Talk:Electrical reactance

Archives (Index)

Talk:Electrical reactance/Archive 1 Talk:Electrical reactance/Archive 2

This page is archived by ClueBot III.

Error in lede

There seems to be a word omitted in the lede: "... but differs in that reactance does lead to dissipation of electrical energy as heat". I have inserted 'not', i.e. 'but differs in that reactance does not lead to dissipation of electrical energy as heat'. Please correct me if I'm wrong. PhilUK (talk) 11:15, 30 August 2020 (UTC)

That's fine. A simple typo on my part. SpinningSpark 13:02, 30 August 2020 (UTC)

Dirty AC

@Em3rgent0rdr: Reactance only has meaning in respect of sine waves. Yes AC can be, and frequently is, non-sinusoidal, but that has no relevance to the definition of reactance. So I don't agree with your comment in your edit summary; guitar amps, triangular waves and dirty AC are all irrelevant to this issue. "Quarter-cycle" precisely defines for the reader how long the energy is stored. "Temporarily stored" is just vague to the point of meaningless. Energy can be temporarily stored in inductors and capacitors, in principle, for an indefinite period. But not when they are driven by a sinusoidal source. SpinningSpark 11:08, 19 March 2022 (UTC)

@Spinningspark well what I *want* to say is a quarter cycle of the frequency. I seem unable to fit that in. I don't like saying "cycle" without having any definition of what cycle means. If can shift some wording around, like maybe saying "a quarter-cycle of the sinusoidal AC" then I think that would better. Em3rgent0rdr (talk) 11:18, 19 March 2022 (UTC)

We do have a wikilink for cycle (unit) which is used in the cycles per second page. That might address your issue. SpinningSpark 11:27, 19 March 2022 (UTC)

Oh great...I think I can be happy with that. I went back to the earlier wording, though also with "momentarily".

Instead, energy is momentarily stored in the reactance, and a quarter-cycle later returned to the circuit, whereas a resistance continuously loses energy. Em3rgent0rdr (talk) 13:06, 19 March 2022 (UTC)

That's good for me. SpinningSpark 13:58, 19 March 2022 (UTC)

Oliver Heaviside

Why does this article not mention Oliver Heaviside? According to the Oliver Heaviside article, he was the guy that brought complex numbers to circuit analysis. Why does this whole article not even mention his name? K00la1dx (talk) 21:21, 29 November 2022 (UTC)

Because it would be ridiculously repetitive to mention Heaviside in every article that touched on complex impedance. Besides which, Heaviside did not introduce the concept of complex impedance (that was Kenneliy), nor did he coin the term reactance (that was Hospitalier). SpinningSpark 22:43, 29 November 2022 (UTC)

Why don't you take a look at the Oliver Heaviside article? Do you really think he coined all the other terms but just so happen someone else coined the term reactance? Please. Anyways, in the article it says "Oliver Heaviside was an English self-taught mathematician and physicist who brought complex numbers to circuit analysis." So there should be a section in this article regarding the history of complex impedance. Is this how the English remember their fallen heroes? K00la1dx (talk) 13:32, 30 November 2022 (UTC)

I did look at it, and I've put a citation needed tag on it. The claim is contradicted by sources. Please stop ranting and instead look for sources on this. Meanwhile you might want to read what Heaviside himself says on the coining of reactance – "The term 'reactance' was lately proposed in France, and seems to me to be a practical word.", Heaviside, Electromagnetic Theory, vol. 1, p. 439, 1893. SpinningSpark 13:58, 30 November 2022 (UTC)

I am calling for a section of this article to be about how these the mathematical techniques came about. Oliver Heaviside was very generous citing where he got his ideas from. This article should follow the same respect. Heaviside made popular many mathematical techniques where were not well not known. Take the Laplace transform. It was Heaviside that made it popular. In this article it should be known that Heaviside made the concept of Electrical reactance popular. K00la1dx (talk) 18:38, 30 November 2022 (UTC)

Do you have a reference that says "Heaviside made the concept of Electrical reactance popular" ? Constant314 (talk) 03:24, 1 December 2022 (UTC)

I have a degree in Electrical Engineering. I took a class, "systems theory." It is all based on Heaviside. (even though Heaviside is not mentioned at all) Just take a look at SpinningSpark's reference, Electromagnetic Theory vol. 1 p 439 1893. Heaviside popularized the term 'reactance' which was coined in France. K00la1dx (talk) 13:17, 1 December 2022 (UTC)

Your credentials are not relevant. I do not doubt you, but we have been burned by incompetent editors that also claimed excellent credentials. The mere fact that Heaviside mentioned a term in one of his works does not mean that he "popularized" it. You need a reliable source, not Heaviside, that says explicitly that Heaviside popularized the term 'reactance'. If you can find that, then we can discuss the issue of notability. The originator of the term reactance is probably notable in an article on reactance, a person that merely parroted it probably is not. Constant314 (talk) 14:54, 1 December 2022 (UTC)

It says in the article: Oliver Heaviside. "Heaviside was an English self-taught mathematician and physicist who brought complex numbers to circuit analysis."

Are you saying that article is wrong?

This is not a good faith arrangement that my post got deleted. You have no post in the article about the history of reactance. It reads like a dry textbook.

Why do I have to defend myself?

How are you in good faith?

K00la1dx (talk) 17:16, 1 December 2022 (UTC)

Wikipedia is not a reliable source. This is a well-established principle. You might review WP:RS. Constant314 (talk) 17:37, 1 December 2022 (UTC)

https://www.electronics-notes.com/articles/history/pioneers/oliver-heaviside-biography.php

This website accredits Heaviside to Reactance:

"Also during his latter years, Heaviside introduced the concept of reactance. He further postulated the concept of an ionised layer above the Earth that reflected or refracted radio signals. Although this is now known as the ionosphere, the regions in the ionosphere were for many years known as the Heaviside layers or the Heaviside-Kennelly Layers because Kennelly also proposed the idea of the layers."

Can you please update the article? (as the website seems credible)

I would do it myself, but as I keep getting deleted, can you do it for me?

Please

K00la1dx (talk) 18:02, 1 December 2022 (UTC)

We know that "Heaviside introduced the concept of reactance" is incorrect since Heaviside himself attributed to French origin. However, I will look at the web site. I know that this is nuanced, but Heaviside's publication is not a reliable source for "Heaviside popularized the concept of reactance," but it is a reliable source for Heaviside's own words. Constant314 (talk) 00:23, 2 December 2022 (UTC)

I checked the website electronics-notes. Sorry, it is not a reliable source. It is just a blog attached to a commercial web site. Not everything on the internet is reliable, even if it seems to be so. Constant314 (talk) 00:27, 2 December 2022 (UTC)

Can we be real? Can't you see that Heaviside invented the term Reactance and was ridiculed by the mathematics community. Why would the French invent Reactance? It is not even a French word. It is obviously a joke in Heaviside's book. Heaviside must have been really upset to put something so funny in his book.

"Also during his latter years, Heaviside introduced the concept of reactance. " K00la1dx (talk) 13:19, 2 December 2022 (UTC)

• I'm real and diligent. I'm pretty sure that @Spinningspark: is real and diligent also. I cannot see that Heaviside invented the term Reactance.
• I can see that Heaviside was treated poorly and ignored by many of his contemporaries. It probably took then 10 to 20 years to catchup. That was their tragedy. However, that fact is not evidence for anything that Heaviside did do. We are not citing any of his detractors, so that fact is also irrelevant.
• The French word is réactance. I suppose they invented it because they needed a useful word and were pretty clever.
• Sometimes, we do try to determine an author's real intentions, but only a reason to exclude material. If we have an otherwise reliable source, but we suspect that the source is for some reason being deceptive, that is a reason to not use that source as a reference for material that is in the Wikipedia article. It is not a reason to assert the opposite.

This discussion is getting tedious and repetitive. By his own words, Heaviside affirms that he did not coin the term reactance. That fact will always prevail over any argument to the contrary. I am not inclined to continue this discussion. Constant314 (talk) 17:40, 2 December 2022 (UTC)

We need to be careful here to distinguish the coining of the term and the recognition of the concept. We should treat with extreme caution sources that credit Heaviside with either of these unless written by a recognised historian of science. Just as 19th century sources frequently incorrectly credit Morse with the invention of the telegraph, Heaviside is frequently credited with being the first for things he was not. I recommend reading Ronald R. Kline, Steinmetz: Engineer and Socialist, section "Electricity from the square root of minus one" which shows quite clearly that Heaviside was not the first to use complex numbers in circuit analysis, and even after recognising that impedance was a complex number, did not actually use that fact much until quite late. I'm intending to use that source to write something better in the electrical impedance article on hte history of this. SpinningSpark 19:03, 2 December 2022 (UTC)

You just want to bash Heaviside because your not English. Regardless of who was the first to coin the term Reactance, and who was first to use impedance as a complex number, I assure you, the techniques discussed in this article were primarily a product of Heaviside. K00la1dx (talk) 21:54, 2 December 2022 (UTC)

Did you know Steinmetz' greatest influence was Oliver Heaviside? K00la1dx (talk) 00:15, 30 December 2022 (UTC)

capacitors?

Ideal capacitors do not have zero resistance! Gah4 (talk) 20:57, 23 May 2024 (UTC)

How so? Constant314 (talk) 21:02, 23 May 2024 (UTC)

The usual model for an inductor is an ideal inductor in series with an ideal resistor. For a capacitor, and ideal capacitor in parallel with an ideal resistor. Ideal capacitors have infinite resistance, or zero conductance. Dielectrics have permittivity and conductivity. Gah4 (talk) 07:58, 24 May 2024 (UTC)

If they had nonzero conductance, then they would not be ideal. An ideal capacitor is the same as a pure capacitor. No other shunt terms and no other series terms. Constant314 (talk) 08:26, 24 May 2024 (UTC)

In the case of Telegrapher's equations, there is a inductor resistance term and capacitance conductance term. Not the other two. Seems to me that an ideal capacitor has no leads, so no possibility of series resistance. Similarly, an ideal inductor has no material for shunt resistance. A not so ideal one can have both of those, though usually so low as not to measure. On the other hand, inductance of capacitor leads, and capacitance of inductor windings can be, and often are, important. Gah4 (talk) 01:49, 29 May 2024 (UTC)

If we take shunt conductance to be frequency-dependent, we can represent a series resistance in the capacitance conductance. I think the conductance term would be ${\frac {G+(R^{2}+R)C^{2}\omega ^{2}}{(RC\omega )^{2}+1}}$, though I may have made an arithmetic error. XabqEfdg (talk) 07:38, 29 May 2024 (UTC)

User:Constant314: Ideal inductors have zero series resistance, (and therefore infinite series conductance). Ideal capacitors have zero conductance, (and therefore infinite resistance. That's what the word "respectively" was supposed to mean.
If you think it's unclear, go recast the sentence, but you cannot remove only the word "respectively". Nothing can have "zero resistance and conductance" at the same time by definition, and stating so only introduces confusion.
If you're thinking about "parasitic" impedances, e.g. shunt conductance due to imperfect inductor insulation, those are second-level effects, and should not be considered in the introductory section. As Gah4 suggested, your edits to a long-standing material only introduce apparent contradictions, rather than clarifying matters. Thank you. No such user (talk) 07:28, 29 May 2024 (UTC)

Just to be sure we are on the same page, do we agree that:

• 1. An inductor with a non-zero series resistance would not be ideal.
• 2. A capacitor with a non-zero shunt conductance would not be ideal.
• 3. An inductor with a non-zero shunt conductance would not be ideal.
• 4. A capacitor with a non-zero series resistance would not be ideal.

And if we agree, why do we tell the reader about #1 and #2 while adding a word to avoid telling the reader about #3 and #4? Constant314 (talk) 08:38, 29 May 2024 (UTC)

No. 4 is incorrect as stated. It should read "a capacitor with a finite series resistance would not be ideal". #2 and #3 are technically correct, but my point is that it's a too fine detail (you don't expect any circuit element to have shunt conductance, so that goes without saying). No such user (talk) 11:21, 29 May 2024 (UTC)

All physical capacitors with a solid dielectric have both nonzero series resistance and nonzero shunt conductivity. The series resistance comes from the fact that the plates are not perfect conductors. The shunt conductance comes from the fact that all solid dielectric materials are not perfect insulators and thus have some nonzero conductivity. On a data sheet, the conductivity may be specified as insulation resistance or may be specified as leakage current at a particular voltage. Constant314 (talk) 15:23, 29 May 2024 (UTC)

The plates could be made from superconductors, in which case they would have no series resistance. But regular metals are normally good enough. It is inductance that you can't get away from, even with superconductors. It is interesting for capacitors in that the shunt conductivity and capacitance permittivity are proportional. RC depends on the material, and not the geometry. I vote for keeping the respectively. Gah4 (talk) 15:59, 29 May 2024 (UTC)

I think that we should first agree on what is true and then agree on language. Constant314 (talk) 16:26, 29 May 2024 (UTC)

Since the impedance (and thus the admittance) of ideal capacitors and inductors is purely imaginary, both have zero resistance and conductance. Conductance is only equal to 1/R if there is no reactance. XabqEfdg (talk) 16:06, 29 May 2024 (UTC)

Yes, series resistance and shunt conductance are two separate mechanisms which cause the reactance to not be ideal. Both mechanisms can be present. Both mechanisms are important enough for capacitor manufactures to specify limits on both mechanisms. Constant314 (talk) 16:29, 29 May 2024 (UTC)

From the capacitor article

Real capacitor model that adds an inductance and resistance in series and a conductance in parallel to its capacitance. Its total impedance is: ${\begin{aligned}:::Z_{\Sigma }&{=}Z_{\text{ESL}}+R_{\text{lead}}+(Z_{\text{C}}\parallel G_{\text{dielectric}})\\:::&{=}j\omega \cdot {\text{ESL}}+R_{\text{lead}}+{\frac {1}{j\omega \cdot C+G_{\text{dielectric}}}}.:::\end{aligned}}$ :::

Constant314 (talk) 18:44, 29 May 2024 (UTC)

Yes. But if you don't have lead inductance, you also can't have lead (series) resistance. Or, the other way, if you do have series resistance, you have to have series inductance. Even with zero lead inductance, the plates still have inductance. My favorite reference is this one. It includes the plate inductance as frequency gets higher and higher. Gah4 (talk) 01:54, 30 May 2024 (UTC)

So, the issue is, which of these parasitic elements must be zero to have an ideal capacitor? Unless I misunderstand, one of the participants of this discussion has stated that G_dielectric and R_lead cannot both be zero at the same time. I completely fail to grasp the argument, although I suspect it is a case of unshared unstated assumptions and once, we figure that out, we all quicky come to an agreement. Constant314 (talk) 02:18, 30 May 2024 (UTC)

I didn't figure that one out. My argument is that ideal capacitors don't have leads, and so by definition can't have lead resistance. But also, in the cases that count, lead resistance is so low as not to matter. At low frequencies, 0 in the limit, dielectric conductance still matters. In EPROM and Flash memory, bits are stored as charge on capacitors. It can stay for many years, as leakage is low enough. At high frequencies, where lead resistance might matter, lead inductance reactance is much bigger. As noted in Telegrapher's equations, at high frequencies it is L and C that are significant, at low frequencies R and G. No mention of capacitor series resistance or inductance parallel resistance. Gah4 (talk) 04:17, 30 May 2024 (UTC)

Unless I misunderstand, one of the participants of this discussion has stated that G_dielectric and R_lead cannot both be zero at the same time. – Yes, we have a misunderstanding here, since we aren't using the same [mental] model. Your model on the above image is technically correct, but not the only possible one, nor the first thing I'd imagine.
Simply, the model described in the article (and in minds of Gah4 and myself) does not include R_lead (nor ESL) since it's negligible and irrelevant for most intents and purposes. What is important (and often used in finer capacitor analysis) is the value of G_dielectric, which is zero for ideal capacitors, and its inverse value R_dielectric is thus obviously infinite (and that's what my sentence referred to).

As for inductors, I'm having in mind the simple model of R and X in series, and I'm having a hard time even to imagine where you'd put a leakage conductance in it, and which effect it would account for. Granted, parasitic capacitance is a thing, but we should not get that far in an introductory sentence. No such user (talk) 08:01, 30 May 2024 (UTC)

I am glad we agree on the fundamentals. It comes down to what is significant and how to best say it.

Inductors are usually wound from insulated wire with the individual turns touching the adjacent turns. Insulation being imperfect provides a shunt conductance. We don't think about it too much, since at DC, the inductor itself is a huge conductance and at high AC, the winding capacitance is a large conductance. In fact, above the self-resonance, it comes down to the loss tangent of the insulation. The real part of the conductance is a few percent of the imaginary part. Designers don't generally spend a lot of effort thinking about it, but it is there.

Even capacitors without leads still have plates which have resistance. There is always some series resistance. Designers working with precision DC circuits worry about the shunt conductance and have no concern about series resistance. High frequency and switched mode power supply designers mostly worry about ESR (equivalent series resistance) which includes not only the actual series resistance (SR) but additionally accounts for all losses including those due to dialectric loss tangent and dc conductivity.

But before jumping into a debate about what is significant and what is not, let me propose changing "ideal inductors and capacitors have zero resistance and conductance respectively," to "ideal reactors have no shunt conductance and no series resistance." By explicitly calling out shunt and series, we lock down the mental model and we cover all cases whether significant or not. Constant314 (talk) 19:01, 30 May 2024 (UTC)

I would have gone for just the no shunt conductance, but otherwise it does fix the original comment. Yes that is fine to me. Gah4 (talk) 11:58, 31 May 2024 (UTC)

Alternatively, we could get rid of the entire sentence about the definition of "ideal" elements from the lead, and/or relegate those fine details to one paragraph in the article body, with links to appropriate articles (i.e. Parasitic element (electrical networks), which should be better renamed to parasitic impedance [Edit: boldly moved now] ). Let's have in mind that this is an introductory material, something one would find in a high-school textbook, and jumping into such details straight from the lead is bound to create confusion for the readers. See, the four of us who have discussed this are obviously quite knowledgeable about the matter, and we had a hard time communicating what we meant. I'm a firm believer in the principle "less is more" when it comes to writing matters. No such user (talk) 12:37, 31 May 2024 (UTC)

I am ok with removing the entire sentence. Constant314 (talk) 13:52, 31 May 2024 (UTC)