700nm
Newly Enlightened
I bought a 3V IR led and when I tested it the LED becomes hot to the touch and i thought it was my hand that was hot but it wasn't. Is it normal for it to become hot to the touch?
Well, both IR and visible light can heat things up -- take a bright enough visible LED, and focus the light from it on your skin and you'll feel the heat just from the visible rays being absorbed.VidPro said:IR is more heat than visable light, that is why your supposed to be carefull with exposing your eyes to it.
Do you mean you feel the heat radiating from it, or that the LED itself is hot to the touch? Keep in mind that in any LED there will be some inefficiency, meaning some of the electricity you put in will go into heating the LED itself, rather than radiating out. Higher-powered LEDs require heatsinks for this reason.I bought a 3V IR led and when I tested it the LED becomes hot to the touch and i thought it was my hand that was hot but it wasn't. Is it normal for it to become hot to the touch?
Bertrik said:I guess your LED gets hot because you are overdriving it, which means that it's carrying too much current and dissipating a lot of power. What kind of driver are you using? You mention that it's a 3V IR LED, but LEDs require a current, not a voltage, to avoid being overdriven.
rivethead147 said:bandwidth of light
The heating is only dependent on the power/amplitude, not on the wavelength. One watt of IR will heat up a black object as much as one watt of visible light. Then there's the issue of waste heating of the LED itself (rather than heat projected in the beam), that has to do how efficient your LED is, and how hard you're driving it. Greater efficiency means less waste heat. I believe IR are usually the most efficient LEDs, followed by blue.Do you mean wavelength? If so, then I believe that is why IR light creates significant (comparitively) amounts of heat.