The project is designed as a security system based on photo sensing arrangement. It uses a 14- stage ripple carry binary counter to sense the light intensity through LDR. The output drives a buzzer and a relay for necessary action. This concept is very useful to deter burglars from banks, malls, jewellery stores and also in homes.
The system is based on an electronic eye: it is an LDR sensor, called light dependant resistor. When light falls on the sensor, its resistance drastically decreases which lead to triggering an alarm to alert the user. This system best suits in the application of providing friendly security system for cash boxes and lockers, which can be found in malls, jeweler shops, and banks.
The circuit is placed inside the cash box or locker in such a way that, when the burglar opens the locker and uses a torch light to find the valuables, the light falls on the circuit which contains an electronic eye (LDR) and gives a signal to the ripple counter. This activates the alarm, and indicates a burglary attempt. Also a lamp is used to indicate the theft when the light falls on the LDR.
Further the project can be enhanced by using a GSM modem and a microcontroller. Gsm modem can be interfaced to the microcontroller to send an SMS to the user in case of burglary.
- Slide switch
- Ripple Counter IC