Easy Laser Alarm Kit
Easy Laser Alarm Kit, Easy Laser Alarm KitExperience Level: Beginner Protect your home with the Easy Laser Alarm kit. It uses a 741 op-amp and 4017 decade counter as the brain and is powered by a 9V battery. If you like, connect a 9V wall transformer to the power connections to save your batteries. The kit works by sensing the light from the laser hitting the photoresistor which lowers the resistance, once the beam is broken the resistance increases and the 741 chip sends a pulse to the 4017 which sets off the buzzer. To reset the circuit the laser must be back on the photoresistor and then you push the reset button. If you add mirrors to reflect the laser you can protect multiple entrances at once. Please note: Due to inventory packaging methods, you may receive extra components for some products. Kit Includes: Part No. (Qty.) - Description 24539 (1) - LM741 Op Amp 45891 (1) - 4017 Decade Counter 202403 (1) - Photoresistor 315678 (1) - Pushbutton switch 138713 (1) - Piezo buzzer 18922 (1) - Enclosure 2128067 (1) - Battery holder 2210204 (1) - Laser diode 2155452 (1) - Breadboard 690865 (10) - 1K ohm resistor Required Tools: Knife Drill Philips screwdriver 9V battery Wire Hot glue Check out more fun and exciting electronic projects