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Re: "impedance mismatch", was: Re: JavaScript unfairly blamed?

From Denis McMahon <denismfmcmahon@gmail.com>
Newsgroups comp.lang.javascript
Subject Re: "impedance mismatch", was: Re: JavaScript unfairly blamed?
Date 2014-01-31 00:35 +0000
Organization A noiseless patient Spider
Message-ID <lcer4t$tc4$1@dont-email.me> (permalink)
References (6 earlier) <la7ie9tifqa4eq43tdm6i6557q3j2j4f0s@4ax.com> <5938dd39-59f3-4d13-89b9-5b54f250d618@googlegroups.com> <XnsA2C571A54D08Beejj99@194.109.133.133> <lcdbne$2ds$1@dont-email.me> <XnsA2C58EE643EDeejj99@194.109.133.133>

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On Thu, 30 Jan 2014 14:02:51 +0100, Evertjan. wrote:

> Denis McMahon <denismfmcmahon@gmail.com> wrote on 30 jan 2014 in
> comp.lang.javascript:
> 
>> On Thu, 30 Jan 2014 11:10:18 +0100, Evertjan. wrote:
>> 
>>> Impedance is the same, be it that the value is not linear for
>>> alternating current, but depends on the frequency, so Ohm's law only
>>> appies with a fixed frequency.
>>
>> Speaking as an electrical engineer by training, ohms law holds true for
>> all frequencies when considering impedance.
> 
> Speaking aas someone that likes to discuss by argument, not by anyone's
> status, I would say that wile true in mathemetical effect, it still is
> nonsense.
>> As the impedance varies with frequency, so the relationship between
>> current and voltage varies in accordance with Ohms law such that at any
>> frequency, voltage (rms or peak) = current (rms or peak) * impedance.
> 
> Indeed, but that is not Ohm's law,
> it is only a formula looking like Ohms' law.
> 
> Ohm's law expects dissipation.
> 
>> You also get a phase shift depending on the nature of the impedance
>> (capacitative or reactive) unless the impedance is a pure resistance.
> 
> The latter souds fishy to me.
> A pure resistance is just that, a resistance.
> An impedance is not the non-resistive part of the load.

I was obviously unclear. Impedance normally has a capacitive or inductive 
component, also referred to as the reactive part, as well as the purely 
resistive part. Impedance is the vector sum of reactance and resistance, 
where reactance is at a phase angle of either +90 or -90, depending on 
whether you consider v to i or i to v, and whether it is capacitive 
reactance or inductive reactance.

> Yes, I know we sometimes call them impedance together,
> but strictly speaking that is not correct.
> 
> Yes, I know that you can match a required and frequency dependent load
> impedance to a pure resistic, so frequency independent, load, but that
> does not mean they are the same.

Indeed, as soon as AC is involved, frequency becomes part of the equation 
that you can not ignore.

>> A single set of v/i/z values
> 
> Eh? This to do with lawn tennis?

voltage / current / impedance

>> may only apply to a given frequency, but I have to correct you as the
>> statement that "Ohm's law only applies with a fixed frequency" is
>> incorrect.
> 
> I did not say that, so why correct me?

You said: "Ohm's law only appies with a fixed frequency". It is the last 
phrase of the first quoted paragraph of yours above. I added what I 
perceived to be a missing l to change "appies" into "applies".

-- 
Denis McMahon, denismfmcmahon@gmail.com

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Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-26 02:37 -0800
  Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-26 11:52 +0100
    Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-26 12:04 -0800
      Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-26 22:24 +0100
        Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-26 14:49 -0800
          Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-27 02:14 +0100
            Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-27 18:30 -0800
              Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-28 19:08 +0100
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-28 19:50 +0100
                Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-28 21:18 +0100
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-28 22:27 +0100
                Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-28 23:23 +0100
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-29 17:12 +0100
                Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-31 22:30 +0100
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-02-01 22:35 +0100
                Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-28 19:59 -0800
                Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-31 14:08 +0100
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-02-01 22:52 +0100
                Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-02-02 10:09 -0800
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-02-04 23:42 +0100
                Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-28 19:40 -0800
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-29 17:17 +0100
                Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-29 16:51 -0800
                Re: JavaScript unfairly blamed? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-31 01:06 +0100
                Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-28 19:36 -0800
                Re: JavaScript unfairly blamed? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-31 14:47 +0100
      Re: JavaScript unfairly blamed? John Harris <niam@jghnorth.org.uk.invalid> - 2014-01-27 14:36 +0000
        Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-27 16:05 -0800
          Re: JavaScript unfairly blamed? John Harris <niam@jghnorth.org.uk.invalid> - 2014-01-29 15:26 +0000
            Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-29 16:44 -0800
              "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-30 11:10 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Tim Streater <timstreater@greenbee.net> - 2014-01-30 10:38 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-30 13:30 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Denis McMahon <denismfmcmahon@gmail.com> - 2014-01-30 12:45 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-30 14:05 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-01-31 21:32 +0000
                OT: "impedance mismatch" (was: "impedance mismatch", was: Re: JavaScript unfairly blamed?) Christoph Michael Becker <cmbecker69@arcor.de> - 2014-02-01 01:15 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Denis McMahon <denismfmcmahon@gmail.com> - 2014-02-01 02:40 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-01 10:02 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-01 09:54 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Denis McMahon <denismfmcmahon@gmail.com> - 2014-01-30 11:06 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-30 14:02 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "ViLco" <villiber@tin.it> - 2014-01-30 16:24 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Denis McMahon <denismfmcmahon@gmail.com> - 2014-01-31 00:35 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-31 11:16 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-30 15:14 -0800
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-31 00:56 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-30 22:13 -0800
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-31 11:51 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Dr J R Stockton <J.R.Stockton@physics.org> - 2014-01-31 19:58 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-01 09:30 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-02-02 17:44 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-03 01:15 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? John Harris <niam@jghnorth.org.uk.invalid> - 2014-02-03 14:58 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Tim Streater <timstreater@greenbee.net> - 2014-02-03 15:36 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-03 17:59 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Tim Streater <timstreater@greenbee.net> - 2014-02-03 17:18 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-03 19:47 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? John Harris <niam@jghnorth.org.uk.invalid> - 2014-02-04 10:33 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-06 13:40 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-02-06 10:12 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-07 10:32 +0100
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-02-08 23:06 +0000
                Re: "impedance mismatch", was: Re: JavaScript unfairly blamed? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-09 10:33 +0100

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