Sean Breheny wrote:
> 
> Hi All,
> 
> Thanks for all the answers on the thermal conductivity of PCBs.
> 
> I am trying to make a temperature controlled cavity (this is part of the
> autonomous helicopter project) to hold some accelerometers and rate gyros
> that are temp. sensitive. I hope to keep the temperature constant to within
> 0.1 deg C (it doesn't matter at exactly WHAT temp, as long as it is stable
> to within 0.1 deg C,and between 35 and 45 deg C).

Hi Sean, 40¡C is easy to keep steady if you build a thermal chamber. If
you build a metal box, with heaters inserted or attached mechanically to
the walls, insert it in a styrofoam box, and measure the temperature
directly to the metal walls.  Small holes are necessary to generate a
refrigeration curve.  The only problem is that your chamber should be
stable before you launch the aircraft, it can take few minutes.  If you
have enough tools, why not use the aircraft exaust temp to heat the box?
use somehow a air valve to control it.