On 2020-06-18 10:27, Tauno Voipio wrote:> Teflon (PTFE) is notoriously microphonic. > > Years ago I made a femtoampere-class electrometer, and when testing it > the output swinged back and forth at a leisurely rate. The swinging > happened synchronously with the movements of the Teflon-insulated > input coaxial cable.I noticed that too, in pH meter inputs. Teflon had low leakage but high triboelectric charge generation. Ever seen demo set ups for ESD generation? They place a metal plate on top of a teflon block, then press (or slide) it, then pull it up. Kilovolts get generated (big sparks). Teflon seen to be very (negative charge) triboelectric, see https://en.wikipedia.org/wiki/Triboelectric_effect
Some capacitor leakage measurements
Started by ●June 14, 2020
Reply by ●June 18, 20202020-06-18
Reply by ●June 19, 20202020-06-19
On Sunday, June 14, 2020 at 6:31:16 AM UTC-5, Tim Williams wrote:> https://www.eevblog.com/forum/metrology/film-and-ceramic-capacitor-leakage-current/ > > Tim > > -- > Seven Transistor Labs, LLC > Electrical Engineering Consultation and Design > Website: https://www.seventransistorlabs.com/I'm sure many have seen this, but for those that haven't it I interesting. https://www.electronicdesign.com/technologies/test-measurement/article/21773611/whats-all-this-teflon-stuff-anyhow Mikek
Reply by ●June 19, 20202020-06-19
On Fri, 19 Jun 2020 04:04:33 -0700 (PDT), amdx62@gmail.com wrote:>On Sunday, June 14, 2020 at 6:31:16 AM UTC-5, Tim Williams wrote: >> https://www.eevblog.com/forum/metrology/film-and-ceramic-capacitor-leakage-current/ >> >> Tim >> >> -- >> Seven Transistor Labs, LLC >> Electrical Engineering Consultation and Design >> Website: https://www.seventransistorlabs.com/ > > >I'm sure many have seen this, but for those that haven't it I interesting. >https://www.electronicdesign.com/technologies/test-measurement/article/21773611/whats-all-this-teflon-stuff-anyhow > MikekElectronic Design is pitiful. I received the printed mag yesterday; I have no idea why. The entire issue isn't much thicker than a business card. The few articles are pitiful, mostly blather about silly software. The online version is unbearable. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●June 20, 20202020-06-20
On Sat, 20 Jun 2020 05:56:48 -0500, amdx <nojunk@knology.net> wrote:>On 6/19/2020 8:36 AM, jlarkin@highlandsniptechnology.com wrote: >> On Fri, 19 Jun 2020 04:04:33 -0700 (PDT), amdx62@gmail.com wrote: >> >>> On Sunday, June 14, 2020 at 6:31:16 AM UTC-5, Tim Williams wrote: >>>> https://www.eevblog.com/forum/metrology/film-and-ceramic-capacitor-leakage-current/ >>>> >>>> Tim >>>> >>>> -- >>>> Seven Transistor Labs, LLC >>>> Electrical Engineering Consultation and Design >>>> Website: https://www.seventransistorlabs.com/ >>> >>> >>> I'm sure many have seen this, but for those that haven't it I interesting. >>> https://www.electronicdesign.com/technologies/test-measurement/article/21773611/whats-all-this-teflon-stuff-anyhow >>> Mikek >> >> Electronic Design is pitiful. I received the printed mag yesterday; I >> have no idea why. The entire issue isn't much thicker than a business >> card. The few articles are pitiful, mostly blather about silly >> software. The online version is unbearable. >> > > I think you have mentioned this before. It seems with the internet >revolution, most print media has gone downhill, even my local newspaper >has shrunk in pages and in physical dimensions. > But that's a different subject, I presented the link to show info >about Teflon, that I thought was interesting. I do think I originally >saw the write up in a different source, but when I searched, this is the >source I found. Sorry it set you off!It's a discussion group. We need stuff to discuss, ideally on the topic of electronics.> I suggest you unsubscribe and don't read the online version of >Electronic Design.I have no idea why they have started mailing me the silly skinny mag. I don't look at their online version any more. It's annoying and useless. I do need to keep current on what's happening. The mags (ED, EDN, EE Times, Electronics Weekly, All About Circuits) are barely worth a quick glance, and some are so loaded up with web tricks that they are unbearable. Why does anyone need 35 cookies? Once a month roughly, I cruise the various semiconductor web sites and look at the new product listings. Digikey and Mouser have new product pages too. Any other ideas on how to keep up to date? One would think that such a giant industry as ours would support at least one decent mag. The optics mags are still fat and good, full of ads and articles and product releases. As are the microwave mags, but I don't do RF (ie, narrowband frequency domain) much, so only a fraction of their content is useful to us. Repeated rant: the DC specs of RF parts are usually terrible. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
