P3D Re: Cooling fan protects projector, not slides

[michaelk@xxxxxxxxxxx (Michael Kersenbrock)]

> > 
> The function of the fan is mainly to cool the projector, not the slides.  

Is this just an attribute of the TDC projector or is cooling the slide just
thought secondary?  I know my Compco Traid's fan does blow some air on the slide,
and therefore seems like it should be cooling it, even if it isn't the primary
purpose .

> 
> This is from an earlier posting in this list:
>
> >The cooling fan is there to protect the projector and not the slides. 
> >This is based on the observation that the temperature of the slide in
> >the projection beam rises steadily as it absorbs radiation.  One would
> >expect that the cooling stream of air will cause the temperature to reach
> >an equilibrium point. However, my observation has been that the temperature
> >is still rising in the short period of time that the slide remains in the
> >beam's path.  The heat-absorbing filters or cold mirrors block the IR
> >radiation from heating the slide and these are the ones that essentially 
> >protect the slide.

Would the slide temperature rise at the same rate without the airflow? Would
the eventual equilibrium point be at the same temperature?


Mike K.


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