Jon Bertrand wrote:
>
>      What's your favorite opto-transistor?  I need to be able to "see"
>      sunlight with an opto-transistor (no accuracy required, using an
>      infrared transistor seems fine).
>
>      Dark current doesn't matter, "high noon" current of less than 1 mA is
>      okay.
>
>      Any suggestions?
>
>      Thanks
>
>      Jon Bertrand
>      jonb@cirris.com


I prefer photodiodes generally, because they have more consistent
sensitivity from unit to unit.  Of course, their sensitivity is much
lower, since no current gain is involved.  However, as posted earlier,
if you use a sufficiently high value of load resistance, you can
interface a photodiode directly to a port input and achieve adequate and
highly repeatable sensitivity.

Among the world's most popular photodiodes:

BPW34   (clear resin 2 leaded thru-hole pkg)
BPW34F  as above except with visible light blocking filter
BPW34S  surface mount, clear resin
SFH203FA T1-3/4 bullet pkg, filter
SFH229FA T1 pkg, filter

If you insist on a phototransistor, there are many.  Some good ones:

SFH314FA  80 degree FOV T1-3/4, filter
SFH313FA  as above exc 20 degree FOV
SFH303FA  as above exc 40 degree and base lead is available

Above P/Ns are available form Siemens OED and, for some of the more
popular P/Ns, several other suppliers.

--

Paul Mathews, consulting engineer
AEngineering Co.
optoeng@whidbey.com
non-contact sensing and optoelectronics specialists