Talk:Electrical impedance/Archive 2

message: I have removed the following text from the introduction:
"Because these sinusoids comprise a basis (basis means here that we can express any function f(t) as a summation of sine functions using Fourier Series (like in vectors  any vector in space can be expressed in terms of i,j,k so i,j,k are called the basis vectors)) over the space of real functions, the impedance of a linear system describes its response to any time-varying signal, not just to a sinusoid."
I have three reasons for this:
(1) The section "Circuits with General Sources" already covers this concept.
(2) This statement doesn't belong, IMHO, in the introductory paragraph.
(3) This statement is not entirely correct.  The impedance (as a function of s) of a linear system describes its complex frequency domain voltage response to a time domain unit impulse of current, not a general time-varying signal.
Alfred Centauri 04:21, 21 February 2006 (UTC)
thread_title:  Sinusoidal basis... 

message: Please stop inserting the erroneous negative sign in the equation for capacitive impedance.  The math, as it stood before your edits, is correct.  If you do not see this, then consider the following:
:\frac{1}{j}=-j\,
:\frac{1}{j \omega C}= \frac{-j}{\omega C}\,
:X_C = \Im(Z_C) = \frac{-1}{\omega C}\,
With the negative sign you inserted, X_C becomes positive which is clearly incorrect.  Alfred Centauri 00:26, 2 March 2006 (UTC)
thread_title:  Edits 

message: Disagree to both merge suggestions.  Both articles should instead be candidates for deletion.  The author of these two articles has been known to insert unformatted incomprehensible rubbish to the Electromagnetic induction article.  Alfred Centauri 21:22, 30 March 2006 (UTC)
replies: text: Too late, already merged. You do realize that a merge doesn't mean a copy edit - I think my merge smothely incorporates whatever "full electric impedance" may be, and disregards the crappy explanations and definitions that are already better explained in this article. Fresheneesz 05:13, 21 April 2006 (UTC)
thread_title:  Merge Suggestions 

message: I've seen the circuit symbolization of an impedance element as both a box (like the european way to show a resistor), and I *think* i've seen it also drawn like an american resistance (i can't quite remember). In any case, we should have a picture of how to draw it on this page. Fresheneesz 04:41, 21 April 2006 (UTC)
replies: text: — Omegatron 15:25, 21 April 2006 (UTC)
replies: text:  Thanks, I'll add that to the intro. Fresheneesz 04:49, 26 April 2006 (UTC)

text: Really?  That's an inductance everywhere I've seen it. — Omegatron 07:03, 12 June 2006 (UTC)
thread_title:  circuit symbol 

message: I was wondering if impedance only works with passive elements. The only reason I asked is that "passive element" was specified in an article I merged here. Comments? Fresheneesz 05:14, 21 April 2006 (UTC)
replies: text: Impedance is the ratio of a phasor voltage and a phasor current regardless of whether the voltage and current are associated with a passive or active element or even the same port.  Consider the two-port 'z' parameters.    Alfred Centauri 14:24, 21 April 2006 (UTC)
thread_title:  passive elements only? 

message: Someone should organize the see also section into subcategories. Fresheneesz 05:18, 21 April 2006 (UTC)
thread_title:  See also should be organized 

message: This article needs a phasor diagram, to show geometrically what the impendance is.
RZ heretic 00:55, 1 November 2006 (UTC)
thread_title:  Needs a phasor Diagram

message: I removed this sketch, under the heading "Four Quadrant Operation":
--Heron 20:56, 8 February 2007 (UTC)
thread_title:  Removed sketch 

message: This article contains a lot of useful information, however I feel that anyone who is not already reasonably familiar with the concept of impedance is likely to leave non the wiser.
I am a grad student in experimental physics and recently wrote a short paper on impedance for the benefit of undergrad project students in our lab and thought it might be nice to put a version of it online.
I have created an initial outline that you can find here.
I realise that a lot of people have put a lot of work into this article over the years and I don't want to step on peoples toes; my main concern is to make clear from the beginning how impedance differs from resistance, particularly the inclusion of the voltage-current phase relationship.
I would appreciate comments from any and all interested parties on my talk page.
--DJIndica 23:51, 26 May 2007 (UTC)
replies: text: See my comments above in the section titled "Shockingly Bad".  To summarize, feel free to make wholesale changes if you like; be bold.  I did the same thing a couple of years ago and it is time for this article to be 'reset' again.  Just keep in mind that this article is subject to lots of well-meaning but ill-informed edits.  Alfred Centauri 01:54, 27 May 2007 (UTC)
replies: text:  The edit on DJIndica's page looks like a pretty big improvement in understandability. I would guess quite a bit of information is left out of that subpage that's in the current one, but the new edit looks good enough to replace the current one, as long as the left out information is considered. Fresheneesz 19:23, 27 May 2007 (UTC)
thread_title:  [[User:DJIndica/Impedance|Possible changes]] 

message: While I am sympathetic with the point made in the edit summary associated with the addition of this section ("who came up with the term doesn't need to be in the first sentence"); the creation of a full section seems like overkill unless there are other points of interest in the etymology of the word impedance.  A mention of Oliver Heavyside does not need to be in the first sentence, but given his importance in the development of this and related concepts, I feel he is worthy of a mention and the opening section is probably the best place for it.  I will revert shortly unless there are good arguments made for keeping it, or suggestions for additional etymological content.--DJIndica 21:56, 12 September 2007 (UTC)
replies: text: Yes, a new section is probably overkill, but can you try something different like making it the second sentence. No need to state everything in one sentence. —Pengo 02:42, 13 September 2007 (UTC)
thread_title:  Etymology section 

message: It has been noted by a number of contributors that this page can vary significantly in quality over time due to the large number of edits, some of which are ill informed and detract from the information content and/or readability, and can add false or misleading information.  It seems to me that it would be a good idea to rate the quality and importance of the article using the WikiProject Electronics scales.
My thinking is that this will in the first instance hopefully put it on the radar of more people with genuine knowledge and interest in this area.  In the long run, if the article reaches the point where it is assessed as a good article then it may encourage more thoughtful edits in the future.  I have added the banner at the top of this page and taken the liberty of adding a 'high importance' tag; I don't think it is controversial to state that impedance is an important topic in electronics.
It would be good to see comments here, suggesting people's thoughts on the current quality of the article along with suggestions for improvements, perhaps based on good and featured articles on related topics.--DJIndica 23:02, 19 October 2007 (UTC)
thread_title:  [[Wikipedia:WikiProject_Electronics|WikiProject Electronics]] [[Wikipedia:WikiProject_Electronics/Assessment#Quality_scale|quality]] and [[Wikipedia:WikiProject_Electronics/Assessment#Importance_scale|importance]] assessment 

message: This article is one of only a couple of those listed in the electromagnetism template that does not include the template.  There are definitely arguments against including it (not least that it is rather long and would require moving the images around), but I think it is probably worth having.  I have tried playing around with the positioning of the first image in combination with the template; an example of one possibe arrangement can be found here. --DJIndica 16:57, 22 October 2007 (UTC)
thread_title:  [[Template:Electromagnetism|Electromagnetism template]] 

message: It is proposed to merge Impedance of different devices (derivations) into this article.  The article says little or nothing that is not already said here and said better and in places is just plain wrong.  Besides which it is practically orphaned. SpinningSpark 18:42, 14 June 2008 (UTC)
replies: text: I have created a version of this article including the derivations at User:DJIndica/Sandbox2.  I'd appreciate any comments.--DJIndica (talk) 12:29, 18 July 2008 (UTC)
thread_title:  Merger proposal 

message: Vp stands for peak voltage, right? I'm referring to the part about capacitors in the Device Examples section of the article. If not please explicitly state what Vp is, since I don't think it is something that can be easily inferred from the article. 96.60.80.133 (talk) 03:09, 13 November 2008 (UTC)
replies: text: Vp is the voltage amplitude, which is indeed the peak voltage given that there is no DC offset.--DJIndica (talk) 19:01, 13 November 2008 (UTC)
thread_title: Question