“There is no need to check manually mobile phones in the exams hall when you have a smartphone detector in your pocket.
Motivation behind the project
Nowadays students have become smart enough that they can bring their mobile phones to the exams hall where they are strictly not allowed to use mobiles. Sometimes teachers can find phones but when there is a large number of students it is hard to check every student manually. This mobile phone detector can easily detect any RF transmitting device. This is portable, easy to carry, and accurate in detecting the presence of mobile phones.
Working on the project
The MOSFET OP amplifier CA3130 used in this project is used to detect mobile phones in restricted areas. Whenever there is a mobile phone detected in an area it will go high and will lighten up the LED showing that there is a phone otherwise it will remain off when there is no phone detected. The capacitor 0.22uF attached with the OP amplifier will act as an RF signal detector which will further send the signal to the OP amp that will decide whether there is a phone or not. It is a frequency detector circuit that will detect the frequency of a defined range and will convert that signal to some voltage or current level like in the form of LED to tell the presence of any device.”