1 Jul
2010
1 Jul
'10
12:18 p.m.
Although=2C I've not tried this=2C it was
mentioned that most digital came=
ras
have some sensitivity to IR ( even though they have filters to block most )=
Yes, Most semiconductior sensors, such as CCDs, respond to near-IR. I am
told you can 'see' most remote cotnrol outputs using one, for examplke. something much simpler and smaller using not very many
components which
would serve as well or better. Actually probably quite a lot better as
When I was setting uphe CX scanner, I used a simple remote control tester
that I'd built from a Mpalin kit. A photodiode driving a 3 transisor (I
think -- it's certainly discrete transistors, no ICs) amplifier, driving
an LED. The amplifier is AC coupled, so it responds well to the
flickering IR output of the average TV remote control.
It also responds to the IR laser beam from the CX scanner being swept
across the ptoodikode by the spinning mirror. So by holding the
photodiode in various positions I could see where the sweeping beam was
going.
And I have to say that 3 transisotrs is a lot fewer than the number you
find in a digital camera :-)
-tony