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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
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-11 16:23 +1000 |
| Message-ID | <11806pd$2kpki$1@dont-email.me> |
| In reply to | #747351 |
On 8/09/2026 4:52 am, john larkin wrote: > On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: > >> On 9/7/26 16:18, 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. >>> >> >> What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >> working at that level, put in a cheap relay and a rated heatsink >> wirewound resistor to dump the energy, when the power goes off. >> Cheap, and lossless as well. Motor drive inverters often have >> big resistors to brake the motor. >> >> >>> John Larkin >>> Highland Tech Glen Canyon Design Center >>> Lunatic Fringe Electronics > > It's a 1500 amp laser driver. So it's a bunch of modules which you have glommed together. The 0.2F of capacitance is a lot of smaller capacitors in parallel. You are trying to design in safety as an after-thought. If you put a discharge circuit into each module and broadcast a "discharge" signal to all the modules, the problem would be a lot easier to solve. > The input to our box is DC, from an external power supply. > > I do want a circuit that's foolproof, that always discharges the caps > but doen't often go up in flames. > > A resistor makes an exponential decay which could be a very long time > to get down to safe levels. > > I thought the group might like a circuit design problem once in a > while, a break from politics. This looks more like a dumb newbie afterthought question, with the usual dumb newbie fault of insufficient background information, released incidentally half-way down the thread. -- Bill Sloman, Sydney
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-11 07:45 -0700 |
| Message-ID | <fj48al5jdrg4jd2mahanivd0c224g0umj5@4ax.com> |
| In reply to | #747562 |
On Fri, 11 Sep 2026 16:23:29 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 8/09/2026 4:52 am, john larkin wrote: >> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >> >>> On 9/7/26 16:18, 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. >>>> >>> >>> What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>> working at that level, put in a cheap relay and a rated heatsink >>> wirewound resistor to dump the energy, when the power goes off. >>> Cheap, and lossless as well. Motor drive inverters often have >>> big resistors to brake the motor. >>> >>> >>>> John Larkin >>>> Highland Tech Glen Canyon Design Center >>>> Lunatic Fringe Electronics >> >> It's a 1500 amp laser driver. > >So it's a bunch of modules which you have glommed together. > >The 0.2F of capacitance is a lot of smaller capacitors in parallel. Six, 30mF 200v each, in parallel. The caps are bigger than beer cans. > >You are trying to design in safety as an after-thought. It's not my design, but I thought I should try to keep people from being killed. > >If you put a discharge circuit into each module and broadcast a >"discharge" signal to all the modules, the problem would be a lot easier >to solve. There are no "modules", and complex safety schemes can fail and kill people. > >> The input to our box is DC, from an external power supply. >> >> I do want a circuit that's foolproof, that always discharges the caps >> but doen't often go up in flames. >> >> A resistor makes an exponential decay which could be a very long time >> to get down to safe levels. >> >> I thought the group might like a circuit design problem once in a >> while, a break from politics. > >This looks more like a dumb newbie afterthought question, with the usual >dumb newbie fault of insufficient background information, released >incidentally half-way down the thread. It's a discussion group, not a lecture platform. You might introduce an interesting topic some day too. In full detail. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-12 01:59 +1000 |
| Message-ID | <11818h6$31htb$1@dont-email.me> |
| In reply to | #747576 |
On 12/09/2026 12:45 am, john larkin wrote: > On Fri, 11 Sep 2026 16:23:29 +1000, Bill Sloman <bill.sloman@ieee.org> > wrote: > >> On 8/09/2026 4:52 am, john larkin wrote: >>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>> >>>> On 9/7/26 16:18, 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. >>>>> >>>> >>>> What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>> working at that level, put in a cheap relay and a rated heatsink >>>> wirewound resistor to dump the energy, when the power goes off. >>>> Cheap, and lossless as well. Motor drive inverters often have >>>> big resistors to brake the motor. >>>> >>>> >>>>> John Larkin >>>>> Highland Tech Glen Canyon Design Center >>>>> Lunatic Fringe Electronics >>> >>> It's a 1500 amp laser driver. >> >> So it's a bunch of modules which you have glommed together. >> >> The 0.2F of capacitance is a lot of smaller capacitors in parallel. > > Six, 30mF 200v each, in parallel. The caps are bigger than beer cans. > >> >> You are trying to design in safety as an after-thought. > > It's not my design, but I thought I should try to keep people from > being killed. Always a good idea. You are still trying to design in safety as an after thought, but at least it is somebody else's fault >> If you put a discharge circuit into each module and broadcast a >> "discharge" signal to all the modules, the problem would be a lot easier >> to solve. > > There are no "modules", and complex safety schemes can fail and kill > people. So can simple ones. The idea is to keep as simple as is practical, but excessively simple schemes have their own risks. Putting a discharger on each capacitor might not be a bad idea. At least it keeps each discharge current loop as compact as possible,and if one of six fails, at least the other five won't be a menace. >>> The input to our box is DC, from an external power supply. >>> >>> I do want a circuit that's foolproof, that always discharges the caps >>> but doen't often go up in flames. It shouldn't ever go up in flames. There were liquid filled capacitors when I started in the business, but if the liquid was a halo-carbon they didn't burn - they put out fires. Some of the chloro-carbon fluids were pretty nasty but the fluoro-carbons weren't as bad. >>> A resistor makes an exponential decay which could be a very long time >>> to get down to safe levels. And a series inductor could let you make the discharge path critically damped, which does offer faster decay. Even one inductor per 30mF capacitor is going to need big inductors, but one big inductor per beer can - a toroid that was dropped over each capacitor - might allow neat packaging, if probably not the packaging that was originally intended, >>> I thought the group might like a circuit design problem once in a >>> while, a break from politics. A good thought. Pity you took so long to make it clear what the problem was. >> This looks more like a dumb newbie afterthought question, with the usual >> dumb newbie fault of insufficient background information, released >> incidentally half-way down the thread. > > It's a discussion group, not a lecture platform. But the more detail you put in up-front, the better the discussion > You might introduce an interesting topic some day too. In full detail. I'm applying for a provisional patent on a neater way of making a non-progressively wound toroidal inductor. Obviously I can't talk about that until the provisional patent has been registered. I've certainly posted the occasional detailed question here in the past, but I'm retired - whether I like it or not - and that does means that I don't get introduced to other peoples interesting problems all that often. -- Bill Sloman, Sydney
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2026-09-17 07:19 +0000 |
| Message-ID | <118g4a3$t7v$1@reader1.panix.com> |
| In reply to | #747351 |
john larkin <jl@glen--canyon.com> wrote: > On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: > >>On 9/7/26 16:18, 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. >>> >> >>What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>working at that level, put in a cheap relay and a rated heatsink >>wirewound resistor to dump the energy, when the power goes off. >>Cheap, and lossless as well. Motor drive inverters often have >>big resistors to brake the motor. >> >> >>> John Larkin >>> Highland Tech Glen Canyon Design Center >>> Lunatic Fringe Electronics > > It's a 1500 amp laser driver. > > The input to our box is DC, from an external power supply. > > I do want a circuit that's foolproof, that always discharges the caps > but doen't often go up in flames. > > A resistor makes an exponential decay which could be a very long time > to get down to safe levels. What is your version of safe levels? The NEC says 50 volts or less. What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like that. If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power goes off and a door interlock that does the same, you're reinventing the wheel. If you want a goofy solution, discharge your cap bank into another cap bank to drop the voltage at a high rate nearly instantaneously, then bleed it off with power resistors. You might be able to play some diodes games to make sure you don't accidentally end up with double the energy blowing up your laser if the discharge circuit faults. Old power packs for studio strobes had all sorts of weird stuff like this going on inside to divide up the energy across smaller or multiple stobe heads. 4800J units were considerd decent sized unit and not unusual. Lookup Speedotron Blackline 4800. > I thought the group might like a circuit design problem once in a > while, a break from politics. > > > 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 07:46 -0700 |
| Message-ID | <mutnall6vr7o1lj0hd6q582lj5kr1gikob@4ax.com> |
| In reply to | #747835 |
On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader <presence@MUNGEpanix.com> wrote: >john larkin <jl@glen--canyon.com> wrote: >> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >> >>>On 9/7/26 16:18, 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. >>>> >>> >>>What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>working at that level, put in a cheap relay and a rated heatsink >>>wirewound resistor to dump the energy, when the power goes off. >>>Cheap, and lossless as well. Motor drive inverters often have >>>big resistors to brake the motor. >>> >>> >>>> John Larkin >>>> Highland Tech Glen Canyon Design Center >>>> Lunatic Fringe Electronics >> >> It's a 1500 amp laser driver. >> >> The input to our box is DC, from an external power supply. >> >> I do want a circuit that's foolproof, that always discharges the caps >> but doen't often go up in flames. >> >> A resistor makes an exponential decay which could be a very long time >> to get down to safe levels. > >What is your version of safe levels? The NEC says 50 volts or less. >What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or >less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like >that. > 50 volts DC is safe from a shock standpoint, but will still make a gigantic bang if shorted, so I want to ultimately discharge to zero volts. The customer wants it discharged in under two minutes. They have a serious safety team. >If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power >goes off and a door interlock that does the same, you're reinventing the wheel. I'm an engineer. I invent things. What drives the relay coil? What happens if it fails, on or off? > >If you want a goofy solution, discharge your cap bank into another cap bank to drop the voltage at a high rate nearly >instantaneously, then bleed it off with power resistors. I like goofy. Slamming caps in parallel is interesting from a circuit theory standpoint, conservation issues, but not practical in my case for lots of reasons. "Nearly instantaneously" will be the fun part. >You might be able to play some diodes games to make sure you don't >accidentally end up with double the energy blowing up your laser if the discharge circuit faults. Old power packs for studio >strobes had all sorts of weird stuff like this going on inside to divide up the energy across smaller or multiple stobe heads. >4800J units were considerd decent sized unit and not unusual. Lookup Speedotron Blackline 4800. Yikes, they have a 9600 joule (they call it a watt/second!) version. A few of those would blind everybody and set the studio on fire. I worked on a kilojoule discharge thing once, but it used oil caps and was giant. I also did the timing system for a gadget that fires 400 megajoules per shot. I've never been there when it fired. It would be interesting to know how they dischage their caps. > > >> I thought the group might like a circuit design problem once in a >> while, a break from politics. >> >> >> John Larkin >> Highland Tech Glen Canyon Design Center >> Lunatic Fringe Electronics John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2026-09-18 04:54 +0000 |
| Message-ID | <118ig6l$2i9$1@reader1.panix.com> |
| In reply to | #747841 |
john larkin <jl@glen--canyon.com> wrote: > On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader > <presence@MUNGEpanix.com> wrote: > >>john larkin <jl@glen--canyon.com> wrote: >>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>> >>>>On 9/7/26 16:18, 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. >>>>> >>>> >>>>What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>>working at that level, put in a cheap relay and a rated heatsink >>>>wirewound resistor to dump the energy, when the power goes off. >>>>Cheap, and lossless as well. Motor drive inverters often have >>>>big resistors to brake the motor. >>>> >>>> >>>>> John Larkin >>>>> Highland Tech Glen Canyon Design Center >>>>> Lunatic Fringe Electronics >>> >>> It's a 1500 amp laser driver. >>> >>> The input to our box is DC, from an external power supply. >>> >>> I do want a circuit that's foolproof, that always discharges the caps >>> but doen't often go up in flames. >>> >>> A resistor makes an exponential decay which could be a very long time >>> to get down to safe levels. >> >>What is your version of safe levels? The NEC says 50 volts or less. >>What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or >>less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like >>that. >> > > 50 volts DC is safe from a shock standpoint, but will still make a > gigantic bang if shorted, so I want to ultimately discharge to zero > volts. > > The customer wants it discharged in under two minutes. They have a > serious safety team. Not impossible. How about a two stage bleeder system? At say 50 volts a second relay de-energizes and the NC contacts throw a smaller resistor across the cap bank to finish it off? >>If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power >>goes off and a door interlock that does the same, you're reinventing the wheel. > > I'm an engineer. I invent things. > > What drives the relay coil? What happens if it fails, on or off? Your source of power. NC relays failed with a spring closing a set of contacts closed. Power opens them up. This follows standard fail-safe practices where Everthing not working results in the safe state. Same for cabinet interlock switches and safety pull/emergency stop loops. Opening the circuits, even through broken cables or connectors failing will stop the process. DC operated relays and contactors tend to magnetize and have all sorts of hystersis curves with when they mechanically turn on vs. off, so thinking you can just pick some resistors and get a relay to turn off at a specific voltage can be tricky. AC coils for contactors are lossier and won't tend to magnetize so even though you'd be working off the data sheet, it may be easier to control when a coil really drops out. >>If you want a goofy solution, discharge your cap bank into another cap bank to drop the voltage at a high rate nearly >>instantaneously, then bleed it off with power resistors. > > I like goofy. > > Slamming caps in parallel is interesting from a circuit theory > standpoint, conservation issues, but not practical in my case for lots > of reasons. > > "Nearly instantaneously" will be the fun part. you just need some resistance so you don't weld your contacts. 200 volts with a 10 amp relay = 20 ohms, which is a 4 second time constant. 10 amps is pretty wimpy as far as relays go too. >>You might be able to play some diodes games to make sure you don't >>accidentally end up with double the energy blowing up your laser if the discharge circuit faults. Old power packs for studio >>strobes had all sorts of weird stuff like this going on inside to divide up the energy across smaller or multiple stobe heads. >>4800J units were considerd decent sized unit and not unusual. Lookup Speedotron Blackline 4800. > > Yikes, they have a 9600 joule (they call it a watt/second!) version. A > few of those would blind everybody and set the studio on fire. > > I worked on a kilojoule discharge thing once, but it used oil caps and > was giant. I also did the timing system for a gadget that fires 400 > megajoules per shot. I've never been there when it fired. It would be > interesting to know how they dischage their caps. the 4800 watt second systems don't seem to leave the wake of destruction and kill as many people as you'd expect. The shut down process is to fire off the strobes, but this seems to have changed in the classic Speedotrons made in Chicago vs. the designs they're using after they were bought. 200 volts is too low to just dump into a flash tube, but there are triggeable gas discharge tubes out there. The classic SCR crowbar would be fun too, with a current limiting resistor sizes so you don't exceed the ripple current rating of the capacitor. Power SCRs are cheap, can have high current ratings and are very reliable. Camera strobes actually use a SCR and inductor crowbar (I think across the tube itself) to quench the arc in a flash tube to turn the power down. Low intensity flashes are actually just really short flashes of light. The capacitor is still always charged to the same voltage needed for a full power flash. You can hear the click of the current in the inductor in cheapo speedlights from the 70s and 80s marked "Thyristor". I used to have a magneformer which ran at about 9kJ. It had sturdy energy dischage capacitors rated in the tens of thousands of amps, so it was fine to really just throw grounding wires across the terminals and switch when you were done. Rebound can be high on high voltage caps which is why they're always stored and shipped with a wire across the terminals. >>> I thought the group might like a circuit design problem once in a >>> while, a break from politics. >>> >>> >>> John Larkin >>> Highland Tech Glen Canyon Design Center >>> Lunatic Fringe Electronics > > John Larkin > Highland Tech Glen Canyon Design Center > Lunatic Fringe Electronics
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-18 07:57 -0700 |
| Message-ID | <nljqaldhi591e0c4t3mmhijegqqn7hsv39@4ax.com> |
| In reply to | #747852 |
On Fri, 18 Sep 2026 04:54:45 -0000 (UTC), Cydrome Leader <presence@MUNGEpanix.com> wrote: >john larkin <jl@glen--canyon.com> wrote: >> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >> <presence@MUNGEpanix.com> wrote: >> >>>john larkin <jl@glen--canyon.com> wrote: >>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>> >>>>>On 9/7/26 16:18, 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. >>>>>> >>>>> >>>>>What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>>>working at that level, put in a cheap relay and a rated heatsink >>>>>wirewound resistor to dump the energy, when the power goes off. >>>>>Cheap, and lossless as well. Motor drive inverters often have >>>>>big resistors to brake the motor. >>>>> >>>>> >>>>>> John Larkin >>>>>> Highland Tech Glen Canyon Design Center >>>>>> Lunatic Fringe Electronics >>>> >>>> It's a 1500 amp laser driver. >>>> >>>> The input to our box is DC, from an external power supply. >>>> >>>> I do want a circuit that's foolproof, that always discharges the caps >>>> but doen't often go up in flames. >>>> >>>> A resistor makes an exponential decay which could be a very long time >>>> to get down to safe levels. >>> >>>What is your version of safe levels? The NEC says 50 volts or less. >>>What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or >>>less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like >>>that. >>> >> >> 50 volts DC is safe from a shock standpoint, but will still make a >> gigantic bang if shorted, so I want to ultimately discharge to zero >> volts. >> >> The customer wants it discharged in under two minutes. They have a >> serious safety team. > >Not impossible. How about a two stage bleeder system? At say 50 volts a second relay de-energizes and the NC contacts throw a >smaller resistor across the cap bank to finish it off? That's what my depletion fet circuit does, with no switches and no logic and minimum failure modes. https://www.dropbox.com/scl/fi/w86g1m4si37dhadi9hw5u/P200_Discharge_1.jpg?rlkey=e1gyhxtivgjqzi85izlixk6sf&raw=1 > > >>>If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power >>>goes off and a door interlock that does the same, you're reinventing the wheel. >> >> I'm an engineer. I invent things. >> >> What drives the relay coil? What happens if it fails, on or off? > >Your source of power. NC relays failed with a spring closing a set of contacts closed. Power opens them up. This follows >standard fail-safe practices where Everthing not working results in the safe state. Same for cabinet interlock switches and >safety pull/emergency stop loops. Opening the circuits, even through broken cables or connectors failing will stop the >process. A circuit failure, namely fast-discharging when power is still on, could be ugly. And my box gets DC power and I don't know when the external supply loses AC power. I mentioned that. > >DC operated relays and contactors tend to magnetize and have all sorts of hystersis curves with when they mechanically turn on >vs. off, so thinking you can just pick some resistors and get a relay to turn off at a specific voltage can be tricky. AC >coils for contactors are lossier and won't tend to magnetize so even though you'd be working off the data sheet, it may be >easier to control when a coil really drops out. > >>>If you want a goofy solution, discharge your cap bank into another cap bank to drop the voltage at a high rate nearly >>>instantaneously, then bleed it off with power resistors. >> >> I like goofy. >> >> Slamming caps in parallel is interesting from a circuit theory >> standpoint, conservation issues, but not practical in my case for lots >> of reasons. >> >> "Nearly instantaneously" will be the fun part. > >you just need some resistance so you don't weld your contacts. 200 volts with a 10 amp relay = 20 ohms, which is a 4 second >time constant. 10 amps is pretty wimpy as far as relays go too. Slaming caps in parallel has interesting conservation issues. > >>>You might be able to play some diodes games to make sure you don't >>>accidentally end up with double the energy blowing up your laser if the discharge circuit faults. Old power packs for studio >>>strobes had all sorts of weird stuff like this going on inside to divide up the energy across smaller or multiple stobe heads. >>>4800J units were considerd decent sized unit and not unusual. Lookup Speedotron Blackline 4800. >> >> Yikes, they have a 9600 joule (they call it a watt/second!) version. A >> few of those would blind everybody and set the studio on fire. >> >> I worked on a kilojoule discharge thing once, but it used oil caps and >> was giant. I also did the timing system for a gadget that fires 400 >> megajoules per shot. I've never been there when it fired. It would be >> interesting to know how they dischage their caps. > >the 4800 watt second systems don't seem to leave the wake of destruction and kill as many people as you'd expect. The shut >down process is to fire off the strobes, but this seems to have changed in the classic Speedotrons made in Chicago vs. the >designs they're using after they were bought. > >200 volts is too low to just dump into a flash tube, but there are triggeable gas discharge tubes out there. The classic SCR >crowbar would be fun too, with a current limiting resistor sizes so you don't exceed the ripple current rating of the >capacitor. Power SCRs are cheap, can have high current ratings and are very reliable. > >Camera strobes actually use a SCR and inductor crowbar (I think across the tube itself) to quench the arc in a flash tube to >turn the power down. Low intensity flashes are actually just really short flashes of light. The capacitor is still always >charged to the same voltage needed for a full power flash. You can hear the click of the current in the inductor in cheapo >speedlights from the 70s and 80s marked "Thyristor". > >I used to have a magneformer which ran at about 9kJ. It had sturdy energy dischage capacitors rated in the tens of thousands >of amps, so it was fine to really just throw grounding wires across the terminals and switch when you were done. Rebound can >be high on high voltage caps which is why they're always stored and shipped with a wire across the terminals. > > >>>> I thought the group might like a circuit design problem once in a >>>> while, a break from politics. >>>> >>>> >>>> John Larkin >>>> Highland Tech Glen Canyon Design Center >>>> Lunatic Fringe Electronics >> >> John Larkin >> Highland Tech Glen Canyon Design Center >> Lunatic Fringe Electronics 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 15:45 +1000 |
| Message-ID | <118ij73$v9sj$2@dont-email.me> |
| In reply to | #747841 |
On 18/09/2026 12:46 am, john larkin wrote: > On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader > <presence@MUNGEpanix.com> wrote: > >> john larkin <jl@glen--canyon.com> wrote: >>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>> >>>> On 9/7/26 16:18, 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. >>>>> >>>> >>>> What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>> working at that level, put in a cheap relay and a rated heatsink >>>> wirewound resistor to dump the energy, when the power goes off. >>>> Cheap, and lossless as well. Motor drive inverters often have >>>> big resistors to brake the motor. >>>> >>>> >>>>> John Larkin >>>>> Highland Tech Glen Canyon Design Center >>>>> Lunatic Fringe Electronics >>> >>> It's a 1500 amp laser driver. >>> >>> The input to our box is DC, from an external power supply. >>> >>> I do want a circuit that's foolproof, that always discharges the caps >>> but doen't often go up in flames. >>> >>> A resistor makes an exponential decay which could be a very long time >>> to get down to safe levels. >> >> What is your version of safe levels? The NEC says 50 volts or less. >> What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or >> less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like >> that. >> > > 50 volts DC is safe from a shock standpoint, but will still make a > gigantic bang if shorted, so I want to ultimately discharge to zero > volts. > > The customer wants it discharged in under two minutes. They have a > serious safety team. > > >> If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power >> goes off and a door interlock that does the same, you're reinventing the wheel. > > I'm an engineer. I invent things. Not really. John Larkin's only patent was taken out by a team that included him. > > What drives the relay coil? What happens if it fails, on or off? The industry has been using relay coils for quite a while now. You could probably find somebody who would know, if you search skills were a little better developed. >> If you want a goofy solution, discharge your cap bank into another cap bank to drop the voltage at a high rate nearly >> instantaneously, then bleed it off with power resistors. > > I like goofy. > > Slamming caps in parallel is interesting from a circuit theory > standpoint, conservation issues, but not practical in my case for lots > of reasons. > > "Nearly instantaneously" will be the fun part. > > >> You might be able to play some diodes games to make sure you don't >> accidentally end up with double the energy blowing up your laser if the discharge circuit faults. Old power packs for studio >> strobes had all sorts of weird stuff like this going on inside to divide up the energy across smaller or multiple stobe heads. >> 4800J units were considerd decent sized unit and not unusual. Lookup Speedotron Blackline 4800. > > Yikes, they have a 9600 joule (they call it a watt/second!) version. A > few of those would blind everybody and set the studio on fire. > > I worked on a kilojoule discharge thing once, but it used oil caps and > was giant. I also did the timing system for a gadget that fires 400 > megajoules per shot. I've never been there when it fired. It would be > interesting to know how they dischage their caps. >> >>> I thought the group might like a circuit design problem once in a >>> while, a break from politics. Not that he was best-pleased when I looked at it as critically damped LCR circuit. -- Bill Sloman, Sydney > Highland Tech Glen Canyon Design Center > Lunatic Fringe Electronics
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-18 08:02 -0700 |
| Message-ID | <sakqalti2ssmrqqgau03fpkgo373bfo53f@4ax.com> |
| In reply to | #747854 |
On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 18/09/2026 12:46 am, john larkin wrote: >> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >> <presence@MUNGEpanix.com> wrote: >> >>> john larkin <jl@glen--canyon.com> wrote: >>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>> >>>>> On 9/7/26 16:18, 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. >>>>>> >>>>> >>>>> What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>>> working at that level, put in a cheap relay and a rated heatsink >>>>> wirewound resistor to dump the energy, when the power goes off. >>>>> Cheap, and lossless as well. Motor drive inverters often have >>>>> big resistors to brake the motor. >>>>> >>>>> >>>>>> John Larkin >>>>>> Highland Tech Glen Canyon Design Center >>>>>> Lunatic Fringe Electronics >>>> >>>> It's a 1500 amp laser driver. >>>> >>>> The input to our box is DC, from an external power supply. >>>> >>>> I do want a circuit that's foolproof, that always discharges the caps >>>> but doen't often go up in flames. >>>> >>>> A resistor makes an exponential decay which could be a very long time >>>> to get down to safe levels. >>> >>> What is your version of safe levels? The NEC says 50 volts or less. >>> What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or >>> less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like >>> that. >>> >> >> 50 volts DC is safe from a shock standpoint, but will still make a >> gigantic bang if shorted, so I want to ultimately discharge to zero >> volts. >> >> The customer wants it discharged in under two minutes. They have a >> serious safety team. >> >> >>> If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power >>> goes off and a door interlock that does the same, you're reinventing the wheel. >> >> I'm an engineer. I invent things. > >Not really. John Larkin's only patent was taken out by a team that >included him. I didn't want that patent. The startup that I was working with, atom probe tomography, wanted a lot of patents for show. The patent was silly, a pretty obvious way to make imaging delay-line anodes. Most patents are silly and expensive. 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 16:40 +1000 |
| Message-ID | <118laos$1ubd5$4@dont-email.me> |
| In reply to | #747863 |
On 19/09/2026 1:02 am, john larkin wrote: > On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> > wrote: > >> On 18/09/2026 12:46 am, john larkin wrote: >>> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >>> <presence@MUNGEpanix.com> wrote: >>> >>>> john larkin <jl@glen--canyon.com> wrote: >>>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>>> >>>>>> On 9/7/26 16:18, 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. >>>>>>> >>>>>> >>>>>> What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>>>> working at that level, put in a cheap relay and a rated heatsink >>>>>> wirewound resistor to dump the energy, when the power goes off. >>>>>> Cheap, and lossless as well. Motor drive inverters often have >>>>>> big resistors to brake the motor. >>>>>> >>>>>> >>>>>>> John Larkin >>>>>>> Highland Tech Glen Canyon Design Center >>>>>>> Lunatic Fringe Electronics >>>>> >>>>> It's a 1500 amp laser driver. >>>>> >>>>> The input to our box is DC, from an external power supply. >>>>> >>>>> I do want a circuit that's foolproof, that always discharges the caps >>>>> but doen't often go up in flames. >>>>> >>>>> A resistor makes an exponential decay which could be a very long time >>>>> to get down to safe levels. >>>> >>>> What is your version of safe levels? The NEC says 50 volts or less. >>>> What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or >>>> less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like >>>> that. >>>> >>> >>> 50 volts DC is safe from a shock standpoint, but will still make a >>> gigantic bang if shorted, so I want to ultimately discharge to zero >>> volts. >>> >>> The customer wants it discharged in under two minutes. They have a >>> serious safety team. >>> >>> >>>> If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power >>>> goes off and a door interlock that does the same, you're reinventing the wheel. >>> >>> I'm an engineer. I invent things. >> >> Not really. John Larkin's only patent was taken out by a team that >> included him. > > I didn't want that patent. The startup that I was working with, atom > probe tomography, wanted a lot of patents for show. The patent was > silly, a pretty obvious way to make imaging delay-line anodes. > > Most patents are silly and expensive. I'm inclined to agree. Patents do cost money to take out, and rarely recover enough in royalties to cover that cost, but it's like venture capitalism, in that the ones that do pay off can cover the cost of taking out a lot of duff patents. The problem is that if you want to claim that you invent things you really need to be able to point to a patent that covers that invention. There are clearly loads of things that are invented, but not patented, but there's a much bigger pool of stuff that it's inventors like to imagine to have been an invention which those skilled in the art write off as obvious. You claim to have invented stuff and designed circuits, and Donald Trump claims to have a high IQ. Some people find those claims implausible. Donald Trump may actually have a high IQ, but since he has the attention span of a flea, he can never absorb enough information about the subject he has to decide on for his "high" IQ have anything to work on. -- Bill Sloman, Sydney
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-19 08:48 -0700 |
| Message-ID | <8cbtal9gheb9ncq2e59eigcalig1ajc14b@4ax.com> |
| In reply to | #747890 |
On Sat, 19 Sep 2026 16:40:13 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 19/09/2026 1:02 am, john larkin wrote: >> On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> >> wrote: >> >>> On 18/09/2026 12:46 am, john larkin wrote: >>>> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >>>> <presence@MUNGEpanix.com> wrote: >>>> >>>>> john larkin <jl@glen--canyon.com> wrote: >>>>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>>>> >>>>>>> On 9/7/26 16:18, 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. >>>>>>>> >>>>>>> >>>>>>> What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>>>>>> working at that level, put in a cheap relay and a rated heatsink >>>>>>> wirewound resistor to dump the energy, when the power goes off. >>>>>>> Cheap, and lossless as well. Motor drive inverters often have >>>>>>> big resistors to brake the motor. >>>>>>> >>>>>>> >>>>>>>> John Larkin >>>>>>>> Highland Tech Glen Canyon Design Center >>>>>>>> Lunatic Fringe Electronics >>>>>> >>>>>> It's a 1500 amp laser driver. >>>>>> >>>>>> The input to our box is DC, from an external power supply. >>>>>> >>>>>> I do want a circuit that's foolproof, that always discharges the caps >>>>>> but doen't often go up in flames. >>>>>> >>>>>> A resistor makes an exponential decay which could be a very long time >>>>>> to get down to safe levels. >>>>> >>>>> What is your version of safe levels? The NEC says 50 volts or less. >>>>> What is your definition of a very long time? The NEC used to specify energy storage systems should discharge to 50 volts or >>>>> less in 5 minutes. I believe this was updated to 50 volts or less in 1 minutes for things like EV chargers and things like >>>>> that. >>>>> >>>> >>>> 50 volts DC is safe from a shock standpoint, but will still make a >>>> gigantic bang if shorted, so I want to ultimately discharge to zero >>>> volts. >>>> >>>> The customer wants it discharged in under two minutes. They have a >>>> serious safety team. >>>> >>>> >>>>> If you're final solution is anything more complicated than a NC relay that drops a resistor across the cap bank when the power >>>>> goes off and a door interlock that does the same, you're reinventing the wheel. >>>> >>>> I'm an engineer. I invent things. >>> >>> Not really. John Larkin's only patent was taken out by a team that >>> included him. >> >> I didn't want that patent. The startup that I was working with, atom >> probe tomography, wanted a lot of patents for show. The patent was >> silly, a pretty obvious way to make imaging delay-line anodes. >> >> Most patents are silly and expensive. > >I'm inclined to agree. Patents do cost money to take out, and rarely >recover enough in royalties to cover that cost, but it's like venture >capitalism, in that the ones that do pay off can cover the cost of >taking out a lot of duff patents. VCs like to pump-and-dump, which is what happened with the atom probe thing. Part of the public pumping is to cite a lot of patents. The investment there is not science or electronics but just lawyers. One can patent any sort of nonsense these days. > >The problem is that if you want to claim that you invent things you >really need to be able to point to a patent that covers that invention. I accept purchase orders too. > >There are clearly loads of things that are invented, but not patented, >but there's a much bigger pool of stuff that it's inventors like to >imagine to have been an invention which those skilled in the art write >off as obvious. > >You claim to have invented stuff and designed circuits, and Donald Trump >claims to have a high IQ. Some people find those claims implausible. Always Trump. That's psychotic. > >Donald Trump may actually have a high IQ, but since he has the attention >span of a flea, he can never absorb enough information about the subject >he has to decide on for his "high" IQ have anything to work on. Always Trump. That's psychotic. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-20 16:30 +1000 |
| Message-ID | <118nuhl$2sjqb$2@dont-email.me> |
| In reply to | #747904 |
On 20/09/2026 1:48 am, john larkin wrote: > On Sat, 19 Sep 2026 16:40:13 +1000, Bill Sloman <bill.sloman@ieee.org> > wrote: > >> On 19/09/2026 1:02 am, john larkin wrote: >>> On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> >>> wrote: >>> >>>> On 18/09/2026 12:46 am, john larkin wrote: >>>>> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >>>>> <presence@MUNGEpanix.com> wrote: >>>>> >>>>>> john larkin <jl@glen--canyon.com> wrote: >>>>>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>>>>> >>>>>>>> On 9/7/26 16:18, john larkin wrote: <snip> >> The problem is that if you want to claim that you invent things you >> really need to be able to point to a patent that covers that invention. > > I accept purchase orders too. If you sell something as invention without having got a patent, that makes you a confidence trickster, but if you think that you could have got a patent it would be a hard case to prosecute. A patent search used to cost $100k. >> There are clearly loads of things that are invented, but not patented, >> but there's a much bigger pool of stuff that it's inventors like to >> imagine to have been an invention which those skilled in the art write >> off as obvious. >> >> You claim to have invented stuff and designed circuits, and Donald Trump >> claims to have a high IQ. Some people find those claims implausible. > > Always Trump. That's psychotic. On the contrary. Trump is a classic example of the twit who over-promises and under-delivers. Has he got peace with Iran yet? >> Donald Trump may actually have a high IQ, but since he has the attention >> span of a flea, he can never absorb enough information about the subject >> he has to decide on for his "high" IQ have anything to work on. > > Always Trump. That's psychotic. Find a definition of "psychotic" that includes "referring to the most obvious example of the bad behavior in question". -- Bill Sloman, Sydney
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-20 02:17 -0700 |
| Message-ID | <ur8valpjlc2ok04rcdrd313op7rtv6a809@4ax.com> |
| In reply to | #747926 |
On Sun, 20 Sep 2026 16:30:13 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 20/09/2026 1:48 am, john larkin wrote: >> On Sat, 19 Sep 2026 16:40:13 +1000, Bill Sloman <bill.sloman@ieee.org> >> wrote: >> >>> On 19/09/2026 1:02 am, john larkin wrote: >>>> On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote: >>>> >>>>> On 18/09/2026 12:46 am, john larkin wrote: >>>>>> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >>>>>> <presence@MUNGEpanix.com> wrote: >>>>>> >>>>>>> john larkin <jl@glen--canyon.com> wrote: >>>>>>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>>>>>> >>>>>>>>> On 9/7/26 16:18, john larkin wrote: > ><snip> > >>> The problem is that if you want to claim that you invent things you >>> really need to be able to point to a patent that covers that invention. >> >> I accept purchase orders too. > >If you sell something as invention without having got a patent, that >makes you a confidence trickster, but if you think that you could have >got a patent it would be a hard case to prosecute. A patent search used >to cost $100k. > >>> There are clearly loads of things that are invented, but not patented, >>> but there's a much bigger pool of stuff that it's inventors like to >>> imagine to have been an invention which those skilled in the art write >>> off as obvious. >>> >>> You claim to have invented stuff and designed circuits, and Donald Trump >>> claims to have a high IQ. Some people find those claims implausible. >> >> Always Trump. That's psychotic. > >On the contrary. Trump is a classic example of the twit who >over-promises and under-delivers. Has he got peace with Iran yet? Apparently he got what he wanted in Greenland. Iran is riskier so may take a bit longer. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Simon Simple <nothanks@nottoday.co.uk> |
|---|---|
| Date | 2026-09-20 12:30 +0100 |
| Message-ID | <118og58$32kn1$1@dont-email.me> |
| In reply to | #747935 |
On 20/09/2026 10:17, john larkin wrote: > Apparently [Trump] got what he wanted in Greenland. “A wise Danish politician once said that you can achieve almost anything if you are willing to let others take the credit,” said Mr Dahl. “So let us give Donald Trump the credit for something very close to the status quo. From a Danish and Greenlandic perspective, it could hardly be much better.” -- SS
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-09-21 00:52 +1000 |
| Message-ID | <118orvm$36jhl$1@dont-email.me> |
| In reply to | #747935 |
On 20/09/2026 7:17 pm, john larkin wrote: > On Sun, 20 Sep 2026 16:30:13 +1000, Bill Sloman <bill.sloman@ieee.org> > wrote: > >> On 20/09/2026 1:48 am, john larkin wrote: >>> On Sat, 19 Sep 2026 16:40:13 +1000, Bill Sloman <bill.sloman@ieee.org> >>> wrote: >>> >>>> On 19/09/2026 1:02 am, john larkin wrote: >>>>> On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote: >>>>> >>>>>> On 18/09/2026 12:46 am, john larkin wrote: >>>>>>> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >>>>>>> <presence@MUNGEpanix.com> wrote: >>>>>>> >>>>>>>> john larkin <jl@glen--canyon.com> wrote: >>>>>>>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>>>>>>> >>>>>>>>>> On 9/7/26 16:18, john larkin wrote: >> >> <snip> >> >>>> The problem is that if you want to claim that you invent things you >>>> really need to be able to point to a patent that covers that invention. >>> >>> I accept purchase orders too. >> >> If you sell something as invention without having got a patent, that >> makes you a confidence trickster, but if you think that you could have >> got a patent it would be a hard case to prosecute. A patent search used >> to cost $100k. >> >>>> There are clearly loads of things that are invented, but not patented, >>>> but there's a much bigger pool of stuff that it's inventors like to >>>> imagine to have been an invention which those skilled in the art write >>>> off as obvious. >>>> >>>> You claim to have invented stuff and designed circuits, and Donald Trump >>>> claims to have a high IQ. Some people find those claims implausible. >>> >>> Always Trump. That's psychotic. >> >> On the contrary. Trump is a classic example of the twit who >> over-promises and under-delivers. Has he got peace with Iran yet? > > Apparently he got what he wanted in Greenland. He's now got something which he says is what he wanted all along. > Iran is riskier so may take a bit longer. He didn't kill off any EU leaders during his "negotiations" with them. Iran may take a lot more sweet-talking and some much bigger bribes. There is the point that while Saudi Arabian and Iranian crude isn't getting onto the world market, the more expensive oil that the US (amongst others) gets by fracking is now selling like hot cakes. Some people my be paying Donald Trump large bribes to drag out the peace-making process as long as possible. Except that Donald Trump would never take a bribe ... -- Bill Sloman, Sydney
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-20 08:46 -0700 |
| Message-ID | <2svval1g09mkl0spgms80dufm1sbgobp3j@4ax.com> |
| In reply to | #747941 |
On Mon, 21 Sep 2026 00:52:37 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 20/09/2026 7:17 pm, john larkin wrote: >> On Sun, 20 Sep 2026 16:30:13 +1000, Bill Sloman <bill.sloman@ieee.org> >> wrote: >> >>> On 20/09/2026 1:48 am, john larkin wrote: >>>> On Sat, 19 Sep 2026 16:40:13 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote: >>>> >>>>> On 19/09/2026 1:02 am, john larkin wrote: >>>>>> On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote: >>>>>> >>>>>>> On 18/09/2026 12:46 am, john larkin wrote: >>>>>>>> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >>>>>>>> <presence@MUNGEpanix.com> wrote: >>>>>>>> >>>>>>>>> john larkin <jl@glen--canyon.com> wrote: >>>>>>>>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>>>>>>>> >>>>>>>>>>> On 9/7/26 16:18, john larkin wrote: >>> >>> <snip> >>> >>>>> The problem is that if you want to claim that you invent things you >>>>> really need to be able to point to a patent that covers that invention. >>>> >>>> I accept purchase orders too. >>> >>> If you sell something as invention without having got a patent, that >>> makes you a confidence trickster, but if you think that you could have >>> got a patent it would be a hard case to prosecute. A patent search used >>> to cost $100k. >>> >>>>> There are clearly loads of things that are invented, but not patented, >>>>> but there's a much bigger pool of stuff that it's inventors like to >>>>> imagine to have been an invention which those skilled in the art write >>>>> off as obvious. >>>>> >>>>> You claim to have invented stuff and designed circuits, and Donald Trump >>>>> claims to have a high IQ. Some people find those claims implausible. >>>> >>>> Always Trump. That's psychotic. >>> >>> On the contrary. Trump is a classic example of the twit who >>> over-promises and under-delivers. Has he got peace with Iran yet? >> >> Apparently he got what he wanted in Greenland. > >He's now got something which he says is what he wanted all along. Right. He wrote a book about making deals. 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 17:41 +1000 |
| Message-ID | <118qn46$3ot7q$4@dont-email.me> |
| In reply to | #747945 |
On 21/09/2026 1:46 am, john larkin wrote: > On Mon, 21 Sep 2026 00:52:37 +1000, Bill Sloman <bill.sloman@ieee.org> > wrote: > >> On 20/09/2026 7:17 pm, john larkin wrote: >>> On Sun, 20 Sep 2026 16:30:13 +1000, Bill Sloman <bill.sloman@ieee.org> >>> wrote: >>> >>>> On 20/09/2026 1:48 am, john larkin wrote: >>>>> On Sat, 19 Sep 2026 16:40:13 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote: >>>>> >>>>>> On 19/09/2026 1:02 am, john larkin wrote: >>>>>>> On Fri, 18 Sep 2026 15:45:59 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote: >>>>>>> >>>>>>>> On 18/09/2026 12:46 am, john larkin wrote: >>>>>>>>> On Thu, 17 Sep 2026 07:19:31 -0000 (UTC), Cydrome Leader >>>>>>>>> <presence@MUNGEpanix.com> wrote: >>>>>>>>> >>>>>>>>>> john larkin <jl@glen--canyon.com> wrote: >>>>>>>>>>> On Mon, 7 Sep 2026 19:33:35 +0100, chrisq <syseng@gfsys.co.uk> wrote: >>>>>>>>>>> >>>>>>>>>>>> On 9/7/26 16:18, john larkin wrote: >>>> >>>> <snip> >>>> >>>>>> The problem is that if you want to claim that you invent things you >>>>>> really need to be able to point to a patent that covers that invention. >>>>> >>>>> I accept purchase orders too. >>>> >>>> If you sell something as invention without having got a patent, that >>>> makes you a confidence trickster, but if you think that you could have >>>> got a patent it would be a hard case to prosecute. A patent search used >>>> to cost $100k. >>>> >>>>>> There are clearly loads of things that are invented, but not patented, >>>>>> but there's a much bigger pool of stuff that it's inventors like to >>>>>> imagine to have been an invention which those skilled in the art write >>>>>> off as obvious. >>>>>> >>>>>> You claim to have invented stuff and designed circuits, and Donald Trump >>>>>> claims to have a high IQ. Some people find those claims implausible. >>>>> >>>>> Always Trump. That's psychotic. >>>> >>>> On the contrary. Trump is a classic example of the twit who >>>> over-promises and under-delivers. Has he got peace with Iran yet? >>> >>> Apparently he got what he wanted in Greenland. >> >> He's now got something which he says is what he wanted all along. > > Right. He wrote a book about making deals. He didn't. It was ghost-written for him. https://www.newyorker.com/magazine/2016/07/25/donald-trumps-ghostwriter-tells-all Tony Schwartz probably would be a better president of the US than Donald Trump. At least he has the attention span to write a book. -- Bill Sloman, Sydney
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| From | Jan Panteltje <alien@comet.invalid> |
|---|---|
| Date | 2026-09-08 07:46 +0000 |
| Message-ID | <117oeg7$3vnql$1@dont-email.me> |
| In reply to | #747349 |
>chrisq <syseng@gfsys.co.uk>wrote: >>On 9/7/26 16:18, 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. >> > >What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >working at that level, put in a cheap relay and a rated heatsink >wirewound resistor to dump the energy, when the power goes off. >Cheap, and lossless as well. Motor drive inverters often have >big resistors to brake the motor. No relay, use an thyristor
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-09-08 07:26 -0700 |
| Message-ID | <pj60all8t1ptif283uft7prktqj91m8rql@4ax.com> |
| In reply to | #747376 |
On Tue, 08 Sep 2026 07:46:14 GMT, Jan Panteltje <alien@comet.invalid> wrote: >>chrisq <syseng@gfsys.co.uk>wrote: >>>On 9/7/26 16:18, 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. >>> >> >>What sort of design needs 0.2 Farad cap, at 200 volts ?. If you are >>working at that level, put in a cheap relay and a rated heatsink >>wirewound resistor to dump the energy, when the power goes off. >>Cheap, and lossless as well. Motor drive inverters often have >>big resistors to brake the motor. > >No relay, use an thyristor If it got a glitch, It would latch and keep the discharge resistors on, even if the power supply was still up. Brownouts are difficult to analyze, and dangerous. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Lasse Langwadt <llc@fonz.dk> |
|---|---|
| Date | 2026-09-07 21:18 +0200 |
| Message-ID | <117n2mp$3i7bs$1@dont-email.me> |
| In reply to | #747328 |
On 9/7/26 17:18, 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. > is a relay (or two) controlled by the AC not dumb enough? maybe use a PTC self limiting heater to dump the energy in
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