Author Topic: DC PMG efficiency and wire gauge/coil questions  (Read 11583 times)

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doctormiaoux

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DC PMG efficiency and wire gauge/coil questions
« on: September 28, 2008, 01:38:01 AM »
knowledgeable peoples, i am trying to be able to recharge a 12V battery bank with a homemade PM assembly...


so i suppose my first question would be: is it possible to make a DC generator that does this reasonably efficiently? my idea, before getting immersed in all the talk about loss at high voltage (or was it current) in a DC generator, was to have a ring of 1"x1" cylinder N50 NdFeB magnets (105+ lbs of pull) N to S poles like so:



hopefully that is pretty self-explanatory, but i guess i'll be getting a lot of questions if it isnt...


moving on, i have a crapload of 10 gauge magnet wire and would love to use it since it was expensive. any suggestions as to how many windings and/or which coils to connect where (series/parallel, delta/wye, number of phases if applicable) would be awesome.


i guess that is plenty for now. thanks in advance for putting up with my noobness.


j

« Last Edit: September 28, 2008, 01:38:01 AM by (unknown) »

KilroyOdin

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Re: DC PMG efficiency and wire gauge/coil
« Reply #1 on: September 28, 2008, 06:00:04 AM »
 Hi, nice design. I look forward to seeing a working proto-type. Try using 9 coils and twelve magnets. Connect the coils in a Wye configuration. The site explain the physics of the coils and magnets relationship.


http://www.6pie.com/faradayslaw.php


If your design prove to be to much of a challenge try searching this site for some ideas. Best of luck and have a good one.

« Last Edit: September 28, 2008, 06:00:04 AM by KilroyOdin »

tanner0441

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Re: DC PMG efficiency and wire gauge/coil
« Reply #2 on: September 28, 2008, 12:31:21 PM »
Hi


Just one question.  Your drawing show toroidal coils, how do you keep the magnets  concentric?


Brian

« Last Edit: September 28, 2008, 12:31:21 PM by tanner0441 »

doctormiaoux

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Re: DC PMG efficiency and wire gauge/coil
« Reply #3 on: September 28, 2008, 02:53:30 PM »
sorry if i have this wrong, but i think what you are asking is how would the center of the magnets stay aligned with the center of the coils... most likely for now, i would use a combination of wood and zip ties or epoxy to keep everything in place, and i could measure to .0001" if i wanted to, but i am going to doing this by hand, so i'll probably make some rough outlines and eyeball a lot of it with a rotary tool for the first try. i am mainly going for a proof-of-concept with this.


ideally, if this all works nicely, i would make the magnet ring out of some super thick plexiglass that i have and probably have the coils around small segments of PVC tube that are just wider that the magnet assembly.


hope that answers your question. thanks for your time.

« Last Edit: September 28, 2008, 02:53:30 PM by doctormiaoux »

stop4stuff

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re:
« Reply #4 on: September 28, 2008, 11:49:07 PM »
with your magnets in that configuration, you'll have cancellation within the coils, i.e. the magnetic south passes one half of the coil and tries to move electrons clockwise, the north tries to move electrons counter-clockwise from the other half of the coil.


trun the magnets trhough 90 degrees so that the coils have their magnetic faces perpendicular to the circumference of the rotor and you have a setup like a speaker coil/magnet arrangement... align the magnets so like faces are towards each other and you get a 'projected' magnetic field, which introduces possibilities of different configurations like this... http://www.fieldlines.com/story/2004/12/2/5455/05495

« Last Edit: September 28, 2008, 11:49:07 PM by stop4stuff »

zeusmorg

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Re: DC PMG
« Reply #5 on: September 29, 2008, 04:10:34 AM »
 I have an even bigger question, you're showing coils wrapped around a "dough nut" how are you going to turn the thing? if you had the coils moving, how are you going to anchor the magnets?


 Whatever mechanical device you used would slice through your coils on the first revolution..


 I think you need to look at simple practical generators that have already been built, rather than trying to dream up your own scheme.


 windstuffnow ed has played around with several other designs for homebuilt generators other than the common axial flux design that is usually used here.


http://www.windstuffnow.com/main/


There are also quite a few designs for different generators on this site itself.


 The questions you have to ask, what will drive this generator? wind? water? pedal power? These are things you have to take into consideration when designing a generator, such as how much power in what form do I have available? Do I need to design a high rpm generator or a low rpm generator?


 Then when you figure out what resources you have to create power with, it's time to start utilizing it.

« Last Edit: September 29, 2008, 04:10:34 AM by zeusmorg »

doctormiaoux

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Re: DC PMG
« Reply #6 on: September 29, 2008, 08:12:10 AM »
zeus, i appreciate your constructive criticism, however, while not knowing all the ins and outs of electronics, i feel that i have a reasonably good grasp on mechanical operations. just because i have not outlined every detail of my plan here, doesn't mean i dont know how the rest of my contraption will function...


i have a stationary bike and a way of hooking it up to the rotor, all the while keeping the rotor and coils concentric. that being said, apparently, i need to reconfigure my magnets a bit.


i realize there has been a tremendous amount of research, etc. that has been done in this field, however, if people did not dream occasionally, there would not be half of the developments in the world there are today, so please consider this next time you tell someone not to dream.


thank you.

« Last Edit: September 29, 2008, 08:12:10 AM by doctormiaoux »

doctormiaoux

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Re: re:
« Reply #7 on: September 29, 2008, 08:45:55 AM »
stop, thank you for the important info. do i gather that you are suggesting AC over DC?


also, your 90-degree comment confused me a bit. do you mean like this:



like this:



or were you simply saying reverse the polarity of half the magnets from the original drawing?


danke.

« Last Edit: September 29, 2008, 08:45:55 AM by doctormiaoux »

Flux

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Re: DC PMG
« Reply #8 on: September 29, 2008, 11:27:53 AM »
I think you are going down the route of the homopolar generator and it doesn't work.


If you want to dream please do so it may bring you hours of pleasure. Put it in a diary to let us know how you get on if you wish but it looks a dead end route to me.


Flux

« Last Edit: September 29, 2008, 11:27:53 AM by Flux »

doctormiaoux

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Re: DC PMG
« Reply #9 on: September 29, 2008, 01:11:33 PM »
ok, since this is getting totally trashed, i am going to share my original idea... perhaps the saying of going with your first choice is what i should be paying attention to.


lets start out with this then:



at steady RPMs, this would generate pretty good AC if the magnet was strong enough, right?


so then if you had something like this:



couldn't that be a really easy way to do a small 3-phase AC generator if it was wired properly... which i don't really know how to do yet.


sorry if i sound arrogant or whatever, but i think telling someone presumably much younger than yourself to stop dreaming is probably some of the worst advice ever and will inevitably be cited as the root of the failure of humankind as a species.


purely opinion, obviously.

« Last Edit: September 29, 2008, 01:11:33 PM by doctormiaoux »

Flux

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Re: DC PMG
« Reply #10 on: September 29, 2008, 02:10:54 PM »
OK you have got over the misconception that you can produce dc directly and this is far from the first idea which I still think has its roots in the homopolar machine.


Yes this will work, it is crazy but it will work. What merit has it and why do it but that is your issue.


I didn't tell you to stop dreaming, in fact I encouraged you to do it as a diary entry and I would have seen if it was ever going somewhere.


This place is basically for people who want to do something practical with alternative energy. By all means dream it may change the world but most likely it won't. If you want advice and help this is the place but it is not the place to criticise those prepared to tell you that your original proposal was wrong and worthless.


I can't see anyone giving much encouragement for your reciprocating monstrosity, there have been attempts to produce the motor equivalent in the form of electric engines but the direct rotary motor has always held the field. Why introduce complications as well as neglecting the progress of 150 years.


Except for superconductors I haven't seen anything revolutionary in electrical generation since the turn of the last century, there has been lots of steady progress with materials and with rectification with the coming of semiconductors but the basic ideas were laid by Faraday and the pioneers following him. Many ideas impractical at the time due to deficiencies in materials are now possible so it is not a bad idea to look at what has been done before but don't kid yourself that you have any real hope of a revolution when you have not the slightest grasp of basic principles or what has been done before.


I have spent many hours here offering practical advice often to those with very limited knowledge but I kept quiet on this one as it was a no hope case in its original form. I often watch progress and sometimes as people manage to explain their ideas and I get a feeling that they really may be on to something then I choose to help.


You came asking for advice and then criticised Zeusmorg for telling you some of the best advice you got so far ( understand what you are trying to do before going down your own blind alleys).


I suppose before the days of the internet peoples crazy dreams were never criticised as others never knew about them. I am sure there are places on the net where dreamers can offer each other moral support but I haven't the time to do it here.


Flux

« Last Edit: September 29, 2008, 02:10:54 PM by Flux »

TomW

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Re: DC PMG
« Reply #11 on: September 29, 2008, 03:31:29 PM »
Flux;


Well said.


I would also add that so few disclose their actual idea in detail which leads to these misunderstandings.


This particular one has many issues including magnetic and mechanical issues as originally presented.


Getting ticked off at folks providing accurate reality checks is rather less than conducive to getting further help for sure.


Tom

« Last Edit: September 29, 2008, 03:31:29 PM by TomW »

stop4stuff

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Re: re:
« Reply #12 on: September 29, 2008, 07:45:15 PM »
more like this...



where same poles of the magnets face each other


each coil would be as you have in your original, except for the size, which would need to be small enough to just cover the side of one pole ie. cover the north half of the magnet


where a speaker coil has a recipricating motion, this ring would provide a continuous output, the mechanicals would be difficult to get right, but hey that's all down to talent, time & effort... (i gave up persuing this idea as i couldn't imagineer a method for building the coils & ring)

« Last Edit: September 29, 2008, 07:45:15 PM by stop4stuff »

doctormiaoux

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Re: re:
« Reply #13 on: September 30, 2008, 07:07:19 PM »
stop: my "comma" button isnt working so please excuse the bastardization... thank you again. this looks pretty cool and like it is definitely worth putting some R & D time into the mechanism/contraption that will make it happen.


i really appreciate your open-mindedness to my non-traditional (and in all probability unwise) choice of routes. nonetheless  i would like to think that i know much of what i know now because i generally chose to start from the ground up and make my own mistakes.


i was hoping that the "Newbies" section of an alternative energy forum would be a safe place to seek constructive criticism and again i am thankful that not everyone is so quick attack someone for not being an expert.

« Last Edit: September 30, 2008, 07:07:19 PM by doctormiaoux »

ghurd

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Re: DC PMG
« Reply #14 on: October 01, 2008, 12:23:33 AM »
The first error as I see it is not researching with the proper terms, with 'google search the board'...

Linear

Linear alternator

Shake light

Maybe 'wave', and 'ocean wave'.


Then check...

bearing losses

inertia


It will work.  It won't work very well.

The second error is maybe contained in "original idea", which I can read 2 ways...


First way is believing it is a new idea.  It is clearly not.  It was conceived back when dirt was still clean.


Second way is wanting specific answers related to a question that was intentionally misleading.

"like so (sketch) ... self-explanatory"

The sketch is nothing like the 'my original idea' sketch, neither mechanically or electrically.


Becoming irate with people who point out the mechanical and electrical deficiencies of the information they were given won't make it work any better.


By all means, "Dream On" if you enjoy it.


And the answer to the original question is no.

G-

« Last Edit: October 01, 2008, 12:23:33 AM by ghurd »
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doctormiaoux

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Re: DC PMG
« Reply #15 on: October 06, 2008, 09:30:00 AM »
i apologize profusely if i have offended any of the regulars around here. i clearly have no idea what i am doing, and i am sorry that i thought this might be the right place to go for constructive criticism.


i further apologize for being overly defensive about comments made in regards to my "dreams". i suppose it is not good enough that someone under 25 wants to try to contribute a field that is about bettering the conditions of our planet and people's lives. and, furthermore, i apologize that someone actually interpreted my words as being "irate".


so, good. we have established that the alpha males preside over this forum. i am sorry to have intruded on your pristine [newbies] section with my crappy sketches and improper terminology.


it really blows my mind that some of you are so eager to be critical to the point of discouragement. i am not saying that trying to get someone not to go down a dead end path isn't a worthy, even compassionate, cause, but seriously, you guys need to work on your sensitivity or something. i guess that is realistically too much to ask from a bunch of DIY engineers though...


thanks to those of you who tried to actually help.


peace,


j

« Last Edit: October 06, 2008, 09:30:00 AM by doctormiaoux »

TomW

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Re: DC PMG
« Reply #16 on: October 06, 2008, 11:14:44 AM »
I guess your experience in this thread emphasizes the sensibility of reading a forum awhile to get a handle on the dynamics before diving in with posts that probably will not "fit" the forum?


This place has always been a bastion of brutal reality when it comes to information related to creating energy from forces in nature.


Despite your personal sorrowful and deeply traumatic reality check we will survive and many more will pass through here on their way to creating their own power with workable devices.


Perhaps you wish us to dumb down the site and simply tell folks "yes, it will work" so they can go on and waste time and resources on unworkable ideas? Thus sparing tender egos.


Every hobby or field of interest has its own vocabulary. It is the newcomers responsibility to learn the lingo as it were in order to avoid confusion when seeking assistance.


You will be missed. Good luck in your search for enlightenment.


Your membership fees will be refunded in full post haste.


Tom

« Last Edit: October 06, 2008, 11:14:44 AM by TomW »