MEMM

[PaulLowrance]

Hi Rob,

It is fine to extend the coils, but it will make very little difference. If we understand how closed loop cores react to magnetic fields we know that the wire locations make very little difference unless you are talking about very high frequencies. Also it is the magnetic field from the wire that enters the core that makes nearly all the difference. FEMM simulation is DC current on a closed loop core, so extending the coils will only make a slight difference.

The reason I used Iron instead of creating a Metglas property is for two reasons:

1. The permeability of Metglas is not 600000 at 30 KHz. More like ~10000.
2. It takes a lot of time and it was a quick job; i.e., I'm spending far too much time on such things when I should be working on the "smoking gun."

The only way you could make the FEMM more accurate than mine is if you create a metglas property for the core and k-factor the coil current way down to adjust for the fact that the cores permeability drastically changes at 30 KHz. Also extending the actuator coil will help a tiny smidgen.

My Metglas samples arrived. :-)  Two of them no less, lol! Although they are very small and round toroids, but that's fine since I am testing the MCE theory, not the MEG. Also I asked for a different material, 2714AF, which has nearly zero saturation Magnetostriction, <<1ppm, and annealed permeability of 1 million.  Now if I can just get some time to work on it. I did not ask for the same material because you had already ordered it and it seemed highly unlikely they were going to give out a huge 320 core anyway. My goal is to first analyze the material to see if it is has high potential as the 2605SA1 (Naudin's core). The material I really want is Hitachi's Finemet. Man that stuff has "free energy" spelt all over it!!!

Attached is a very poor picture of the two MP3210P4AF cores. Sorry, my camera is very poor. There are two toroid cores and come in plastic cases. I removed one of the plastic cases so you see the core material.

Regards,
Paul Lowrance

[MeggerMan]

Hi Paul,
Good news about your cores then.
Yes I read up about the Hitachi cores and it does mention Metglas in their litrature so I don't know if they are related.

So its onwards with the testing, I am putting together more orders for components, wires, plugs, boxes etc.

You can get multi-stranded enamelled wire which is design for high frequency circuits, and I was wondering if this could be used on the output coil to get the voltage down and the current up.
I will go with single core wire for now and put in a couple of taps so I will have some options.
I am really looking forward to getting this this up and running, quite exiciting really.
;o)


Regards

Rob

[PaulLowrance]

Hi Rob,

I think you're right that starting with solid wire is best first option. Stranded wire is probably better in the MHz region. At 30 KHz it would probably just add more wire resistance. Solid magnet wire with really good electrical insulation sounds good. After all we're talking roughly a thousand volts.

BTW, my Metglas 2714AF cores have an inner diameter of 0.78 inches.

About two weeks ago I place a sample request for Finemet, but Metglas contacted me and said, "I received notice from our sister company, Finemet, that you are also interested in nanocrystalline cores.  Did you have a particular core in mind?"  So Finemet is a sister company of Metglas. I was too embarrassed to ask for another sample, so I'll probably have to pay for a Finemet core. Do you know how much Finemet cores cost relative to Metglas?

Rob, now that you'll have a legitimate Naudin Metglas MEG do you think Naudin would reply to an email for possible pointers?  It sure would be great if he could get involved at least a little.

Regards,
Paul Lowrance

[MeggerMan]

Hi Paul,
I agree with MrAmos, be cheeky and ask them for a nanocrystalline core sample too.
Also see if they do a cut C core in that material.
I saw somewhere on the Hitachi website a cut C core that was about 1Kg in weight but I am not sure what material it was made of.

Regards

Rob

[hartiberlin]

Hi Paul,
maybe could one use videotape as super thin core material ?

Or audio pure iron tape ?
There is then only a few mikrometer thick surface layer of this
magnetic material on the plastic tape background layer...

Or won?t this work ?

Thanks.

Regards, Stefan.