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Are there symbols for drawing schematics of magnetic circuits? — Omegatron 14:50, 29 November 2006 (UTC)
There is a magnetic circuit drawn in the section "Circuit Laws" but it does not seem to be mentioned in the text and doesn't have anything useful to say. For example there are 5 flux arrows labelled Φ1 to Φ5. But this is a series magnetic circuit so all 5 values are identical! There are 5 lines called A1 to A5 which make most sense as areas. This drawing would be more useful if Φ values were converted to B values (flux density). Then we would have Flux Density times Area = Flux. B1 x A1 = B2 x A2 = B3 x A3 = B4 x A4 = B5 x A5 87.113.149.155 ( talk) 21:56, 23 June 2013 (UTC)LOG
Someone needs to actually DRAW something. — Preceding unsigned comment added by 99.225.225.1 ( talk) 21:14, 23 February 2015 (UTC)
If we're making analogies to electric circuits, we probably shouldn't use R for both reluctance and resistance on the same page. The Reluctance article uses S for reluctance, but I don't know if this is in common use elsewhere. Is it? We don't want to make up our own terminology unless absolutely necessary. — Omegatron 15:15, 29 November 2006 (UTC)
I am proposing merging magnetic reluctance, magnetic complex reluctance, magnetic capacitance, and magnetic capacitivity into this article. Together they would make an ok start to magnetic circuits; apart they cannot carry their own weight. Eventually these articles will make great sub-articles to the main page of magnetic circuits; but eventually is not now.
Unless someone objects I will probably do the merge myself. TStein ( talk) 03:25, 11 May 2009 (UTC)
I agree with Chetvorno - it was a relief to me to find the "reluctance" definition directly. —Preceding unsigned comment added by Shumpi ( talk • contribs) 17:35, 11 June 2009 (UTC)
Isn't there a mistake in the heading of the table comparing the two types. It seems the magnetic header is above the electrical proporties —Preceding unsigned comment added by 129.31.80.191 ( talk) 14:18, 24 May 2009 (UTC)
Yes. However the table also just seems plain ol' broken in several places, so I'm reluctant to just switch the headers around. I'm sorely tempted to just delete it and wait for someone to put it back in more accurate form, but I'll restrain myself and let someone more expert sort it out. -- 207.173.201.99 ( talk) 16:57, 11 June 2009 (UTC)
I am seriously seeing the need for a navigation template for these things. The information right now seems to appear really scattered. Also, there does not seem to be any clear justification for merging all these materials. Separate articles are preferable. The use of navigation template would facilitate transparency to the material. I see no need for this to be approved. As I soon finish working up some of the other articles to maintain consistency, then I will do something about the navigation template. Kmarinas86 (6sin8karma) 04:13, 23 June 2009 (UTC)
We got a mess to clean up. There are two different systems of magnetic circuits: the common one, and the gyrator capacitor model [1]. They are different--different variables, different analogies between physical quantities and circuit variables. But we've got a single navbox that unifies them all. Ack!!!
I think we should have just two articles--one on magnetic circuits and one on the cap-gyrator model. An alternative would be to have two headings in the navbox to show that they are two different systems. If you mix them up you get nonphysical stuff happening--energy sources, etc.
I'm going to go ahead and delete the navbox from the main articles, because I think sending people off to incompatible components is more harm than help. - Ccrrccrr ( talk) 01:31, 25 July 2009 (UTC)
Recently, some changes were made to the third bullet point of the "Limitations of the analogy" section, pointing out that electrical circuits can have nonlinearity and hysteresis like magnetic circuits. With respect, this is not relevant to the article. This article specifically compares a magnetic circuit to a linear, resistive electric circuit, with only voltage sources and resistances, that obeys Ohm's law. It is based on the similarity between Ohm's law and Hopkinson's law. Typical resistive electric circuits obey Ohm's law to accuracies of 4 to 6 significant figures. Typical magnetic circuits obey Hopkinson's "law" only very approximately, with variations of the flux due to nonlinearity of 50% or more, and residual flux of 20% or more left in the circuit after the "sources" are turned off. -- Chetvorno TALK 19:40, 12 May 2012 (UTC)
Just as the poorly-named 'electromotive force' has been renamed 'electromotance' ( EMF), the 'magnetomotive force', which is not a force, should be renamed magnetomotance. TAB ( talk) 18:47, 11 June 2012 (UTC)
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Cheers.— cyberbot II Talk to my owner:Online 04:57, 27 May 2016 (UTC)
At the moment we have:
"R is the reluctance [...] in [...] (a unit that is equivalent to turns per henry)."
and
"P = 1/R [...] Its SI derived unit is the henry (the same as the unit of inductance, although the two concepts are distinct)."
If the unit for R is turns/henry, then the unit for P is henry/turn, and is thus not confused with plain henry.
Doubtless confusion on this point arises from SI's classification of units for phenomena such as angle and turn as "optional", and by attempting to cover them with the "special unit 1" (as distinct from the number 1). Treating "special 1" as though it's number 1 (and thus droppable) leads to apparent equivalence of incompatible quantities when attempting to perform dimensional analysis, or, as here, just trying to convey to users the nature of a quantity.
My suggestion would be to at least provide units for R and P that are consistent, and to choose the option to include "turns" in the units so as to make clear the distinction from units that lack turns, and to allow the units to work in dimensional analysis. Gwideman ( talk) 12:59, 19 June 2016 (UTC)
At the moment, the Circuit Laws section is illustrated by a figure which is misleading in itself, and very misleading relative to the narrative it accompanies.
First off, the figure shows a magnetic circuit in which fluxes phi1, phi2...phi5 should all be equal, yet they are represented by different numbers of arrows (lines). Either this is wrong, or these arrows, though labeled as fluxes, are confusingly not intended to represent lines of flux.
Second, the narrative states the analog to Kirchoff's current law, spelling out phi1 + phi2.. = 0. Clearly this does not correspond to the diagram where phi1, phi2... do not all enter a particular node (and don't sum to zero... indeed they are all equal).
In short, it's not clear the intended purpose of the figure, and as it stands, it strongly detracts from the narrative. Gwideman ( talk) 23:17, 20 June 2016 (UTC)
The edit summary proposing the merge of magnetomotive force here reads "just a definition, not an article". Well, first of all, many readers look up basic concepts on Wikipedia just to get the definition. We should not unnecessarily make them plough through another article to find it. Secondly magnetomotive force is an important parameter, maybe on the same level as magnetic flux so should have its own article, just as electromotive force and electric current have their own pages. Finally, I am sure the article is capable of being expanded significantly. William Gilbert (astronomer) could be mentioned just to start off with and I'd like to see more on the history of the term - when it first came into use, how it came to be called a force etc. When elastance, a rather more obscure parameter, was put up for deletion I thought that it was going to be a dead duck for sure, but with a bit of effort I was able to make this edit. Spinning Spark 18:53, 14 March 2018 (UTC)
I have removed the history section from the article which I think is extremely problematic. The original text read,
References
Problems include,
I might be changing my mind about Joule, the cited source is actually a collection of earlier papers. The paper in question is cited to Annals of Electricity vol. 5 which would put it in 1840/41 although I can't find the original paper in the volume because the pagination seems to be screwed up. We still have the problem of no secondary sources and duplication. Spinning Spark 15:02, 17 March 2018 (UTC)
The schematic at the top of the page shows field lines that are not perpendicular to the material at the interface between air and the material.
In my understanding of ferromagnetism, field lines should leave the material with a right angle. Dosettes-beryl ( talk) 16:43, 13 January 2024 (UTC)
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Are there symbols for drawing schematics of magnetic circuits? — Omegatron 14:50, 29 November 2006 (UTC)
There is a magnetic circuit drawn in the section "Circuit Laws" but it does not seem to be mentioned in the text and doesn't have anything useful to say. For example there are 5 flux arrows labelled Φ1 to Φ5. But this is a series magnetic circuit so all 5 values are identical! There are 5 lines called A1 to A5 which make most sense as areas. This drawing would be more useful if Φ values were converted to B values (flux density). Then we would have Flux Density times Area = Flux. B1 x A1 = B2 x A2 = B3 x A3 = B4 x A4 = B5 x A5 87.113.149.155 ( talk) 21:56, 23 June 2013 (UTC)LOG
Someone needs to actually DRAW something. — Preceding unsigned comment added by 99.225.225.1 ( talk) 21:14, 23 February 2015 (UTC)
If we're making analogies to electric circuits, we probably shouldn't use R for both reluctance and resistance on the same page. The Reluctance article uses S for reluctance, but I don't know if this is in common use elsewhere. Is it? We don't want to make up our own terminology unless absolutely necessary. — Omegatron 15:15, 29 November 2006 (UTC)
I am proposing merging magnetic reluctance, magnetic complex reluctance, magnetic capacitance, and magnetic capacitivity into this article. Together they would make an ok start to magnetic circuits; apart they cannot carry their own weight. Eventually these articles will make great sub-articles to the main page of magnetic circuits; but eventually is not now.
Unless someone objects I will probably do the merge myself. TStein ( talk) 03:25, 11 May 2009 (UTC)
I agree with Chetvorno - it was a relief to me to find the "reluctance" definition directly. —Preceding unsigned comment added by Shumpi ( talk • contribs) 17:35, 11 June 2009 (UTC)
Isn't there a mistake in the heading of the table comparing the two types. It seems the magnetic header is above the electrical proporties —Preceding unsigned comment added by 129.31.80.191 ( talk) 14:18, 24 May 2009 (UTC)
Yes. However the table also just seems plain ol' broken in several places, so I'm reluctant to just switch the headers around. I'm sorely tempted to just delete it and wait for someone to put it back in more accurate form, but I'll restrain myself and let someone more expert sort it out. -- 207.173.201.99 ( talk) 16:57, 11 June 2009 (UTC)
I am seriously seeing the need for a navigation template for these things. The information right now seems to appear really scattered. Also, there does not seem to be any clear justification for merging all these materials. Separate articles are preferable. The use of navigation template would facilitate transparency to the material. I see no need for this to be approved. As I soon finish working up some of the other articles to maintain consistency, then I will do something about the navigation template. Kmarinas86 (6sin8karma) 04:13, 23 June 2009 (UTC)
We got a mess to clean up. There are two different systems of magnetic circuits: the common one, and the gyrator capacitor model [1]. They are different--different variables, different analogies between physical quantities and circuit variables. But we've got a single navbox that unifies them all. Ack!!!
I think we should have just two articles--one on magnetic circuits and one on the cap-gyrator model. An alternative would be to have two headings in the navbox to show that they are two different systems. If you mix them up you get nonphysical stuff happening--energy sources, etc.
I'm going to go ahead and delete the navbox from the main articles, because I think sending people off to incompatible components is more harm than help. - Ccrrccrr ( talk) 01:31, 25 July 2009 (UTC)
Recently, some changes were made to the third bullet point of the "Limitations of the analogy" section, pointing out that electrical circuits can have nonlinearity and hysteresis like magnetic circuits. With respect, this is not relevant to the article. This article specifically compares a magnetic circuit to a linear, resistive electric circuit, with only voltage sources and resistances, that obeys Ohm's law. It is based on the similarity between Ohm's law and Hopkinson's law. Typical resistive electric circuits obey Ohm's law to accuracies of 4 to 6 significant figures. Typical magnetic circuits obey Hopkinson's "law" only very approximately, with variations of the flux due to nonlinearity of 50% or more, and residual flux of 20% or more left in the circuit after the "sources" are turned off. -- Chetvorno TALK 19:40, 12 May 2012 (UTC)
Just as the poorly-named 'electromotive force' has been renamed 'electromotance' ( EMF), the 'magnetomotive force', which is not a force, should be renamed magnetomotance. TAB ( talk) 18:47, 11 June 2012 (UTC)
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Cheers.— cyberbot II Talk to my owner:Online 04:57, 27 May 2016 (UTC)
At the moment we have:
"R is the reluctance [...] in [...] (a unit that is equivalent to turns per henry)."
and
"P = 1/R [...] Its SI derived unit is the henry (the same as the unit of inductance, although the two concepts are distinct)."
If the unit for R is turns/henry, then the unit for P is henry/turn, and is thus not confused with plain henry.
Doubtless confusion on this point arises from SI's classification of units for phenomena such as angle and turn as "optional", and by attempting to cover them with the "special unit 1" (as distinct from the number 1). Treating "special 1" as though it's number 1 (and thus droppable) leads to apparent equivalence of incompatible quantities when attempting to perform dimensional analysis, or, as here, just trying to convey to users the nature of a quantity.
My suggestion would be to at least provide units for R and P that are consistent, and to choose the option to include "turns" in the units so as to make clear the distinction from units that lack turns, and to allow the units to work in dimensional analysis. Gwideman ( talk) 12:59, 19 June 2016 (UTC)
At the moment, the Circuit Laws section is illustrated by a figure which is misleading in itself, and very misleading relative to the narrative it accompanies.
First off, the figure shows a magnetic circuit in which fluxes phi1, phi2...phi5 should all be equal, yet they are represented by different numbers of arrows (lines). Either this is wrong, or these arrows, though labeled as fluxes, are confusingly not intended to represent lines of flux.
Second, the narrative states the analog to Kirchoff's current law, spelling out phi1 + phi2.. = 0. Clearly this does not correspond to the diagram where phi1, phi2... do not all enter a particular node (and don't sum to zero... indeed they are all equal).
In short, it's not clear the intended purpose of the figure, and as it stands, it strongly detracts from the narrative. Gwideman ( talk) 23:17, 20 June 2016 (UTC)
The edit summary proposing the merge of magnetomotive force here reads "just a definition, not an article". Well, first of all, many readers look up basic concepts on Wikipedia just to get the definition. We should not unnecessarily make them plough through another article to find it. Secondly magnetomotive force is an important parameter, maybe on the same level as magnetic flux so should have its own article, just as electromotive force and electric current have their own pages. Finally, I am sure the article is capable of being expanded significantly. William Gilbert (astronomer) could be mentioned just to start off with and I'd like to see more on the history of the term - when it first came into use, how it came to be called a force etc. When elastance, a rather more obscure parameter, was put up for deletion I thought that it was going to be a dead duck for sure, but with a bit of effort I was able to make this edit. Spinning Spark 18:53, 14 March 2018 (UTC)
I have removed the history section from the article which I think is extremely problematic. The original text read,
References
Problems include,
I might be changing my mind about Joule, the cited source is actually a collection of earlier papers. The paper in question is cited to Annals of Electricity vol. 5 which would put it in 1840/41 although I can't find the original paper in the volume because the pagination seems to be screwed up. We still have the problem of no secondary sources and duplication. Spinning Spark 15:02, 17 March 2018 (UTC)
The schematic at the top of the page shows field lines that are not perpendicular to the material at the interface between air and the material.
In my understanding of ferromagnetism, field lines should leave the material with a right angle. Dosettes-beryl ( talk) 16:43, 13 January 2024 (UTC)