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testing NTC caps

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  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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#446702 — testing NTC caps

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. 


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

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#446703

Den onsdag den 8. februar 2017 kl. 00.36.25 UTC+1 skrev John Larkin:
> 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. 
> 

how small and what would you pay for one?

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#446710

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

Personally I just use cold spray and a heat gun. ;)

Cheers

Phil Hobbs


-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

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#446714

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.




-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

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#446753

"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

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#446787

On Wed, 8 Feb 2017 00:21:55 -0500, "tom" <tmiller11147@verizon.net>
wrote:

>
>"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
>

I don't really need the case. Just a small hot/cold platform would
work for testing parts or small circuits. 0 to maybe 80C would be
enough. I'd have to deal with condensation, but there are ways to do
that.

I could sit my solder-roll thing on the platform. Or a die-cast box
with feedthrus.








-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

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#446756

John Larkin wrote:
> 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.

For $2 more this gets to 300 F.

https://www.amazon.com/dp/B00030DLEE

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#446735

On Wednesday, February 8, 2017 at 11:39:50 AM UTC+11, Phil Hobbs 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

Those very small fridges tend to use Peltier junction heat pumps, which are inherently bidirectional, but regular air-conditioners in Sydney tend to be offered as bi-directional heat pumps, for cooling in summer and heating in winter. I know of people in England who used heat-pumps for winter warming, but they needed to be quite big and expensive to deliver enough heat to warm a poorly insulated English house in an English winter.
 
> Personally I just use cold spray and a heat gun. ;)

Cheapskate.

-- 
Bill Sloman, Sydney

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#446777

On 07/02/2017 23:36, 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.
>
>
I use a vacuum flask with wadding in the neck.  I use a small aquarium 
bubbler pump to pump air through silicone tubing via a power resistor 
(one with a cooling tube through the middle) through the wadding to the 
bottom of the flask.  A cheap Chinese PID controller and solid state 
switch to heat the resistor closes the loop.

It's nice and even, low power and can be left on for days.

Cheers
-- 
Clive

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#446790

On 02/08/2017 10:12 AM, Clive Arthur wrote:
> On 07/02/2017 23:36, 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.
>>
>>
> I use a vacuum flask with wadding in the neck.  I use a small aquarium
> bubbler pump to pump air through silicone tubing via a power resistor
> (one with a cooling tube through the middle) through the wadding to the
> bottom of the flask.  A cheap Chinese PID controller and solid state
> switch to heat the resistor closes the loop.
>
> It's nice and even, low power and can be left on for days.
>
> Cheers

A bit tough to cool with that setup, though.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

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#446792

On 08/02/2017 16:47, Phil Hobbs wrote:
> On 02/08/2017 10:12 AM, Clive Arthur wrote:
>> On 07/02/2017 23:36, 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.
>>>
>>>
>> I use a vacuum flask with wadding in the neck.  I use a small aquarium
>> bubbler pump to pump air through silicone tubing via a power resistor
>> (one with a cooling tube through the middle) through the wadding to the
>> bottom of the flask.  A cheap Chinese PID controller and solid state
>> switch to heat the resistor closes the loop.
>>
>> It's nice and even, low power and can be left on for days.
>>
>> Cheers
>
> A bit tough to cool with that setup, though.

Just connect the resistor the other way round.

> Cheers
>
> Phil Hobbs

Cooling is much harder because of condensation, at least for boards or 
components.  With my setup, and using a stainless flask, I can run at 
200'C without problems.


Cheers
-- 
Clive

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#446795

On 02/08/2017 11:56 AM, Clive Arthur wrote:
> On 08/02/2017 16:47, Phil Hobbs wrote:
>> On 02/08/2017 10:12 AM, Clive Arthur wrote:
>>> On 07/02/2017 23:36, 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.
>>>>
>>>>
>>> I use a vacuum flask with wadding in the neck.  I use a small aquarium
>>> bubbler pump to pump air through silicone tubing via a power resistor
>>> (one with a cooling tube through the middle) through the wadding to the
>>> bottom of the flask.  A cheap Chinese PID controller and solid state
>>> switch to heat the resistor closes the loop.
>>>
>>> It's nice and even, low power and can be left on for days.
>>>
>>> Cheers
>>
>> A bit tough to cool with that setup, though.
>
> Just connect the resistor the other way round.

Of course.  Silly of me.

> Cooling is much harder because of condensation, at least for boards or
> components.  With my setup, and using a stainless flask, I can run at
> 200'C without problems.

Depends on how long you need it to run.  Starting it out cold (e.g. by 
putting the open flask in a deep freeze overnight, with some sort of 
thermal mass in the bottom) would probably work fine. I used to use a 
chest freezer for this sort of thing, back when I worked out of my 
house.  Nowadays I'd  probably just use a heating loop and run it inside 
the freezer compartment of the lab fridge, for those rare cases where 
the heat gun and cold spray (a spray duster held upside down) aren't 
good enough.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

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#446791

On Wed, 8 Feb 2017 15:12:08 +0000, Clive Arthur
<cliveta@nowaytoday.co.uk> wrote:

>On 07/02/2017 23:36, 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.
>>
>>
>I use a vacuum flask with wadding in the neck.  I use a small aquarium 
>bubbler pump to pump air through silicone tubing via a power resistor 
>(one with a cooling tube through the middle) through the wadding to the 
>bottom of the flask.  A cheap Chinese PID controller and solid state 
>switch to heat the resistor closes the loop.
>
>It's nice and even, low power and can be left on for days.
>
>Cheers

I'd like to go from 0 to maybe 80C. I guess the ideal oven would be a
small box that I can put my circuit inside, that would ramp slowly
from high to low temp. If I don't want to bother to automate the
measurements, I could use a kitchen timer to alert me every, say, 10
or 20 minutes to walk over to my bench and take my data. These
measurements are better if the temperature changes slowly, and that
makes this sort of thing tedious.

Our big oven will sweep temp, and even can be remotely controlled, but
it's a big deal to get wires in and out of the chamber, from DUT to
instruments. It's great for big-deal automated measurements of whole
products, with custom software.



-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

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#446793

On 02/08/2017 11:49 AM, John Larkin wrote:
> On Wed, 8 Feb 2017 15:12:08 +0000, Clive Arthur
> <cliveta@nowaytoday.co.uk> wrote:
>
>> On 07/02/2017 23:36, 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.
>>>
>>>
>> I use a vacuum flask with wadding in the neck.  I use a small aquarium
>> bubbler pump to pump air through silicone tubing via a power resistor
>> (one with a cooling tube through the middle) through the wadding to the
>> bottom of the flask.  A cheap Chinese PID controller and solid state
>> switch to heat the resistor closes the loop.
>>
>> It's nice and even, low power and can be left on for days.
>>
>> Cheers
>
> I'd like to go from 0 to maybe 80C. I guess the ideal oven would be a
> small box that I can put my circuit inside, that would ramp slowly
> from high to low temp. If I don't want to bother to automate the
> measurements, I could use a kitchen timer to alert me every, say, 10
> or 20 minutes to walk over to my bench and take my data. These
> measurements are better if the temperature changes slowly, and that
> makes this sort of thing tedious.
>
> Our big oven will sweep temp, and even can be remotely controlled, but
> it's a big deal to get wires in and out of the chamber, from DUT to
> instruments. It's great for big-deal automated measurements of whole
> products, with custom software.
>
>
>

I have a beautiful Extech 3-channel thermocouple data logger that writes 
to an SD card.    If it had a couple of ordinary ADC inputs, that would 
be about perfect, but alas.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

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#446833

On 2/8/2017 10:57 AM, Phil Hobbs wrote:
> On 02/08/2017 11:49 AM, John Larkin wrote:
>> On Wed, 8 Feb 2017 15:12:08 +0000, Clive Arthur
>> <cliveta@nowaytoday.co.uk> wrote:
>>
>>> On 07/02/2017 23:36, 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.
>>>>
>>>>
>>> I use a vacuum flask with wadding in the neck.  I use a small aquarium
>>> bubbler pump to pump air through silicone tubing via a power resistor
>>> (one with a cooling tube through the middle) through the wadding to the
>>> bottom of the flask.  A cheap Chinese PID controller and solid state
>>> switch to heat the resistor closes the loop.
>>>
>>> It's nice and even, low power and can be left on for days.
>>>
>>> Cheers
>>
>> I'd like to go from 0 to maybe 80C. I guess the ideal oven would be a
>> small box that I can put my circuit inside, that would ramp slowly
>> from high to low temp. If I don't want to bother to automate the
>> measurements, I could use a kitchen timer to alert me every, say, 10
>> or 20 minutes to walk over to my bench and take my data. These
>> measurements are better if the temperature changes slowly, and that
>> makes this sort of thing tedious.
>>
>> Our big oven will sweep temp, and even can be remotely controlled, but
>> it's a big deal to get wires in and out of the chamber, from DUT to
>> instruments. It's great for big-deal automated measurements of whole
>> products, with custom software.
>>
>>
>>
>
> I have a beautiful Extech 3-channel thermocouple data logger that writes
> to an SD card.    If it had a couple of ordinary ADC inputs, that would
> be about perfect, but alas.
>
> Cheers
>
> Phil Hobbs

What happened to your Labjack?

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#446864

On 02/08/2017 02:02 PM, John S wrote:
> On 2/8/2017 10:57 AM, Phil Hobbs wrote:
>> On 02/08/2017 11:49 AM, John Larkin wrote:
>>> On Wed, 8 Feb 2017 15:12:08 +0000, Clive Arthur
>>> <cliveta@nowaytoday.co.uk> wrote:
>>>
>>>> On 07/02/2017 23:36, 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.
>>>>>
>>>>>
>>>> I use a vacuum flask with wadding in the neck.  I use a small aquarium
>>>> bubbler pump to pump air through silicone tubing via a power resistor
>>>> (one with a cooling tube through the middle) through the wadding to the
>>>> bottom of the flask.  A cheap Chinese PID controller and solid state
>>>> switch to heat the resistor closes the loop.
>>>>
>>>> It's nice and even, low power and can be left on for days.
>>>>
>>>> Cheers
>>>
>>> I'd like to go from 0 to maybe 80C. I guess the ideal oven would be a
>>> small box that I can put my circuit inside, that would ramp slowly
>>> from high to low temp. If I don't want to bother to automate the
>>> measurements, I could use a kitchen timer to alert me every, say, 10
>>> or 20 minutes to walk over to my bench and take my data. These
>>> measurements are better if the temperature changes slowly, and that
>>> makes this sort of thing tedious.
>>>
>>> Our big oven will sweep temp, and even can be remotely controlled, but
>>> it's a big deal to get wires in and out of the chamber, from DUT to
>>> instruments. It's great for big-deal automated measurements of whole
>>> products, with custom software.
>>>
>>>
>>>
>>
>> I have a beautiful Extech 3-channel thermocouple data logger that writes
>> to an SD card.    If it had a couple of ordinary ADC inputs, that would
>> be about perfect, but alas.
>>
>> Cheers
>>
>> Phil Hobbs
>
> What happened to your Labjack?
>
>
I have three of them, but that requires writing code, which John doesn't 
want to do, I don't think.  (LJ may have some logging program that works 
under Windows, but I wiped my last Win7 box when they changed the EULA 
so that they own the contents of my hard disk.)

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

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#446870

On Wed, 8 Feb 2017 16:14:05 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 02/08/2017 02:02 PM, John S wrote:
>> On 2/8/2017 10:57 AM, Phil Hobbs wrote:
>>> On 02/08/2017 11:49 AM, John Larkin wrote:
>>>> On Wed, 8 Feb 2017 15:12:08 +0000, Clive Arthur
>>>> <cliveta@nowaytoday.co.uk> wrote:
>>>>
>>>>> On 07/02/2017 23:36, 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.
>>>>>>
>>>>>>
>>>>> I use a vacuum flask with wadding in the neck.  I use a small aquarium
>>>>> bubbler pump to pump air through silicone tubing via a power resistor
>>>>> (one with a cooling tube through the middle) through the wadding to the
>>>>> bottom of the flask.  A cheap Chinese PID controller and solid state
>>>>> switch to heat the resistor closes the loop.
>>>>>
>>>>> It's nice and even, low power and can be left on for days.
>>>>>
>>>>> Cheers
>>>>
>>>> I'd like to go from 0 to maybe 80C. I guess the ideal oven would be a
>>>> small box that I can put my circuit inside, that would ramp slowly
>>>> from high to low temp. If I don't want to bother to automate the
>>>> measurements, I could use a kitchen timer to alert me every, say, 10
>>>> or 20 minutes to walk over to my bench and take my data. These
>>>> measurements are better if the temperature changes slowly, and that
>>>> makes this sort of thing tedious.
>>>>
>>>> Our big oven will sweep temp, and even can be remotely controlled, but
>>>> it's a big deal to get wires in and out of the chamber, from DUT to
>>>> instruments. It's great for big-deal automated measurements of whole
>>>> products, with custom software.
>>>>
>>>>
>>>>
>>>
>>> I have a beautiful Extech 3-channel thermocouple data logger that writes
>>> to an SD card.    If it had a couple of ordinary ADC inputs, that would
>>> be about perfect, but alas.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>> What happened to your Labjack?
>>
>>
>I have three of them, but that requires writing code, which John doesn't 
>want to do, I don't think. 


Not for something simple like this cap test. And neither the temp
meter nor the cap meter is interfaced.

I don't mind taking a dozen or so data points and plotting them by
hand. Gets me out of my chair.




-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

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#446844

On Wed, 08 Feb 2017 08:49:10 -0800, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>If I don't want to bother to automate the
>measurements, I could use a kitchen timer to alert me every, say, 10
>or 20 minutes to walk over to my bench and take my data. These
>measurements are better if the temperature changes slowly, and that
>makes this sort of thing tedious.

Put the cap meter, digital thermometer, and maybe a clock where they
can all be seen at the same time.  Set your digital camera to take a
photo of the displays every 10 minutes.  I do this for long term
battery discharge testing.  No computah required.

See my comment elsewhere about condensation problems going from low
temp to high temp.

-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

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#446898

On Wed, 08 Feb 2017 08:49:10 -0800, the renowned John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>
>
>I'd like to go from 0 to maybe 80C. I guess the ideal oven would be a
>small box that I can put my circuit inside, that would ramp slowly
>from high to low temp. If I don't want to bother to automate the
>measurements, I could use a kitchen timer to alert me every, say, 10
>or 20 minutes to walk over to my bench and take my data. These
>measurements are better if the temperature changes slowly, and that
>makes this sort of thing tedious.

What kind of heat load? That's going to be decisive on whether
Peltiers are pracdical. 

>
>Our big oven will sweep temp, and even can be remotely controlled, but
>it's a big deal to get wires in and out of the chamber, from DUT to
>instruments. It's great for big-deal automated measurements of whole
>products, with custom software.
>

Really? The one I use has big silicone rubber stoppers in the side. We
just stick BNCs, loose wires, serial cables USB cables, etc, through
and stuff the bung in. Nice fan to keep everything isothermal. 

It does suck 3-phase power and I didn't spec the really low
temperature refrigerant. 

--sp 


-- 
Best regards, 
Spehro Pefhany

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#446803

On Tue, 07 Feb 2017 15:36:15 -0800, John Larkin
<jjlarkinxyxy@highlandtechnology.com> wrote:

>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.

We were testing chip caps at a former employer in roughly the same
manner.  The idea was to match the tempco curve so that the two caps
in a Colpitts oscillator would be roughly the same.  However, we did
it starting from hot and then going toward cold, so that moisture
would not condense on everything.  For hot, we used a hot air gun. For
cold, a bottle of CO2.  The test box (plastic pipe) was fairly well
insulated to speed up the testing.  To keep the test box from
affecting the measurements, the cap was supported by two screws with
point contacts and coil spring tension.  We found that caps from
different vendors and different lots varied considerably.

>It would be great to have a very small benchtop oven, peltier
>hot/cold, to test small parts or circuits. 

I vaguely recall that they do make such things designed to fit on
common LRC bridges and meters.  However, I couldn't find anything
affordable at the time, so we built our own.

-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

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