BEMF current reversal.

[Allen Burgess]

Reluctance and reactance.

Still don't know the difference between reluctance and reactance, do you?

@bistander,

Reactance is the resistance in the inductor to current that increases as frequency increases. After a magnetic field develops in the inductor, we calculate the resistance to the fluctuating current as Reluctance, and the Reluctance is directly proportional to the magnetic field strength of the Inductor.

The higher the frequency of the input the higher the Reactance of the Inductor. Got it? The higher the magnetic field strength in the Inductor, the higher the Reluctance.

Why not take some time to think these things over for yourself if you're new to them?

[bistander]

Reluctance

... After a magnetic field develops in the inductor, we calculate the resistance to the fluctuating current as Reluctance, and the Reluctance is directly proportional to the magnetic field strength of the Inductor.
...
The higher the magnetic field strength in the Inductor, the higher the Reluctance.

..

These two statements are incorrect.

It is ambiguous as to exactly what you mean by magnetic field strength (is it intensity or density?), but decreasing the reluctance in a magnetic circuit increases the flux for a given mmf, which is opposite to the impression given by your two statements. Insert an iron core into a coil and you will increase the magnetic field for a given current. This will lower the reluctance. That lower reluctance will increase the coil's inductance which will increase its reactance and it will resist changing current more than the air core coil (higher reluctance).

Inductance in Terms of Magnetic Reluctance and Magnetic Permeance

See equation [4-32]. Inductance = turns squared / reluctance. Also note that since turns is deminsionless, inductance and reluctance have inverse units.

So as reluctance decreases, inductance increases which increases reactance and impedance which resist changing current.

[Allen Burgess]

These two statements are incorrect.

It is ambiguous as to exactly what you mean by magnetic field strength (is it intensity or density?), but decreasing the reluctance in a magnetic circuit increases the flux for a given mmf, which is opposite to the impression given by your two statements. Insert an iron core into a coil and you will increase the magnetic field for a given current. This will lower the reluctance. That lower reluctance will increase the coil's inductance which will increase its reactance and it will resist changing current more than the air core coil (higher reluctance).

Inductance in Terms of Magnetic Reluctance and Magnetic Permeance

See equation [4-32]. Inductance = turns squared / reluctance. Also note that since turns is deminsionless, inductance and reluctance have inverse units.

So as reluctance decreases, inductance increases which increases reactance and impedance which resist changing current.

@bistander,

Thanks for raising this issue:

"Air and vacuum have high reluctance, while easily magnetized materials such as soft iron have low reluctance. The concentration of flux in low-reluctance materials forms strong temporary poles and causes mechanical forces that tend to move the materials towards regions of higher flux so it is always an attractive force (pull)".

Your formula introduces "The relative magnetic permeability of the core material" The formula I posted is for an "Air Core" inductor. Magnetic flux takes the path of least resistance. The low reluctance core acts as a pathway for the flux. You're right that the inclusion of the ferrite core increases inductance, but the low reluctance of the ferrite core presents an avenue for the flux to travel through, so any increased resistance from charge is canceled. My analysis works with an air core "Windings Charge" only.

[bistander]

What?

@bistander,

Thanks for raising this issue:

"Air and vacuum have high reluctance, while easily magnetized materials such as soft iron have low reluctance. The concentration of flux in low-reluctance materials forms strong temporary poles and causes mechanical forces that tend to move the materials towards regions of higher flux so it is always an attractive force (pull)".

Your formula introduces "The relative magnetic permeability of the core material" The formula I posted is for an "Air Core" inductor. Magnetic flux takes the path of least resistance. The low reluctance core acts as a pathway for the flux. You're right that the inclusion of the ferrite core increases inductance, but the low reluctance of the ferrite core presents an avenue for the flux to travel through, so any increased resistance from charge is canceled. My analysis works with an air core "Windings Charge" only.

My analysis works with an air core "Windings Charge" only.

This goes miles off-topic. You claim reluctance of an air core coil changes with the level of induction. Look back at your graphic which I have reposted several times. See his formula for calculating reluctance. Either your coil would need to change shape or the permeability of space changes. Neither are likely. Believe what you want. I'm through.

bi

[Allen Burgess]

This goes miles off-topic. You claim reluctance of an air core coil changes with the level of induction. Look back at your graphic which I have reposted several times. See his formula for calculating reluctance. Either your coil would need to change shape or the permeability of space changes. Neither are likely. Believe what you want. I'm through.

bi

@bistander,

The reluctance changes with the level of magnetic force. The magnetic force level acts like Ohmic resistance in the "Resistance Formula". The higher the Ohms the higher the resistance in the circuit, and equally, the greater the magnetic force in the inductor, the greater the Reluctance! Got it?

[Allen Burgess]

Negative Henry.

Quote from Tinselkoala:

"A negative correlation has nothing to do with "negative Henry" nor does it imply that one or the other of the correlated variables is "negative". By posting what you have posted you reveal that you do not understand correlation or inverse relationships".

Tinselkoala can not find a correlation between the "Inverse Henry" term of magnetic reluctance, and the minus sign that appears before the number on the inductance meter when set to read in Henries. He always couples his misstatements with some kind of personal insult. (He's revealing his stupidity again) to help make his malarkey stick.

[Allen Burgess]

Lenz's Law:

When a magnet approaches a coil, a current runs in one direction and the ammeter registers a plus indicating a positive current. When the magnet's pulled away from the coil, the current runs in the opposite direction and the ammeter registers a negative indicating a reverse or negative current.

[Allen Burgess]

Negative current and Henries.

Tinselkoala maintains that "Negative Current" is imaginary, even though we measure it with our amp meters. It comes as no surprise to anyone when we see him try and pull the same stunt and invalidate a "Negative Henry" reading on our inductance meters as again imaginary.

[bistander]

Bull

@bistander,

The reluctance changes with the level of magnetic force. The magnetic force level acts like Ohmic resistance in the "Resistance Formula". The higher the Ohms the higher the resistance in the circuit, and equally, the greater the magnetic force in the inductor, the greater the Reluctance! Got it?

Pure BS. You can show no supporting theory or derivation, or find anyone in the world agreeing with you. Could it be you're wrong?

[RAMSET]

Allen you burn thru people ....trying to find support for your vendetta against
a man who only tried to help you [one of many ]

most have not got a clue what you are actually talking about
perhaps you can teach here and leave out the finger pointing

if your argument has merit ...
it needs no screaming yelling or funny movies

it should be able to withstand investigation.
I would imagine a build to prove your....Whatsit

just one mans opinion

[Allen Burgess]

BS

Pure BS. You can show no supporting theory or derivation, or find anyone in the world agreeing with you. Could it be you're wrong?

@bistander,

You can't read nor understand basic algebraic expressions. You hide your ignorance with insults just like your protégé.

Watch this video:

https://www.coursera.org/learn/elect...netic-circuits

[Allen Burgess]

Dead Thread

Allen you burn thru people ....trying to find support for your vendetta against
a man who only tried to help you [one of many ]

most have not got a clue what you are actually talking about
perhaps you can teach here and leave out the finger pointing

if your argument has merit ...
it needs no screaming yelling or funny movies

it should be able to withstand investigation.
I would imagine a build to prove your....Whatsit

just one mans opinion

@ramset,

The moderators killed the bifilar thread not the commentators. You did this with culpable bias. TK kept complaining about my "Fake Deaf Sign Interpreter" video parodying him, while I had to tolerate a video posted by Tinman of me in a straight jacket as Louis the 14th. Who moderates the moderators?

The only thing Tinselkoala would offer to help with is rearranging furniture in a home for the blind.

[bistander]

Circle

@bistander,

You can't read nor understand basic algebraic expressions. You hide your ignorance with insults just like your protégé.

Watch this video:

https://www.coursera.org/learn/elect...netic-circuits

You have circled around to where I came in yesterday; to the very proof you're wrong. The link is to the University of Colorado Boulder lecture displaying and explaing (teaching) this graphic:



See the red highlighted line of characters? That is the definition of reluctance. There is no dependence on magnetic force as you claim.

[Allen Burgess]

You have circled around to where I came in yesterday; to the very proof you're wrong. The link is to the University of Colorado Boulder lecture displaying and explaing (teaching) this graphic:



See the red highlighted line of characters? That is the definition of reluctance. There is no dependence on magnetic force as you claim.

@bistander,

Look again on the bottem left you'll see Reluctance times H-1. This means Reluctance multiplied by "Inverse Henries". Look at the right for the equivalent and you see Resistance multiplied by Ohms!

"Magnetic reluctance, or magnetic resistance, is a concept used in the analysis of magnetic circuits. It is analogous to resistance in an electrical circuit, but rather than dissipating electric energy it stores magnetic energy".

What are the units of stored magnetic energy?

The units are Teslas and Gauss! Therefore the (Reluctance is the product of the stored magnetic energy). The "Inverse Henry" is a measure of stored magnetic energy that factors into Tesla and Gauss.

The stored magnetic energy is similar to numbers of Ohms in the resistance formula. Both in brackets [ ].

@bistander,

This is at least the tenth time you made me repeat myself and I'm getting tired of it!

[bistander]

Confusing units still

@bystander,

Look again on the bottem left you'll see Reluctance =H-1.

The characters inside the brackets [ and ] are the units, not variables or constants in the equation.

[Webers] are units of flux.

[A] are units of Ni. (or [amperes] are units of mmf, magnetomotive force, Ampere turns)

[H^-1] are units of reluctance. The unit for reluctance is the inverse henry.

The units are not part of the equation which is why they are set in the brackets [ and ]. The units are not part of the arithmetic.

[ohms] are the units for R. It does not mean to multipy R times Omega.

[V] units for v. (or [volts] are the units for emf)

[A] units for i. (or [amperes] are the units for current)