If I recall, I read a spec indicating that a color (output freq) shift=20
when the LED is driven so hard that its junction
is overheated. If you pulse-modulate the LED, iits junction will stay=20
cooler and its "apparent" output will be greater.

--Bob

Marc Nicholas wrote:

> Attila...
>
> I'm not sure I'd recommend more than doubling the input power on one=20
> LED, but is there an issue doubling up on the number of LEDs?
>
>
> -marc
>
>
>
> Attila Muhi wrote:
>
>> Hi list,
>>
>> I need a monochrome (almost)  light source for a project. So far I=20
>> have been playing with high intensity LED:s around 650 nm=20
>> (EL383-2SDRC), with an  output of about 3700 mcd at 20mA.  For some=20
>> reasons I need more light than that, so I run the LED:s at 50mA. This=20
>> is way out of specs, which says a max fwd current of 35-40mA. I also=20
>> need to run the current continously. I get a temp rise of course, the=20
>> surface of the LED goes up to 42-43 degrees. The temp rise itself is=20
>> no problem, but I wonder how much the overpowering affects the LED:s=20
>> lifetime ?
>> As far  as I can see, I have three alternatives:
>>
>> Continue as before
>> Finding a better LED (Any ideas ?)
>>
>> Use a laser.  (expensive solution)
>>
>> Regards
>>
>> Attila - SM4RAN
>> ______________________________________________________
>>
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>>
>>
>>
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>>
>> =20
>>
>
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