After all the Lorentz Force (of Lenz' drag) is a force...

[dieter]

To those interested in and understanding induction, if you want to discuss / pick up the following, you're welcome.

Pity, that Lenz law, and noble the quest for the "lenzless" is. Thinking about all these, I came to some startling conclusions:

Normally, if we're approaching, say, a permantent magnet PM towards a coil, the field strength in the coil is increasing. We know the result, the current flow generates a secondary field that repelles the pm while approaching (=increasing field strength), and attracting it when it's moving away(=decreasing field strength).

So I realized, all that is needed is a magnet that causes a decreasing field strength when it is approaching, and an increasing field strength when it is moving away.

In response the coil would then, according to Lenz's law, attract the magnet when it is approaching, and repell it, when it is moving away. In other words, whatever direction the magnet is moving, its motion is accellerated by what is formerly known as "Lenz drag", probably best named "Reverse Lorentz Force Accelleration", or the "Marfurt Effect" if you prefer.

Of course, that would require a flowing current and furthermore, the heavier the attached load, the more selfaccelleration.

So to stop this selfrunner, eg. to prevent a runaway situation (not unthinkable with ferrite cores etc.), one had to unplug the load .

Such a fancy magnet, or pseudo magnet, would be great, wouldn't it? I wonder if anybody was every successful in implementing such a thing. Well, if I were, I seriously were in troubles, not knowing how to proceed.

[penno64]

=rtv3

Tinman has the device you describe but won't disclose.

Says it eats brushes just like lockridge.

Penno

[Floor]

@Dieter

I work with permanent magnets, because their interactions
are in some ways simple. Or should I say rather that the
bottom line of their I : O  is simpler. 

I see some times, what I think of as analogies between the curves in
force x displacement integrations and the curves in a single
wave form. I think this is especially interesting in the context of pulse motors.
...........................
If I am using these terms in the right place.... as I recall and put very simply....
reluctance is current lagging behind voltage while reactance gives us the back spike.

There is also some kind of analogy in the resistance to acceleration of a
mass against inertia and a coils reluctance... and the resistance to DEceleration
(momentum) of a mass due to inertia and a coils reactance. 
............................
This of course all relates to the expansion and contraction of  magnetic "fields" giving rise
to electric currents which in turn give rise to secondary magnetic fields, and so on.
...........................
I have been working with a hypothesis that near 90 deg. interactions (and although they may largely negate momentum) may lead to increased cop if not OU, under certain conditions.

This hypothesis may or may not add to your bag of tricks in accomplishing what you suggest to
explore.
.................
Also.... Some thing I have pondered is;  do two permanent magnet approaching one another (pole to
pole)  either attracting or repelling, induce electric currents each in the other ?


Thank you very much for your time
                floor

[shylo]

Hi Dieter, "Normally, if we're approaching, say, a permantent magnet PM towards a coil, the field strength in the coil is increasing. We know the result, the current flow generates a secondary field that repelles the pm while approaching (=increasing field strength), and attracting it when it's moving away(=decreasing field strength).

Isn't it more like an approaching magnet creates current flow in such a direction to create an electro-magnet of the same polarity and this is the repulsion, and after TDC the current reverses, thus creating an opposite pole which is now pulling the leaving magnet back? Also all of this only happens if there is a load attached to the coils leads.
artv

[ALVARO_CS]

In a system designed to serve as an exciter, where the inducing and induced field interactions are orthogonal, where one assumes that the induced circuit, under "normal" circumstances is configured series cancelling, and the inducing circuit is from a magnetics standpoint "unidirectional", an inversion of Lenz's law can be experienced when the excited circuit is placed under load.

Erfinder:
Does that "inversion" means attraction force in  magnet to coil before TDC and repulsion after ?
I think (intuitively) that there is a clue in that word "orthogonal" (from a geometric point of view)