To avoid the mobile phone using in sequre places.

1. MOBILE PHONE
DETECTOR AND JAMMER
By
Sarathkumar.T
Saravanakumar .P
Sivakumar.S
III-Year ECE

2. Abstract:-
 The basic principle behind this circuit is the idea of
using a Schottky diode to detect the cell phone
signal. Mobile phone signal is in the frequency
range of 0.9 to 3GHZ.
 Schottky diodes have a unique property of being
able to rectify low frequency signals, with low
noise rate. When an inductor is placed near the RF
signal source, it receives the signal through mutual
induction. This signal is rectified by the Schottky
diode.
 This low power signal can be amplified and used to
power any indicator like an LED in this case.

3. Introduction:-
 This project is a simple cell phone detector project. This
handy cell phone detector, pocket size mobile
transmission sniffer can sense the presence of an active
cell phone in a radius of 1m-1.5m.
 As the cell phone sends or receives a message or call, it
sends off a signal. This signal is detected by our circuit
and will cause the LED to blink and buzzer to sound. This
is the basic principle of the project.
 This simple circuit can detect any cellphone activities like
sending or receiving calls or SMS, or any type of data
transmission.

4. Circuit Diagram:-

5. Circuit components:-
• V1 = 12V
• L1 = 10uH
• R1 = 100Ohms
• C1 = 100nF
• R2 = 100K
• R3 = 3K
• Q1 = BC547
• R4 = 200 Ohms
• R5 = 100 Ohms
• IC1= LM339
• R6 = 10 Ohms
• LED = Blue LED

6. Working:-
 The transmission frequency of a mobile ranges from
0.9GHz to 3GHz.So a circuit capable of detecting
gigahertz signals is needed.
 So we use a disk capacitor C4(220nF), which will capture
the signals from the active cell phone transmission. The
disk capacitor along with its leads form a small gigahertz
loop to catch the signals.
 The IC CA3130 is an op-amp, that is used in this circuit as
a current to voltage converter. The capacitor C4 leads are
the input for the IC1.
 The IC1 provides the base voltage to the transistor Q1.

7. Applications:-
 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.

8. THANK YOU
Any quries?