Archived posting to the Leica Users Group, 1996/08/25
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It's true. Don't run the fan after shutting off the bulb. Most modern
overhead projectors, as well as my Prodovit, aren't even wired to allow you
to do so.
My guess is that cooling too quickly causes the evaporated filiment metal
to condense on the bulb's envelope rather than redepositing itself on the
filiment.
kw
>> From owner-leica-users@mejac.palo-alto.ca.us Sun Aug 25 03:01:52 1996
><snip> ...
>
>> From: Eric Welch <ewelch@cdsnet.net>
>> Date: Sat, 24 Aug 1996 22:19:32 PST
>> Subject: Re: Pradovit P-2002 projector
><snip> ...
>
>> And also, don't run the fan after you turn it off. It's hard on the bulb.
>> Just turn it off completely. Found that based on research done by some
>> magazine. Fans without the light on shortens the bulb's life.
>
> Hi LU's -
>
> Sorry! "... some magazine ..." This sounds like rumor.
> Or the people running the magazine should go back to
> publishing. I can't believe that this is true!
>
> The only way that could be true is if the fan is causing
> excessive vibrations of the (unlit) filament. If this
> projector causes that, it shows poor engineering. Lousy
> design of the fan, its mounting, the mounting of the bulb
> and fragility of the bulb itself.
>
> If true, purchase of this projector should not even be
> considered by someone who shoots with a Leica!
>
> -- Wolfgang
>
>|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
>| Wolfgang Sachse Phone: +1/607/255-5065 |
>| Theoretical and Applied Mechanics E-mail: sachse@msc.cornell.edu |
>| Cornell University FAX: +1/607/255-9179 |
>| Ithaca, NY - 14853-1503 USA Department Secretary: 607/255-5062 |
>| WWW Home Page http://www.msc.cornell.edu/~sachse |
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
----
Ken Wilcox Carolyn's Personal Touch Portraits
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