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<div class="moz-cite-prefix">On 12. 1. 2015 16:47, <a class="moz-txt-link-abbreviated" href="mailto:Cihak@dkv.cd.cz">Cihak@dkv.cd.cz</a>
wrote:<br>
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<blockquote
cite="mid:932C4BA36EAC9D4AB8C39461AFD90E4002C2D35C@cd00000unlnt050.mail.cd.cz"
type="cite">
<pre wrap="">A zkoušel jste někdy z objektu cca 2x20mm odvést 1W výkonu ? Navíc pokud nemůžete použít proudění ? Myslím, že pak byste mluvil naprosto jinak... Můj odhad byl cca 100 a více stupňů.</pre>
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Uz som sa k tomu nemienil vracat, ale dovolim si par citatov:<br>
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"The image below shows the results that Citizen Electronics have
achieved after continuously running their LED chip for 50,000hrs.
The chips being tested were run at maximum junction temperature of
120deg C. ... <strong>Lumen maintenance</strong> is still at 85%
that means the light output after 50,000hrs has only degraded by
15%." - <a class="moz-txt-link-freetext" href="http://www.switch-lighting.co.nz/tech-specs/">http://www.switch-lighting.co.nz/tech-specs/</a><br>
<br>
"Thus, thermal management of high power LEDs is a crucial area of
research and development. It is highly necessary to keep the
junction temperature below 120°C to run the LED's for maximum
lifetime." -
<a class="moz-txt-link-freetext" href="http://en.wikipedia.org/wiki/Thermal_management_of_high-power_LEDs">http://en.wikipedia.org/wiki/Thermal_management_of_high-power_LEDs</a><br>
<br>
"Cree specifies a maximum junction temperature of 150°C for the XM-L
Easy White LED." -
<a class="moz-txt-link-freetext" href="http://www.digikey.com/en/articles/techzone/2011/jun/calculating-led-junction-temperature-in-lighting-applications">http://www.digikey.com/en/articles/techzone/2011/jun/calculating-led-junction-temperature-in-lighting-applications</a><br>
<br>
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Co je zle na 100 stupnoch?<br>
<br>
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A len tak mimochodom, blahozelam k pomerne presnemu odhadu.<br>
<br>
<br>
<br>
<blockquote
cite="mid:932C4BA36EAC9D4AB8C39461AFD90E4002C2D35C@cd00000unlnt050.mail.cd.cz"
type="cite">
<pre wrap=""> Kdosi kdo si tady dal tu práci a spočítal to napočítal dokonce přes 200°C
</pre>
</blockquote>
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A pozerali ste, co pocital?<br>
<br>
<blockquote
cite="mid:932C4BA36EAC9D4AB8C39461AFD90E4002C2D35C@cd00000unlnt050.mail.cd.cz"
type="cite">
<pre wrap="">
Martin.
</pre>
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