In this post I have explained a method which can be probably used for enhancing a passive infrared sensor ability to detect even a static or stationery human presence. This feature is normally not possible with the conventional PIR sensors. How PIR Detect Human Presence I have already discussed many PIR based motion detector applications […]
Security and Alarm
Laser Diode Driver Circuit
The current controlled circuit of a laser pointer power supply explained in the following post was requested by Mr. Steven Chiverton (stevenchiverton@hotmail.com), who himself is an intense electronic hobbyist and researcher. Technical Specifications Dear swagatam, I’m emailing you to ask you for your expertise, and you being one of India’s finest electronics engineers I thought you be […]
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 high sensitivity of the circuit ensures that even the slightest of air turbulence created by a temperature difference or fire is quickly detected and an […]
Loop-Alarm Circuits – Closed-Loop, Parallel-Loop, Series/Parallel-Loop
In this article I have explained a few simple loop based security alarm circuits, categorized under closed loop, parallel loop, and series/parallel loop. All these designs could be customized and used for a variety of security alarm applications. Overview In a loop alarm circuit, more than one sensor is used, each one wired with a […]
Infrared Remote Controlled Door Lock Circuit
In this article I have explained about a simple infrared remote controlled door lock circuit which can be used for securely locking doors through unique foolproof IR frequencies. The proposed infrared remote controlled door lock circuit can be used for locking your main door, gate, garage door, shop or any entrance which may need a […]
Make this Solar Powered Fence Charger Circuit
A Fence charger or energizer is an equipment which is used for charging(electrifying) a fence or a boundary in order to protect the inside premise from human or animal interventions. Since these boundaries are mostly of large fields and parks, are normally away from the main cities, and powering them through some renewable option becomes […]





