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From: Watson 'Atto Parsec' Name
Subject: Re: luxeon star leds
References: <3DDD9A57.58900EFB@RobertsResearchInc.com> <firstname.lastname@example.org> <3DDDB646.96D0D9D2@RobertsResearchInc.com> <3DDE7264.CD48F4F8@RobertsResearchInc.com> <email@example.com> <3DDEB081.884EC92A@RobertsResearchInc.com>
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Date: Sat, 23 Nov 2002 16:15:01 -0800
NNTP-Posting-Date: Sat, 23 Nov 2002 18:18:38 PST
Organization: InReach Internet
In article <3DDEB081.884EC92A@RobertsResearchInc.com>,
Vic@RobertsResearchInc.com talked about...
> However, a
> small fraction of the power will be dissipated via
> convection from the top of the LED package.
> [..] When the whole device is at higher
> temperature than it was while mounted on the heat sink, then
> a greater percentage of the 1.1 watts will be dissipated
> from the top side of the package via convection, leaving a
> slightly smaller amount of power flowing to the "base" via
> conduction. Since the actual thermal resistance between the
> junction and the "base" does not change, the reduced power
> flow between junction and base will reduce the temperature
> differential between the junction and the "base". Therefore,
> the thermal resistance between junction and base will appear
> to decrease, since for the same power we now have a lower
> temperature differential.
I don't buy this convection from the top because I'm using the Luxeon
Star/O which has the whole top of the LED covered by the lens assembly.
> So many words for such a small effect.
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you put NOSPAM in the
Subject: line. alondra101 hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
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