This is a project presentation for our electronics lab .The name of our project is cell phone detector.

2. Group No. 05
Members-
• 1.Nurjahan Begum (ID-011 123 046)
• 2.Farzana Gisan (ID-011 131 167)
• 3.Zahidul Islam Razu (ID-011 132 047)
• 4.Shubhra Sarker (ID-011 132 056)
• 5.Rownok Alahi Islam (ID-011 132 075)
• 6.Pankaj Debnath (ID-011 132 076)
Submitted to : Abu Shafin Mohammad Mahdee Jameel
Senior Lecturer, Dept. of CSE

3. Cell phone detector
Cell phone detector is a handy, pocket sized mobile detector
which is one of the most common electronic equipment used
in modern era.
A cell phone transmits signal s between 0.9 to 3 Ghz.
A cell phone detector detects the activity of a cell phone by
detecting the incoming and outgoing calls and messages.

4. Equipments
 Breadboard
 Battery 9V
 IC CA3130
 Transistor BC548

5.  Capacitor 47pF, 0.22uF, 100uF
 Resistor 1k, 100k, 2.2M
 LED
 Battery Clip

6. CIRCUIT DIAGRAM

7.  Insert BC548 transistor, LED & IC CA3130 on the breadboard.
 Connect Base of transistor with 2.2M ohm resistor & connect other end of
resistor with pin 2 of IC.
 Connect 1k resistor with emitter of transistor & other end of resistor with positive
end of voltage source.
 Connect positive end of LED with collector of transistor & negative end of LED
with negative end of voltage source.
Implementation

8.  Connect 100k resistor with pin3 of IC & with negative end of voltage source.
 Connect 0.22uF capacitor with pin2 & pin3 of IC. Then connect 47pF capacitor
with pin1 & pin8 of IC.
 Connect positive end of 100uF capacitor with 2.2M resistor & connect that end with
pin3 of IC. Then connect negative end of capacitor with negative end of voltage
source & connect other end of resistor with positive end of voltage source.
 Connect pin6 of IC to base of transistor.
 Connect pin7 & pin4 with positive & negative end of voltage source respectively.

9.  Mobile phone uses RF with wavelength of 30cm at 0.9 to 3
GHz. That is the signal with high frequency and
wavelength.
 To detect mobile signal, the sensor part should be like an
aerial, so the capacitor 0.22uF is arranged like a mini-
loop(like a TV antenna).
 In short with this arrangement, the capacitor works like an
air core coil with ability to oscillate and discharge current.
How the circuit works!

10.  When the mobile phone radiates high energy pulsations,
capacitor oscillates and releases energy in the inputs of IC.
 This oscillation is indicated by flashing of the LED.
 In short, capacitor carries energy and is in an electromagnetic
field.
 So, a slight change in field caused by the RF from phone will
disturb the field and forces the capacitor to release energy
which helps in blipping of the LED.

11. Timeline
 1st week : Bought the equipments needed & checked if those are okay.
 2nd week : Started assembly of the circuit.
 3rd week : Completed the circuit implementation & made sure it
worked.
 4th week : Tried to find out if there were any errors and modified the
project.

12. Screenshot of the Project

13.  There were some problems in finding the IC CA3130.
 The capacitor 0.22uF we brought at first wasn’t working.
 Our LED was burning out too often.
Problems We Faced

14. 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.

15.  We will try to improve our detection range.
 Our circuit only works when a call is going on or a
message is being sent or received, so we want to
implement a circuit which can detect whenever an active
mobile phone is found within our range.
Future Works

16. Thank you!