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
The post explains 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 particular intended office […]
Power Switch ON Alarm with Auto OFF Circuit
The post discusses a simple monostable based power switch ON alarm circuit which automatically switches OFF after an adjustable preset delay. The idea was requested by Mr. Will Boswell. Technical […]
Laptop Anti-theft Security Alarm Circuit
The post explains 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 intruder tries to […]
Simple Water Heater Alarm Circuit
The post explains a simple water heater alarm circuit which may be used as a safety device for getting indications regarding the switched position of a water heater or a […]