G'Day,
I am looking for a sensor that will create a normally open or normally closed state when exposed to a laser generated light.
The ones I have tried so far are activated by all light and the constant light causes malfunctions and engages my relay. I have a relay that I want to activate outside so ambient light is a real problem.
Any ideas?
Thanks....
(deleted)
A laser is light so there may not be a perfect solution. You can adjust sensitivity (since a laser is very "bright") and a filter (that only passes the laser bandwidth) may also help.
And, you can pulse the laser and only trigger when there is a high/low pulse at the correct frequency. But, that will only help with false-triggers. You can still get a "miss" if the detector is overloaded with sunlight, etc. Laser alarms work something like that... If you don't receive the correct data/pattern the alarm is triggered. (i.e. The alarm will be triggered if the detector is blocked or if it's flooded with light.)
Another option is to use a color filter and a laser that emits only that color. Or modulate the laser like an IR remote does and detect the modulation frequency.
Paul
Thank you all so much. It looks like my project is not dead.
I will try the filter approach first, both wavelength-limited and color filtered.
It seems a more refined process may be the frequency modulation. At that point, the
laser could be of many colors and intensities but have a singe modulation frequency.
If moving in that direction seems most prudent, how might I proceed best with my 650nm
test laser?
Thanks....