[sdiy] what are these?

[KA4HJH]

>> > Regular optos I can find a use for (and I have some,  and plans for
>> > them), but not ones driven by a neon bulb.  Any of you guys have a use
>> > for these?
>>
>> Could these be for detecting the presence of AC Mains?
>
>I suppose with the appropriate resistor (which is going to be rather different
>depending on whether that's an NE2 or an NE2H in there!) they could be used
>for such a thing...
>
>The only thoughts I've had along those lines lately involve the building of a
>zero-crossing detector,  and this wouldn't work for that at all.

Too slow for that. Probably used in some tube circuit because of the high
voltages.

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"