Talk:Phasor

message: Phasors are used for a lot more than just AC circuit analysis. I think actually the exact definition may differ depending on the field you are worrying about, such as the Signal Processing, where phasors most definitely do have a frequency. This is probably the best general definition of this mathematical tool: 
:i wrote this page to fill a link before i had a particularlly solid understanding of phasors myself. At some point i need to rewrite this article but thats quite a bit of work. Plugwash 13:52, 17 Apr 2005 (UTC)
thread_title: Untitled

message: Well, I think that the phasors for electronics is an application of those concepts....
Gabriel
The electronics phasors dont behave like the vectors , and they dont obey the rules of vectors studied in Physics (Statics & Dynamics)
Nauman  —Preceding unsigned comment added by 202.83.173.10 (talk) 11:55, 24 October 2007 (UTC)
thread_title: Different from the concept of Physics?

message: I removed the following text from the intro:
(Important note: The phasor approach is for "steady state" calculations involving sinusoidal waves. It cannot be used when transients are involved. For calculations involving transients, the Laplace transform approach is often used instead.) 
I don't believe that this statement is necessary even if it were true but, that fact is, phasors can be used to analyze transients.  The bottom line is that the complex coefficents of a Fourier series or the inverse Fourier integral are phasors.
It is usually stated that phasor analysis assumes sinusoidal steady state at one frequency and this is true as far as it goes.  However, it is quite straightforward to extend phasor analysis to a circuit with multiple frequency sinusoidal excitation.  When one does this, it is clear this extension is nothing other than frequency domain analysis.  In other words, phasor analysis is frequency domain analysis at a fixed frequency.  Alfred Centauri 23:22, 27 April 2007 (UTC)
thread_title:  Transients & Phasor analysis 

message: This article (Phasor (electronics)) describes essentially the same thing as Phasor (physics). I believe there is no reason to maintain two different articles. The main difference between them is that this article describes the concept of phasors from the viewpoint of an engineer who uses it in a specific domain, while the other article is more general, but lacks some details that this one has. —The preceding unsigned comment was added by 129.177.44.96 (talk) 13:32, 2 May 2007 (UTC)
replies: text: Merging does not mean removing information. The techniques discussed in Phasor (electronics) do not only apply to electronics. A more general context would be appropriate. —The preceding unsigned comment was added by 129.177.44.134 (talk) 15:11, 10 May 2007 (UTC)

text: I agree with the above suggestion. We can call the Phasor (Physics) simply Phasor and rename the electronics article to Applications of Phasors in Electronics. We would cut down on redundancy, and make both articles mesh together better.xC | ☎  22:16, 1 November 2007 (UTC)
thread_title:  Merge with [[Phasor (physics)]] 

message: I like the section on Phasor arithmetic and I suggest noting that the role of linearity is also an important component of the technique.  If, for example, the differential equation in the example were not linear then phasors would be for naught. gaussmarkov 0:28, 6 September 2007 (UTC)
replies: text: Done.  Alfred Centauri 00:52, 6 September 2007 (UTC)
thread_title:  The Role of Linearity 

message: The word "phasor" has two meanings.  One meaning includes the e^{j\omega t} factor, and the other excludes it.  Until recently these were relegated to different articles, one called "Phasor (physics)" and the other called "Phasor (engineering)" (I think).  But there was fairly strong sentiment to merge the articles, which resulted in this one.  The new introduction appears to be heading back to the "Phasor (engineering)" article.
--Bob K (talk) 17:29, 17 December 2007 (UTC)
replies: text: My bias is showing; but the opening paragraph should follow the forumula of giving at least a concise definition of the subject. The introduction isn't new, it's a rehash of a paragraph from a month or so ago.  Let's rewrite the opening so that it allows both definitions. If the meanings are really disparate we need two articles, though I don't think we ever had "Phasor (engineering)". --Wtshymanski (talk) 17:43, 17 December 2007 (UTC)
thread_title:  problem with the new introduction 

message: I think that there should be separated article dedicated to phasor diagrams - describing their making and meaning.
--User:Vanished user 8ij3r8jwefi 17:06, 21 May 2008 (UTC)
thread_title:  Phasor diagrams 

message: Does anyone have images of phasors in relation to FM and PM modulation? That would be a good section to add.  —Preceding unsigned comment added by Daviddoria (talk • contribs) 17:27, 14 September 2008 (UTC)
thread_title:  Phasors in Communication Systems 

message: I teach a course on linear circuits, including a section on Phasors.  The illustration titled "Graph of a phasor as a rotating vector" is both helpful and awkward at the same time.  Some students find it harder to understand a typical phasor diagram (stationary, drawn on paper) after looking at the spinning phasor illustrated.  I have two suggestions.
1.)  In the top half of the illustration, some students cannot fathom that in the present illustration the time axis itself is sinking down the screen as the vector rotates.  Instead, fix the time axis in place and let the dot move both vertically and horizontally.  One could show exactly one cycle of a (stationary) sinusoid so that as the phasor rotates through one revolution a dot on the sinusoid sweeps upwards following the function, then rolls over to the bottom and starts upwards again with the next rotation of the phasor.  A dashed line to show the dot's projection on the time axis would also help.  Be sure the sinusoid has some initial phase offset, for example, 
y(t) = cos(t + 2pi/3) 
Label the horizontal y(t) axis with "+1" on the right and "-1" on the left.  Label the vertical axis with a "t" at or near the top and with a few tic marks labeled in radians from 0 to 2pi.  
2.)  On the bottom half of the illustration create a strobe-light effect to illustrate a stationary view of the phasor, as would be drawn on paper.  Show the rotating phasor dimmed to grey and dark blue most of the time.  When the dot in the top half of the illustration rolls over to the t = 0 spot, show the bottom half with a bright white background and bright blue lines (as is presently shown).  Then as the phasor continues to rotate, return to the dimmed view in the bottom half of the illustration.  What I have in mind is the effect of a strobe light that flashes at time t = 0 and every period (T, 2T, 3T, etc.) thereafter, thus illustrating how we interpret a phasor diagram drawn on paper.  Students need to understand that what we draw statically on a page of paper represents the angular relations at time t = 0. 
(I sure wish I had the tools to put such an illustration together and just show it!)   
Dfdeboer (talk) 22:58, 18 November 2009 (UTC)
replies: text: The rotating phasor isn't actually a phasor; phasors are time-independent, so they can't rotate by themselves. What rotates are sinors (also known as instantaneous complex value), which are equal to a phasor times e^(j w t). --Alej27 (talk) 19:06, 30 October 2020 (UTC)
thread_title:  The illustration: "Graph of a phasor as a rotating vector" 

message: The Phasor Addition section took me a little bit of time to make sense of.  The step by step calculation is trivial for the first few step (combining terms in the Re operator, etc), and then out of nowhere: Boom!  A3 and theta3 are introduced with a fairly complex definition for each.  It eventually made sense to me when I drew out the phasor diagram and looked at the x/y components, but something should help fill that gap. 
--Gradenko (talk) 07:44, 23 January 2011 (UTC)
thread_title:  Phasor addition missing steps 

message: I am not sure how to fix them, so it would be great if somebody else could fix the syntax so that the equations start showing up. Cheers. Vignesh.Mukund (talk) 11:20, 10 February 2014 (UTC)
thread_title:  Formatting errors 

message: The article had quite a poorly developed lead. I've added more essentials, including the origin as it is commonly attributed in (US) EE textbooks, but upon glancing on some Google Books snippets from Kline's biography of Steinmetz, I think the origin story was more complex. Alas I don't have immediate access to Kline's, but it's something to keep in mind (and go to) if counterclaims appear. 86.121.137.79 (talk) 22:11, 13 January 2015 (UTC)
thread_title:  Origin 

message: Phasors are used almost everywhere in power engineering and their usefulness should be linked. There is also not a significant mention of lead and lag, which is important when we compare between voltages and currents. A picture would help to illustrate the example of lead and lag for example. Phase angles also should be mentioned as being relative to each other and that you can set a reference point(which is usually the voltage source.)  — Preceding unsigned comment added by 204.98.7.11 (talk) 06:15, 7 December 2016 (UTC)
thread_title:  Added an extra section of why study phasors and a bit more information on phasor diagrams 

message: In the first paragraph of this article, it is stated that phasors are also called sinors (in older textbooks), and even a reference was cited to this. So, it seems like this is true.
However, in the book Fundamentals of Electric Circuits by Charles Alexander and Matthew Sadiku, phasors and sinors are defined differently. In the case of phasors, they are defined as usual, that is as Ae^(jθ); but sinors are defined as Ae^(jθ)e^(jωt) = Ae^(j(θ+ωt)).
I think this should be cleared, so I'd like to confirm if, whoever who cited that sinors are the same as phasors, actually didn't confuse those two terms. Perhaps they could share a screenshot/photo of the page of the cited textbook.
Alej27 (talk) 07:01, 31 March 2019 (UTC)
thread_title:  Mistake on the definition of sinor? 

message: I was recently editing the article of Fourier transforms, and I found a citation to a source with a ton of information on phasors. It's about the difference between i and j as representations of the complex component of phasors, as i is the usual standard in theoretical physics and j is the usual standard in electrical engineering, and all of the sign conventions that relate to that. It seems to be of sufficient relevance and importance to warrant being included in this article, but this doesn't mention anything of the sort. I don't have sufficient interest to want to invest the time to add the info to this article, but I figured I'd mention it here so that someone with an interest could. The source is  74.96.192.195 (talk) 08:54, 8 October 2021 (UTC)
replies: text: There's some very odd claims going on in that paper which I would treat as dubious without reliably published sources backing it up. The j in EE is defined exactly the same as the i in mathematics.  I find it hard to believe that i (physics) = −j, and by implication, = −i (mathematics).  Likewise, the idea that physics defines the positive direction of phasor rotation as clockwise, in cotradistinction to EE, is also debatable.  In mathematics, the positive direction of rotation is right-handed rotation, that is, anticlockwise as looking down on the axis of rotation.  I think the author is discussing one particular quantity (complex refractive index) where there is a difference of definition and drawing unwarranted conclusions from it by implication. SpinningSpark 17:37, 8 October 2021 (UTC)
thread_title:  Physics vs EE sign conventions