Electronically generate rotating magnetic fields

[CompuTutor]

Title Quote:
"Electronically generate rotating magnetic fields"

Is there an example anywhere in nature where a magnetic field isn't rotating in relation to the matter it is interacting with please ?

I do agree though, bad topic naming aside, zero-beating an excitation against the enviromental oppositions so that it retards or advances as a "Walking" field around a toroid core is a legit persuit.

But what is to be gained via this ?



Remember, the compass is only a two dimentional representation of the field it is placed in, it doesn't show the real picture at all.

I sure wish an X x Y + Z(axis) pair of right angle torroids or something was available for an oscilloscope to display and model/render what the real picture is...

For those not familier, the "Z" axis is only brightness on an O-Scope.

Imagine looking at a (2D) "Slice" of our reality and trying to understand it, we think in 3D modeling, but a compass only shows 2D worth of info, how can we respect those findings ?

Even our "Magnetic Modeling" programs make an effort to represent it as 3D,
even though the display is still not a holographic projector.

You pick a single point of reference in relation to the test currently undergone,
and it displays the 2D representation on a 2D screen at best.

Only a program that allows mouse-rotation to orientate,
and is represented in a 3D display medium as well
can come close to representing the truth.

We laugh at 3D models etched into a plexiglass cube at our malls,
but an "Etch" of a REAL TPU RUNNING would yield all the answers.

[Eighthman]

I was under the impression that Mark's device spun a compass needle round and round, giving evidence of switched fields that created a sort of rotation.  In addition, the gyroscopic effect suggests a rotation of fields. Add to that the visual of 3 or 4 windings placed on the black speaker form, hinting at such a circuit.

EDN is a top level design magazine so the construction details may not be for the 'do-it-yourself' type.  I would think other, simpler arrangements could be made for generating the pulses, however the driver chip looked interesting.

[Lakes]

If you really want to build your own circuit...

http://letsmakerobots.com/node/2898

[Eighthman]

The main puzzlement I have with Mark's device is the fact of its simplicity together with contrasting profound effects, especially if the story about a weirdly exploding TV set is to be believed. ( I wish there was some independent testimony on this. I had once heard about exploding TV sets in the former Soviet Union but was told that it was because of poor quality capacitors).

Obviously, there are plenty of rotating magnetic fields around ever since Tesla invented the induction motor. Is it enough difference that Mark's device used rotating fields on air cores?Hasn't anyone else stumbled onto this phenomena?  Maybe Hendershot, maybe Searl (if he can be believed).

[CompuTutor]

First, let me help you with the website link & PDF file,
I don't know why you aren't able to post them though:

Page:
http://www.edn.com/article/457397-Electronically_generate_rotating_magnetic_fields.php

PDF's:
http://www.edn.com/contents/images/6718481.pdf
http://www.edn.com/file/10550-Figure_2.pdf?force=true
http://www.edn.com/file/10715-Figure_3.pdf?force=true

Code:
http://www.edn.com/file/10724-Click_here.zip
http://www.edn.com/file/10724-Click_here.zip?force=true

Second, picture a 3-dimensional pattern. like a Lissajous pattern.
Now view it in only 2D, like the compass sees it, it would appear to spin.

I attached an animated .GIF picture as an easy example.
remove all vertical information a compass would not indicate,
and look at the crossing points on the horizontal line only.

See the problem with using 2D tools to see a 3D field ?

We need a proper 3D projection, from a 3D environment sensor,
to really know what the harmonics and patterns are in the TPU.

It's not like we can throw iron fillings at it in zero gravity,
or submerse it into a tank of ferro-fluid to see the patterns...

Your right though, simplicity is natures way, we just need better tools.

Don't get me wrong, I am not inferring a Lissajous is what they make,
look at magnetic modelling programs plots of Rodin coils instead please,
you'll clearly see why the ball magnet suspended in the ceneter spins,
this was just the simplest waveform to make the 2D-tool/3D-field issue clearer.