A electronic combination lock is a device which is designed to activate an electrical solenoid locking system whenever the correct combination of numbers are entered into an attached keypad. To […]
Password Lock Circuit Using IC 4017
In this post we are going to construct a general purpose password based electronic lock circuit without any involvement of microcontroller. You can use this circuit for numerous applications where […]
Intruder Alarm Circuit using Photodiodes
The post explains a simple infrared intruder alarm circuit using an IR transmitter and an IR receiver module. The transmitter and the receiver photo diodes used in the two modules […]
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 […]