- Powerful Security Siren
- Mini Alarm
- Safety Guard
- Fire Alarm Using Thermistor
- Broken Charger Connection Alarm Circuit
- Fridge Door Alarm Circuit
- Two-Tone Siren Using One IC
- Water Level Alert
- Low Cost Burglar Alarm For Boats
- Midnight Security Light Circuit Schematic
- Water Alarm Circuit Diagram
- Bell Alarm
- Mains Supply Failure Alarm
- Smoke Alarm Battery Life Extender
- Simple Knock Alarm With Piezo Sensor
- Night Alert
- Speed Alarm For Cars
- Laser Alarm
- Model Railway Short-Circuit Beeper
- Simple Darkness Activated Alarm
- General-Purpose Alarm
- Infrared Proximity Detector Alarm
- Power Buzzer
- A 4-Digit Keypad Controlled Alarm Circuit
- Alarm Control Keypad
- Melody generator using UM66
- Light Alarm with Timer 555
