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Kal_Electri
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The inductor is initially an air cored one.When the Iron core is introduced,the resistance is found to increase considerably.Please explain.
Losses.yungman said:Why is the resistance which is the real part increase?
DC? DC hasn't been mentioned.yungman said:Like how? When you measure at DC, it is only the resistance of the wire and is constant no matter what. How is the induction of core change the DC resistance?
jim hardy said:DC resistance doesn't change.
But if you measure AC impedance and phase angle and do a polar to rectangular calc you get a real component that is different from what a DC ohm-meter would report.
That's because the core losses are energy losses which can only show up as resistance.
And they're only present when excitation is AC.
NascentOxygen said:DC? DC hasn't been mentioned.
NascentOxygen said:DC? DC hasn't been mentioned.
The theory of eddy current losses in transformer laminations is given in http://www.elect.mrt.ac.lk/EE201_em_theory.pdfyungman said:But R is the DC value only! Or are you implying the skin effect cause the R to go up and this has nothing to do with the inductance. It is pure resistance that increase with frequency! That actually makes sense! I think I answer my own question!
jim hardy said:Yungman - check my thinking
Iron losses in the core come out as heat so must cause an in-phase component of current. Else there'd be no net electrical energy transfer into core. P=VICos(Theta) and theta can't be 90 degrees if there's any watts heating the core.
So they will appear to be another resistance in parallel
which will show up as series in theveniin equivalent
and the DC ohms will differ from the ohms in real component of complex Z.
am i on track?
old jim
jim hardy said:Yungman - check my thinking
Iron losses in the core come out as heat so must cause an in-phase component of current. Else there'd be no net electrical energy transfer into core. P=VICos(Theta) and theta can't be 90 degrees if there's any watts heating the core.
So they will appear to be another resistance in parallel
which will show up as series in theveniin equivalent
and the DC ohms will differ from the ohms in real component of complex Z.
am i on track?
old jim
Averagesupernova said:I would agree that in order for heat to be generated the current would have to be in phase with the voltage. Would we look at this as a parallel resistance or a series one?
The resistance of an inductor increases when an iron core is introduced because the iron core has a higher magnetic permeability than air. This means that the magnetic field produced by the current passing through the inductor will be stronger and more concentrated, resulting in an increase in the inductance of the inductor. This increase in inductance leads to a higher opposition to changes in current, resulting in an increase in resistance.
The introduction of an iron core increases the inductance of an inductor. The iron core has a higher magnetic permeability than air, which means that it can store more magnetic energy for a given current. This leads to a stronger and more concentrated magnetic field, resulting in an increase in the inductance of the inductor.
Yes, the size of the iron core can affect the resistance of an inductor. The larger the iron core, the more magnetic energy it can store, resulting in a stronger magnetic field and an increase in inductance. This increase in inductance leads to a higher opposition to changes in current, resulting in an increase in resistance.
An iron core is preferred over other materials for increasing the inductance of an inductor because it has a higher magnetic permeability. This means that it can store more magnetic energy for a given current, resulting in a stronger and more concentrated magnetic field. Other materials may also increase inductance, but not to the same extent as an iron core.
Yes, the introduction of an iron core can lead to overheating in an inductor if the current passing through the inductor is too high. The iron core can cause the magnetic field to become too strong, resulting in increased resistance and heat generation. This can be prevented by using an iron core with appropriate dimensions and by limiting the current passing through the inductor.