Lurking and Tempcos

[Harry Bissell]

Beats me... I'd wonder how hot the "hot glue" was and if it would damage the
semiconductor... other than that it would serve as insulator... but it may not
be thermally
conductive. That would be bad. Maybe some styrofoam covering the chip (still use
the thermal compound between the tempco and chip) might be better.

:^) Harry

Rob wrote:

> How about hot glue? That stuff seems to have pretty good thermal insulative
> properties (as shown by how long it holds heat when it burns the crap out of
> my fingers)
>
> :)
>
> Rob
>
> ----- Original Message -----
> From: <harrybissell at prodigy.net>
> To: Scott Chicoine <scottc at zeno.com>
> Cc: <synth-diy at mailhost.bpa.nl>
> Sent: Tuesday, December 14, 1999 5:14 PM
> Subject: RE: Lurking and Tempcos
>
> > If you can't get "thermal mass" the next best thing is to carefully
> isolate the mass you you have from rapid temperature changes. I wouldn't
> want to epoxy a $10 tempco (or whatever the price is...) to a $1 transistor
> array. Too much chance you will want to upgrade later...
> > I epoxied mine to a MAT-01 (analog devices) ina little plastic "cup". Not
> much chance I'll want to improve that transistor...
> >
> > :^) Harry
> >
> >
> >  ---- On Dec 14 scottc at zeno.com (Scott Chicoine) wrote:
> > > Thanks for the info, Harry (and PaulS and RoyT and RoryMcD).
> > >
> > > I think I might try out your heater some time later, Harry, but I think
> I'll
> > > just go with a tempco solution.  It's only one component and doesn't
> need
> > > near the PCB real estate a properly controlled heater does.  Besides,
> Paul's
> > > got 'em, so what the heck.  :)
> > >
> > > About the "thermal mass":  I assume this is to keep the device from
> changing
> > > temperature too rapidly, keeping the diff amp and the resistor from
> > > heating/cooling at different rates?  I was planning on just making a
> little
> > > clip from copper sheet that would go from under the CA3046, up and over
> the
> > > side and along the top to end in a little curly-Q that I would stick the
> > > tempco in, along with a small amount of thermal grease.  Kind of like a
> > > paper clip.  I'm a little spooked at the idea of potting the thing, it's
> so
> > > _permanent_.
> > >
> > > -ScottC
> > >
> >
> >
> >
> >