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Re: Instead scopes

From	Jan Panteltje <alien@comet.invalid>
Newsgroups	sci.electronics.design
Subject	Re: Instead scopes
Date	2024-09-01 07:36 +0000
Message-ID	<vb15i5$20n23$3@solani.org> (permalink)
References	(8 earlier) <h9v3dj54jf6n748a7rj88p28e0jle14jil@4ax.com> <vauboa$t47f$2@dont-email.me> <j486dj51k87h5pouh1i3c2smi99riea3ua@4ax.com> <vavdnj$12846$1@dont-email.me> <t5p6djh6vdfl5kmosb54bdpnn7e9np0smg@4ax.com>

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On a sunny day (Sat, 31 Aug 2024 11:57:03 -0700) it happened john larkin
<jl@650pot.com> wrote in <t5p6djh6vdfl5kmosb54bdpnn7e9np0smg@4ax.com>:

>>> Here's my millikelven temperature controller.
>>> 
>>> https://www.dropbox.com/scl/fi/emxfaurnyj35t0y84tvwl/Oven_Cables_pub.jpg?rlkey=jpcnmnt1pcooz9nj7d0j4rah0&raw=1
>>> 
>>> That's a dual-stage Mach-Zender e/o modulator whose extinction is
>>> much better if the temperature is stable to milllikelvins. The big
>>> hogged-aluminum box is heated by six mosfets on the bottom, and there
>>> are four thermistors for feedback. It runs at 30C.
>>
>>Why four thermistors? The only temperature that matters is that of the 
>>modulator itself. People who need to minimise temperature gradients do 
>>need more than one temperature sensor, but it isn't clear why you would 
>>have. I used a second thermistor to monitor the temperature of the 
>>exhaust side of my Peltier cooler (which does matter) but you seem to 
>>have used mosfets as resistive heaters which is rather easier.
>
>One thermistor is on the heater board, on the bottom of the big block.
>Three are on the platform that mounts the e/o modulator. We really
>don't need three up there, but we wanted to error check and snoop for
>gradients and optionally do some averaging if we had noise.
>
>The EOM platform is spaced off the bottom of the big block, which
>makes us a 2nd order thermal system. The main block has a 75 minute
>time constant, and the platform inside is 17 minutes. Our control
>algorithm uses the difference as, essentially, a derivative term.
>
>Coolers have lots of problems, including condensation. Heating to 30C
>worked fine. This is in maybe the world's  biggest single clean room
>and the local air is always 20C.


Decent temperature stability over several years:
 https://panteltje.nl/panteltje/tri_pic/
 https://panteltje.nl/panteltje/tri_pic/tritium_decay_experiment_black_box_open_on_main_PCB_with_beeper_IMG_3874.GIF
 https://panteltje.nl/panteltje/tri_pic/tritium_decay_experiment_closed_black_box_IMG_3868.GIF


Much better time constant, much cheaper, took an hour to code, maybe 2 to build 
Uses less power, can run on batteries if main fails, 
:-)

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Instead scopes Martin Rid <martin_riddle@verison.net> - 2024-08-27 10:40 -0400
  Re:Instead scopes Martin Rid <martin_riddle@verison.net> - 2024-08-27 10:48 -0400
    Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-27 15:07 +0000
      Re: Instead scopes wmartin <wwm@wwmartin.net> - 2024-08-29 12:24 -0700
        Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-29 19:42 +0000
    Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-27 09:30 -0700
  Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-27 09:04 -0700
    Re: Instead scopes Martin Rid <martin_riddle@verison.net> - 2024-08-27 14:55 -0400
      Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-27 19:23 -0700
        Re: Instead scopes Sergey Kubushyn <ksi@koi8.net> - 2024-08-28 04:28 +0000
          Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-28 08:08 -0700
            Re: Instead scopes Sergey Kubushyn <ksi@koi8.net> - 2024-08-28 15:21 +0000
              Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-28 09:32 -0700
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 05:46 +0000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-29 06:55 -0700
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-29 07:16 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-30 00:43 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-29 08:49 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-30 14:10 +1000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 16:21 +0000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:47 -0700
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-30 06:47 +0000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-30 07:13 -0700
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-30 08:29 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 16:08 +1000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 01:39 +1000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-30 10:18 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 15:40 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 06:53 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 02:11 +1000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-30 18:22 +0000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-31 07:38 +0000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 17:45 +1000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-01 11:06 +0000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 21:38 +1000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-01 12:41 +0000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 01:56 +1000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:34 +0000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 16:54 +1000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 10:37 +0000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 23:28 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 07:09 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 02:20 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 13:32 -0700
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:48 +0000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:53 +0000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 17:13 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:31 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-03 15:11 +1000
                Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-09-01 17:55 +0000
                Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-01 15:53 -0400
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 13:17 -0700
                Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-01 17:43 -0400
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 19:49 -0700
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:56 +0000
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 17:52 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:45 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-03 15:20 +1000
                Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-02 10:02 -0400
                Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-09-02 15:25 +0000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 14:57 -0700
                Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-09-02 22:32 +0000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-04 07:41 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-03 15:30 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-04 07:50 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-05 16:54 +1000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-09-03 11:39 -0700
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:51 -0700
                Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-02 12:47 -0400
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:36 -0700
                Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-02 12:39 -0400
                Re: Instead scopes piglet <erichpwagner@hotmail.com> - 2024-09-09 19:51 +0100
                Re: Instead scopes Jeroen Belleman <jeroen@nospam.please> - 2024-09-09 22:24 +0200
                Re: Instead scopes liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2024-09-09 22:15 +0100
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-09-09 14:40 -0700
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-09-09 14:27 -0700
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 16:15 +0000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:50 -0700
                Re: Instead scopes liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2024-08-29 21:50 +0100
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 07:24 -0700
                Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-31 17:59 +0000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-31 11:44 -0700
                Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-31 20:14 +0000
                Re: Instead scopes ehsjr <ehsjr@verizon.net> - 2024-08-31 17:43 -0400
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 16:40 -0700
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 16:06 +0000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:52 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-29 20:23 +1000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:59 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-30 14:17 +1000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-30 10:14 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 16:03 +1000
                Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 07:03 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 01:43 +1000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-31 11:57 -0700
                Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 15:15 +1000
                Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-01 07:36 +0000
              Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-28 17:41 +0000
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-28 13:05 -0700
                Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-29 19:15 -0400
                Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 16:44 -0700
  Re: Instead scopes Joerg <news@analogconsultants.com> - 2024-09-09 14:57 -0700

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