Question on inductance with magnetic material core.

[yungman]

Is there a difference in inductance of an inductance with magnetic material whether it is magnetized or not. Meaning is there an increase of inductance if the core has been magnetized ( become magnet) vs the same material but not magnetized?

Does magnetization increase the $\mu$ of the material?

 

[cabraham]

Yes.

 

[yungman]

Yes.

So the stronger the magnetization, the higher the $\mu$? How much difference.

Is it true that if I have an inductor with a iron core. I can increase the inductance by putting a magnet near it to induce magnetism onto the core? And the stronger the induction, the higher the inductance.

Can someone point me to reading materials in this subject?

Thanks

Alan

 

[cabraham]

Near the origin is "hard magnetization". As the winding current increases, the flux increases non-linearly since mu increases. Then mu is roughly constant as amp-turns increase & flux increases linearly. This region is "easy magnetization". Then as the saturation flux density value is approached, mu decreases. THe curve, known as the "B-H loop" is non-linear.

For reading materials, any good e/m fields text is recommended. Kraus & Carver, Griffiths, Hayt, are 3 that come to mind, but there are others as well. Also, makers of xfmr & inductor core material like Philips magnetics, Arnold Engr., Magnetics Inc., are good resources. They know magnetic materials better than anybody. That should get you started.

Claude

 

[sardar]

Yes, there is a difference in inductance between an inductor with a magnetized core and one with a non-magnetized core. When a magnetic material is magnetized, it becomes more susceptible to the effects of magnetic fields, which can increase its permeability (\mu). This increase in permeability leads to a higher inductance in the inductor. Therefore, there is an increase in inductance when the core is magnetized compared to when it is not. This is because the magnetic field created by the current flowing through the inductor is able to penetrate the magnetized core more easily, resulting in a stronger and more concentrated magnetic field. So, while the material itself does not change, the magnetization of the core does affect its ability to store energy in the form of a magnetic field, thus impacting the inductance of the inductor.