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 […]
Security and Alarm
How to Make a Barcode Security Lock Circuit
A simple barcode security lock circuit or barcode scanner circuit is explained in the following article using just a handful of ordinary components such as an op amp, an LDR […]
Office Call Bell Network Circuit with LED Monitor
In this post I have explained an office call bell network circuit for office complexes which could be used for calling and monitoring office member’s attendance and response from the […]
Power Switch ON Alarm with Auto OFF Circuit
In this post I have explained a simple monostable based power switch ON alarm circuit which automatically switches OFF after an adjustable preset delay. The idea was requested by Mr. […]
Laptop Anti-theft Security Alarm Circuit
In this post I have explained a simple laptop anti-theft alarm circuit which can used with any concerned object such as a laptop which needs to be protected, when an […]
Simple Water Heater Alarm Circuit
In this post I have explained a simple water heater alarm circuit which may be used as a safety device for getting indications regarding the switched position of a water […]
