Re: Boy...is it HOT in here!

[P3D Gregory J. Wageman <gjw@xxxxxxxxxx>]

Gary Nored inquires:

>I think something's wrong. Shouldn't the air be sucking _in_ around
>the slides? Blowing out over the bulbs?

I can tell you that in Kodak Carousel projectors, very warm air is
intentionally blown over the slides that are in the tray just prior
to the gate in order to "pre pop" them.

You typically would not want to draw the hot air out over the fan
motor, either, because of the risk of melting the fan, overheating
the windings, melting insulation, etc.  A good design would not want to
work against the tendency for hot air to rise, and so would typically
suck cool air in through the fan, and blow it upward past the bulbs
and out a vent at the top in a sort of "cooling tower" effect.

Carousels use a "cold mirror" to bounce only the visible light towards
the slide in the gate.  The lamp in a Carousel projector actually is
pointed towards the right-rear corner (looking from back to front).

        -Greg W.


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