The document describes the design and development of a mobile phone detector circuit. It begins with background information on the need for detecting mobile phones in restricted areas. It then discusses the history of mobile phone detection and technologies like GSM, 3G and 4G. The document provides an overview of the mobile phone detector project and explains the motivation was to prevent phone use in exams and confidential areas. It describes different detector designs and the basic components and workings of a detector circuit to identify activated phones from 1.5 meters away based on radio frequency signals.

1. 1
Project Report
ON
MOBILE PHONE DETECTOR
Submitted In Partial Fulfillment of the Requirements for the
Diploma of Electronics and Telecommunication
EngineeringBy
Mr. Pankaj Rai
Under the guidance of
Ms.Meenal Vatsaraj
DEPARTMENT OF ELECTRONICS AND TELECOMMUNICATION
ENGINEERING (DIPLOMA)
ARMIET
Alamuri Ratnamala Institute of Engineering and Technology
(Run by Koti Vidya Charitable Trust)
A.S. Rao Nagar, Sapgaon, Tal Shahapur, Dist Thane-421601

2. 2
Alamuri Ratnamala Institute of Engineering and Technology
(Run by Koti Vidya Charitable Trust)
A.S. Rao Nagar, Sapgaon, Tal Shahapur, Dist Thane-421601
Project Report Submitted By
Name: Mr. Pankaj Rai
Title of project: MOBILEPHONEDETECTOR
Guide Name: Ms. Meenal Vatsaraj
Ms. Meenal Vatsaraj Mr. NagababuChekuri Mr. NagababuChekuri
(Project Guide) (H.O.D.) (Principal)

3. 3
CERTIFICATE
This is to certify that Mr.Pankaj Rai has delivered a project
report for the Project Topic “MOBILE PHONE DETECTOR”
and submitted report in the “Alamuri Ratnamala Institute of
Engineering and Technology”, Sapgaon, Tal Shahapur, Dist,
Thane, in the partial fulfillment of the diploma of “Electronics
and telecommunication Engineering” from MSBTE for the year
2015-16
Guide H.O.D. Principal
Ms. Meenal Vatsaraj Nagababu Chekuri Nagababu Chekuri

4. 4
Acknowledgement
I would like to acknowledge and extend our heartfelt gratitude to all those people who have been
associated with this project and have helped us with it thus making it a worthwhile experience.
Firstly I extend our thanks to various people which include my project Guide Ms. Meenal
Vatsaraj my H.O.D. Nagababu Chekuri, who have shared their opinions and experiences through
which I received the required information for my report. I am also thankful to all the staff
members of EXTC Dept. for their highly cooperative and encouraging attitudes, which have
always boosted me.
I also take this opportunity with great pleasure to thank our Honorable Founder Trustee A.V.
Gupta, Honorable Alternate Chairman Dr. L.S. Bothra and Principal Prof. Nagababu Chekuri
whose timely support and encouragement has helped us succeeds in our venture.
Pankaj Rai

5. 5
INDEX
Sr. Topic Name Page No.
1 Abstract 9
2 List of acronyms 10
3 Introduction 11
1 Background 11
2 History 12
3 Cellular Phone Technology 13
4 Cellular Phone Communication Standard 14
5 Secure Facilities 15
6 Overview 16
7 Problem statement 17
8 Motivation 18
4 Mobile Phone Detector 19
5 Different Types of Design 20
6 Basic Information about Detector 21
7 Block Diagram 22
8 Block Diagram Explanation 23
9 Circuit Diagram 24
10 Circuit Explanation 25
11 Component Used 26

6. 6
12 Capacitor 27
13 Ceramic capacitor 28
14 Electrolytic capacitor 29
15 Resistor 30
16 Transistor 31
17 LED 32
18 Piezo Buzzer 33
19 Component Specification 34
20 IC Diagram IC555 35
21 Pin Description of IC555 36
22 IC Diagram of IC3130 37
23 Pin Description of IC3130 38
24 Advantages of Mobile Phone Detector 39
25 Application 40
26 Conclusion 41
27 Future scope 42
28 Reference 43

7. 7
Table Description
Sr. No. Table Name Page No.
1 Component Specifications 34
2 Pin Description of IC NE555 36
3 Pin Description of IC CA3130 38

8. 8
DiagramDescription
Sr. No. Diagram Name Page. No
1 Berkeley Varitronics Systems Wolfhound Cellphone Detector 20
2 Cellbusters Cell Phone Detector 20
3 Block Diagram 22
4 Circuit Diagram 24
5 IC NE555 35
6 Pin Diagram 35
7 IC CA3130 37
8 Pin Diagram 37

9. 9
Abstract
This work involves the design and development of a digital signal detector which is capable of
detecting incoming and outgoing signals from mobile phones. The presence of an activated
mobile phone can be detected by this handy, pocket-size mobile signal detector from a distance
of one and a half meters, which could be used in preventing the use of mobile phones in
examination halls, confidential rooms etc. It is also suitable for detecting the use of mobile phone
for spying and unauthorized video transmission. The circuit can detect the incoming and outing
calls, text messages, and video transmission even if the mobile is kept in the silent mode. The
moment the gadget detects Radio Frequency (RF) transmission signal from an activated mobile
phone, it starts sounding a beep alarm and the Light Emitting Diode (LED) blinks. The alarm
continues until the signal transmission ceases. The circuit is assembled on a general purpose
PCB as compact as possible and enclosed in a small box.

10. 10
List of Acronyms
GSM Global system for mobile
RF Radio Frequency
AM Amplitude Modulation
FM Frequency Modulation
LED Light Emitted Diode
BJT Bipolar Junction Transistor
UJT Unipolar Junction Transistor
FET Field Effect Transistor
JFET Junction Field Effect Transistor
MOSFET Metal Oxide Semiconductor Field Effect Transistor
CMOS Complementary Metal Oxide Semiconductor
TTL Transistor-Transistor Logic
OP-AMP Operational Amplifier
UHF Ultra High Frequency

11. 11
Introduction
1. Background
In recent years, there has been increasing focus on issues relating to the use of mobile
phones in restricted, prohibited, and unauthorized areas. The reason for this increased interest is
largely due to disturbance, as well as wrong and inappropriate usage of mobile phones by the
owners and users alike. Other areas like churches, mosques, offices, and prisons, just to mention
a few, are not left out. There is need for the detection of mobile phone signals in areas like these.
Efforts have been put in place in tackling this issue but they all have their own
shortcomings, one of which is the mobile phone jammer. A mobile phone jammer is an
instrument used to prevent cellular phones from receiving signals from base stations. When used,
the jammer effectively disables cellular phones. These devices can be used in practically any
location, but are found primarily in places where a phone call would be particularly disruptive
because silence is expected.
Mobile phones uses RF with a wavelength of 30cm at 872 to 2170 MHz that is, the signal
is high frequency with huge energy. When the mobile phone is active, it transmits the signal in
the form of sine wave which passes through the space. The encoded audio/video signal contains
electromagnetic radiation which is picked up by the receiver in the base station.

12. 12
2. History
Since cellular phone detection is a more recent problem, there are only a few articles that have
already researched this area. Two articles were published in 2007 and provide good analysis.
Thefirst article, "Detecting and Locating Cell Phones in Correctional Facilities," was written by
EVI Technology, LLC. The second article, "Cell Phone Detection Techniques," was written by a
Contractor hired by the U.S. Department of Energy (DOE).
This article details the growing problem with cellular phones in correctional facilities and lays
out the constraints used to develop their solution. According to the research, cellular phones in a
correctional facility are used to operate criminal enterprises, threaten witnesses, harass victims,
plan uprisings, and undermine security. Their problem is monitoring, controlling, and locating
cellular phones in a correctional facility. EVI's possible solutions include physical search, non-
linear junction detectors, signal jamming, shielding, network provider location based screening,
RF detection, and their custom proprietary solution. They rule out all solutions but their own
custom solution that uses a system of networked sensors that are controlled by a central
computer. EVI uses proprietary software that determines the cell phone's location and detects any
RF emissions. The location of detected cellular devices is displayed on a 14 facility map
This solution was developed for detecting cellular phones in a prison. It relies on the cellular
phone remaining stationary which, in prison facilities makes sense since movement is limited.
EVI's detection system finds cellular phones after they have already been in the facility for at
least 30 minutes or if someone is making a cell phone call. EVI doesn't provide any details on the
signal detection technique used since it is all proprietary. Also, there are no reviews or articles
stating that this system works as advertised

13. 13
3.Cellular Phone Technology
Cellular phonetechnology is rapidly changing. Features like Bluetooth, USB, high resolution
cameras, microphones, Internet, 802.11 wireless, and memory cards are added every year.Also,
the communication technology a cellular phone uses such as CDMA, GSM, 3G, and 4G are
rapidly changing.
Bluetooth is a secure wireless protocol that operates at 2.4 GHz. The protocol uses a master slave
structure and is very similar to having a wireless USB port on your cellular phone. Devices like a
printer, keyboard, mouse, audio device, and storage device can be connected wirelessly.This
feature is mainly used for hands-free devices but can also be used for file transfer of
pictures,music, and other data. Universal serial bus (USB) is a way for cellular phones to connect
to a computer for data transfer. This feature is very similar toBluetooth for a cellular phone with
the exception of using a cable. On today's cellular phones this feature is mainly used for charging
the battery or programming by the manufacturer. It can also be used to transfer pictures, music,
and other data. Cameras on cellular phones are a very popular feature that was added in the last
10 years. In recent years, high resolution camerashave become a standard feature. Most cellular
phones will come with at least a 2 mega pixel camera and the more expensive phones canbe as
much as 8 mega pixels. Microphones have been featured on cellular phones since they first came
out.In the last 10 years the microphones have become dual purpose;now there are programs on
the phone that record voice to file such as a simple voice recorder or as part of a video. Almost
every available cellular phone today has a connection to the Internet. This allows users to
transfer files and data wherever they are. Cellular phones can send emails, text messages, picture
text messages, videotext messages, and upload data to the Internet. Some cellular phones come
with 802.11 wireless built in and allows the phone to connect to any nearby wireless networks.
This provides an alternate connection method to the Internet and saves money if you're on a
limited data plan. Also, connecting with 802.11 is most likely going to provide better throughput
than using the cellular phone network.
Since cameras and music have become popular features on cellular phones, manufacturers have
started adding memory card slots. These memory cards provide expanded memory and allow
more pictures to be taken or music files to be stored. Most memory cards can plug directly into
the computer for easy data transfer. All these features make cellular phones today very versatile.
They can connect with almost any storage medium or computer. In the years to come, cellular
phones will continue to gain more and more features.

14. 14
4.CellularPhone Communication Standards
Currently the three main technologies used by cellular phone providers are 2G,3G, and 4G.
Each generation of technology uses a different transmission protocol. Thetransmission
protocols dictate how a cellular phone communicates with the tower. Someexamples are:
frequency division multiple access (FDMA), time division multiple access(TDMA), code division
multiple access (CDMA), global system for mobilecommunications (GSM) , CDMA2000,
wideband code division multiple access(WCDMA), and time-division synchronous code-division
multiple access (TD-SCDMA).All of these protocols typically operate in the 824- 894 MHz band
in the United States.Some protocols, such as GSM (depending on the provider)will use the 1800
- 2000 MHzband
To provide a good example of how a cellular phone transmission works, take a look at Diagram
1 which shows how FDMA works. Each phone call uses a different frequency within the 45
MHz bandwidth. FDMA is normally used for analog transmissions and is capable of digital
transmissions

15. 15
5. Secure Facilities
Many businesses such as psychiatric hospitals, correctional facilities, pharmsutical
companies, government facilities, and military bases rely on keeping information protected.
They build security fortresses that shield their money making information from getting to the
general public. These have many computers that house the valuable information and are not
connected to the Internet. Generally, access is restricted by guards with metal detectors and
electronic devices are not allowed in or out without proper approval. 6 In every secure facility
it is hard to ensure that employees and visitors aren't violating the policies. The only way to
ensure someone isn't carrying a cellular phone is to search everyone as they enter and exit.
This requires a great deal of manpower and most companies can't afford that level of
security.Additionally, it will make the employees feel like the company doesn't trust them.

16. 16
6. Overview
As increase in the technology in the world using electronics equipment are being used in a
wrong way like, in the examination hall and confidential room.to avoid this we are introducing a
project called CELL PHONE DETECTOR
This handy, pocket-size mobile transmission detector or sniffer can sense the presence
of an activated mobile phone from a distance of one and half-meter.so it can be used to prevent
use of mobile phone in examination hall, confidential rooms, etc.it is also use full for detecting
the use of mobile phone for spying and unauthorized video transmission. The circuit can detect
the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in
the silent mode. the movement dug detects RF transmission signal from an activated mobile
phone.it starts sounding a beep alarm and the LED blinks .the alarm continue until the signal
transmission ceases

17. 17
7. Problem Statement
Previously, there was no technology to detect the cell phones in the examination hall and in cell
phone restricted areas. There is manual checking and there is still a change of having the cell
phone with the person if he is not checked properly. So to avoid this problem, an automatic
detection of cell phone is introduced

18. 18
8. Motivation
Cell phones are used in good way and also in a bad way. when the class is going on,
students intend to use there cell phones and not listening to what is being taught. These days,
students are also carrying their cell phones to the examination halls to copy which would help
them to get good marks
To avoid this problem, the cell phone detector is introduced

19. 19
Mobile Phone Detector
We are most familiar with cell phone active detectors. The cell phone detectors are mostly hand
and pocket-size mobile transmission detectors. It can sense the presence of an activated mobile
phone from a distance of one and a half meters. So it can be used to prevent use of mobile
phones in examination halls, confidential rooms, etc.
It is also useful for detecting the use of mobile phone for spying and un-authorized video
transmission. Certain places where use of mobile phones are not allowed like exam hall, temple,
offices and theaters, in those places to detect and restrict the use of mobile phones this proposed
system is very helpful. This must detect the incoming and outgoing calls, SMS and video
transmission even if the mobile phone is kept in the silent mode. The illegal use of cell phones is
a growing and dangerous problem in correctional institutions worldwide. These devices are a
significant threat to prison security and circumvent the monitoring processes in prisons, while
helping inmates commit new crimes both inside and outside the facility.

20. 20
Different Types Of Design
1. Berkeley Varitronics Systems Wolfhound Cellphone Detector
Berkeley Varitronics Systems Wolfhound Cellphone Detector
2. Cellbusters Cell Phone Detector
Cellbusters Cell Phone Detector

21. 21
Basic Information about Detector
The transmission frequency of mobile phones ranges from 0.9 to 3 GHz with a wavelength of 3.3
to 10 cm. So a circuit detecting gigahertz signals is required for a mobile bug. The lead length of
the capacitor is fixed as 18 mm with a spacing of 8 mm between the leads to get the desired
frequency. The disk capacitor along with the leads acts as a small gigahertz loop antenna to
collect the RF signals from the mobile phone.
When mobile phone is active, it transmits the signal in the form of sine wave which passes
through the space. The encoded audio/video signal contains electromagnetic radiation which is
picked up by the receiver in the base station. The transmitter power of the modern 2G antenna in
the base station is 20-100 watts. The mobile phone transmits short signals at regular intervals to
register its availability to the nearest base station. Distance to cellular base station is the most
important environmental factor. Generally, the nearer a cellular phone is to a base station or
transmitting tower, the weaker will be the signal that needs to come from the phone. Range of
frequencies of different categories are, AM radio frequencies between 180 kHz and 1.6MHz,FM
radio uses 88 to 180 MHz, TV uses 470 to 854MHz.waves at higher frequencies but within the
RF region is called Micro waves. Mobile phone uses high frequency RF wave in the micro wave
region carrying huge amount of electromagnetic energy.

22. 22
BLOCK DIAGRAM
Block Diagram
Antenna Frequency
Comparator
Timer
Indicator

23. 23
Block Diagram of Cell Phone Detector:
The circuit uses a 0.22μF disk capacitor to capture the RF signals from the mobile phone. This
part should be like an aerial, so the capacitor is arranged as a mini loop aerial. In short with this
arrangement the capacitor works like an air core with ability to oscillate and discharge current.
The output of transistor is within 10 mV of either supply voltage terminal. The lead inductance
acts as a transmission line that intercepts the signals from the mobile phone. An ordinary RF
detector using tuned LC circuits is not suitable for detecting signals in the GHz frequency band
used in mobile phones that’s why circuit detecting gigahertz signals is required for a mobile bug.
Op-amp is used in the circuit is act as a comparator. It may come with MOSFET inputs and
bipolar output. The input contains MOSFET transistors to provide very high input impedance
very low input current. It has high speed of performance and suitable for low input current
application. Hence the result is in very low input current and very high speed of performance. It
is used in applications like ground referenced single supply amplifiers, fast sample hold
amplifiers, long duration timers etc.
IC-555 is a highly stable controller capable of producing accurate timing pulses. With the
monostable operation the time delay is controlled by one external resistor and one capacitor.
With an astable operation the frequency and duty cycle are accurately controlled by two external
resistors and one capacitor. These are used in applications like precision timing, pulse
generation, time delay generation etc.

24. 24
Circuit Diagram
Circuit Diagram

25. 25
CIRCUIT EXPLANATION
Here the circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the
mobile phone. The lead lengthof the capacitor is fixed as 18 mm with a spacing of 8 mm
between the leads to get the desired frequency. The disk capacitoralong with the leads acts as a
small gigahertz loop antenna to collect the RF signals from the mobile phone.
Op-amp IC CA3130 (IC1) is used in the circuit as a current-to-voltage converter with
capacitor C3 connected betweenits inverting and non-inverting inputs. It is a CMOS version
using gate-protected p-channel MOSFET transistors in the inputto provide very high input
impedance, very low input current and very high speed of performance.The output CMOS
transistor is capable of swinging the output voltage to within 10 mV of either supply voltage
terminal.
Capacitor C3 in conjunction with the lead inductance acts as a transmission line that
intercepts the signals from themobile phone. This capacitor creates a field, stores energy and
transfers the stored energy in the form of minute current tothe inputs of IC1.This will upset the
balanced input of IC1 and convert the current into the corresponding output voltage.
Capacitor C4 along with high-value resistor R1 keeps the non-inverting input stable for
easy swing of the output tohigh state. Resistor R2 provides the discharge path for capacitor C4.
Feedback resistor R3 makes the inverting input highwhen the output becomes high.
Capacitor C5 (47pF) is connected across ‘strobe’ (pin 8) and ‘null’ inputs (pin 1) of IC1 forphase
compensation and gain control to optimize the frequency response.
When the mobile phone signal is detected by C3, the output of IC1 becomes high and low
alternately according to thefrequency of the signal as indicated by LED1. This triggers
Monostable timer IC2 through capacitor C7. Capacitor C6maintains the base bias of transistor T1
for fast switching action. The low-value timing components R6 and C9 producevery short time
delay to avoid audio nuisance.
Assemble the circuit on PCB and enclose in a small box like junk mobile case. As
mentioned earlier, capacitor C3should have a lead length of 18 mm with lead spacing of 8
mm.carefully solder the capacitor in standing position with equalspacing of the leads. Use the
miniature 12V battery of a remote control and a small buzzer to make the gadgetpocket-size.

26. 26
COMPONENTS USED
 Operational Amplifier (CA3130)
 Timer (NE555)
 Capacitors
 Resistors
 Buzzer
 LED
 Transistors
 Antenna

27. 27
CAPACITOR
A capacitor or condenser is a passive electronic component consisting of a pair of
conductors separated by a dielectric. When a voltage potential difference exist between the
conductors, an electric field is present in the dielectric. This field stores energy and products a
mechanical force between the plate. The effect is greatest between wide, flat, parallel, narrowly
separated conductors
An ideal capacitor is characterized by a single constant valve, capacitance, which is
measured in farads. This is the ratio of the electric charge on each conductors to the potential
difference between them. In practice, the dielectric between the plates passes a small amount of
leakage current. The conductors and leads introduce an equipment series resistance and the
dielectric has an electric field strength limit resulting in a breakdown voltage

28. 28
CERAMIC CAPACITOR
A ceramic capacitor is a fixed value capacitor in which ceramic material acts as the dielectric. It
is constructed of two or more alternating layers of ceramic and a metal layer acting as the
electrodes. The composition of the ceramic material defines the electrical behavior and therefore
applications. Ceramic capacitors are divided into two application classes:
 Class 1 ceramic capacitors offer high stability and low losses for resonant circuit
applications.
 Class 2 ceramic capacitors offer high volumetric efficiency for buffer, by-pass, and
coupling applications.
Ceramic capacitors, especially the multilayer style (MLCC), are the most produced and used
capacitors in electronic equipment that incorporate approximately one trillion (1012) pieces per
year
Class 1 ceramic capacitors are accurate, temperature-compensating capacitors. They offer the
most stable voltage, temperature, and to some extent, frequency. They have the lowest losses and
therefore are especially suited for resonant circuit applications where stability is essential or
where a precisely defined temperature coefficient is required, for example in compensating
temperature effects for a circuit. The basic materials of class 1 ceramic capacitors are composed
of a mixture of finely ground granules of paraelectric materials such as Titanium dioxide (TiO
2), modified by additives of Zinc, Zirconium, Niobium, Magnesium, Tantalum, Cobalt and
Strontium, which are necessary to achieve the capacitor’s desired linear characteristics
Class 2 ceramic capacitors have a dielectric with a high permittivity and therefore a better
volumetric efficiency than class 1 capacitors, but lower accuracy and stability. The ceramic
dielectric is characterized by a nonlinear change of capacitance over the temperature range. The
capacitance value also depends on the applied voltage. They are suitable for bypass, coupling
and decoupling applications or for frequency discriminating circuits where low losses and high
stability of capacitance are less important.

29. 29
ELECTROLYTIC CAPACITOR
An electrolytic capacitor is a type of capacitor that uses an ionic conducting liquid as one of its
plates with a larger capacitance per unit volume then other types. They are valuable in relatively
high-current and low-frequency electric circuits. This is especially the case in power supply
filters. Where the store charge needed to moderate output voltage and current fluctuations in
rectifier output. They are also widely used as coupling capacitor in circuit where AC should be
conducted but DC should not
Electrolytic capacitors can have a very high capacitance. Allowing filters made with them to
have very low corner frequencies

30. 30
RESISTOR
A resistor is a passivetwo-terminalelectrical component that implements electrical resistance as
a circuit element. Resistors act to reduce current flow, and, at the same time, act to lower voltage
levels within circuits. In electronic circuits, resistors are used to limit current flow, to adjust
signal levels, bias active elements, and terminate transmission lines among other uses. High-
power resistors, that can dissipate many watts of electrical power as heat, may be used as part of
motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have
resistances that only change slightly with temperature, time or operating voltage. Variable
resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or
as sensing devices for heat, light, humidity, force, or chemical activity.
Resistors are common elements of electrical networks and electronic circuits and are ubiquitous
in electronic equipment. Practical resistors as discrete components can be composed of various
compounds and forms. Resistors are also implemented within integrated circuits.
Ohm's law
The behavior of an ideal resistor is dictated by the relationship specified by Ohm's law:
Ohm's law states that the voltage (V) across a resistor is proportional to the current (I), where the
constant of proportionality is the resistance (R). For example, if a 300 ohm resistor is attached
across the terminals of a 12 volt battery, then a current of 12 / 300 = 0.04 amperes flows through
that resistor.

31. 31
TRANSISTOR
A transistor is a semiconductor device commonly used to amplify or switch electronic signal. .A
transistor is made of a solid piece of a semiconductor material. with at least there terminals for
connection to an external circuit. A voltage or current applied to one pair of the transistors
terminals changes the current flowing through another pair of terminals. Because the controlled
(output) power can much more than the controlling (input) power, the transistor provides
amplification of a signal. Some transistors are packaged individually but most are found in
integrated circuit
The transistor is fundamental building block of modern electronic devices, and its
presence is ubiquitous in modern electronic system
Advantages
The key advantagesthat have allowed transistors to replace their vaccum tube predecessors in
most applications are
 Highly automated manufacturing process, resulting in low per-unit cost.
 No warm-up period for cathode heater required after power application.
 Small size and minimal weight, allowing the development of miniaturized electronic
devices.
 Lower possible operating voltage, making transistors suitable for small, battery-
powered applications

32. 32
Light-emitting Diode (LED)
A light-emitting diode (LED) is an electronics light source. LEDs are used as
indicator lamps in many kinds of electronics for lighting. LEDs work by the effect of
elctroluminescence, discovered by accident in 1907. LED was introduced as a practical
electronic component in 1962. All early devices emitted low-intensity red light, but modern
LEDs are available across the visible, ultraviolet and infrared wavelength, with very high
brightness.
LEDs present many advantages over traditional light source including low energy
consumption, longer lifetime, improved robustness, smaller size and switching. However. They
are relatively expensive and require more precise current and heat management than traditional
light source
Applications of LEDs are diverse. they are used as low-energy indicators but also for
replacement for traditional light source in general lighting,automotive lighting and traffic signal.
The compact size of LEDs has allowed new text and video display and sensors to be developed,
while their high switching rates are useful in communication technology.

33. 33
PIEZO BUZZER
Piezoelectricity is the ability of some materials (notably crystals and certain
ceramics, including bone) to generate an electric field or electric potential in response to applied
mechanical stress.the effect is closly related to a change of polarization density within the
materials valum. If material is not short-circuited,the applied stress induces a voltage across the
material. The world is derived from the Greek piezo or piezein, which means to squeeze or press
A buzzer or beeper is a signaling device. usually electronic, typically used in
automobiles, household appliances such as microwave ovens, or game shows.
It most commonly consists of a number of switches or sensors connected to a control
unit that determines if and which buttons was pushed or a preset time has lapsed, and usually
illuminates a light on the appropriate button or control panel, and sounds a warning in the form
of a continues or intermittent buzzing or beeping sound

34. 34
Component Specifications
Component Name Component Value
Resistor
R1 = 2.2 Ω
R2 = 100K Ω
R3 = 2.2 Ω
R4 = 1K Ω
R5 = 12K Ω
R6 = 15K Ω
Capacitor
C1 = 22pF
C2 = 22pF
C3 = 0.22 µF
C4 = 100µF
C5 = 47pF
C6 = 0.1µF
C7 = 0.1µF
C8 = 0.01µF
C9 = 4.7µF
Power Supply 12V
Component Specifications

35. 35
Component Diagram
IC NE555
NE555
______________________________________________________________
Pin Diagram
Pin Diagram

36. 36
Pin Description of IC NE555
Pin Number Pin Name Description
1 -Offset +OFFSET NULL
2 -Input INVERTING INPUT
3 +Input NON-INVERTING INPUT
4 V- NEGETIVE POWER SUPPLY
5 +Offset -OFFSET NULL
6 O/p OUTPUT
7 V+ POSITIVE POWER SUPPLY
8 NC DUMMY PIN
Pin Description of IC NE555
__________________________________________________________________

37. 37
IC CA3130
IC CA3130
Pin Diagram
Pin Diagram

38. 38
Pin Description of IC CA3130
Pin Description of IC CA3130
Pin Number Pin Name Description
1 GND Ground
2 TRIG Start Timing Input
3 OUT High Current Timer Output
and Discharge timing
capacitor
4 RESET Reset Pin
5 CONT Control Pin
6 THRES Threshold Pin
7 DISCH Discharge Pin
8 VCC Input Supply Voltage

39. 39
Advantages of Cell Phone Detector:
 Smaller in size
 Detection of hidden cell phones
 Low Cost
 More Reliable
 Simple Circuit
 Less Component Used
 Can be Install Anywhere

40. 40
APPLICATIONS
 It can be used to avoid the usage of mobile phones in examination hall, seminar hall,
quizzes etc.
 It can be used to avoid video transmission in secret or private meeting.
 It can be used for military and civil defense purpose to detect mobile phone body
increasing is radius of range.
 It can be used in hospitals and airplanes where, mobile signals interfere with the
electronic equipment which may have fatal consequences.
 Petrol pumps
 Gas station
 Historical places
 Religious places
 Court of laws
 Examination halls
 Spying and unauthorized video transmission
 Military bases
 Hospitals
 Theatres
 Conferences
 Embassy

41. 41
FUTURE SCOPE
Trying to increase the detecting range of cell phone detector to few more meter for
observing wide range of area

42. 42
CONCLUSION
 It is the technology which will make every student mad
 No one can break the rule

43. 43
References
By Books
Linear Integrated circuits :RamakantGaikwad
Electronic Devices and Circuits :Salivahan
Electronic Devices and Circuits :Millman and Halkias
Electronic Devices and Circuits :Boylestad
By Websites
http://www.circuitbasics.com/build-a-great-sounding-audio-amplifier-with-bass-boost-from-the-
lm386/
http://www.learningaboutelectronics.com/Articles/How-to-connect-a-LM386-audio-amplifier-
chip
http://www.electroschematics.com/552/lm386-audio-amplifier/
http://www.ti.com/lit/ds/symlink/lm386.pdf
http://www.electronicsforu.com/electronicsforu/circuitarchives/view_article.asp?sno=74&article
_type=1&id=466&tt=unhot
http://8085projects.info/principles-and-application-of-the-op-amp-lm324.html
http://www.engineersgarage.com/electronic-components/lm324n-datasheet