[sdiy] temperature testing

[Dave Magnuson]

Hi Matt,

 

I bet unplugging a refrigerator would probably work in theory.   But I don’t think the problem will be too fast of a temp change; it should be insulated well enough that it might occur fairly slowly … perhaps annoying so ;)

 

Dave

 

From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of matt holland
Sent: Thursday, May 11, 2017 2:05 PM
To: Neil Johnson
Cc: *SYNTH DIY
Subject: Re: [sdiy] temperature testing

 

Perfect, thanks Neil. I guess "Incubator" is the magic search term. definitely hobby budget! Hopefully I can find an equivalent in the states. So I'm guessing your process with the incubator is manually stepping up the temperature with a stabilizing period in between, with the thermocouple for the accurate temperature readout? Is the superglue for the thermocouple?

 

I like the fridge idea for single point measurement. What would be the downside to say, unplugging the fridge and taking measurements while it warms up to ambient? Temp changing too fast to be sure the data is accurate?

 

Multiple thermocouples... to be certain you aren't being misled by hotspots on the PCB?

 

thx,

mh

 

 

 

 

On Thu, May 11, 2017 at 2:13 AM, Neil Johnson <neil.johnson71 at gmail.com> wrote:

Hi Matt,

> searched a bit through the archives and didn't find anything so... how do
> you all go about testing your circuits over temperature? i imagine there's a
> decent amount of dust cleaner and hair dryers involved but i'm hoping some
> of you have some recommendations for something resembling a hobbyist budget
> temp chamber to make things a bit more objective and repeatable.

I use a Gallenkamp "economy incubator size 1" that I picked up on ebay
for very little.  It's quite large, but gives a stable temperature
environment.  It only heats, so that's anything above ambient.  It
doesn't have a fan, which for some tests can cause problems (air flow
cooling) and for home use it's good enough.

I also have a fridge in the same room, which is mainly used for
keeping beer cool, although it can also be used for single-point low
temperature tests (about 4 Celsius).  For anything inbetween I need to
wait for winter....

Oh, and to do this properly you need a bunch of thermocouples,
superglue, and a means of recording the temperature against the other
parameters you're measuring.  At work we use an Agilent 34970A and
relay cards to monitor 5-6 points on the unit under test.

Cheers,
Neil
--
http://www.njohnson.co.uk

 

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