🚀 go-pugleaf

moskin@iccgcc.decnet.ab.com says:
>>From "LED Circuits and Projects", by Forrest M. Mims, III, 1973:
>
>>       In recent years, a family of semiconductor devices capable of
>>       emitting visible and infrared light has become available.
>>       Semiconductor light emission was first discovered in 1907 by
>>       H.J. Round, but it was not until 1960 that efficient light 
>>       generation in a semiconductor was obtained.
>>
>
>        I heard once that the early semiconductor diodes used in computers
>had clear casings but they were changed to opaque because they glowed red
>and alarmed people who didn't know that this was normal.  Could this be 
>considered a Light Emitting Diode?  Can anyone verify this story?

Or perhaps it was because the transistors were acting like phototransistors.

I have made phototransistors in a pinch by carefully removing the top of a 
metal cased NPN transistor (such as a 2N2222).  The exposed semiconductor
is sensitive to light.  To protect the semiconductor, I would put a drop of 
clear glue or expoy over it.  Worked out reasonably well for a couple of
situations.

      Bob
-- 
  Bob Billson, KC2WZ                          | internet: bob@kc2wz.bubble.org
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