Pulse coil and wheel travel

[capthook]

Gyula -
Thanks for the excellent thoughts and comments!

For some reference, the idea is similar to patent #: 5,258,697
( http://www.google.com/advanced_patent_search and input the patent number in the search parameter)

The magnet is attracted to the EM core.  As the magnet centers over the core, the EM is pulsed for a very short duration with just enough current to negate the attraction and let the PM spin on past.

There are a number of differences to this patent, but it's the same general idea.

Also, the output shaft is connected to a generator, specifically a dual-rotor axial flux (air coils/low drag).
The output is collected on a capacitor and then used as input.
Final design I suppose should use Lio-Ion rechargeable batteries as they offer ~99% efficiency. (vs. 50% capacitor, ~85% lead acid depending on SOC)

As to COP, I'm hesitant to make specific claims at this point, but will share some figures in the near future.

I've seen your mention of the DMMPOWER 'super electromagnet' in the past - an interesting idea.  A possible construction method might be using steel bars to surround a PM.  Like 4 pieces of 1/2" 1018 for the top/bottom/sides and then wrapping a coil around that.
A backing magnet might offer the same principal?

An attraction magnet placed at the far end of the core/coil can offer an advantage.
For example, when attracting a PM over a distance and pulsing with 9V:
1) core/coil:                                2" attraction distance / 1" airgap needed to negate attraction
2) core/coil with backing attraction magnet: 4" attraction distance / 2" airgap needed to negate attraction
So it takes 1" of added airgap to gain 2" of attraction distance ~ 2:1
With a repulsion backing magnet, the EM repulsion strength is increased, but the attraction distance is reduced to almost nothing as you must get close enough to the core to overcome the repulsion field provided by the PM.

I'm wondering whether the current coil, with an attraction backing magnet, would outperform the other 2 coil design that use both ends of the coil.
Hmmm, I guess one might use the horizontal/2 end coil and then place attracting magnets to the backsides... (see attached pic)

edit: or even the 'horseshoe' magnet like the 2nd pic
Which of the 3 coil designs might be best?
Hmmm.... then again, the backing magnets on the 2 coils pictured wouldn't probably work...

[capthook]

Dual-rotor axial flux generator build pics and info

1) stator mold out of 1/2" plywood.  Bottom piece square, mold/upper piece cutout to diameter of stator, center piece cut to form center hole.  Pieces sealed with caulk and then waxed to ease stator removal.  Bolts to tighten lid.

2) finished stator.  Wired 3-phase star.  Each Coil: 3/4"ID, 2"OD, 3/8"depth, 24 AWG, 500 turns, 4.7 ohms, 14.10 ohms per phase.

3) left rotor.  Rotors normally made with solid steel to complete magnetic circuit, this is cut from 1"x 12" pine with (3) circles of 16 gauge steel then affixed to reduce weight by 65%. (steel cut by hand with a jigsaw with steel blades)

4) right rotor.  Duct tape to protect magnets and extra hold as they are usually poured in epoxy and I wanted the ability to change/modify the magnets.

5) Assembled axial flux.  This picture has additional pulleys added (and since removed), 1:4 ratio.  Increasing RPM's massively increases output, at the cost - of course - of increased Lenz drag.

Specs:
Magnets: 3/4"D x 1/2"H N42 Neos
airgap between each rotor and stator: 1/8"
Output @ 60 RPM: 12 watts : 20 volts @ 0.6 amps
Output @ 240 RPM: 190 watts (4x RPMs = 16x output, thus the pulley idea)

[capthook]

Thanks for the reference to the Flynn PPMT.  I've re-read and studied the patent and various discussions and has given me some ideas.
While some argue Flynns PPMT is similar to the 'astroboots' and thus the patent is not novel, the volume of details and unique methods is beyond a doubt novel and the information presented is of great value and interest.

Referring to Patent 6,342,746 : Figures 16B & 16C also 47 & 48
Please refer to numbered attached pictures.

(1) Using polarized armatures.  Graph line 391 shows current required (point 393) for flux to =0 on lower armature.
(1 amp @ (x?) volts = (y?)  watts?)

(2) 2 permanent magnets with non-polarized armatures.

(3) Combining 1 & 2

The goal would be to lift 5 lbs. from a distance of 1/2" and then fully release the load (flux = 0) with a small coil input using method (3).

A primary question is magnet strength.
Ceramic magnets are normally recommended to prevent core saturation.
However, Jan Vink's replication ( http://peswiki.com/index.php/Directory:FPPP:Replication:Jan_Vink ) uses N42 neos and 15 watts.  He reports N35 neos as using .88 watts (although magnet dimensions aren't given. I would suppose they are a bit smaller given the results??)
Larger/stronger magnets will provide greater/further lift.

Using 2 permanent magnets in the device adds additional 'free' flux vs. the 1 of picture (1).
Might additional magnets be of benefit? A row of 4 or 6 etc?  Or stacking them 2 or 3 deep?

Will the additional power required to negate the polarized armature be overall less efficient than just using a non-polarized armature?

What advice, methods, thoughts might result in achieving the goal?
What power input might be required?

[gyulasun]

Hi,

One more measurement report on ppt, if you are not yet aware of: http://www.flynnresearch.net/young%20scientist/Josh%20Jones/josh.htm  see Josh's research paper http://www.flynnresearch.net/young%20scientist/Josh%20Jones/PPMT%20Research%20Paper.pdf
From Page 3 of Josh' paper:

" The armature pull-off tests that were performed with no magnets, the 1,200 turn coils on and powered, and the 0.070 shim produced an average of 3.72 newtons of force. The configuration with the magnets, no coils, and the 0.070 shim produced an average of 8.75 newtons of force. Therefore one would think that by adding the two configurations together that the force would equal 3.72 newtons plus 8.75 newtons. But with the two configurations together the pull-off force increased considerably to an average of 22.82 newtons. This does not violate the laws of conservation because there are a total of 3 flux producing sources in the fixture â€" two magnet stacks and a solenoid. All must be considered when looking at the effect. The apparatus uniquely concentrates the sources in a single armature. "

Re on your question on magnet strength,  I believe it all depends on two things:  the core saturation data (ferrite -> lamination/hypersil -> metglas) and core cross section area.  You have to consider saturation for the COMBINED flux where-ever it appears in the magnetic  path (it is mainly in the end pieces or armatures).

Have little time now, will be travelling for a week or so.

rgds, Gyula