This presented refrigerator door open alarm circuit which alerts you after a period of time whenever your refrigerator door is left open. This circuit becomes very handy, because in case the door is left due to carelessness may cause significant increase in the consumption and affect the life of the fridge. Circuit Operation This circuit […]
Alarm
Simple Shadow Sensor Alarm Circuit
This shadow detector circuit operates using two LDRs and effectively detects the difference between the light levels and triggers a loud audible warning siren. In circuits which uses a single LDR (photoresist), the detection may not be as sharp as with two LDRs discussed here.Operational details of the shadow detector circuit may be studied as […]
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 […]
Simple Ultrasonic Sound Sensor Alarm Circuit using Opamp
This article discusses a simple ultrasonic sound sensor alarm circuit which may be appropriately set for detecting sound pressures well above the normal human listening capacity, that may range from 20 kHz and over. Ultrasonic Concept Ultrasound or ultrasonic sound waves was probably invented even before humans existed on this planet by a few of […]
5 Simple Alarm Circuits for Protecting your Home/Office from Theft
The following article discusses a few very simple intrusion detector circuits, or ant-theft alarms. The presented designs are easy to build yet extremely effective with the functions. How the Circuits Works An intruder alarm basically consists of a sensor and a trigger stages, which work together to produce the required detection. The sensor detects the presence […]
Simple Car Burglar Alarm Circuit
Learn how to build a simple car burglar alarm circuit right in your home. The circuit is built around a few trivial components and yet proves to be totally fool proof with the security of car accessory to which it has been integrated. You certainly won’t like waking up just to see your car audio […]