Z
Zucker
Guest
I would like to be able to count the number of people entering (count up)
and leaving (count down) a room. I was thinking about using two photocells
driven by two small lasers, spaced 6" to 12" apart, to detect if a person is
entering or leaving. If photocell A was tripped before photocell B, the
counter would count up. If photocell B was tripped before photocell A, the
counter would count down. My problem is that I'm trying to come up with a
circuit that can detect the AB or BA pattern. May be a circuit that can
detect the lag between the two photocell voltages? I don't know.
If anyone has a suggestion for this circuit or any other ideas, I would
appreciate it.
Thanks,
Steve
and leaving (count down) a room. I was thinking about using two photocells
driven by two small lasers, spaced 6" to 12" apart, to detect if a person is
entering or leaving. If photocell A was tripped before photocell B, the
counter would count up. If photocell B was tripped before photocell A, the
counter would count down. My problem is that I'm trying to come up with a
circuit that can detect the AB or BA pattern. May be a circuit that can
detect the lag between the two photocell voltages? I don't know.
If anyone has a suggestion for this circuit or any other ideas, I would
appreciate it.
Thanks,
Steve