Laser "reactive" target?

[Uranium]

Some have a CDS cell, some shut off when the solar panel stops giving current. However He'll still need a 555 timer circuit, or else the buzzer's sound will be too short to hear. He'll also need a way to turn ON the buzzer when the lamp turns OFF, and thus more circuitry than the design I posted.

 

[BShanahan14rulz]

if laser is <5mW you could put a box on its side and put a cat in there. Wherever the clawmarks are is where you shot...

You could take the laser to a game store and see if the lasertag kits detect the radiation. From there it would be a simple physical modification instead of a circuit build. Unless you like that sort of thing.

HIML9's idea is the most creative thing I've heard, though. I didn't know that about LEDs Might be hard to use if what you said about the LED only detecting shorter wavelengths is true. Makes sense, though.

 

[Asa]

What you need to do is to go to Disney World and ride "Buzz Lightyear's Space Ranger Spin."