In this article I will show how to construct a GSM fire alert circuit system using Arduino and DHT11 sensor, which will alert the user via text message (SMS), regarding a fire hazard within the premise where it is installed. Using DHT11 Sensor We are using DHT11 sensor for sensing unusual temperature rise around the […]
Security and Alarm
A Homemade Fence Charger, Energizer Circuit
The electric fence charger circuit presented here is basically a high voltage pulse generator. The super high voltage is derived from a commonly used automobile ignition coil. An astable multivibrator is used to generate the required frequency to drive the ignition coil. Another astable is used to control the pulses supplied to the fence. Audio/Video […]
LPG Gas Leakage Detector Alarm Circuit
Are you feeling vulnerable or suspecting a possible LPG gas leakage in your house? Then may be this gas leakage alarm circuit might help you. Written by: Sai Srinivas The Concept This circuit is a simple solution for detecting LPG gas leakage in households which causes severe physical and monetary losses if left unattended for […]
PIR Burglar Alarm Circuit
The PIR burglar alarm explained here will detect a human intruder within the stipulated range and sound an alarm. Thus, the system could be effectively use for detecting trespassing, theft, intrusion, burglars, or any form of unlawful entry inside a restricted area or zone. Basic Principle The operating principle of the proposed burglar alarm circuit […]
Impact Collision Switch Sensor Module and Circuit Diagram
Here we are going to learn about a very interesting small sensor called the Impact Collision Switch Sensor Module. This module is super simple but very useful especially when we want to detect a shock, collision, hit or a sudden tap on a surface. Now let us go step-by-step to understand everything about it. What […]
3 Accurate Infrared Intruder Alarm Circuits using Photodiodes
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 used in the two modules are aligned in line at a distance of around 2 meters within the restricted area. When a burglar tries to […]