The MQ-3 based Breathalyzer/Alcohol Detection circuit is used to check the alcohol concentration in your breath. Take a drink, breath into the orange sensor and the buzzer will go off. A fairly easy to build project and great for anyone interested in understanding electronic sensors.
Build Difficulty Level: Beginner
Build Time: 10-20 minutes
Build Instructions: The component values are printed directly on the PCB for easy reference and installation.
Input Voltage: 5-7V DC
Circuit Size: 6.2*3.6cm
Post Build Instructions:
1. Connect to Power source and turn on the switch
2. Wait 5-10 minutes for the orange sensor to heat up
3. Use the trimmer pot to increase or decrease the concentration threshold
4. breath into the sensor