque and can most
likely do  a six to one gear up to the head.
   I have to get another pair of weights yet and a drive belt that is the correct length. I
really only need to generate 60watts over the needs of the wheel to charge up the batt
stack.

thaelin

 

OneLink