Permanent Magnets are the way to go.

[janmarsh]

I had to post a pic of this ridiculously small rotor which belonged to a 750 Watt servo motor. It is dwarfed by the 47mm O.D. drive end bearing.

It is 8 pole with each of the 8 Neodymium Magnets 1" in length. If such a little motor was capable of 1HP @ 6000 rpm,  it will be interesting to find it's output when rewound as an alternator & run at 10,000 rpm +..........  as long as the magnets don't separate at such a speed ! 

[Bob]

HAHA man that is a tiny Rotor !
 But Why are you thinking 10,000 rpm ?
that's way to fast for anything but solid steel !
and magnets are brittle as all get out...
Personally I'd be cautious about the 6000 RPM they say... any faster and the magnets probably come apart....
....
Bob...

[Manta]

I was wondering the same.  Why would you want to run an alternator at 10k rpm ?  The only reason I can think of is if you are trying to get very smooth dc after rectification.

Manta

[janmarsh]

Bob,Dave,    10k will be the max for comparison sake to other units on the market.


http://www.windbluepower.com/Wind_Blue_Motor_Hydro_Permanent_Magnet_Alternator_p/dc-500.htm            


  I shouldn't expect to have it as a constant service speed.  I want to make a graph of each unit I rewind when driven on the bench by an electric motor controlled by an inverter. I will also measure the demand on the drive motor at this point & compare it to the output of the alternator & get an impression of efficiency.  

I can make note of all figures from zero to max rpm ( Including winding temperature, sensor embedded ) & familiarise myself with performace characteristics of such units.

I am winding to gain max amps by all windings being in parallel & with delta configuration.  Those in-the-know at work tell me as long as each winding is identical ......... length & also proximity to the rotor being identical,  results should be interesting.

                                                                                                                   Marshall.

[janmarsh]

Here is a shot of the housing & iron core the little rotor belongs to.



Core design of the range of low inertia motors this little unit is part of seem to be unique in that the core itself is segmented in to 12 separate pieces.  If I were to loosen the clamp all 12 pieces would fall out.  Segmentation plays a major part in the output of the unit for it's size seemingly.

O.D. of the core is 3.2",  Bore 1.5"   Depth is no more than 1"  ( Same as magnet length on rotor ).   To gain that 750 Watt output as a motor is impressive to me & certainly worth the time to experiment to gain such performance as an Alternator.   

                                                                                       Marshall.

[Manta]

As that is as close to 1 horse power as makes no difference it is indeed impressive.
Where do you buy your wire from ?

Dave

[janmarsh]

Dave,

                        http://www.brocott.co.uk/

Poly-Amide 200 Enamelled Copper Winding Wire.     Seem's as though the 200 is degrees centigrade it is capable of sustaining. Certain diameter wire is capable of reaching 220.

[Manta]

Marshall,

Thanks for the link. One of the many ' sometime in the future' projects is the winding of a special transformer to give me 0 to 2.5 Volt (in 0,5 Volt steps) at up to 50 Amp.

Dave

[Bob]

I have wondered more than once if it wouldn't be better to power a Vandie-graph generator with a small electric motor and use that power to power the Hydroxy cells....
 You know, the disk with magnets glued to it spinning by a coil of wire... very simple but very very powerful... deadly in the wrong hands no doubt! but something with so much power could indeed power a Hydroxy cell... but Plate spacing may be an issue sense we are dealing with Thousands of volts and many many amps.... arcing between the plates may be the major problem with this kind of power
...
but think of it.... a 2 amp motor turning a disk with 8 new earth magnets on it spinning at say 1340RPM
... a heavy coil of  Magnet wire, capable of handling large amp loads...
and you have a High voltage, high amperage power supply for the Hydroxy Generator...
far exceeding any alternator available today...
...  there has been some experiments done on High voltage/lower amperage and the results were indeed promising .... if not conclusive.   
but this is much different ... its like plugging a cell into a High tension Power line and expecting it to work.... chances are it would just melt!... but IF you could get it to work  its possible that you could have your cake and eat it too !....
 for the minor amp draw off the car battery you'd have high voltage high amperage more than whats needed to run the Hydroxy cell.... but you could regulate the amount taken by the cell by the electrolyte mixture...
...
 I have NO IDEA at all if it would work and get you really large LPM output or not... but if you would rather not tax your cars alternator  this may be a way around it.
...
 the possibilities that this implies could be staggering ! with no expensive 300amp alternator
a good Hardy cell or Cells, and the power to run it at its max output ...the possibilities of a 100% Hydroxy powered vehicle may be possible !
...
 However I don't believe you can get something for nothing and it may take a hefty DC motor to turn the disk with strong magnets on it at full load.... but even that is preferred over  a 300amp alternator running at 3/4 its capacity all the time...  I don't see how you could loose going this route...
 I personally doubt you'd need a 5hp motor to turn the disk.... and You know a large alternator will take more than that to turn it when loaded down.
... and to be quite frank a 5hp motor turning a Vandy-graph generator sounds scary as heck to me!
heheheheheheh visions of 3 foot arc's of lightning bouncing around might put on a real light show!
...
but I have seen many types of generators and alternators and I am always puzzled as to why the simple but powerful Vandy-graph generator isn't used more... perhaps it can be utilized to power a Hydroxy Cell.... if enough caution is used....Obviously!
...
Comments ?
...
Bob.....

[Manta]

Bob,

...Thousands of volts and many many amps....

This equates to many Watts and many horses to drive it.  It won't fly.

Good to see that the peyote is still as strong as ever in your neck of the woods.

Dave
(Manta)

[Bob]

Welll.... your probably right in the power NEEDED... I dunno...
but Not the Piote.... <GRIN>
...
I vividly remember turning the HAND crank of a Vandy-graph machine in school many centuries ago....
and It did NOT take much power to get an extreme amount or power going....
.... you can't turn a alternator with a hand crank and get a bulb to light...or a generator unless you are very fast with your hands!...but the Vandy-graph generator was simple to get Lots of power with little work.... so its OBVIOUSLY much more efficient.... RIGHT ?
 so why not use the Most efficient power generation devise ya know of to make the power needed?
...
Marshals experiments are working toward a highly effecient generator... so why not make a Vandy-graph generator and see what that does? it may indeed out power any car system for generateing electricity  ever used....
....
Bob......

 

[janmarsh]

Holy smoke Bob,    I dont know about using one of these thing's for Cell supply !    Although you may have suggested a way I can deal with my little engine ignition problem.      Two Million Volts !!!!!!!!.............   JESUS  

http://en.wikipedia.org/wiki/Van_de_Graaff_generator

[Manta]

The thing is that Van De Graff generators work in very low amperage and high voltage. I do believe we are talking micro amps.  Also all that arcing capability would give some interesting problems with hydroxy.

Dave
(Manta)

[Bob]

I may be using the wrong name for the device Dave... i can't remember the name of it....
but its not the long rubber-band and metal dome contraption that makes static electricity... that one does indeed make Lots of voltage and minimal amps so a person can play with it all day and not get hurt... the one I am talking about is the disk (usually Plexiglas) with a series of bar magnets glued around its circumference at equal separations...
 Un like the static electric generator , this magnet on a disk spinning by a coil of wire is indeed Deadly.... and you don't get that with micro-amps its power is realy amazing !
I remember seeing one hooked up to a regular 100watt light bulb  when I was a Kid and spinning it by hand was easy and it lit the bulb fairly well at moderate to low  speed.
....
obviously the size of the disk makes a big difference in the generators output... the one I saw had a 24" disk on it !  I was so intrigued with the thing that I asked all kinds of questions after class let out and looked it over very carefully.... I've been going to build one every sense! HAHAHA!
I think I was in 6th grade then... but it burned into my memory HAHAHAHA...
after the demonstration he put a LOCK in the frame so it wouldn't turn... I got him to remove it so I could turn the handle and it was indeed surprisingly easy to turn.  It had a gap and 2 metal rods where a arc would strike between them every so often , they were a good 2" apart... as well
... when in later years I was in Highschool I had that man as my science teacher before he retired
I can't even remember his name now but I learned allot from him ! HAHAHAHAHA
... it was one of the classic "Lets see if we can get the Kids interested in science" things and it worked on me quite well !
....
I've often wondered why such a simple device isn't utilized more...
although some of the better wind generators Now use the same idea... just more coils of wire.
its been a very long time coming... <GRIN>
...
the coils of wire can be set to make any amount of voltage you desire but it does take a bunch of windings to make a small amount of amperage.
...
 I think like Manta Said.... It'll Never Fly !  but its an IDEA ...LOL !
...
Bob......

 

[janmarsh]

Bob,   Wimshurst Machine ?

http://en.wikipedia.org/wiki/Wimshurst_Machine