open pole concept

[artv]

Hi all,..I've read alot of stories here ,lots more to go.
I haven't seen this idea yet, but it has probably been tried,..I made a 48 pole mag rotor, but used E-core laminates as the magnet back plate. The poles are stacks of three (cut up ring magnets),.... the E-cores are in ~ the middle of the stacks.
That way I can run a coil on both sides of the magnet plate, the coils have their own individual  metal back plate as well.
With this design it seems you can have twice as many coils, twice the output for the same amount of magnets.
The E-cores in the center of the magnet stacks have to be in contact with each other ,in order to complete magnetic circut, the metal plates behind the coils are isolated from each other, preventing eddy build up.
Thats how I see it working ,but there's a good chance I am wrong...
This is a pretty crude set up , my tools consist mainly a 4 1/2" grinder , a cordless drill and a jig-saw ,plus I have zero money to spend on this ,the wife would kill me lol.
Here's the mag rotor
With three coil pairs running at 100 rpm....I'm reading 10.8 volts AC , 3.6/pair....48 pairs should give ~170 volts AC at 100 rpm I can't seem to type anymore and still see my words........artv

Next pictures... [Here's how the E-core with magnet stack was made one stack per E-core hole & Here's the huge air gap I'm stuck working with] Dropped triplicate pixs,

[electrondady1]

your camera works differently than the human eye.
try shooting with the light coming over your shoulder to illuminate the object your photographing
i can't see a thing.

[artv]

Hi looks like I got the wrong pics in there...that pic is the air gap,.......I'll try again
this should be the mag rotorthis should be the E-core with magnet stack
I ran out of typing room in the first post,
What I wanted to ask was about winding the coils,..I think I have around 20 awg wire.....I wound 230 turns , then I took the same coil unwound it ,cut it in half and rewound it two in hand, but I hooked it in sereis instead of parallel, so basically it is the same coil,...but the output of the two in hand was ~1.8vac , where the single strand output was only about half of the two in hand.
Then I tried three in hand ,same guage same amount of linear footage ,but hooked series ,so basically the same as the 230 turn single wire, but the output was bouncing on the 2 vac mark???
Both my digital meter's are fried ,so I'm using an anolouge cheapy, since my rotor dosen't spin true the needle jumps around alot, but stays in the same area ,I just go with the average
Just curious about the coils and should I maybe wind 2 in hand the proper way to give more current handeling ability....fun stuff for not costing anything...........artv

[artv]

Hi Electron1,..sorry I screwed up the first post that black blob you see at the top left of the pic are the coils the 1/8" daylight you see is the gap, also there are 3 coils on the right with the same gap,just can't see it in the photo.
As the rotor spins that gap closes up in some spots ,it's very hard to make a true rotor using 144 pieces of ring magnets that are different thickness and size...artv

[zap]

The first picture tweaked a bit

[artv]

Thanks  Zap ,..that is alot clearer.....here are two better ones
I previewed them so they should be o.k...........Any reason for those readings...........artv

[ghurd]

I don't understand it.

The (2?) magnets are in the slots in the E core laminations?
If so, then the magnetic flux is being shorted in the E core instead of reaching out to the coils.
G-

[artv]

Hi G-,...There are 24 of those E-cores around the outside of the wooden rotor(an old croque board),....a stack of magnets on each hole,....I tried to get equall amounts of magnet material on each side of the hole , so as to be = in strength.
That pic is just to give an idea of what I did,...some stacks are 3 magnets ,some 4...
The purpose of the E-core is to complete a path from stack to stack,(magnet back plate but in the center instead of on one side).....Also it is only one laminate layer ,so very thin ...
I did try putting the stacks on the legs of the E-core but that did short my flux path,...but on the holes the flux was just as strong at both ends of the stack...
I tried the conventional method with the stack  on a steel plate (thick enough not to allow leakage out the back)
the flux strength was the same as the E-core method ,but with the E-core I can place a coil on both sides, as opposed to only one coil in the conventional......twice the output for the same magnet material....so basically 96 poles instead of 48
Also the coils have a piece of laminate behind them to draw the flux through the legs of the coil...thats what that little square is in the pic "E-core" ...the big square in the pic was tried as well (behind the coil) ,...it just created more drag but didn't increase out-put
still curious about output readings I'm getting..........thanks .........artv









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[electrondady1]

hats off for your ingenuity.
 i know what"s like to be creative on a budget
but your configuration is not very efficient.
your leaking flux sideways from mag to mag and needing two coils where one could do.

 
can you talk about the individual magnets.
you mentioned they were ring magnets
are they from loud speakers?
are they uniform in any way ?as in shape ,thickness, length,width?

 

[artv]

Hi Electron1,...The magnets were cut from a wide variety of speaker and micro-wave ring magnets.
I concentrated mostly on trying to get the stacks = in width, that is from one side of the rotor to the other.
Pole faces I tried to keep as close as possible to the same width, but they do vary...so when I layed them out I just made sure they were centered on the 7.5 degree mark( 360 degrees divided by 48)....by no means perfect but the best I have to work with.
As for the length ,I tried to keep that close as well ,but not really an issue since the top and bottom of the coils don't produce anyway......artv

[electrondady1]

i ended up purchasing a used tile saw for about twenty bucks.
with that i could cut the mags up into more uniform pieces and then used those pieces to form shaped multi magnet poles.

[electrondady1]

  just trying to make something out of nothing.

you have lots of mags.
i have found that the flux from ceramic mags can be contained by as thin as 22 gauge steel
if at some point you feel you have reached the limit as to what you can do with your present lay out
consider this,
out of sheet steel (body metal ) form a bunch of u shaped pieces and glue your odd size mags to the inside of those.
placing them carefully on your big wooden rotor you can form a kind of dual rotor.
run your coils in between.

 

[artv]

Hi All,...I made a mistake in the wire guages,....the coils were wound at different times I thought they were the same wire turns out they weren't. I just finished two more coils of the same amount of wire ,off the same spool......230 turns single strand, same length of wire 4 in-hand ,they gave identical readings.....sorry for the confusion..
Electron1,....that first pic is what inspired me to cut magnets,....I just use a zippy disk...score the magnet ,then break it over the edge of the bench,....sometimes it works ......needless to say I have a couple handfuls of magnet chunks.......
I thought about using the pieces ,but how to keep them from flipping until the glue dries,or to even get a chance to get the glue in there???
In that second pic would it not create a stronger pole by stacking those pieces??....Is there a certian point where the size of the pole face becomes too large???....I'm going to try a bunch of different things with this set-up for now , but will definately keep your suggestion in mind........thanks ....artv

[electrondady1]

i have no gauss meter, but i have read and proven to myself that stacking the mags increases flux density by perhaps 20% over a single layer, nothing wrong with that.
but  doubling the no. of poles more than doubles the output.
if i recall ,you are familiar with ed lenz's work 
ed uses thinner mags but with greater surface area.

last night i built a 64 pole rotor.
first i glue every second mag down (as in  all the north poles )and let them set up
then one at a time i glue the south poles down and keep them from drifting around by laying a flat piece of steel across  two mags 
to build multi magnet poles it's the same
i  let the first one set up.
i  glue and hold the second mag in place by laying a flat piece of steel across both mags.
that will keep it in place with out flipping over.

[GoVertical]

http://matrix.ene.ttu.ee/files/kuressaare2007/Kuressaare2007_186Kallaste-Kilk.pdf

Hi, I found a paper that is similar in design to your design. Great work. 

[ghurd]

We still really have no clue of what you did.

If the magnets are inside iron, like jambed into the slots of an E core, then the flux is being shorted.
Period.

Any increases are a result of improper coil placement or measurements.
Period.

[artv]

GoV,...Thats a very interesting design, alot more sophisticated than mine, you could probably build it ,I might be able to if I won the lottery..lol
E1 & G-,...I'll show a drawing of what I think the flux is doing I don't really see where the flux could be leaking or being shorted...the magnets are stacked on both sides of the hole in the E-core,...so about a 32th of an inch keeping the magnets from joining together,...I think being this close together but not being able to join intensifies the flux lines...
I don't know maybe I've got it all wrong???
On my first build I had 8 poles ,six coils,  more magnet material in the stack , and more wire in the coils, and alot more steel in the laminated core.......at 100rpm it put out 2.2VAC per phase( two coils)..........with this design I get 3.2 VAC at 100 rpm per coil pair...with less magnets ,...less wire and less steel.
I can put 96 coils on this , with the wobble the rotor has I could safely get 1.5VAC per coil (I opened the gap up losing a little output).........thats 144 VAC at 100rpm..........432 VAC @ 300 rpm.....then I am thinking step-down transformer ..I just exp..

[artv]

I was running out of room so I posted...here is a pic of the test board the starts and ends of each coil are seperate so I could test individually,... 10 coils total they all came in within .2VAC of each other...the best rectified #'s I got so far were with the cap( I don't know if you can see it)
it was hooked with the neg on the DC neg out of bridge but with the pos of the cap going to one of the AC inputs of the bridge.....and it has to be the right AC input......I don't know why but one AC side gives about .5 VDC more than the other???
the cap was a 16v 1000uf ...at 200rpm it popped and let out its' little puff of smoke...lol.....more coils to wind ........caps to pop.....
thanks for your time .....artv










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[electrondady1]

 your sketch shows you understand what's happening in a dual rotor.
but i think there is more going on in your open pole layout than you show
i had to google to find out what a e-core was,some sort of ferrite object, so if it works to transfer the flux, good.

the pieces of steel behind your coils are stationary and offer  no flux return path.
during operation the magnets will  link to those metal pieces and be reluctant to release.
the more coils , the more cogging.
try runnig the cap across the two dc rectifier terminals .
try running  coils in parallel /series reducing voltage and increasing amperage.

isn't this is a lot of fun !



 

[artv]

Hi E1,...My term E-core may be misleading ,...It is a single layer laminate out of a micro-wave transformer as seen in reply #2 (2nd pic)
I tried running the coil with nothing behind it , with thick steel behind it and with the thin steel behind it,...the 2 types of steel gave the same output , but the thin steel was alot less cogging,..with nothing behind the coil the output didn't even register....
Running the cap across the DC output terminals of the bridge ,does give better output than the bridge alone,.but running the caps'  negative to the negative DC out on the bridge , and the caps' positive lead on one of the AC inputs is better yet.....
And I also found that one AC connection gives a little bit better output than the other ~.5VDC ,but that could be connections.....
One thing I did notice is the capacitor really smooths out the DC output...
Am wondering if a transformer would also smooth out the AC?? or even how to hook one up??...artv

[artv]

Hi all,....I'm up to 24 coils (finally).....some are single strand, some 2 ,3 , 4,....(getting low on wire)...
that shows the front ,..here's the back
the meter ( anolouge) bounces  32-38 VAC at 100 rpm, since my rotor wobbles
with 72 more coils I should be able to just multiply by 4???....with some losses to connections and wire lenght??
Also any ideas what kind of tranformer I could use?......step the volts down and boost the current

Thanks......artv

[artv]

Hi all,....I was checking amp readings with an 18volt ,2.4ah ni-cad battery
All the tests were at 100rpm, ...with just the bridge 30 vdc ,60ma does that = 1.8 watts?
with the bridge and 25volt caps paralleled hooked jerry neg to neg on bridge positive to pos on bridge, 35 vdc ,55ma = 1.925 watts?
with caps hooked neg to neg on bridge ,positive of caps hooked to ethier leg of AC input to bridge,  50 vdc, 52ma = 2.6 watts??
When getting the amp readings the meter was connected in series with the battery to the bridge.
The voltage readings were taken straight of the bridge outputs with no battery connected.
Power is ExI squared .......Just wondering if I'm doing the math right or not........Thanks  ....artv

[GoVertical]

P = volts * Amps
 

[TomW]

This chart is pretty handy




Tom

[artv]

so that means the #'s are right???......

[TomW]

30 vdc ,60ma does that = 1.8 watts?

NO

.60 ma =.0006 amps so 30*.0006 = .018 watts.

ma are very tiny units it takes 1000 of them to make an amp. You are talking .6 of one one thousandths of an amp.

Tom

[Tritium]

30 vdc ,60ma does that = 1.8 watts?

NO

.60 ma =.0006 amps so 30*.0006 = .018 watts.

ma are very tiny units it takes 1000 of them to make an amp. You are talking .6 of one one thousandths of an amp.

Tom

Tom that is a comma in front of that 60ma so I think he means .06A

Thurmond

[artv]

Hi all,..I made a dual magnet rotor,...
here's the back plate
the front
here's the gap when mounted
The readings I got were very low .....
Since the pole faces of the two plates are different in size.....
will this cause problems???.....the two plates still try to pull together.....the poles are lined up pretty good ( center of pole to pole)
the coils are just a bit smaller ( ID) than the front rotor mags....so bigger inside dia. than the pole of the inside rotor....
As long as the centers of the poles are lined up ....does the actual width matter???........artv

[artv]

Hi All,.....I decided to try a comparison on three different set-ups',....my open-pole idea,..a mag rotor with a spinning blank, and the dual rotor..here's the open pole
the spinning blank
the rotors
I have to wait until the foam is dry so I can't do any testing on the dual,...
But the open pole gave better readings ,than the blank steel....
I suspect the backplates are robbing flux......still more stuff to do...........artv

[artv]

Hi all,..here's the dual rotor assembled
The open pole gives 2VAC..
The spinning blank disc with a steel shim behind the coil gives   1.2VAC
The spinning blank disc with no steel shim behind the coil gives   .8VAC
The dual rotor gives 2VAC
All the testes were done at 100rpm,.the same coil,..the same amount of magnet material, and on the same steel disk....
It is obvious the dual rotor gives the best output since the open pole needs twice as much copper(2 coils)...1VAC/coil..
but the output from the two coils in the open pole , on this smaller diameter rotor wasn't as high as the bigger wooden rotor(3.2VAC)
the poles were the same spacing ,the same coil , and actually less magnet material (on the wooden rotor)......is that beacause of the bigger  diameter??
It's ethier the bigger diameter or the E-cores..........just not sure how diameter plays its' role ......thanks for reading......artv

[artv]

So,... I decided to try the E-cores.........here are the two rotors
this,. one of the poles placed
This gave the same out as the dual rotor 2VAC at the same rpm.
Also the E-cores' had alot of leakage out the back,...the thicker steel didn't,....but this didn't seem to make much difference??
Maybe we don't need big steel plates adding lots of weight ,stealing power??
Dual rotor seems to be the best so far....but, I think the bigger dia. gives better output........artv