Infrared Laser Alarm Kit, When light is shining on the Photoresistor, the Triode is Turned Off. when Beam is Broken, and no Light on Photo Resistor, the Triode is Turned On, and Buzzer Activated
Overview
Features
Working principle: When no light is irradiated onto the photoresistor the triode is turned on, and the buzzer gets power and starts to chirp.
When light is shining on the photoresistor, the triode is turned off, the buzzer is powered off, and the tweet is stopped.