Security Alarm Circuit
₹200.00
In StockA Security Alarm Circuit using the LM358 IC is a simple yet effective system designed to trigger an alarm when unauthorized access or movement is detected. The LM358, a dual operational amplifier (Op-Amp), is used as a comparator to detect voltage changes from sensors like LDRs, IR sensors, or switches, and then activate a buzzer or relay.
Description
Security systems often rely on detecting changes in the environment — such as light, motion, or contact — and triggering an alert. The LM358 is a dual op-amp IC that can be used to compare voltages from these sensors and output a HIGH or LOW signal based on the input condition.
In a typical light-based security alarm, an LDR (Light Dependent Resistor) is used to monitor ambient light. When someone passes by or blocks the light (e.g., in a doorway), the light level changes, causing a voltage difference across a voltage divider. The LM358 detects this change and activates a buzzer.
Applications:
1.Home Security Systems
1.Detect entry or light disturbance in doorways and windows.
2.Locker / Safe Alarms
1.Trigger alarm when the door is opened.
3.Garage or Entry Detection
1.Activates when someone passes through a beam.
4.Industrial Safety Systems
1.Detect light interruptions near machinery.
5.School or Lab Projects
1.Simple and educational project for understanding op-amps and sensors.
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