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Groups > sci.electronics.design > #446891
| From | Frank Miles <fpm@u.washington.edu> |
|---|---|
| Newsgroups | sci.electronics.design |
| Subject | Re: Capacitor soakage |
| Date | 2017-02-08 22:36 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <o7g6hg$1v2$1@dont-email.me> (permalink) |
| References | <b90d7cca-cbde-457c-9ef8-8e9ff14d941a@googlegroups.com> <m30h9c5ss1phtv430bo8din2koiovcl1fp@4ax.com> <21dd5db3-043e-4ab0-8706-4717052b4136@googlegroups.com> <vq-dncrOcPvL0wbFnZ2dnUU7-K-dnZ2d@supernews.com> <02bf1a7f-7f88-4fc2-ad80-201abf1af6fa@googlegroups.com> |
On Wed, 08 Feb 2017 10:30:28 -0800, George Herold wrote: > On Wednesday, February 8, 2017 at 11:59:10 AM UTC-5, Phil Hobbs wrote: >> On 02/08/2017 11:43 AM, Prof78 wrote: >> > On Monday, 6 February 2017 13:57:52 UTC, Spehro Pefhany wrote: >> >> On Mon, 6 Feb 2017 05:31:04 -0800 (PST), the renowned Prof78 >> >> <scott.hamilton@manchester.ac.uk> wrote: >> >> >> >>> Looking for advice/experience on measurement of capacitor >> >>> soakage. Would like to determine an approximate equivalent >> >>> circuit for a 1uF polypropylene capacitor at very low >> >>> frequency/time intervals of tens of seconds. >> >>> >> >>> Scott Hamilton. >> >> >> >> >> >> Did you read Bob Pease's article? A bunch of RC's in parallel with >> >> an ideal cap should do it. >> >> >> >> --sp >> >> >> >> >> >> -- Best regards, Spehro Pefhany >> > >> > Yes I have read the articles by Bob Pease but I need to be able to >> > measure and determine the equivalent circuit for a given capacitor so >> > that compensation can be applied. Each unit is hand adjusted. >> >> Yikes, that sounds like nailing jello to a tree. Do you have any reason >> to suppose that all the internal time constants would be >> temperature-independent? Cuz otherwise that's a nasty calibration table >> to create. > > Is there any reason to believe it will be linear with the voltage step? > (Sounds like a research project.) > > I thought I read once that teflon caps had low soakage. Maybe they > are better than polypropylene? > > George h. >> >> Cheers >> >> Phil Hobbs >> >> -- >> Dr Philip C D Hobbs >> Principal Consultant >> ElectroOptical Innovations LLC >> Optics, Electro-optics, Photonics, Analog Electronics >> >> 160 North State Road #203 >> Briarcliff Manor NY 10510 >> >> hobbs at electrooptical dot net >> http://electrooptical.net My dim recollection is that teflon is not so good. It wouldn't be surprising - fluorine having such strong electronegativity would likely have a "polarizing" effect that could be subject to relaxation responses. Mylar is definitely bad; polycarbonates not great either. Polypropylene is good, perhaps nearly as good as the ever-meltable polystyrene. The ceramics are mostly mediocre (or worse), though some of the newer C0Gs are close to polypropylene. Ah yes... got me to look it up in AoE3(p301): mostly what I've been sayin', except for the PTFE! This may be another case like the C0Gs - i.e. dependent on manufacturer/unknown parameters.
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Capacitor soakage Prof78 <scott.hamilton@manchester.ac.uk> - 2017-02-06 05:31 -0800
Re: Capacitor soakage Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-02-06 08:57 -0500
Re: Capacitor soakage Prof78 <scott.hamilton@manchester.ac.uk> - 2017-02-08 08:43 -0800
Re: Capacitor soakage Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-08 11:59 -0500
Re: Capacitor soakage George Herold <gherold@teachspin.com> - 2017-02-08 10:30 -0800
Re: Capacitor soakage Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-08 13:39 -0500
Re: Capacitor soakage John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-08 12:38 -0800
Re: Capacitor soakage Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-08 16:11 -0500
Re: Capacitor soakage John Larkin <jjlarkin@highlandtechnology.com> - 2017-02-09 08:30 -0800
Re: Capacitor soakage Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-09 14:55 -0500
Re: Capacitor soakage bill.sloman@ieee.org - 2017-02-08 14:53 -0800
Re: Capacitor soakage Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-02-08 19:11 -0500
Re: Capacitor soakage Frank Miles <fpm@u.washington.edu> - 2017-02-08 22:36 +0000
Re: Capacitor soakage George Herold <gherold@teachspin.com> - 2017-02-08 17:48 -0800
Re: Capacitor soakage John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-09 11:17 -0800
Re: Capacitor soakage "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-09 16:46 -0600
Re: Capacitor soakage krw@notreal.com - 2017-02-09 20:44 -0500
Re: Capacitor soakage bill.sloman@ieee.org - 2017-02-09 19:15 -0800
Re: Capacitor soakage John Larkin <jjlarkin@highlandtechnology.com> - 2017-02-09 20:54 -0800
Re: Capacitor soakage John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-09 11:16 -0800
Re: Capacitor soakage George Herold <gherold@teachspin.com> - 2017-02-09 12:02 -0800
Re: Capacitor soakage Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:50 -0800
Re: Capacitor soakage George Herold <gherold@teachspin.com> - 2017-02-09 06:36 -0800
Re: Capacitor soakage Phil Allison <pallison49@gmail.com> - 2017-02-08 17:10 -0800
Re: Capacitor soakage Phil Allison <pallison49@gmail.com> - 2017-02-06 06:51 -0800
Re: Capacitor soakage Prof78 <scott.hamilton@manchester.ac.uk> - 2017-02-08 08:32 -0800
Re: Capacitor soakage Tim Wescott <seemywebsite@myfooter.really> - 2017-02-08 17:48 -0600
Re: Capacitor soakage "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-08 17:56 -0600
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