Groups > sci.electronics.design > #446753

Re: testing NTC caps

From	"tom" <tmiller11147@verizon.net>
Newsgroups	sci.electronics.design
Subject	Re: testing NTC caps
Date	2017-02-08 00:21 -0500
Organization	A noiseless patient Spider
Message-ID	<o7e9om$hq8$1@dont-email.me> (permalink)
References	<iclk9cp9l3b7oidhpb2asjuaap7snjdhmj@4ax.com> <x9ednUxggOVT9QfFnZ2dnUU7-IvNnZ2d@supernews.com> <o7sk9cl80lljg3puk5jj20h3a6poo8989v@4ax.com>

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"John Larkin" <jjlarkinxyxy@highlandtechnology.com> wrote in message 
news:o7sk9cl80lljg3puk5jj20h3a6poo8989v@4ax.com...
> On Tue, 7 Feb 2017 19:40:06 -0500, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>>On 02/07/2017 06:36 PM, John Larkin wrote:
>>>
>>>
>>> We special-ordered a reel (4000 pieces) of NTC caps from Capax. They
>>> are 0805, 3.3 pF, N4700. 23 cents each.
>>>
>>> I figured I should test them. I made an oven out of a roll of solder,
>>> with the cap and a thermocouple inside.
>>>
>>> https://dl.dropboxusercontent.com/u/53724080/Parts/Caps/NTC_Setup.JPG
>>>
>>> It has a nice long thermal time constant. I started with a heat gun to
>>> get it to 50C, covered it with a cloth, and took data slowly as it
>>> cooled. Near room temp, a spritz of freeze spray into the solder coil
>>> cooled it down, and then I took data as it slowly warmed up.
>>>
>>> https://dl.dropboxusercontent.com/u/53724080/Parts/Caps/NTC_Data.JPG
>>>
>>> The measured tempco is close to -7000, but that's OK. I'm going to
>>> compensate a 600 MHz coaxial ceramic resonator oscillator, with this
>>> cap and a series NPO padder, so too-high tempco is OK.
>>>
>>> It would be great to have a very small benchtop oven, peltier
>>> hot/cold, to test small parts or circuits.
>>
>>There are small beer fridges that have heating capability too, for some
>>reason, e.g.
>>https://www.amazon.com/Desktop-Fridge-Cooler-Personal-Black/dp/B005JAVC94
>
> Warm beer? Yuk.
>
> That might work, maybe connected to a DC power supply to adjust the
> temp. For $29, it's no big risk to try.
>
>>
>>Personally I just use cold spray and a heat gun. ;)
>
> Me too. A little acetone squirted into my solder roll cools it nicely
> too.
>
> We have a gigantic environmental oven, but it's a big deal to use. It
> would cool a keg to -70C.
>
>
>
>
> -- 

Be sure to read the feedback. The plastic case has no insulation, the cold 
plate is on the bottom, and nothing to stir the volume.

Regards

Thread

testing NTC caps John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-07 15:36 -0800
  Re: testing NTC caps Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-07 15:41 -0800
  Re: testing NTC caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-07 19:40 -0500
    Re: testing NTC caps John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-07 17:18 -0800
      Re: testing NTC caps "tom" <tmiller11147@verizon.net> - 2017-02-08 00:21 -0500
        Re: testing NTC caps John Larkin <jjlarkin@highlandtechnology.com> - 2017-02-08 08:41 -0800
      Re: testing NTC caps "Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> - 2017-02-08 02:41 -0500
    Re: testing NTC caps bill.sloman@ieee.org - 2017-02-07 19:15 -0800
  Re: testing NTC caps Clive Arthur <cliveta@nowaytoday.co.uk> - 2017-02-08 15:12 +0000
    Re: testing NTC caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-08 11:47 -0500
      Re: testing NTC caps Clive Arthur <cliveta@nowaytoday.co.uk> - 2017-02-08 16:56 +0000
        Re: testing NTC caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-08 12:04 -0500
    Re: testing NTC caps John Larkin <jjlarkin@highlandtechnology.com> - 2017-02-08 08:49 -0800
      Re: testing NTC caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-08 11:57 -0500
        Re: testing NTC caps John S <Sophi.2@invalid.org> - 2017-02-08 13:02 -0600
          Re: testing NTC caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-08 16:14 -0500
            Re: testing NTC caps John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-08 13:28 -0800
      Re: testing NTC caps Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 11:40 -0800
      Re: testing NTC caps Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-02-08 18:08 -0500
  Re: testing NTC caps Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 09:29 -0800
  Re: testing NTC caps Robert Baer <robertbaer@localnet.com> - 2017-02-08 21:45 -0800
    Re: testing NTC caps John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-09 11:20 -0800
      Re: testing NTC caps Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-09 14:29 -0500
        Re: testing NTC caps Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-09 22:52 +0000
          Re: testing NTC caps pcdhobbs@gmail.com - 2017-02-09 16:58 -0800
            Re: testing NTC caps Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-10 09:01 +0000
            Re: testing NTC caps John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-10 11:39 -0800
              Re: testing NTC caps Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-02-10 22:49 -0500
        Re: testing NTC caps krw@notreal.com - 2017-02-09 21:18 -0500
          Re: testing NTC caps pcdhobbs@gmail.com - 2017-02-09 18:54 -0800
            Re: testing NTC caps Clifford Heath <no.spam@please.net> - 2017-02-10 14:18 +1100

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