seoul P4 temperature measurements

[ergotelis]

Hello, I used my IR thermometer to measure some temps directly into the core of the led,distance 2 cm.The IR thermometer is accurate, proven by tests with different ways. after running a seoul P4 at ~800mA and ~3,5V, i measured after 10 minutes 70 C on core . Is this considered a safe temperature?Or should i improve heatsinking?Thanks!Generally, which are the limits of a Seoul led?I tried some search, i found some info mentioning that the limit is 125 C. Is this accurate?

 

[HKJ]

Led can take rater high temperatures, but they are measured on the die, not outside the led.

I would be a little worried about 70 degrees, because IR meters typically measures an circle of 1" and does not measure correctly of reflecting surfaces.

 

[ergotelis]

Led can take rater high temperatures, but they are measured on the die, not outside the led.

I would be a little worried about 70 degrees, because IR meters typically measures an circle of 1" and does not measure correctly of reflecting surfaces.

I guess that the measured temperature is the one of the silicone over the core. I guess that there wouldn't be much difference between the silicone and the core.Also, i believe that it is accurate,the "eye" of the IR thermometer has about the same diameter as the led, so i guess that by almost touching the led, the reading is accurate.

 

[gratewhitehuntr]

it was my impression that as long as it isn't blue shifting it is ok

no?

 

[ergotelis]

it was my impression that as long as it isn't blue shifting it is ok

no?

But if it starts getting blue, then the led starts getting destroyed, so its performance will get worser, am i right?
We should be able to prevent that, because i wouldn't like to see my flashlight dead in a critical situation...
(but because we are flashaholics we always have a second and third and forth one! :twothumbs)