[Fwd: Re: [sdiy] super-nice LED interface ..]

[Ian Fritz]

Yes, Jason, you have it right.  An LED needs to be illuminated with light 
at or above its band gap energy.  So shorter wavelength emitters illuminate 
longer wavelength detectors.

   Ian


At 02:55 AM 10/14/05, Jason Tribbeck wrote:
>owner-synth-diy at dropmix.xs4all.nl wrote:
> > ----- Original Message -----
> >>> http://archive.chipcenter.com/eexpert/akruger/akruger042.html
> >>
> >> According to that, it appears as though you can illuminate a red LED
> >> with a blue LED - and I would guess a green LED.
> >>
> > Well, no. Quite the opposite, as I read it.
>
>Too many LEDs here!
>
>- Blue illuminating Red should work (given in text)
>
>- Green illuminating Red I think should work (Green bandgap higher than
>Red bandgap) [this is what I was alluding to]
>
>- Red illuminating Green or Blue shouldn't work (Red bandgap lower than
>other two)
>
>- Green illuminating Blue shouldn't work (for reasons above)
>
>- Blue illuminating Green should work (also for reasons above)
>
>Of course, I could be making things up as I go along - it wouldn't be
>the first time :E
>--
>Jason Tribbeck