This is a beefier-version of the Electric Eye that will be be able to turn on a buzzer instead of a LED by increasing the voltage in the circuit. This type of circuit is a light-actuated circuit. When a beam of light hits the sensor (the “eye”), a buzzer sounds. Use this to indicate when a door closes or drawer closes… your suspect will never know what got triggered.
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Materials:
- Red laser (cheap dollar store kind works well)
- 9V Battery
- Three alligator clip leads
- Buzzer (3-6V)
- CdS Cell
Download Student Worksheet & Exercises
Exercises
- How is this circuit different from the Electric Eye experiment we did previously?
- Name three other light sources that work to activate your circuit.
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