Groups > sci.electronics.design > #429713

Re: More inductor talk, Proximity effect, self capacitance

From	amdx <nojunk@knology.net>
Newsgroups	sci.electronics.design
Subject	Re: More inductor talk, Proximity effect, self capacitance
Date	2016-09-28 17:06 -0500
Organization	A noiseless patient Spider
Message-ID	<nshesd$mim$1@dont-email.me> (permalink)
References	<nsh2tn$8cq$1@dont-email.me> <k8coub90opo91a0icbd4mo9ml2e4gg7n5v@4ax.com>

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On 9/28/2016 4:08 PM, boB wrote:
> On Wed, 28 Sep 2016 13:42:06 -0500, amdx <nojunk@knology.net> wrote:
>
>> A fine gentleman did an experiment building two inductors.
>> The coils were wound with 420/46 litz. Both inductors have 40 turns.
>> One inductor is close wound (215uh 7.7pf distributed capacitance).
>> The second has a 0.625/wire diameter space between wires, (187uh and 6.9
>> pf distributed capacitance).
>>    The inductor with spacing has a higher Q, except at the low end
>>
>> where the Q's are equal.
>>
>> The reason for spacing the wire is to reduce Proximity effect.
>>
>>
>> Here is the graph, each coil was tested twice (two lines each)
>>
>>
>>
>>> http://s395.photobucket.com/user/Qmavam/media/Close%20vs%20space%20wound._zpsctlfmjdi.png.html
>>
>>
>> What would be the reason that the Q does not start out higher,
>> but moves up with frequency?
>
>
>
>
>>
>>
>>
>>                                       Mikek
>>
>> Re: the difference in inductance, both 40 turns.
>> The inductance,  215uh vs 187uh = 86.9%
>> The capacitance 7.7 vs 6.9 = 89.6%
>> The capacitance of 40 turns did go down 10.3% with spacing.
>> The inductance went down 13% with spacing.   FWIW



> Probably because of the the AC resistance....  The real part of the

> impedance.

>

> I don't see that figure displayed.

>

> boB

Try the figure again, it works for me.
> http://i395.photobucket.com/albums/pp37/Qmavam/Close%20vs%20space%20wound._zpsctlfmjdi.png


But note: the coils have near identical Q's and then the spaced coils Q
rises quickly, why didn't it just start out higher as it should have
less loss because of less proximity effect. That only shows up at higher 
frequencies, why?

                                 Mikek

Thread

More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-28 13:42 -0500
  Re: More inductor talk, Proximity effect, self capacitance boB <boB@theresnoplacelikehome.com> - 2016-09-28 14:08 -0700
    Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-28 17:06 -0500
      Re: More inductor talk, Proximity effect, self capacitance "Tim Williams" <tiwill@seventransistorlabs.com> - 2016-09-28 23:50 -0500
        Re: More inductor talk, Proximity effect, self capacitance boB <boB@theresnoplacelikehome.com> - 2016-09-28 22:27 -0700
      Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-10-03 15:46 -0500
  Re: More inductor talk, Proximity effect, self capacitance Winfield Hill <hill@rowland.harvard.edu> - 2016-09-28 15:38 -0700
    Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-28 19:16 -0500
    Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-28 22:06 -0500
      Re: More inductor talk, Proximity effect, self capacitance Winfield Hill <hill@rowland.harvard.edu> - 2016-09-28 20:17 -0700
        Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-29 06:13 -0500
          Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-29 08:29 -0500
            Re: More inductor talk, Proximity effect, self capacitance Winfield Hill <hill@rowland.harvard.edu> - 2016-09-29 06:54 -0700
              Re: More inductor talk, Proximity effect, self capacitance boB <boB@theresnoplacelikehome.com> - 2016-09-29 11:57 -0700
                Re: More inductor talk, Proximity effect, self capacitance Winfield Hill <hill@rowland.harvard.edu> - 2016-09-29 12:29 -0700
  Re: More inductor talk, Proximity effect, self capacitance George Herold <gherold@teachspin.com> - 2016-09-29 06:55 -0700
    Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-29 10:59 -0500
      Re: More inductor talk, Proximity effect, self capacitance makolber@yahoo.com - 2016-09-29 09:15 -0700
        Re: More inductor talk, Proximity effect, self capacitance amdx <nojunk@knology.net> - 2016-09-29 13:16 -0500

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