Today security is big problem everywhere. Many time thief try to open bag or suitcase in bus, train or station. We cannot always watch our luggage. This small Luggage Safety Alarm Circuit using IC LM358 help to protect our bag. It uses piezo sensor and LM358 to sense vibration. When someone touches or try to […]
Alarm Circuits
Simple Wire Loop Security Alarm Circuit
Simple wire loop alarm is small security circuit. It uses thin wire as sensor loop. If loop is cut or opened the buzzer will sound. It works on 9V battery, needs few parts, is cheap and easy to make. Circuit Working: Parts List: Component Specification Qty Resistors 4.7M 1/4 watt 1 100k 1/4 watt 1 […]
Simple Refrigerator Door Open Alarm Circuit with IC 555
Sometimes people forget to close the fridge door. This causes loss of cooling and waste of electricity. To solve this problem we can use a Simple Refrigerator Door Open Alarm Circuit with IC 555 When the door is left open a buzzer sound comes to remind the user to close the door. This project uses […]
Simple Shock Sensor Alarm Circuit
In this Simple Shock Sensor Alarm Circuit we can feel vibration or shock, which then makes loud sound with piezo buzzer. This circuit is easy to make and can be used at home, in car and in many places. It is good for security, stop theft and in feel movement. Main parts of the circuit […]
Super Sensitive Intruder Alarm Circuit
This article for Super Sensitive Intruder Alarm Circuit talks about very simple but strong intruder alarm circuit. It is very sensitive. These circuit is good for security. They can catch very small intrusions. This circuit uses IC 741 op-amp and IC 555 timer to work. It also use LDR (light sensor) as main part so […]
Simple Charger Breakdown Alarm Circuit
In electronic system good charger circuit very important. It give power to things like battery. This Simple Charger Breakdown Alarm Circuit check charger working or not. If problem found then buzzer makes sound. So user know fast if charger fails and this stop battery from drain or damage. It uses easy parts like transistor, resistor, […]