Electronic Eye Controlled Security System

Introduction:
           
                   Hello friends, What if we know is there anyone visiting your home before they press the calling bell? It is possible with the help of Electronic eye controlled security system. Let us discuss its design and working further below.

Principle:
             
                The main principle is that whrn there is a person at your doorstep this system glows and makes sound with the help of LDR as Sensor.

Circuit diagram:

     

Design:

            The Circuit consists of two parts one is power Supply part and the other is logic design part.The system works when shadow falls on the LDR.The power Supply part converts 9V supply to 5V supply and logic part opertes buzzer and LED.

Power Supply Design:

           The power supply part consists of battery,diode,regulator. A 9V battery is connected to a 1N4007 diode in its forward biased condition so that it prevents circuit dailure when battery polarity is misplaced unknowingly. A regulator is used for regulating the output voltage . The regulator used her is 7805 here 78 represnts series and 05 represents output voltage. Two capacitors are used to eliminate ripple and maintains constant voltage.

Logic design:
             A LED, buzzer and LDR is used in this system . When LDR is placed in the dar it offers resistance in mega ohms and when exposed to light the resistance gradually decreases . When LDR  is at dark it gives high output and hence LED and the buzzer flashes .


       This system plays a major role in security applications.
Source: https://www.electronicshub.org/electronic-eye-controlled-security-system/