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SuccessTheory
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If a material has a higher permeability (electromagnetism) than another when in the presence of a fixed H field, would it generally also have a higher permeability when in the presence of a changing H field?
dude_ said:no it doesn't : )
it depends on the material properties.
SuccessTheory said:If a material has a higher permeability (electromagnetism) than another when in the presence of a fixed H field, would it generally also have a higher permeability when in the presence of a changing H field?
berkeman said:That is not correct. In general, the permeability is fairly constant over frequency, until eddy current effects start to become noticable.
berkeman said:Yes, the permeability is fairly constant over frequency. It is the relationship between B and H, as shown in the Magnetic Hysteresis plot on this page:
http://en.wikipedia.org/wiki/Hysteresis
dude_ said:
berkeman said:Lordy, that's an involved thread. But from a quick read, it seems off-target. The permeability for normal use of a ferrite or magnetic material has nothing to do with the magnetization M and saturation flux. You use the magnetic material in its linear region, so you stay away from saturation (where mu drops), and you use "soft" materials that do not have much Br. Especially if this is for a radio application, you are going to stay away from saturation and use a soft magnetic ferrite material.
Does that help?
dude_ said:yeah that is true you should stay away from the saturation, this was what i said in that thread.
but, what is more, i am saying that the B/H ratio would change as the frequency is swept. after a certain frequency B/H ratio starts to fall down.
but, what is more, i am saying that the B/H ratio would change as the frequency is swept. after a certain frequency B/H ratio starts to fall down.
SuccessTheory said:I see what you mean from those hysteresis plots, it seems as if there are "two types of slopes", the one going up and then a less steep one when you are fighting the remenance. So I guess this means absolute permeability is actually a range between these values.
Permeability is a measure of the ability of a material to allow magnetic flux to pass through it.
A static H field refers to a magnetic field that does not change over time, while a dynamic H field refers to a magnetic field that varies with time.
In the presence of a static H field, permeability remains constant and does not change.
In the presence of a dynamic H field, permeability can change and is dependent on the frequency and amplitude of the field.
Permeability is an important factor in determining the magnetic properties of materials. It affects the strength of the magnetic field that can be generated in a material and is crucial in the design of electrical devices such as transformers and inductors.