In this post I have explained 3 simple yet accurate infrared intruder alarm circuits using an infrared transmitter and an infrared receiver module. The transmitter and the receiver photo diodes […]
Security and Alarm
7 Interesting IC 555 Siren and Alarm Circuits
In this post I have explained how to use IC 555 to create 7 interesting siren and alarm sound effect generator circuits. The versatile astable multivbrator configuration of IC 555 […]
Simple Anti-Theft Alarm Circuit to Protect Valuable Items
This easy yet useful security alarm circuit is designed to get triggered in response to even a brief movement of the unit, causing a loud alarm sound to set off. […]
How Laser Microphones or Laser Bugs Work
A laser microphone is a security monitoring gadget in which a laser beam is used for detecting audio vibrations across faraway targets, which are normally walls or glass of homes […]
Touch Alarm Circuit
The touch alarm circuit senses the mains hum signal from an intruder’s body and raises the alarm sound. This happens whenever an intruder touches a potential element set as the […]
Ultrasonic Fire Alarm Circuit using Air Turbulence Detection
The simple ultrasonic fire alarm circuit I have explained below detects a fire hazard situation by picking up the variations in the surrounding air waves, or the air turbulence. The […]
