Pages: 1 [2]   Go Down
Author Topic: Hot LEDs  (Read 2096 times)
0 Members and 1 Guest are viewing this topic.
Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 639
Posts: 34726
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
Your finger perceives that radiation as heat
No they don't not at those sort of wavelengths, you fingers peeve them just the same as if they were visible light.
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 33
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
Your finger perceives that radiation as heat
No they don't not at those sort of wavelengths, you fingers peeve them just the same as if they were visible light.

I beg to differ, Mr. Grumpy!  Typical IR LEDs emit around 940nm and that is used extensively in the medical industry because it does penetrate the skin.  Here's some light reading for you:

http://labs.seas.wustl.edu/bme/wang/epub/2004TD-PMB-Thermal.pdf
Logged

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 639
Posts: 34726
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

You will notice that the title of that paper says:-
Quote
a theoretical investigation
Have you ever stuck your finger in front of an IR LED? Have you felt it get hotter? Was this hotter than when the same power was given off by a red LED?
Perception is everything in this question.
Logged

Pages: 1 [2]   Go Up
Jump to: