Thane Heins Perepiteia.

[SkyWatcher123]

Hi kator, heres a pic that may help. the bolt is a 1/2 dia., 3-1/4L., with 1-1/4" hanging off back of rear coil which is threaded with a nut, rear coil depth is 3/4" X 2" dia. with 1-1/4" from front of coil to front of bolt head.
I also tested today the alternating neo magnet configuration and results are the same which are decreased input current below unloaded input current when coil shorted.

[markzpeiverson]

Don't know if this has any relevance, but I dug this out of my files on magnetics...
Note the date of the article!
-Mark

Variation in the Longitudinal Incremental Permeability due to a Superimposed Circular Field
Retyped from NATURE Page 795, October 29, 1938

During the course of an investigation of the variation of the longitudinal incremental permeability by a superimposed circular magnetic field, some rather interesting results were obtained with certain ironnickel alloys. The ferromagnetic materials under investigation were of wire form and served as the core of long slender solenoid. Direct current was passed through the core to produce the circular field, and the longitudinal permeability was calculated from inductance measurements on the solenoid.

Using well-annealed alloys, it was found that rather large increases in longitudinal incremental permeability could be obtained as a function of relatively small superimposed circular field, while upon twisting the conducting core a gradual change from an increase to a decrease in the incremental longitudinal permeability as a function of a superimposed circular field was obtained.

These effects are shown in Fig. 1 where curve (a) gives the variation of the inductance of the solenoid as a function of the direct current through the conducting core of an unstrained sample. Curve (b) is that obtained after the core has been twisted the 120 degrees. Here the inductance of the solenoid without any core is 1.3 millihenries. In all measurements, the effect of the earth's field was reduced to a minimum and the sample were completely demagnetized before each run.

Page 1 of 4

[Kator01]

Hello Mark,

very interesting. Is this the full content ?

I did research on nature.com and found this here, but it is only an abstract and you have to pay for full content I guess.

http://www.nature.com/nature/journal/v142/n3600/pdf/142795a0.pdf

Anybody has acess to the original writing ?


@skywalker123 : thank you for this pic. Do you have a view about your setup which shows how the magnets are driven. This perspective does not give me a clue. I looks for me as if the driving axis leads directly through the coil.
I only can imagine that the coil is mounted on the left rectangular wooden plate and is displaced in direction to the viewer and the motor-driven axis crosses the rectangular wooden frontplate through a hole and drives the wooden disc with the magnets.
Is that so ?

One thing you could test is to take a longer core-shaft so that you have a bigger mass situated to the left coil.
I propose this because it could give us a indication if it is possible to get an increase of the time-delay.
I would assume that the spontaneous magentisation spreads ( longitudianl incrementation)  in a non-uniform way and consumes up more time  spreading to the left that to the right.
It is no big deal to do the change in this setup.

In a next step I would make the corelength eaqal to the coil-length and embedd the coil in a fitting (hole) in your wooden frontplate ( left plate )

What so you think ?

Thank you for your effort


Kator01

[Kator01]

Hello all,

I have to revise my schemativ posted in Replay #4158 on page 416 because of an error.
Diode was wrongly placed.

Here is the revised circuit.

Thank you Gyula for remembering me.

Rgrds

Kator01

[SkyWatcher123]

Hi Kator, yes your description seems accurate and i was thinking as well of increasing ferromagnetic core mass as well. I've been thinking about why the input current is decreasing below unloaded input current and I think I may have an idea. When say the north pole of neo magnet approaches the coil lets say an air core, we have lentz drag and if we set back the coil we still have lentz drag but less intense, now bring the coil back close to the magnet and insert a ferromagnetic core and again we have lentz drag, but now if we set back the coil with the core inserted as the magnet approaches its north pole field prefers the steel bolt as a flux route and the bolt is now a south polarity because thats how ferromagnetic materials work compared to diamagnetic materials like copper which will create the same polarity. So we now have a south pole at bolt core which induces a south pole in set back coil up to a certain point in the approach phase which enhances attraction to bolt core and explains the reduced input current or increase speed/torque. If there is a delay in reactive currrent as you say I cant visualize how that explains the results im seeing and you would have to make that clear to me, however I think my idea fits the observed results. What you folks think.