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Groups > sci.electronics.design > #429817
| From | amdx <nojunk@knology.net> |
|---|---|
| Newsgroups | sci.electronics.design |
| Subject | Re: More inductor talk, Proximity effect, self capacitance |
| Date | 2016-09-29 10:59 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <nsjdon$ij$1@dont-email.me> (permalink) |
| References | <nsh2tn$8cq$1@dont-email.me> <3af0d58a-f078-4230-bc95-5e91025ca506@googlegroups.com> |
On 9/29/2016 8:55 AM, George Herold wrote: > On Wednesday, September 28, 2016 at 2:42:14 PM UTC-4, amdx 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? > > > George H. >> >> >> >> 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 > > I always find some loss in the capacitor part of an LC. > Lower frequency is bigger C, is the loss there? That's a good thought, I'm leaning against it though, I suspect my fine gentleman measured his inductors with either a Boonton 260A or an HP 4342A, both of these use very high Q* capacitors, so even if the cap had more loss at low frequencies, I don't think it would make that much difference in the Q curve. * ISTR reading the Boonton 260A tuning capacitor has a Q near 20,000. I recently saw some silver air variable caps with a Q of 15,000. Run of the mill air variables run from 1,000 on up.
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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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