all circuit Alarms and security related schematics (link)
- Intermittent alarm generator
- Burglar alarm
- Moisture alarm
- Automatic Entry Control System
- Fridge door alarm
- Electronic door codelock (PIC16F84)
- Ultrasonic remote control & alarm system
- Wire loop alarm
- Proximity alarm
- Electronic lock
- Digital entry lock
- Proximity switch
- Toxic Gas Detector
- Door knob alarm (PDF)
- Water seepage alarm (PDF)
- Micro-power over temperature alarm (PDF)
- Personal silent alarm system
- Active IR motion detector
- A Basic RF Transmitter for PIR Sensors
- PIR motion detector
- Simple alarm system
- Home security project
- 5 Zone alarm circuit
- Miniature loop alarm
- Novel Buzzer
- Gate alarm circuit
- Modular Burglar Alarm
- Motorcycle alarm
- Enhanced 5 Digit Alarm Keypad
- Enhanced 4 Digit Alarm Keypad
- RF Alarm
- Single Zone Alarm
- Water Activated Alarm
- Water level alarm
- Perimeter monitor
- Digital combination lock
- Alarm control keypad
- Almost Ultrasonic Motion Sensor
- Alarm loop sensor (LM3915)
- Touch triggered alarm
- Universal alarm system
- Warning strobe flasher for alarm systems
- Collection of alarm circuits
- PIR motion detector light controller
- Micropower wireless motion detector transmitter
- Touch activated alarm system
- Combination Lock (Simple Version)
- Combination Lock (PIC16F84)
- Low power RFID transponder
