Attila Muhi wrote:
> I need a monochrome (almost)  light source for a project. So far I have
> been playing with high intensity LED:s around 650 nm (EL383-2SDRC),
> with an  output of about 3700 mcd at 20mA.  For some reasons I need
> more light than that, so I run the LED:s at 50mA. This is way out of
> specs, which says a max fwd current of 35-40mA. I also need to run the
> current continously. I get a temp rise of course, the surface of the
> LED goes up to 42-43 degrees. The temp rise itself is no problem, but I
> wonder how much the overpowering affects the LED:s lifetime ?
>
> As far  as I can see, I have three alternatives:
>
> Continue as before

Really bad idea since you are using the part out of specification and
clearly abusing it.

> Finding a better LED (Any ideas ?)

There are various higher power LEDs available, but they won't be cheap.
3700mcd is definitely "high brightness", but I've seen numbers around 8000
to 10000.

> Use a laser.  (expensive solution)

Or use more than one LED.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com
_______________________________________________
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist