Magnet coil cores, demagnetization power and Lenz delay.

[MarkE]

@MarkE,

What you wrote above is completely incomprehensible. You may think you're making sense, but I can assure you, MarkE, that your communication skills are extremely poor. You need a basic course in English composition. There's a chance you may understand what you are trying to say, but there's a huge failure on your part to put your thoughts into understandable language.     

Let's take the Lorentz force situation first:

Just take two parallel copper wires each suspended between two posts.   Drive a current through each wire.  If the currents go the same direction, the Lorentz force between the wires pushes them apart.  If the currents oppose then the Lorentz force pulls the wires towards one another.  The delay between change in current in one wire and mechanical force applied to the other wire is s/(c*(uR*eR)^0.5)  Where: is is the distance between the two wires, c is the speed of light in a vacuum, uR, and eR are the relative permeability, and relative permittivity of the material between the wires.  As that material is air, uR and eR are for practical purposes both 1.0, and the delay reduces to: s/c.  If the wires are 10cm apart, the delay is about 333ps.  It would take very specialized instruments to detect the delay. For practical purposes in problems of designing electrodynamic machines like motors, or generators, we can safely treat the delay as zero.

Now change each wire to an air core solenoid.  Two effects result:  For any given DC current the number of Amperes per meter increases by the number of turns per meter.  This also increases the inductance of each lead so that the amount of time that it takes any given voltage to change the current in each lead has now gone way up.  However, all our materials still have uR and eR effectively equal to 1.0 so the electromagnetic field between each conductor assembly still propagates at the speed of light.  Any current change in one winding will be sensed as a mechanical force change on the other winding in a few hundred picoseconds.  IE for any practical motor or generator it is an ignorable delay.

Next insert a material with a uR of 1000 but highly resistive material into the solenoid cores.  Now the magnetic fields are far more concentrated by the permeability of the core material, resulting in much greater Lorentz forces and much greater inductance in the windings. The higher core permeability also slows the propagation of the E/M field through the radius of each of our solenoids.  Our sub nanosecond propagation delay over  is now in the ~10 nanosecond range.  That's still such a short delay that we would ignore it in any practical motor or generator.

Next substitute a core material with the same permeability but with a low resistance.  The magnetic field change in either core that results from any change in current in the winding induces eddy currents in the core.  Those eddy currents establish an image field that opposes the change in magnetic flux.  The external E/M field is suppressed.  The faster the changes in current, the more suppressed that field is due to the induced eddy currents.  If we step the current and hold it, externally the field builds-up as the eddy currents die down.  If the resistance of the core material is very low, like in ingot iron it can take milliseconds for the eddy currents to die down after a current step.  If the cores were superconductors, the eddy currents would never die down and the external field would never respond to the change in winding current.

This is the sort of thing that you have been talking about.  Note that what is happening is energy is put into the system, and the action of the eddy currents is to oppose that energy doing external work.  The eddy currents convert useful energy into heat.  They create loss.  They are a direct result of:  Faraday induction.  Their orientation is determined by Lenz' Law.  The induced eddy currents are not delayed.  The image field that they develop opposes the change in field that induced them and the external result is that the net field changes much more slowly than the applied current.

When you have digested the above we can move on.

[synchro1]

@MarkE,

Here's what it souds like when translated from Mandrian Chinese:

•When the retentivity of a ferromagnetic substance interferes with its re-magnetization in the opposite direction, a condition known as hysteresis occurs

Also, please answer Tinman's question!

[MarkE]

So you are saying that the lenz force that act's against the rotor magnet can indeed be delayed.
It is my understanding that that is what is being ment by! delayed lenz effect!-the apposing magnetic field acting against that of the magnetic field on the rotor is delayed until such time that it pushes the PM away from the coil in an asisting direction.

There is no such thing as a "Lenz force".  There is Faraday induction, and there is Lorentz force.  Lenz' Law dictates the orientation of induced emf due to Faraday induction.  There is nothing that delays the orientation of induced EMF dictated by Lenz' Law.  There are mechanisms that delay external formation of a field such as eddy currents and magnetic viscosity.  Each of those examples are energy loss mechanisms.  If one wants to make a brake or a heater, they can be quite useful.  If one is trying to increase the efficiency of a motor or a generator they are to be carefully minimized.  If one is looking to obtain mechanical or electrical energy back from either of those mechanisms, that is never going to happen.  As the adage goes:  "Losses cannot be made up in volume." 

The Tinsel Koala experiment procedure is very instructive:  Take any mechanism where it is suspected or believed that the mechanism adds net energy, and conduct a null experiment with the alleged energy adding device replaced by a mechanically equivalent null device.  Test to see if the measure of energy is better with the proposed mechanism or its null equivalent.  These experiments quickly expose fallacies in the assumptions behind experiments that do not include a proper null.    In the case of alleged "delayed Lenz effect" devices: Each and every one fails to show energy advantage over its null equivalent. 

[MarkE]

@MarkE,

A rotor magnet passes a ferrite core and the magnetic field from the passng magnet transits from point A to point B through the core. What happens to the timee interval if we increase the magnetizem in the core? Why would anyone want to bypass all the conventional theories and jump to the Lorentz force to help solve this simple problem?

This is gibberish.

[MarkE]

Lets look at a simple Mag Amp:


"To begin, I would like to first show a simple experiment that demonstrates how saturating a magnetic core can lower inductance and allow more AC current to flow through a lamp. The lamp glows brighter when the magnets are near the transformer. The magnetic field saturates the core, lowering the inductive reactance in series with the lamp".

OK so you've got a mag amp.  Those have been used for over a century.  Before the invention of thyratron tubes they were the method of choice for switching large AC power sources.  Under the right circumstances they only dissipate a small percentage of the controlled power.  The Steorn Orbo "core effect" motor is at its heart a mag amp operated device that only consumes net energy from its battery power source each cycle.