[sdiy] Thermal contact of exponential convertor components

[harrybissell]

Hmmm.... why anti-static ??? The conductivity would be a big minus on an
expo comverter.

I'd try a piece od styrofoam packing material. Some of them are in a "bow tie"
shape... and 1/2 of a piece is a nice fit for a TO-5. I used them for thermal
insulation
in infrared detectors

H^) harry

allenre at umich.edu wrote:

> There has to be some kind of anti-static insulating foam I can wrap the expo
> components in.  Adding an aluminum enclosure doesn't sound like much fun.  Off
> to the search engine!
>
> Ryan
>
> > That's fine. The main purpose of course is to try and ensure that both
> > components experience the same temperature affects. I would stay away from
> > epoxy glues etc as Murphy's Law will dictate that you will need to remove one
> > or more components at some time and this will make it all the more difficult.
> > Heatshrink tubing makes a great draught insulator. On the ASM-2 I have set it
> > up so that the TEMPCO can be laid underneath the MAT-02 which helps with the
> > mechanics a bit.
> >
> > It might be worth considering the hardware layout of the VCO so that you can
> > house it, or at least the TEMPCO section in an aluminium enclosure. The main
> > thing would be to keep draughts away from the circuit yet try to maintain a
> > stable temperature environment which would mean a well-ventilated (but
> > draught free) enclosure.
> >
> > Best Regards
> > Laurie Biddulph
> > http://www.elby-designs.com
> >   ----- Original Message -----
> >   From: allenre at umich.edu
> >   To: Laurie Biddulph
> >   Sent: Monday, May 17, 2004 6:31 AM
> >   Subject: Re: [sdiy] Thermal contact of exponential convertor components
> >
> >
> >   I do want very precise tuning, so that I can use my VCOs on microtonal
> > scales
> >   with great accuracy.  I don't know how much of a difference it really
> > makes,
> >   but it might be significant for my uses.  Thanks for the info,
> >
> >   Ryan
> >
> >   > Hello Ryan,
> >   >
> >   > For most applications you don't really need to even bother about this. It
> > is
> >   > only in really critical applications that you will need the higher
> >   > performance of thermally bonding the two components together. If you are
> >   > going to do this then you only need a thin layer of heatsink compound
> > smeared
> >   > on to the two adjoining faces and then hold the two components together
> > which
> >   > is best done with a tie-wrap or even a piece of heatshrink.
> >   >
> >   > You do not need tons of heatsink compound (so goop is probably a bad
> > choice
> >   > of terms).
> >   >
> >   > Best Regards
> >   > Laurie Biddulph
> >   > http://www.elby-designs.com
> >   >   ----- Original Message -----
> >   >   From: allenre at umich.edu
> >   >   To: synth-diy at dropmix.xs4all.nl
> >   >   Sent: Monday, May 17, 2004 3:43 AM
> >   >   Subject: [sdiy] Thermal contact of exponential convertor components
> >   >
> >   >
> >   >   I'm gathering parts for the Rene Schmitz's VCO3, and I am wondering if
> > I
> >   > need to
> >   >   use heat sink compound on the transistor array and tempcos, or if I can
> >   > epoxy
> >   >   them together.  I'm not sure of the method of applying the heat sink
> >   > compound.
> >   >   The ASM-1 page mentions that "The transistor ans the tempco resistors
> > (if
> >   > used)
> >   >   should be gooped up with heatsink compound... and tie-wrapped together,
> > for
> >   >   best thermal result."  So, should I cover the components with the
> > compound,
> >   >   then use a plastic tie-wrap to hold them close?  My understanding is
> > that
> >   > the
> >   >   heat sink compound helps to transfer heat, so I only need to apply it
> >   > between
> >   >   the two components (in this case, a tempco and a 2SC1583), and the
> > tie-wrap
> >   >   holds them together (since the compound is non-adhesive).  Is this
> > correct?
> >   >   Thanks,
> >   >
> >   >   Ryan Allen
> >   >
> >
> >
> >