3Pcs DIY Infrared Laser Aiming Anti-theft Burglar Alarm Module Kit
Note: This is a DIY kit, you need to assemble it, easy to install, not supply instructions.
When no light hits the photosencatalog/productive resistor, the transistor turns on and the buzzer gets the power to start tweeting. When there is light on the photosencatalog/productive resistor, the transistor is turned off, the buzzer is powered off, stop tweet. Transistor used here as an electronic switch.
Working voltage 3V
3 x DIY Infrared Laser Kit