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Groups > sci.electronics.design > #747328 > unrolled thread
| Started by | john larkin <jl@glen--canyon.com> |
|---|---|
| First post | 2026-09-07 08:18 -0700 |
| Last post | 2026-09-26 10:25 -0400 |
| Articles | 20 on this page of 259 — 26 participants |
Back to article view | Back to sci.electronics.design
discharging caps john larkin <jl@glen--canyon.com> - 2026-09-07 08:18 -0700
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-07 17:20 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-07 09:58 -0700
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-07 19:51 +0100
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-08 10:27 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 08:16 -0700
Re: discharging caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-09-08 15:44 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 09:35 -0700
Re: discharging caps ehsjr <ehsjr@verizon.net> - 2026-09-07 12:26 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-07 10:00 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-07 19:32 +0100
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-07 15:38 -0700
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-08 07:41 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 07:57 -0700
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-08 15:23 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 09:38 -0700
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-09 10:33 +0000
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-11 11:54 +0100
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-11 11:01 +0000
Re: discharging caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-09-11 13:59 +0000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-08 04:28 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-07 11:59 -0700
Re: discharging caps chrisq <syseng@gfsys.co.uk> - 2026-09-07 19:33 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-07 11:52 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-08 17:35 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 07:43 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 02:03 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-08 13:10 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 16:25 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 08:00 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 03:09 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-08 12:56 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 16:40 +1000
Re: discharging caps piglet <erichpwagner@hotmail.com> - 2026-09-09 09:51 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-09 03:44 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 20:57 +1000
Re: discharging caps Jeroen Belleman <jeroen@nospam.please> - 2026-09-09 14:25 +0200
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-10 00:12 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-09 07:59 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-10 02:27 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-09 10:42 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-10 17:43 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-10 07:10 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-11 00:58 +1000
Re: discharging caps chrisq <syseng@gfsys.co.uk> - 2026-09-09 17:29 +0100
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-10 03:35 +1000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-10 01:32 +1000
Re: discharging caps Jeroen Belleman <jeroen@nospam.please> - 2026-09-09 23:10 +0200
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-10 18:38 +1000
Re: discharging caps antispam@fricas.org (Waldek Hebisch) - 2026-09-13 00:27 +0000
Re: discharging caps Lane W <cactus_DAC@yahoo.com> - 2026-09-12 18:38 -0600
Re: discharging caps antispam@fricas.org (Waldek Hebisch) - 2026-09-13 03:11 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-13 07:50 -0700
Re: discharging caps Lane W <cactus_DAC@yahoo.com> - 2026-09-13 09:14 -0600
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 02:18 +1000
Re: discharging caps Lane W <cactus_DAC@yahoo.com> - 2026-09-13 10:28 -0600
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 01:28 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-13 12:03 -0700
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-13 23:54 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-13 17:12 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 16:05 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-14 08:21 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-15 18:28 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-15 10:23 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-16 18:39 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-16 03:21 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-16 21:16 +1000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 15:59 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-14 08:22 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-15 18:31 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-12 17:59 -0700
Re: discharging caps wmartin <wwm@wwmartin.net> - 2026-09-12 21:21 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-13 16:27 +1000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-13 16:24 +1000
Re: discharging caps antispam@fricas.org (Waldek Hebisch) - 2026-09-13 13:36 +0000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 02:05 +1000
Re: discharging caps John R Walliker <jrwalliker@gmail.com> - 2026-09-13 19:40 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-13 12:08 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 16:18 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-14 08:24 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-15 18:36 +1000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 16:11 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-14 08:56 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-15 18:50 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-10 07:17 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-11 01:02 +1000
Re: discharging caps chrisq <syseng@gfsys.co.uk> - 2026-09-08 11:19 +0100
Re: discharging caps chrisq <syseng@gfsys.co.uk> - 2026-09-08 11:33 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 07:23 -0700
Re: discharging caps chrisq <syseng@gfsys.co.uk> - 2026-09-08 16:28 +0100
Re: discharging caps chrisq <syseng@gfsys.co.uk> - 2026-09-08 21:13 +0100
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-08 16:06 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 02:10 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-08 12:59 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 16:45 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-09 03:22 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 21:07 +1000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-09 02:10 +1000
Re: discharging caps Buzz McCool <buzz_mccool@yahoo.com> - 2026-09-14 09:44 -0700
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-14 10:15 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-11 16:23 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-11 07:45 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-12 01:59 +1000
Re: discharging caps Cydrome Leader <presence@MUNGEpanix.com> - 2026-09-17 07:19 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-17 07:46 -0700
Re: discharging caps Cydrome Leader <presence@MUNGEpanix.com> - 2026-09-18 04:54 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-18 07:57 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-18 15:45 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-18 08:02 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-19 16:40 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-19 08:48 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-20 16:30 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-20 02:17 -0700
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-20 12:30 +0100
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-21 00:52 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-20 08:46 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-21 17:41 +1000
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-08 07:46 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 07:26 -0700
Re: discharging caps Lasse Langwadt <llc@fonz.dk> - 2026-09-07 21:18 +0200
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-07 12:36 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-07 22:26 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-07 15:14 -0700
Re: discharging caps "Edward Rawde" <invalid@invalid.invalid> - 2026-09-07 20:06 -0400
Re: discharging caps Don Y <blockedofcourse@foo.invalid> - 2026-09-07 19:30 -0700
Re: discharging caps "Edward Rawde" <invalid@invalid.invalid> - 2026-09-07 23:40 -0400
Re: discharging caps Don Y <blockedofcourse@foo.invalid> - 2026-09-07 22:04 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-08 08:45 +0100
Re: discharging caps John R Walliker <jrwalliker@gmail.com> - 2026-09-08 11:59 +0100
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-08 12:30 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-08 07:34 -0700
Re: discharging caps ehsjr <ehsjr@verizon.net> - 2026-09-08 12:55 -0400
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-13 08:15 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-13 07:41 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-13 17:45 +0100
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 03:53 +1000
Re: discharging caps John R Walliker <jrwalliker@gmail.com> - 2026-09-13 19:28 +0100
Re: discharging caps ehsjr <ehsjr@verizon.net> - 2026-09-13 17:16 -0400
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-14 10:20 -0400
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-14 15:41 +0100
Re: discharging caps Carl <carl.ijamesXX@YYverizon.net> - 2026-09-07 21:10 -0400
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-08 10:37 -0400
Re: discharging caps Jeremiah Jones <jj@j.j> - 2026-09-08 22:14 -0700
Re: discharging caps someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-09-09 17:45 +0000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-09 11:40 -0700
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-10 09:55 +0100
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-10 07:20 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-11 16:32 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-11 07:46 -0700
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-11 17:08 +0100
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-11 14:28 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-12 16:24 +1000
Re: discharging caps John R Walliker <jrwalliker@gmail.com> - 2026-09-12 10:49 +0100
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-13 01:09 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-12 07:54 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-13 01:20 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-12 09:12 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-13 02:53 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-12 12:43 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-13 16:37 +1000
Re: discharging caps Joerg <news@analogconsultants.com> - 2026-09-09 15:15 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-10 12:25 +0100
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-10 13:09 +0100
Re: discharging caps John R Walliker <jrwalliker@gmail.com> - 2026-09-10 14:10 +0100
Re: discharging caps Joerg <news@analogconsultants.com> - 2026-09-10 11:05 -0700
Re: discharging caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-09-10 19:12 +0000
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-13 14:52 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-13 12:17 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-14 16:25 +1000
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-14 10:15 -0400
Re: discharging caps "Edward Rawde" <invalid@invalid.invalid> - 2026-09-17 19:53 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-17 19:15 -0700
Re: discharging caps "Edward Rawde" <invalid@invalid.invalid> - 2026-09-17 23:50 -0400
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-18 15:58 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-18 07:26 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-19 16:26 +1000
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-20 11:25 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-20 08:42 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-21 17:54 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-21 10:09 -0700
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-21 08:59 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-21 08:02 -0700
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-21 13:00 -0400
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-21 10:12 -0700
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-22 10:12 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-22 08:25 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-23 03:55 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-22 17:36 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-23 16:18 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-23 09:05 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-24 16:36 +1000
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-24 08:11 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-24 07:26 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-25 00:52 +1000
Re: discharging caps ehsjr <ehsjr@verizon.net> - 2026-09-24 18:40 -0400
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-24 16:22 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-25 16:50 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-25 07:26 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-26 01:32 +1000
Re: discharging caps antispam@fricas.org (Waldek Hebisch) - 2026-09-26 03:12 +0000
Re: discharging caps "Edward Rawde" <invalid@invalid.invalid> - 2026-09-26 00:38 -0400
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-26 07:08 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-27 01:07 +1000
Re: discharging caps JM <sunaecoNoChoppedPork@gmail.com> - 2026-09-26 15:49 +0100
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-28 10:11 -0700
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-23 09:24 -0400
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-21 17:01 +0000
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-20 11:44 -0400
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-23 21:42 +0100
Re: discharging caps Lane W <cactus_DAC@yahoo.com> - 2026-09-23 14:44 -0600
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-23 17:51 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-24 10:07 +0100
Re: discharging caps Simon Simple <nothanks@nottoday.co.uk> - 2026-09-24 12:01 +0100
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-24 13:59 +0100
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-23 14:16 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-24 10:07 +0100
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-24 11:51 -0700
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-24 07:58 -0400
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-24 07:54 -0400
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-24 13:59 +0100
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-24 17:56 -0400
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-24 16:27 -0700
Re: discharging caps liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-25 09:22 +0100
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-24 11:55 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-25 17:09 +1000
Re: discharging caps Jeroen Belleman <jeroen@nospam.please> - 2026-09-25 09:38 +0200
Re: discharging caps John R Walliker <jrwalliker@gmail.com> - 2026-09-25 10:59 +0100
Re: discharging caps Jeroen Belleman <jeroen@nospam.please> - 2026-09-25 12:28 +0200
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-25 22:42 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-25 07:38 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-26 01:11 +1000
Re: discharging caps Jeroen Belleman <jeroen@nospam.please> - 2026-09-25 19:59 +0200
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-26 15:56 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-26 09:24 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-27 16:22 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-27 03:20 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-27 20:55 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-27 07:59 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-28 12:35 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-28 10:15 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-29 17:22 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-26 07:20 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-27 01:26 +1000
Re: discharging caps Jeroen Belleman <jeroen@nospam.please> - 2026-09-26 22:58 +0200
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-26 16:20 -0700
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-27 07:39 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-27 03:29 -0700
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-27 13:50 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-27 08:04 -0700
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-27 15:16 +0000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-27 08:29 -0700
Re: discharging caps Jan Panteltje <alien@comet.invalid> - 2026-09-28 06:38 +0000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-28 17:34 +1000
Re: discharging caps john larkin <jl@htigct.com> - 2026-09-28 10:17 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-29 17:09 +1000
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-28 12:54 +1000
Re: discharging caps john larkin <jl@glen--canyon.com> - 2026-09-27 20:14 -0700
Re: discharging caps Bill Sloman <bill.sloman@ieee.org> - 2026-09-28 16:58 +1000
Re: discharging caps legg <legg@nospam.magma.ca> - 2026-09-26 10:25 -0400
Page 9 of 13 — ← Prev page 1 … 7 8 [9] 10 11 … 13 Next page →
| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2026-09-09 15:15 -0700 |
| Message-ID | <nge43rFpmqpU1@mid.individual.net> |
| In reply to | #747328 |
On 9/7/26 8:18 AM, john larkin wrote: > Suppose we have a box with some big caps inside, for example 0.2 > farads that run at about 200 volts. When AC power is off, we want to > discharge them for several reasons. > > Putting, say, a 1K resistor across them dissipates 40 watts and has a > 200 second time constant. It will take many tau before the voltage > gets low enough for people to poke around inside. > > The ideal discharger would be a constant-current or even better a > constant-power load, all the way down to zero volts. It would be dumb, > not switched by some decision circuit or anything fancy like that. > > And of course we need several LEDs as warnings that the thing is hot. > Maybe a boost converter that regulates to a constant current until it runs out of steam? It would have to run it down to safe levels. The load could be an old-school 500W halogen construction lamp for the European market (230V) which wouldn't get to full brightness but should still be able to light up half the road for a while Griswold-style. https://www.youtube.com/watch?v=iXaw70X7wb4 Or some big resistor array. Or a European style 230V non-fan space heater without any dimmer and stuff. If you did an LED load that should be seen from space. -- Regards, Joerg http://www.analogconsultants.com/
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| From | liz@poppyrecords.invalid.invalid (Liz Tuddenham) |
|---|---|
| Date | 2026-09-10 12:25 +0100 |
| Message-ID | <1s17z4m.dbvqwcupv0ukN%liz@poppyrecords.invalid.invalid> |
| In reply to | #747517 |
Joerg <news@analogconsultants.com> wrote: [...] > The load could be an old-school 500W halogen construction lamp for the > European market (230V) which wouldn't get to full brightness Under-running a halogen lamp considerably shortens its life. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
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| From | Simon Simple <nothanks@nottoday.co.uk> |
|---|---|
| Date | 2026-09-10 13:09 +0100 |
| Message-ID | <117u6l8$1vgt7$1@dont-email.me> |
| In reply to | #747532 |
On 10/09/2026 12:25, Liz Tuddenham wrote: > Joerg <news@analogconsultants.com> wrote: > > [...] >> The load could be an old-school 500W halogen construction lamp for the >> European market (230V) which wouldn't get to full brightness > > Under-running a halogen lamp considerably shortens its life. Depends how much it's under-run, obviously. I've used 12V halogens as interstitial heaters in a string of NaNiCl cells glowing up to red hot and never seen a failure. In any case, John's application is, I'm guessing, pretty low duty cycle. -- SS
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| From | John R Walliker <jrwalliker@gmail.com> |
|---|---|
| Date | 2026-09-10 14:10 +0100 |
| Message-ID | <117ua7p$20q9c$1@dont-email.me> |
| In reply to | #747533 |
On 10/09/2026 13:09, Simon Simple wrote: > On 10/09/2026 12:25, Liz Tuddenham wrote: >> Joerg <news@analogconsultants.com> wrote: >> >> [...] >>> The load could be an old-school 500W halogen construction lamp for the >>> European market (230V) which wouldn't get to full brightness >> >> Under-running a halogen lamp considerably shortens its life. > > Depends how much it's under-run, obviously. I've used 12V halogens as > interstitial heaters in a string of NaNiCl cells glowing up to red hot > and never seen a failure. > > In any case, John's application is, I'm guessing, pretty low duty cycle. The reduced lifetime with under-running is only going to be a problem in the intermediate range where the filament is hot enough for tungsten to evaporate but not hot enough for the tungsten halide to be decomposed and redeposited on the filament. Very low duty cycles or very low filament temperatures should not be a problem. John
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2026-09-10 11:05 -0700 |
| Message-ID | <ngg9rfF5n3hU1@mid.individual.net> |
| In reply to | #747534 |
On 9/10/26 6:10 AM, John R Walliker wrote: > On 10/09/2026 13:09, Simon Simple wrote: >> On 10/09/2026 12:25, Liz Tuddenham wrote: >>> Joerg <news@analogconsultants.com> wrote: >>> >>> [...] >>>> The load could be an old-school 500W halogen construction lamp for the >>>> European market (230V) which wouldn't get to full brightness >>> >>> Under-running a halogen lamp considerably shortens its life. >> >> Depends how much it's under-run, obviously. I've used 12V halogens as >> interstitial heaters in a string of NaNiCl cells glowing up to red hot >> and never seen a failure. >> >> In any case, John's application is, I'm guessing, pretty low duty cycle. > > The reduced lifetime with under-running is only going to be > a problem in the intermediate range where the filament is hot > enough for tungsten to evaporate but not hot enough for the > tungsten halide to be decomposed and redeposited on the filament. > Very low duty cycles or very low filament temperatures should not > be a problem. > John > Yes, you have to set the boost conversion output voltage accordingly. Also, I used to have halogen lamps in my bicycle headlights for many years and when the NiCd started to fade (it did a lot in hilly terrain) there would be an undervoltage. They still lasted nearly forever. I did 6000 miles a year when I was young and usually ran daytime lighting as well, for safety. -- Regards, Joerg http://www.analogconsultants.com/
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| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
|---|---|
| Date | 2026-09-10 19:12 +0000 |
| Message-ID | <117uved$293pd$1@dont-email.me> |
| In reply to | #747534 |
John R Walliker <jrwalliker@gmail.com> wrote: > On 10/09/2026 13:09, Simon Simple wrote: >> On 10/09/2026 12:25, Liz Tuddenham wrote: >>> Joerg <news@analogconsultants.com> wrote: >>> >>> [...] >>>> The load could be an old-school 500W halogen construction lamp for the >>>> European market (230V) which wouldn't get to full brightness >>> >>> Under-running a halogen lamp considerably shortens its life. >> >> Depends how much it's under-run, obviously. I've used 12V halogens as >> interstitial heaters in a string of NaNiCl cells glowing up to red hot >> and never seen a failure. >> >> In any case, John's application is, I'm guessing, pretty low duty cycle. > > The reduced lifetime with under-running is only going to be > a problem in the intermediate range where the filament is hot > enough for tungsten to evaporate but not hot enough for the > tungsten halide to be decomposed and redeposited on the filament. > Very low duty cycles or very low filament temperatures should not > be a problem. > John > > > Another iteration of the halogen bulb urban myth. The halide recycling loop is pretty cool, keeping the bulb envelope clean. That’s all it does, though. Tungsten is lost preferentially from the hot spots, which get hotter as this proceeds, but is redeposited rather uniformly as crystals. There’s no healing of the hot spots. The long filament life comes from the high gas pressure, which slows down tungsten vapor diffusion from the hot spots, which greatly enhances redeposition there. The high pressure requires a very strong envelope that doesn’t melt easily. If it were as big as a normal bulb, it would be an explosion hazard and the convection loss would be horrible. The halogen mechanism makes it possible to use a small envelope without it turning black early in the filament’s life. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
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| From | legg <legg@nospam.magma.ca> |
|---|---|
| Date | 2026-09-13 14:52 -0400 |
| Message-ID | <fjrdalp09u8ck3h66pba1mlibigq9ihrlr@4ax.com> |
| In reply to | #747328 |
On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> wrote: >Suppose we have a box with some big caps inside, for example 0.2 >farads that run at about 200 volts. When AC power is off, we want to >discharge them for several reasons. > >Putting, say, a 1K resistor across them dissipates 40 watts and has a >200 second time constant. It will take many tau before the voltage >gets low enough for people to poke around inside. > >The ideal discharger would be a constant-current or even better a >constant-power load, all the way down to zero volts. It would be dumb, >not switched by some decision circuit or anything fancy like that. > >And of course we need several LEDs as warnings that the thing is hot. > > >John Larkin >Highland Tech Glen Canyon Design Center >Lunatic Fringe Electronics Mechanical safety interlock switch on box lid, applying 50R 50W wirewound or carborundum resistor. Audible or visible indicator across switched load. Takes about 1 minute. Smaller R value gives shorter discharge time, but watch switch ratings and load surface peak temps. RL
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-13 12:17 -0700 |
| Message-ID | <n7tdalpl13kf5hb5u88gnjkc3d7lma9pi3@4ax.com> |
| In reply to | #747682 |
On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: >On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >wrote: > >>Suppose we have a box with some big caps inside, for example 0.2 >>farads that run at about 200 volts. When AC power is off, we want to >>discharge them for several reasons. >> >>Putting, say, a 1K resistor across them dissipates 40 watts and has a >>200 second time constant. It will take many tau before the voltage >>gets low enough for people to poke around inside. >> >>The ideal discharger would be a constant-current or even better a >>constant-power load, all the way down to zero volts. It would be dumb, >>not switched by some decision circuit or anything fancy like that. >> >>And of course we need several LEDs as warnings that the thing is hot. >> >> >>John Larkin >>Highland Tech Glen Canyon Design Center >>Lunatic Fringe Electronics > >Mechanical safety interlock switch on box lid, applying 50R 50W > wirewound or carborundum resistor. Audible or visible indicator >across switched load. > My engineers and test techs need to measure and probe live, with the top cover off. And they may send a failed unit back to production for a fix. One thing that can fail is the discharge circuit. >Takes about 1 minute. Smaller R value gives shorter discharge time, >but watch switch ratings and load surface peak temps. 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors fail from repeated power spikes. And it's around 4K joules. > >RL John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-14 16:25 +1000 |
| Message-ID | <118840e$18ct6$6@dont-email.me> |
| In reply to | #747687 |
On 14/09/2026 5:17 am, john larkin wrote: > On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: > >> On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >> wrote: >> >>> Suppose we have a box with some big caps inside, for example 0.2 >>> farads that run at about 200 volts. When AC power is off, we want to >>> discharge them for several reasons. >>> >>> Putting, say, a 1K resistor across them dissipates 40 watts and has a >>> 200 second time constant. It will take many tau before the voltage >>> gets low enough for people to poke around inside. >>> >>> The ideal discharger would be a constant-current or even better a >>> constant-power load, all the way down to zero volts. It would be dumb, >>> not switched by some decision circuit or anything fancy like that. >>> >>> And of course we need several LEDs as warnings that the thing is hot. >>> >>> >>> John Larkin >>> Highland Tech Glen Canyon Design Center >>> Lunatic Fringe Electronics >> >> Mechanical safety interlock switch on box lid, applying 50R 50W >> wirewound or carborundum resistor. Audible or visible indicator >> across switched load. >> > > My engineers and test techs need to measure and probe live, with the > top cover off. And they may send a failed unit back to production for > a fix. One thing that can fail is the discharge circuit. > > >> Takes about 1 minute. Smaller R value gives shorter discharge time, >> but watch switch ratings and load surface peak temps. > > 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors > fail from repeated power spikes. Were they rated for the peak power involved? Some data sheets are more comprehensive than others. > And it's around 4K joules. Quite a lot of energy, but not exactly intimidating. -- Bill Sloman, Sydney
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| From | legg <legg@nospam.magma.ca> |
|---|---|
| Date | 2026-09-14 10:15 -0400 |
| Message-ID | <klvfal9p9q9ufusn8jd405rc3gt12rgaal@4ax.com> |
| In reply to | #747687 |
On Sun, 13 Sep 2026 12:17:59 -0700, john larkin <jl@glen--canyon.com> wrote: >On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: > >>On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >>wrote: >> >>>Suppose we have a box with some big caps inside, for example 0.2 >>>farads that run at about 200 volts. When AC power is off, we want to >>>discharge them for several reasons. >>> >>>Putting, say, a 1K resistor across them dissipates 40 watts and has a >>>200 second time constant. It will take many tau before the voltage >>>gets low enough for people to poke around inside. >>> >>>The ideal discharger would be a constant-current or even better a >>>constant-power load, all the way down to zero volts. It would be dumb, >>>not switched by some decision circuit or anything fancy like that. >>> >>>And of course we need several LEDs as warnings that the thing is hot. >>> >>> >>>John Larkin >>>Highland Tech Glen Canyon Design Center >>>Lunatic Fringe Electronics >> >>Mechanical safety interlock switch on box lid, applying 50R 50W >> wirewound or carborundum resistor. Audible or visible indicator >>across switched load. >> > >My engineers and test techs need to measure and probe live, with the >top cover off. And they may send a failed unit back to production for >a fix. One thing that can fail is the discharge circuit. > Bypassing a safety interlock isn't encouraged and can have unfortunate results. Testing it and ensuring function requires sensible procedures and training. If you've got both, there's no issue. Providing suitable energy-limited test points can make their job SO much easier. If only part of the installation is hazardous, it can be furnished with appropriate guards with their own interlock. > >>Takes about 1 minute. Smaller R value gives shorter discharge time, >>but watch switch ratings and load surface peak temps. > >200 volts into 50 ohms is 800 watts. I've seen wirewound resistors >fail from repeated power spikes. Both types mentioned are built for it. Consult the literature. Carborundum, in particular, is used in surge applications. 50R recommended, because it is a common value in HV HF gear. > >And it's around 4K joules. > > >> >>RL > >John Larkin >Highland Tech Glen Canyon Design Center >Lunatic Fringe Electronics
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| From | "Edward Rawde" <invalid@invalid.invalid> |
|---|---|
| Date | 2026-09-17 19:53 -0400 |
| Message-ID | <118huik$1l6a$1@nnrp.usenet.blueworldhosting.com> |
| In reply to | #747687 |
"john larkin" <jl@glen--canyon.com> wrote in message news:n7tdalpl13kf5hb5u88gnjkc3d7lma9pi3@4ax.com... > On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: > >>On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >>wrote: >> >>>Suppose we have a box with some big caps inside, for example 0.2 >>>farads that run at about 200 volts. When AC power is off, we want to >>>discharge them for several reasons. >>> >>>Putting, say, a 1K resistor across them dissipates 40 watts and has a >>>200 second time constant. It will take many tau before the voltage >>>gets low enough for people to poke around inside. >>> >>>The ideal discharger would be a constant-current or even better a >>>constant-power load, all the way down to zero volts. It would be dumb, >>>not switched by some decision circuit or anything fancy like that. >>> >>>And of course we need several LEDs as warnings that the thing is hot. >>> >>> >>>John Larkin >>>Highland Tech Glen Canyon Design Center >>>Lunatic Fringe Electronics >> >>Mechanical safety interlock switch on box lid, applying 50R 50W >> wirewound or carborundum resistor. Audible or visible indicator >>across switched load. >> > > My engineers and test techs need to measure and probe live, with the > top cover off. And they may send a failed unit back to production for > a fix. One thing that can fail is the discharge circuit. > > >>Takes about 1 minute. Smaller R value gives shorter discharge time, >>but watch switch ratings and load surface peak temps. > > 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors > fail from repeated power spikes. Philips managed that in the 80s https://www.google.com/search?q=which+80s+philips+colour+tv+had+repeated+surge+limiter+resistor+failure > > And it's around 4K joules. > > >> >>RL > > John Larkin > Highland Tech Glen Canyon Design Center > Lunatic Fringe Electronics
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-17 19:15 -0700 |
| Message-ID | <9g6paltm1ac2etclcup8e73mqkid89aqco@4ax.com> |
| In reply to | #747847 |
On Thu, 17 Sep 2026 19:53:55 -0400, "Edward Rawde" <invalid@invalid.invalid> wrote: >"john larkin" <jl@glen--canyon.com> wrote in message news:n7tdalpl13kf5hb5u88gnjkc3d7lma9pi3@4ax.com... >> On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: >> >>>On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >>>wrote: >>> >>>>Suppose we have a box with some big caps inside, for example 0.2 >>>>farads that run at about 200 volts. When AC power is off, we want to >>>>discharge them for several reasons. >>>> >>>>Putting, say, a 1K resistor across them dissipates 40 watts and has a >>>>200 second time constant. It will take many tau before the voltage >>>>gets low enough for people to poke around inside. >>>> >>>>The ideal discharger would be a constant-current or even better a >>>>constant-power load, all the way down to zero volts. It would be dumb, >>>>not switched by some decision circuit or anything fancy like that. >>>> >>>>And of course we need several LEDs as warnings that the thing is hot. >>>> >>>> >>>>John Larkin >>>>Highland Tech Glen Canyon Design Center >>>>Lunatic Fringe Electronics >>> >>>Mechanical safety interlock switch on box lid, applying 50R 50W >>> wirewound or carborundum resistor. Audible or visible indicator >>>across switched load. >>> >> >> My engineers and test techs need to measure and probe live, with the >> top cover off. And they may send a failed unit back to production for >> a fix. One thing that can fail is the discharge circuit. >> >> >>>Takes about 1 minute. Smaller R value gives shorter discharge time, >>>but watch switch ratings and load surface peak temps. >> >> 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors >> fail from repeated power spikes. > >Philips managed that in the 80s >https://www.google.com/search?q=which+80s+philips+colour+tv+had+repeated+surge+limiter+resistor+failure > >> >> And it's around 4K joules. >> >> >>> >>>RL >> >> John Larkin >> Highland Tech Glen Canyon Design Center >> Lunatic Fringe Electronics > I used some of those giant gold MIL-style 250-watt resistors like this https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 in a high-surge low-duty cycle application. They failed, and tended to fail with one terminal shorted to the case. Bad. I replaced them with planar porcelain-steel thickfilms and that worked fine. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | "Edward Rawde" <invalid@invalid.invalid> |
|---|---|
| Date | 2026-09-17 23:50 -0400 |
| Message-ID | <118ice7$2tuu$1@nnrp.usenet.blueworldhosting.com> |
| In reply to | #747848 |
"john larkin" <jl@glen--canyon.com> wrote in message news:9g6paltm1ac2etclcup8e73mqkid89aqco@4ax.com... > On Thu, 17 Sep 2026 19:53:55 -0400, "Edward Rawde" > <invalid@invalid.invalid> wrote: > >>"john larkin" <jl@glen--canyon.com> wrote in message news:n7tdalpl13kf5hb5u88gnjkc3d7lma9pi3@4ax.com... >>> On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: >>> >>>>On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >>>>wrote: >>>> >>>>>Suppose we have a box with some big caps inside, for example 0.2 >>>>>farads that run at about 200 volts. When AC power is off, we want to >>>>>discharge them for several reasons. >>>>> >>>>>Putting, say, a 1K resistor across them dissipates 40 watts and has a >>>>>200 second time constant. It will take many tau before the voltage >>>>>gets low enough for people to poke around inside. >>>>> >>>>>The ideal discharger would be a constant-current or even better a >>>>>constant-power load, all the way down to zero volts. It would be dumb, >>>>>not switched by some decision circuit or anything fancy like that. >>>>> >>>>>And of course we need several LEDs as warnings that the thing is hot. >>>>> >>>>> >>>>>John Larkin >>>>>Highland Tech Glen Canyon Design Center >>>>>Lunatic Fringe Electronics >>>> >>>>Mechanical safety interlock switch on box lid, applying 50R 50W >>>> wirewound or carborundum resistor. Audible or visible indicator >>>>across switched load. >>>> >>> >>> My engineers and test techs need to measure and probe live, with the >>> top cover off. And they may send a failed unit back to production for >>> a fix. One thing that can fail is the discharge circuit. >>> >>> >>>>Takes about 1 minute. Smaller R value gives shorter discharge time, >>>>but watch switch ratings and load surface peak temps. >>> >>> 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors >>> fail from repeated power spikes. >> >>Philips managed that in the 80s >>https://www.google.com/search?q=which+80s+philips+colour+tv+had+repeated+surge+limiter+resistor+failure >> >>> >>> And it's around 4K joules. >>> >>> >>>> >>>>RL >>> >>> John Larkin >>> Highland Tech Glen Canyon Design Center >>> Lunatic Fringe Electronics >> > > I used some of those giant gold MIL-style 250-watt resistors > > like this > > https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 Yeah I've used similar things in the past. > > in a high-surge low-duty cycle application. They failed, and tended to > fail with one terminal shorted to the case. Bad. > > I replaced them with planar porcelain-steel thickfilms and that worked > fine. I remember the surge limiter resistors in Philips sets being something like wirewound on a ceramic tube and painted over. 4.7 ohm I think. When they had those fail repeatedly they were changed to something like a cement filled ceramic box which were probably wirewound inside. > > > > John Larkin > Highland Tech Glen Canyon Design Center > Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-18 15:58 +1000 |
| Message-ID | <118ijv9$v9sj$3@dont-email.me> |
| In reply to | #747848 |
On 18/09/2026 12:15 pm, john larkin wrote: > On Thu, 17 Sep 2026 19:53:55 -0400, "Edward Rawde" > <invalid@invalid.invalid> wrote: > >> "john larkin" <jl@glen--canyon.com> wrote in message news:n7tdalpl13kf5hb5u88gnjkc3d7lma9pi3@4ax.com... >>> On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: >>> >>>> On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >>>> wrote: >>>> >>>>> Suppose we have a box with some big caps inside, for example 0.2 >>>>> farads that run at about 200 volts. When AC power is off, we want to >>>>> discharge them for several reasons. >>>>> >>>>> Putting, say, a 1K resistor across them dissipates 40 watts and has a >>>>> 200 second time constant. It will take many tau before the voltage >>>>> gets low enough for people to poke around inside. >>>>> >>>>> The ideal discharger would be a constant-current or even better a >>>>> constant-power load, all the way down to zero volts. It would be dumb, >>>>> not switched by some decision circuit or anything fancy like that. >>>>> >>>>> And of course we need several LEDs as warnings that the thing is hot. >>>>> >>>>> >>>>> John Larkin >>>>> Highland Tech Glen Canyon Design Center >>>>> Lunatic Fringe Electronics >>>> >>>> Mechanical safety interlock switch on box lid, applying 50R 50W >>>> wirewound or carborundum resistor. Audible or visible indicator >>>> across switched load. >>>> >>> >>> My engineers and test techs need to measure and probe live, with the >>> top cover off. And they may send a failed unit back to production for >>> a fix. One thing that can fail is the discharge circuit. >>> >>> >>>> Takes about 1 minute. Smaller R value gives shorter discharge time, >>>> but watch switch ratings and load surface peak temps. >>> >>> 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors >>> fail from repeated power spikes. >> >> Philips managed that in the 80s >> https://www.google.com/search?q=which+80s+philips+colour+tv+had+repeated+surge+limiter+resistor+failure >> >>> >>> And it's around 4K joules. > > I used some of those giant gold MIL-style 250-watt resistors > > like this > > https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 > > in a high-surge low-duty cycle application. They failed, and tended to > fail with one terminal shorted to the case. Bad. The data sheet doesn't include any surge specification. There are maximum voltage limitations, but that sounds more like an anti-flash-over limit. Buying a part with specific short term dissipation limits might have made more sense. > I replaced them with planar porcelain-steel thickfilms and that worked > fine. But you haven't posted a link that would let us look at the data-sheet. -- Bill Sloman, Sydney
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-18 07:26 -0700 |
| Message-ID | <tciqaltcbmvkvhorpouuhpe83d0i5i1bhb@4ax.com> |
| In reply to | #747855 |
On Fri, 18 Sep 2026 15:58:53 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 18/09/2026 12:15 pm, john larkin wrote: >> On Thu, 17 Sep 2026 19:53:55 -0400, "Edward Rawde" >> <invalid@invalid.invalid> wrote: >> >>> "john larkin" <jl@glen--canyon.com> wrote in message news:n7tdalpl13kf5hb5u88gnjkc3d7lma9pi3@4ax.com... >>>> On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: >>>> >>>>> On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >>>>> wrote: >>>>> >>>>>> Suppose we have a box with some big caps inside, for example 0.2 >>>>>> farads that run at about 200 volts. When AC power is off, we want to >>>>>> discharge them for several reasons. >>>>>> >>>>>> Putting, say, a 1K resistor across them dissipates 40 watts and has a >>>>>> 200 second time constant. It will take many tau before the voltage >>>>>> gets low enough for people to poke around inside. >>>>>> >>>>>> The ideal discharger would be a constant-current or even better a >>>>>> constant-power load, all the way down to zero volts. It would be dumb, >>>>>> not switched by some decision circuit or anything fancy like that. >>>>>> >>>>>> And of course we need several LEDs as warnings that the thing is hot. >>>>>> >>>>>> >>>>>> John Larkin >>>>>> Highland Tech Glen Canyon Design Center >>>>>> Lunatic Fringe Electronics >>>>> >>>>> Mechanical safety interlock switch on box lid, applying 50R 50W >>>>> wirewound or carborundum resistor. Audible or visible indicator >>>>> across switched load. >>>>> >>>> >>>> My engineers and test techs need to measure and probe live, with the >>>> top cover off. And they may send a failed unit back to production for >>>> a fix. One thing that can fail is the discharge circuit. >>>> >>>> >>>>> Takes about 1 minute. Smaller R value gives shorter discharge time, >>>>> but watch switch ratings and load surface peak temps. >>>> >>>> 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors >>>> fail from repeated power spikes. >>> >>> Philips managed that in the 80s >>> https://www.google.com/search?q=which+80s+philips+colour+tv+had+repeated+surge+limiter+resistor+failure >>> >>>> >>>> And it's around 4K joules. >> >> I used some of those giant gold MIL-style 250-watt resistors >> >> like this >> >> https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 >> >> in a high-surge low-duty cycle application. They failed, and tended to >> fail with one terminal shorted to the case. Bad. > >The data sheet doesn't include any surge specification. There are >maximum voltage limitations, but that sounds more like an >anti-flash-over limit. Buying a part with specific short term >dissipation limits might have made more sense. > I plead the ignorance of youth. >> I replaced them with planar porcelain-steel thickfilms and that worked >> fine. > >But you haven't posted a link that would let us look at the data-sheet. Ask politely and I might. Or learn how to google. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-19 16:26 +1000 |
| Message-ID | <118l9u8$1ubd5$3@dont-email.me> |
| In reply to | #747859 |
On 19/09/2026 12:26 am, john larkin wrote: > On Fri, 18 Sep 2026 15:58:53 +1000, Bill Sloman <bill.sloman@ieee.org> > wrote: > >> On 18/09/2026 12:15 pm, john larkin wrote: >>> On Thu, 17 Sep 2026 19:53:55 -0400, "Edward Rawde" >>> <invalid@invalid.invalid> wrote: >>> >>>> "john larkin" <jl@glen--canyon.com> wrote in message news:n7tdalpl13kf5hb5u88gnjkc3d7lma9pi3@4ax.com... >>>>> On Sun, 13 Sep 2026 14:52:03 -0400, legg <legg@nospam.magma.ca> wrote: >>>>> >>>>>> On Mon, 07 Sep 2026 08:18:22 -0700, john larkin <jl@glen--canyon.com> >>>>>> wrote: >>>>>> >>>>>>> Suppose we have a box with some big caps inside, for example 0.2 >>>>>>> farads that run at about 200 volts. When AC power is off, we want to >>>>>>> discharge them for several reasons. >>>>>>> >>>>>>> Putting, say, a 1K resistor across them dissipates 40 watts and has a >>>>>>> 200 second time constant. It will take many tau before the voltage >>>>>>> gets low enough for people to poke around inside. >>>>>>> >>>>>>> The ideal discharger would be a constant-current or even better a >>>>>>> constant-power load, all the way down to zero volts. It would be dumb, >>>>>>> not switched by some decision circuit or anything fancy like that. >>>>>>> >>>>>>> And of course we need several LEDs as warnings that the thing is hot. >>>>>>> >>>>>>> >>>>>>> John Larkin >>>>>>> Highland Tech Glen Canyon Design Center >>>>>>> Lunatic Fringe Electronics >>>>>> >>>>>> Mechanical safety interlock switch on box lid, applying 50R 50W >>>>>> wirewound or carborundum resistor. Audible or visible indicator >>>>>> across switched load. >>>>>> >>>>> >>>>> My engineers and test techs need to measure and probe live, with the >>>>> top cover off. And they may send a failed unit back to production for >>>>> a fix. One thing that can fail is the discharge circuit. >>>>> >>>>> >>>>>> Takes about 1 minute. Smaller R value gives shorter discharge time, >>>>>> but watch switch ratings and load surface peak temps. >>>>> >>>>> 200 volts into 50 ohms is 800 watts. I've seen wirewound resistors >>>>> fail from repeated power spikes. >>>> >>>> Philips managed that in the 80s >>>> https://www.google.com/search?q=which+80s+philips+colour+tv+had+repeated+surge+limiter+resistor+failure >>>> >>>>> >>>>> And it's around 4K joules. >>> >>> I used some of those giant gold MIL-style 250-watt resistors >>> >>> like this >>> >>> https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 >>> >>> in a high-surge low-duty cycle application. They failed, and tended to >>> fail with one terminal shorted to the case. Bad. >> >> The data sheet doesn't include any surge specification. There are >> maximum voltage limitations, but that sounds more like an >> anti-flash-over limit. Buying a part with specific short term >> dissipation limits might have made more sense. >> > > I plead the ignorance of youth. > >>> I replaced them with planar porcelain-steel thickfilms and that worked >>> fine. >> >> But you haven't posted a link that would let us look at the data-sheet. > > Ask politely and I might. Why bother? > Or learn how to google. "planar porcelain-steel thickfilm" isn't the kind of search string guaranteed to find the part you used. The issue here is your unwillingness to read data sheets and your incapacity to understand what they tell you. Every time you go to the trouble of posting a link to a data sheet it seems to show up an example of your not reading it carefully. Anybody with any sense would have learned to read their data sheets more carefully. You have learned not to post links to data sheets. -- Bill Sloman, Sydney
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| From | legg <legg@nospam.magma.ca> |
|---|---|
| Date | 2026-09-20 11:25 -0400 |
| Message-ID | <c4tvalds0h9mdv2mpi2rkig69026pse18h@4ax.com> |
| In reply to | #747855 |
On Fri, 18 Sep 2026 15:58:53 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: <snip>. >> >> I used some of those giant gold MIL-style 250-watt resistors >> >> like this >> >> https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 >> >> in a high-surge low-duty cycle application. They failed, and tended to >> fail with one terminal shorted to the case. Bad. > >The data sheet doesn't include any surge specification. There are >maximum voltage limitations, but that sounds more like an >anti-flash-over limit. Buying a part with specific short term >dissipation limits might have made more sense. Easy for advertizing to add 'pulse' to literature. Pulse-rated requires a graph. > >> I replaced them with planar porcelain-steel thickfilms and that worked >> fine. > >But you haven't posted a link that would let us look at the data-sheet. He could be refering to thick film porcelain-on-steel construction. Welwyn - WBDR series. SEI - SHP series. IRC-TT - TFS types. Some of these either predate the internet or are company-deleted. An unfortunate acronym (POS). RL
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-20 08:42 -0700 |
| Message-ID | <cevvald3uhjuvt5vhrog9igheakq1ejpim@4ax.com> |
| In reply to | #747942 |
On Sun, 20 Sep 2026 11:25:00 -0400, legg <legg@nospam.magma.ca> wrote: >On Fri, 18 Sep 2026 15:58:53 +1000, Bill Sloman <bill.sloman@ieee.org> >wrote: ><snip>. >>> >>> I used some of those giant gold MIL-style 250-watt resistors >>> >>> like this >>> >>> https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 >>> >>> in a high-surge low-duty cycle application. They failed, and tended to >>> fail with one terminal shorted to the case. Bad. >> >>The data sheet doesn't include any surge specification. There are >>maximum voltage limitations, but that sounds more like an >>anti-flash-over limit. Buying a part with specific short term >>dissipation limits might have made more sense. > >Easy for advertizing to add 'pulse' to literature. Pulse-rated >requires a graph. > AoE X-chapters has a cool section on exploding resistors. With graphs. >> >>> I replaced them with planar porcelain-steel thickfilms and that worked >>> fine. >> >>But you haven't posted a link that would let us look at the data-sheet. > >He could be refering to thick film porcelain-on-steel construction. > >Welwyn - WBDR series. WDBR2-12RKT Like this. https://www.dropbox.com/scl/fi/kup1hbfyqmyq0juav3ubi/Welwyn.JPG?rlkey=3rk5g37hn5bn6kunemr92gpde&raw=1 Welwyn also makes some nice gigohm resistors. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-21 17:54 +1000 |
| Message-ID | <118qns9$3ot7q$5@dont-email.me> |
| In reply to | #747943 |
On 21/09/2026 1:42 am, john larkin wrote: > On Sun, 20 Sep 2026 11:25:00 -0400, legg <legg@nospam.magma.ca> wrote: > >> On Fri, 18 Sep 2026 15:58:53 +1000, Bill Sloman <bill.sloman@ieee.org> >> wrote: >> <snip>. >>>> >>>> I used some of those giant gold MIL-style 250-watt resistors >>>> >>>> like this >>>> >>>> https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 >>>> >>>> in a high-surge low-duty cycle application. They failed, and tended to >>>> fail with one terminal shorted to the case. Bad. >>> >>> The data sheet doesn't include any surge specification. There are >>> maximum voltage limitations, but that sounds more like an >>> anti-flash-over limit. Buying a part with specific short term >>> dissipation limits might have made more sense. >> >> Easy for advertizing to add 'pulse' to literature. Pulse-rated >> requires a graph. >> > > AoE X-chapters has a cool section on exploding resistors. With graphs. > > >>> >>>> I replaced them with planar porcelain-steel thickfilms and that worked >>>> fine. >>> >>> But you haven't posted a link that would let us look at the data-sheet. >> >> He could be refering to thick film porcelain-on-steel construction. >> >> Welwyn - WBDR series. > > WDBR2-12RKT > > Like this. > > https://www.dropbox.com/scl/fi/kup1hbfyqmyq0juav3ubi/Welwyn.JPG?rlkey=3rk5g37hn5bn6kunemr92gpde&raw=1 > > Welwyn also makes some nice gigohm resistors. Trust John Larkin to post a link to an uninformative phootgraph. https://au.mouser.com/datasheet/3/1423/1/WDBR.pdf does spell out pulse ratings on page 3 under "pulse and overload performance". John Larkin really does seem to evolve his designs - there would have been a rational reason to switch from the Ohmite to the Welwyn part, but John doesn't seem to be aware of it. I used Welwyn resistors quite a lot for critical stuff when I worked in the UK. The firm had good reputation, and none of their parts blew up on me. -- Bill Sloman, Sydney
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| From | john larkin <jl@htigct.com> |
|---|---|
| Date | 2026-09-21 10:09 -0700 |
| Message-ID | <p4p2bl1jv0e5vgmec27jf886dvc6m8jbfi@4ax.com> |
| In reply to | #747985 |
On Mon, 21 Sep 2026 17:54:46 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 21/09/2026 1:42 am, john larkin wrote: >> On Sun, 20 Sep 2026 11:25:00 -0400, legg <legg@nospam.magma.ca> wrote: >> >>> On Fri, 18 Sep 2026 15:58:53 +1000, Bill Sloman <bill.sloman@ieee.org> >>> wrote: >>> <snip>. >>>>> >>>>> I used some of those giant gold MIL-style 250-watt resistors >>>>> >>>>> like this >>>>> >>>>> https://www.digikey.com/en/products/detail/ohmite/HS250-5R-F/5306245 >>>>> >>>>> in a high-surge low-duty cycle application. They failed, and tended to >>>>> fail with one terminal shorted to the case. Bad. >>>> >>>> The data sheet doesn't include any surge specification. There are >>>> maximum voltage limitations, but that sounds more like an >>>> anti-flash-over limit. Buying a part with specific short term >>>> dissipation limits might have made more sense. >>> >>> Easy for advertizing to add 'pulse' to literature. Pulse-rated >>> requires a graph. >>> >> >> AoE X-chapters has a cool section on exploding resistors. With graphs. >> >> >>>> >>>>> I replaced them with planar porcelain-steel thickfilms and that worked >>>>> fine. >>>> >>>> But you haven't posted a link that would let us look at the data-sheet. >>> >>> He could be refering to thick film porcelain-on-steel construction. >>> >>> Welwyn - WBDR series. >> >> WDBR2-12RKT >> >> Like this. >> >> https://www.dropbox.com/scl/fi/kup1hbfyqmyq0juav3ubi/Welwyn.JPG?rlkey=3rk5g37hn5bn6kunemr92gpde&raw=1 >> >> Welwyn also makes some nice gigohm resistors. > >Trust John Larkin to post a link to an uninformative phootgraph. Phooey to you too.
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