CELLULAR PHONE
DETECTION USING OP-AMP
PRESENTED BY
1.O161472 Akkidasari Vasavi devi (ECE-01)
2.O161928 Shaik Kandukuru Gousia (ECE-02)
3.O161404 Shaik Hafizun (ECE-04)
4.O161443 Doma Jeshwitha (ECE-04)
5.O161449 V.S Reddy Rithin (ECE-04)
Under the supervision of
Mr.Srenivasa Rao.G (Assistant professor)
MAIN OBJECTIVE
●
To design a circuit that can detect signals
in the rang of 0.9GHz to 3GHz.
●
To produce a notification when the signal in
the range of 0.9 to 3GHz are detected.
●
To design a circuit to detect signals with in
a range of one and half meters.
OVERVIEW
●
WHAT IS A CELL PHONE DETECTOR?
●
CIRCUIT DIAGRAM
●
CIRCUIT COMPONENTS
●
WORKING PRINCIPLE
●
APPLICATIONS
●
LIMITATIONS AND EXTENSION
●
CONCLUSION
WHAT CELL PHONE
DETECTOR IS ?
This handy cell phone detector can sence the
presence of and activated cell phone from a
distance of one and half meters.
It can detect both incoming and outgoing calls,SMS
and video transmission.
The moment the bug detects RF transmission signal
from an activated cell phone LED starts blinking.
CIRCUIT COMPONENTS
●
IC CA3130
●
BC548 Transistor
●
LED
●
Resistors
– 100k
– 1k
– 2.2M(2)
●
Capacitors
– 47 Pico farads
– 100 Micro farads
– 0.224 Micro farads
CIRCUIT COMPONENTS
•
9V Battery
•
Battery clip
•
Connecting wires
•
Breadboard
WORKING PRINCIPLE
●
The Op-Amp part of the circuit acts as RF
signal detector while transistor part of the
circuit acts as the indicator.
●
The capacitors collection are used to
detect RF signals when a cell phone
makes a phone call or texts a message.
WORKING PRICIPLE
●
Ordinary LC circuits are used to detect low frequency radiation it
can detect Maximum MHz frequency.
●
From mobile phone we get frequency in terms of GHz.
●
The transmission frequency of a mobile phone ranges from 0.9 to
3GHz with wave length of 3.3 to 10cm.
●
So a circuit detecting Ghz signals is required.
●
Here 0.22 Micro farad disk capacitor is used to capture the RF
signal from the mobile phone.This along with the leads acts as a
small Ghz loop antena to collect the RF signals.
WORKING PRINCIPLE
●
One lead of the capacitor gets DC from the positive rail and the
other lead goes to the negative input of IC.
●
The capacitor gets energy for storage.This energy is applied to the
input of the IC.
●
IC CA3130 acts as a differential amplifier.It is used in a circuit as
current-to-voltage converter.
●
When the mobile phone radiates high frequency radiation,capacitor
oscillates and release energy in the inputs of IC.
●
This oscillation is indicated by the flasing of the LED.
WORKING PRINCIPLE
●
Capacitor carries energy So a slight change in
the field casued by the RF signals from phone
will disturb the field and forces the capacitor to
relase energy.
●
The LED blinks untill the signal ceases.
●
We can also use the buzzer for indication
purpose.
APPLICATIONS
●
This circuit can be used to detect the presence
of active cell phones at Examination halls and
Meetings.
●
It can be used to detect active cell phones in
hospitals,petrol pumps,court of law,library and
miltery bases.
●
It can also be used as RF detector.
LIMITATIONS
●
It is a low range detector,the order of
centimeters.
●
The persence of this device would jam the
signals of other devices due to fluctuations.
EXTENTIONS
●
Trying to increase the detecting range of a cell phone
detector to few more meters for observing wide range of
area.
●
This circuit is limited to the detection of a cell phone that is
in use,on call,communication via short message service
and internet access.
●
The detection of cell phones that are on stand by mode or
switch off or on airplane mode will not be detected So one
can work on this.
CONCLUSION
●
This pocket size mobile transmission detector can
sense the presence of an activated mobile cell
phone from a distance of one and half meters.
●
So it can be used to prevent use of mobile phone
prohibited areas.It is also usefull for detecting the
use of mobile phones for spying and unauthorized
video transmission.
THANK YOU
