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Groups > sci.electronics.design > #519269
| From | Jasen Betts <jasen@xnet.co.nz> |
|---|---|
| Newsgroups | sci.electronics.design |
| Subject | Re: various OTs |
| Organization | JJ's own news server |
| Message-ID | <pq080q$lfo$2@gonzo.alcatraz> (permalink) |
| References | <r2u1sddojvr815ukjlm0qhsr5bpa2fbe6s@4ax.com> <pprd4s$8s2$1@dont-email.me> <3b61ba6c-2db5-4080-9144-c080861a5432@googlegroups.com> <pfCdnZP8Ctp9_l_GnZ2dnUU7-L2dnZ2d@supernews.com> |
| Date | 2018-10-14 20:13 +0000 |
On 2018-10-13, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: > On 10/13/18 3:24 PM, whit3rd wrote: >> On Friday, October 12, 2018 at 5:10:09 PM UTC-7, Tim Williams wrote: >> >>> The recent spate of reaction wheel failures apparently is an ESD phenomenon. >>> Radiation causes photoemission on the bearing surfaces, accumulating charge, >>> which eventually discharges through the grease, pitting the bearing balls >>> and races, causing rising power consumption until the ratings are met and >>> the thing grinds to a halt. >>> >>> The solution: use insulating (ceramic) bearings. >> >> Yeah, maybe. Or, add a bit of contaminant so the grease conducts. >> I'd worry about chemical stability of oxide ceramics (zirconium oxide, >> for instance) in space; it's like a reducing atmosphere, and you're gonna >> be there for years, and care about microinches of surface finish. Metal >> should hold up well. If ZrO turns to Zr, though, it's gonna lose the >> smooth surface. > > Insulating bearings will make the Van de Graaf problem worse. Pity you > can't use corona points in a vacuum. field emission? photo-electric effect? nanotube brushes? -- Notsodium is mined on the banks of denial.
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various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-12 12:50 -0700
Re: various OTs George Herold <gherold@teachspin.com> - 2018-10-12 13:04 -0700
Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-12 13:48 -0700
Re: various OTs George Herold <gherold@teachspin.com> - 2018-10-12 17:46 -0700
Re: various OTs dplatt@coop.radagast.org (Dave Platt) - 2018-10-12 14:53 -0700
Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-12 15:30 -0700
Re: various OTs Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2018-10-13 10:13 +0100
Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-13 09:33 -0700
Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-13 14:15 -0400
Re: various OTs Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2018-10-15 10:09 +0100
Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-15 06:50 -0700
Re: various OTs Clive Arthur <cliveta@nowaytoday.co.uk> - 2018-10-13 10:37 +0100
Re: various OTs DecadentLinuxUserNumeroUno@decadence.org - 2018-10-13 10:01 +0000
Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-13 11:08 -0700
Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-13 09:55 -0700
Re: various OTs MikeP <mjp993@googlemail.com> - 2018-10-16 03:22 +0000
Re: various OTs Robert Baer <robertbaer@localnet.com> - 2018-10-13 22:39 -0700
Re: various OTs Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2018-10-14 21:43 +0200
Re: various OTs Robert Baer <robertbaer@localnet.com> - 2018-10-15 19:46 -0700
Re: various OTs DecadentLinuxUserNumeroUno@decadence.org - 2018-10-12 23:55 +0000
Re: various OTs Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-12 16:58 -0700
Re: various OTs bill.sloman@ieee.org - 2018-10-12 17:52 -0700
Re: various OTs speff <spehro@gmail.com> - 2018-10-18 06:53 -0700
Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-18 06:59 -0700
Re: various OTs tabbypurr@gmail.com - 2018-10-18 14:10 -0700
Re: various OTs "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-10-18 17:49 -0500
Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-18 21:04 -0400
Re: various OTs Steve Wilson <no@spam.com> - 2018-10-19 01:34 +0000
Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-19 07:11 +0000
Re: various OTs "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-10-12 19:10 -0500
Re: various OTs Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-13 06:22 -0700
Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-13 14:16 -0400
Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-13 17:19 -0700
Re: various OTs whit3rd <whit3rd@gmail.com> - 2018-10-13 12:24 -0700
Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-13 17:30 -0400
Re: various OTs Jasen Betts <jasen@xnet.co.nz> - 2018-10-14 20:13 +0000
Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-14 13:59 -0700
Re: various OTs Steve Wilson <no@spam.com> - 2018-10-14 23:58 +0000
Re: various OTs Steve Wilson <no@spam.com> - 2018-10-15 01:05 +0000
Re: various OTs Jasen Betts <jasen@xnet.co.nz> - 2018-10-15 05:57 +0000
Re: various OTs DecadentLinuxUserNumeroUno@decadence.org - 2018-10-15 11:09 +0000
Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-15 07:23 +0000
Re: various OTs "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-10-13 21:39 -0500
Re: various OTs bitrex <user@example.net> - 2018-10-13 00:08 -0400
Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-13 06:59 +0000
Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-13 12:08 -0700
Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-13 07:27 +0000
Re: various OTs speff <spehro@gmail.com> - 2018-10-18 06:55 -0700
Re: various OTs Winfield Hill <hill@rowland.harvard.edu> - 2018-10-13 07:32 -0700
Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-13 12:17 -0700
Re: various OTs Joseph Gwinn <joegwinn@comcast.net> - 2018-10-15 08:37 -0400
Re: various OTs Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2018-10-15 13:58 +0100
Re: various OTs Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-10-15 14:34 +0100
Re: various OTs Clifford Heath <no.spam@please.net> - 2018-10-16 10:26 +1100
Re: various OTs Clive Arthur <cliveta@nowaytoday.co.uk> - 2018-10-16 10:46 +0100
Re: various OTs tabbypurr@gmail.com - 2018-10-16 08:46 -0700
Re: various OTs Clive Arthur <cliveta@nowaytoday.co.uk> - 2018-10-16 19:53 +0100
Re: various OTs tabbypurr@gmail.com - 2018-10-17 05:56 -0700
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