07-10-2014, 09:50 AM
MOBILE PHONE DETECTOR
[attachment=68844]
INTRODUCTION
The most common electronic equipment used is cell phones. With advancement in communication technology, the requirement of cell phones has increased manifold.
A cell phone typically transmits and receives signals in the frequency range of 0.9 to 3GHz. This seminar provides a simple circuit to detect the presence of an activated cell phone by detecting these signals.
OPERATION OF MOBILE PHONE DETECTOR
In normal condition, when there is no RF signal, the voltage across the diode will be negligible.
Even though this voltage is amplified by the transistor amplifier, yet the output voltage is less than the reference voltage, which is applied to the inverting terminal of the comparator.
Since the voltage at non inverting terminal of the OPAMP is less than the voltage at the inverting terminal, the output of the OPAMP is low logic signal.
APPLICATION OF MOBILE PHONE DETECTOR
This circuit can be used at examination halls, meetings to detect presence of mobile phones and prevent the use of cell phones.
It can be used for detecting mobile phones used for spying and unauthorized transmission of audio and video.
It can be used to detect stolen mobile phones
LIMITATION OF MOBILE PHONE DETECTOR
It is a low range detector, of the order of centimeters.
The Schottky diode with higher barrier height is less sensitive to small signals.
CONCLUSION
From the above seminar I conclude that mobile detector is used in examination hall to prevent used of cell phone
[attachment=68844]
INTRODUCTION
The most common electronic equipment used is cell phones. With advancement in communication technology, the requirement of cell phones has increased manifold.
A cell phone typically transmits and receives signals in the frequency range of 0.9 to 3GHz. This seminar provides a simple circuit to detect the presence of an activated cell phone by detecting these signals.
OPERATION OF MOBILE PHONE DETECTOR
In normal condition, when there is no RF signal, the voltage across the diode will be negligible.
Even though this voltage is amplified by the transistor amplifier, yet the output voltage is less than the reference voltage, which is applied to the inverting terminal of the comparator.
Since the voltage at non inverting terminal of the OPAMP is less than the voltage at the inverting terminal, the output of the OPAMP is low logic signal.
APPLICATION OF MOBILE PHONE DETECTOR
This circuit can be used at examination halls, meetings to detect presence of mobile phones and prevent the use of cell phones.
It can be used for detecting mobile phones used for spying and unauthorized transmission of audio and video.
It can be used to detect stolen mobile phones
LIMITATION OF MOBILE PHONE DETECTOR
It is a low range detector, of the order of centimeters.
The Schottky diode with higher barrier height is less sensitive to small signals.
CONCLUSION
From the above seminar I conclude that mobile detector is used in examination hall to prevent used of cell phone