In a message dated 16/10/2009, gmvoeth@........... writes:

If you  used a current source to keep a steady
10ma or 20 ma to the LED would that  not be
adequate stability for the light output also  ?



Hi Geoff,
 
    No chance. The photo output at a constant current  depends on the 
junction temperature.
 
    Regards,
 
    Chris Chapman






In a message dated 16/10/2009, gmvoeth@........... writes:
If you=20
  used a current source to keep a steady
10ma or 20 ma to the LED would=
 that=20
  not be
adequate stability for the light output also=20
?


Hi Geoff,
 
    No chance. The photo output at a constant cur=
rent=20
depends on the junction temperature.
 
    Regards,
 
    Chris Chapman