INDEX

1.ABSTRACT

2.INTRODUCTION

3.MOBILE SIGNAL JAMMER

4.BLOCK DIAGRAM

4.1 POWER SUPPLY

4.1.1 ADAPTER

4.2 TIMER

4.3 TUNING CIRCUIT

4.4 RF AMPLIFIER

4.5 RF ANTENNA

5.HARD WARE COMPONENTS

5.1 RESISTORS

5.2 CAPACITORS

5.3 INDUCTORS

5.4 DIODE

5.5 LIGHT EMITTING DIODE

5.6 TRANSISTOR

5.7 TRANSFORMER

5.8 RECTIFIER

5.9 VOLTAGE REGULATOR

5.10 FILTER

5.11 PRINTED CIRCUIT BOARD

5.12 WIRES

5.13 HEAT SINK

5.14 SWITCH

6.CIRCUIT DIAGRAM

7. WORKING

8.INSTALLATION

9.SPECIFICATONS

10.APPLICATIONS

11.ADVANTAGES

12.FUTURE SCOPE

13.CONCLUSION

14.BIBILOGRAPHY

ABSTRACT

Mobile jammer is used to prevent mobile phones from receiving (or)

transmitting signals with the base stations mobile jammer effectively disable

mobile phones with in the defined regulated zones without causing any

interference to other communication means mobile jammers can be used in

practically any location but are used in places where a phone call would be

particularly disruptive like temples, hospitals, schools, colleges etc.

As with other radio jamming, mobile jammers block mobile phones

use by sending out radio waves along the same frequencies, that mobile

phones use. This causes enough interference with the communication b/w

the mobile phones and communicating towers to render the phones

unusable. Upon activating mobile jammers, all mobiles will indicate ‘NO

NETWORK’. Incoming calls are blocked as it the mobile phones were off,

all mobile phones will automatically, reestablish communications and

provides full services.

The last few years have witnessed a dramatic boom in the wireless communications industry hence, increasing the no of users in mobile communication devices. This magnified the need for a more efficient reliable signal scrambler. This project deals with the mobile jamming technology. The concept of jamming technology is studied in step-by-step approach. The mobile jammer works in the frequently range as shown below,

GSM - 900 MHZ

CDMA - 800 MHz

DCS - 1800 – 1900 MHz

3G1 - 2000 MHz ((or) 2GHZ)

3g2 - 2100 MHz

INTRODUCTION

Disrupting a cell phone is same as jamming any other type of radio

communication. A cell phone works by communicating with its service

network through a cell tower/Base station. Cell towers divide a city into

small areas can cells. As a cell phone user drives down the street, the signal

is handed from tower to tower.

A jamming device transmits on the same radio frequencies, as the cell

phone, disrupting the communication b/w the phone and base station in the

tower. It a called as an denial of service attack the jammer devices service of

radio spectrum, to the cell phone users with in the range of jamming device .

How does mobile phone work?

In order to remain portable mobile phones used to have relatively

compact antennas and use a small amount of power. The means that mobile

phones can send a signal over only a very short range, just like a walkie-

talkie. The cellular network however, enables you to spread the latest gossip

regardless of how far away your friends are, this is done by dividing upland

into a patch work of cells hexagonal areas of land each equipped with their

own phone most (also called as base station).

How towers work?

When you lock at a cell tower, often there are multiple triangular

platform going up the pole. These usually belong to separate carriers.

The platforms are triangular, so the 360 coverage can be subdivided⁰

again into 40 slices for pin pointed coverage’s. These station pi9cks up the⁰

weak signal from you phones and relay it awards it to another phone mast

(station) nearer to you friend and I you’re on the more while you talk you

phones switches station as you to without interrupting your call.

How cell phone call works?

Cell phones are radio devices, they communicate by transmitting and

receiving voice over an area

first, a cell phone radios the nearest cell towers(or site) when you

make a call or turns your phone On-your phone sends a message via radio

that pick up by the tower station.

Next, a wire or fiber optic line carriers the call down the wireless

access point, connected to multiple switch.

The call gets routed to a back have usually down to an underground.

Wired T₁(or) T₃ line, but sometimes back up the mast to a power full LOS

wireless microwave antenna .

The incoming call (or) data comes back from back have and up

through the switch to antenna where it then hits your phone, if you are

removing then there is a hand off- a new but more or less identical cell site

transmits the data to your phone, once your phone checks in.

What frequency ranges are used for mobile communication?

Modern mobile communications use EM fields to exchange the

information b/’w mobile phones & BS, i.e., to transmit speech and data

mobile communications use certain frequency ranges to transmit this type of

information.

Frequency range mostly consists of 2 frequency bands on half of

frequency band called the up line is used to transmit data from mobile phone

to the base stations. The other half of frequency band is used to transmit data

from base station to mobile phone called as downlink.

There are 3 different frequency bands on which mobile phones are

usually oprates and these are

1. Dual band

2. Tri band

3. Quad band

Dual band operates on 2 frequency bands, they are

1. 900 MHz 2. 1800 MHz spectrum

Tri band operates on 3 frequency bands, they are

1. 900MHz 2. 1800 MHz 3. 1900 MHz

Quad band operates on 4 frequency bands, they are

1.850 MHz 2. 900 MHz 3. 1800 MHz 4. 1900 MHz.

MOBILE SIGNAL JAMMER DESCRIPTION

Basics of cell phone jamming

Cell phones work by communicating with a service network through

the utilization of cellular towers (or) base stations. Individual towers

partition cities into small sections called as cells. As a cell phone user

transverse the cells in an area, the signal is passed from tower to tower.

Jamming devices take advantage of this fact by transmitting on the

spectrum of RF used by cellular devices. Through its concurrent

transmission. The jamming devices are wave to disrupt the 2-way

communication b/w the phone and base station. This form of a denial – of

service attack inhabits all cellular communication within the range of device.

Through the transmission of a high power signal on the same

frequency of a cell phone, the jamming device creates a competing signal

that covides with and in effect can cells out the cellular signal cellular

phones, which are designed to increase the power in the case of low levels

of interference, react to this interference. Consequently, jamming devices

must be aware of any increases in power by the cellular device and match

that power level, accordingly.

As cellular telephones are full – duplex devices utilizing the 2

separate frequencies (one of talking, one for listening, where all parties to

call can talk at the sometime as opposed to half – duplex walkie-talkies and

CBs) , any removal of one of these frequencies tricks the phone into thinking

there is no cellular service consequently, the jammer need only block on of

frequencies.

The less complex jammers can only block a specific frequencies

group while the more complex jammers can block several different networks

thus preventing dual (or) tri mode phones from switching to a different

network, with an open signal. Jammers are able to broadcast on any

frequency and can interrupt AMPS, CDMA, TDMA, GSM, DCS, PCS,

IDEN and Nextel systems. The efficient range of a jammer is dependent

upon the strength of its power source and the immediate physical

environment (hills/walls which may block the jamming signal). Lower

powered jammers have a call block range of about 30m while higher power

units can create a cellular signal free zone about the size of a foot hall field.

In addition, certain units applied by law enforcement have been known to

shut down cellular service approximately 1 mile from the jamming device.

BLOCK DIAGRAM

POWER SUPPLY

Power supply

The electronic circuits like amplifiers, oscillators require a source of

DC power. Electronic gadgets like radio, tape recorder, TV etc are

combination of several amplifiers and oscillators. The digital CKIS like

computers, digital meters etc. are also requires a source of DC power to

drive than. The sources of DC Power are batteries and DC generators.

Batteries are used for power supply in portable equipment. But batteries are

rarely used for this purpose as they are costly and require frequency

replacement. The rechargeable batteries of course also require DC source to

charge it. The AC signal is readily available from generating stations and are

also very ceap. DC power for electronic circuits is most conveniently

obtained from AC lines by using rectifier filter regulator called a power

supply.

Regulated DC power supply:

A DC power supply, which converts AC into DC and maintains the

output voltage constant irrespective of AC mains fluctuations (or) load

variations is known as regulated DC power supply.

A power supply consists of rectifier, filter and regulator. The

conversion of AC voltage into steady voltage is carried out by means of

rectifier. In order to remove the alternating component of rectified output

(Ripple), we need a filter. To obtain constant output voltage irrespective of

load variations (or) a supply variation, we need a regulator.

ADOPTER

ADOPTER

It converts high power AC to low power DC. The circuit diagram of

adopter is as shown below.

Step down transformer is used to reduce the voltage of secondary

winding from primary winding. There bridge rectifier is used in order to

convert AC I/P voltage to pulsated DC, which also contains some ripples.

These ripples are then given to capacitor, which is used to reduce the ripple

contents. Then the o/p is given to the IC 7805, voltage regulator, which

regulates the o/p voltage to 5v and then it is given to the mobile signal

jammer as a power supply.

The Adopter mainly uses a transformer of turns ratio 60: 1, a bridge

rectifier and regulator. This introduces a bulky, costly transformer into the

design but, it is more efficient.

PROS:

1. Easiest to implement

2. Designed for medium current loads

3. Full isolation

4. Relatively inexpensive

CONS

1. Fairly inefficient

2. Bulky

TIMER

TIMER

For generating accurate time delay, a 555 timer circuit is used. In

most of the industries, operations are scheduled according to specific time

requirements. To achieve such timing requirements the timer 555 is

popularly used to build the timing circuits. The basic operation of timer IC

555 can be explained by its use as monostable circuits.

It is basically monolithic timer circuit which can be used in many

applications such as monostable and astable multivibrators, linear ramp

generator missing the pulse detector, pulse width modulator etc.,

Functions of pins:

Pin 1: Ground

All voltages are measured with respect to this terminal

Pin 2: Trigger

The IC 555 uses 2 comparators. The voltage divider consists of 3

equal resistances. Due to voltage divider the voltage of non – terminal of

comparator 2 is fixed to VCC /3. The inverting input of comparator 2 which

is compared with VCC/3 is nothing but trigger I/p brought out as pin 2 when

the trigger I/p is slightly less than VCC/3, the comparator 2 output goes

high. The O/p is given to reset input of RS flip flop. So much output of

comparator 2 resets the Flip – Flop.

Pin 3: Output

The complementary signal output Q of F/F goes to pin 3 which is

the output. The load can be connected in 2 ways. One between Pin 3 and

ground; while the other b/w pin 3 and pin 8.

Pin 4:Reset

This is an interrupt to the timing device, when pin 4 grounded it

stops the working of device and makes it off. Thus pin 4 provides on / off

feature to IC 555. This reset input over rides all other functions within the

timer when it is momentarily grounded.

Pin 5: control voltage input

In most of applications, external control voltage input isn’t used.

This pin is nothing but the inverting input terminal of comparator-1. The

voltage divider holds the voltage input 2/3 VCC. This ret level comparator,

with which threshold is compared. It reference level required is other

required is other than 2/3 VCC for comparator1, the external input is to be

given to pin 5.

Pin 6:Threshold

This non inverting input terminal of con-1, the external voltage is

applied to this pin 6. When this voltage is more than 2/3 VCC, the comp -1

output sets the F/F. This makes Q of F/F high and Q low. Thus O/p of IC

555 at pin3 goes low.

Pin 7: Discharge

This pin is connected to the collector of discharge transistor Qd.

When the O/p is high than Q is low and transistor Qd is off. It acts as an

open circuit to be external capacitor C to be connected across it, so capacitor

C can charge when O/p is low, Q is high, which drives the base of Qd high,

driving transistor is Qd in saturation. It acts as short circuit, shorting the

external capacitor C to be connected across it.

Pin 8:supply

The IC 555 timer can work with any supply voltage b/w 4.0 v to

16v.

TUNING CIRCUIT

TUNING CIRCUIT

A tuning circuit having a coil and a capacitor comprises a resistance –

adjustment circuit connected in parallel with a coil and the capacitor. The

resistance adjustment circuit changes a resistance of turning circuit when

resonant. The LC circuit also called as resonant circuit, tank circuit (or)

tuned circuit, it is an electric circuit consisting of an inductor, represented by

a letter ‘L’ and capacitor represented by ‘C” connected together. The CKT

acts as an electrical resonator.

LC circuits are used for either generating signals at a particular

frequency (or) picking out a signal at particular frequency from a more

complex signal. An LC circuit is an idealized model since it assumes there is

no dissipation of energy due to resistance. Any practical implementation of

an LC circuit will always include loss resulting from small but non – zero

resistance within the components and connecting wires. The purpose of an

LC circuit is usually to oscillate with minimal damping.

RF POWER AMPLIFIER

RF power amplifier:

RF power amplifier are used in wide variety of applications

including wireless communication, TV transmission, RADAR and RF

heating. The basic techniques for RF power amplication can use classes as

A,B,C,D,E & F, frequencies ranging from VLF through Microwave

frequencies. The RF output power can range from few mw to MW,

depending upon application. The introduction of solid state RF power

devices brought the use of wire voltage, higher currents and low load

resistances.

The most important parameters that defines an RF power amplifier

are;

1. Output power

2. Gain

3. Linearity

4. Stability

5. DC supply voltage

6. Efficiency

7. Ruggedness

The power class of amplification determines the type of bias applied

to RF power transistor. The power amplifier’s efficiency is a measure of its

ability to convert DC power of the supply into signal power delivered to the

load. In this, MRF 94751 is used as an RK power amplifier.

RF ANTENNA

RF ANTENNA

RF SPECIFICATIONS

General:

Frequency range: 800MHz-2100MHz

Polarization: vertical

Pattern : omni directional

Performance gain : +3dB 30KHz-32 MHz,rising to

+/- 12 dB at 500MHz

Noise figure : 3.5dB at 500MHz

Power:

Power required : 12 volts DC, 85 mA max (PS not included)

Control units:

Voltage to antenna : 12v Dc , 85 mA max

Noise rejection : 770 dB with respect to output voltage.

Physical:

Antenna size: 16 inches(40 cm)

HARDWARE

COMPONENTS

RESISTOR:

The flow of charge (or) current through any material encounters an

opposing force. This opposing force is called as ‘Resistance of the material”

Resistors are used as a part of electrical networks and electronic circuits.

They are extremely common place in most electronic equipment. Practical

resistors can be made of various components and films, as well as resistance

wire [wire made of a high –resistivity alloy, such as nickel chrome].

Primary characteristics of resistors are their resistance and the power

they can dissipate. Other characteristics include temperature co-efficient,

noise and inductance, less well – known is critical resistance the value

between which power dissipation limits the maximum permitted current

flow, and above which the limit is applied voltage. Critical resistance

depends upon the materials constituting the resistor as well as its physical

dimensions, its determined by design.

Resistors can be integrated into hybrid and printed circuits, as well

integrated circuits. Since position of leads (or terminals) are relevant to

equipment designers; resistors must be physically large enough not to

overhear when dissipating their

A resistor is a two – terminal passive electronic component which

implements electrical resistance as a circuit eliment – when a voltage ‘V’ is

applied across the terminals of a resistor, a current ‘I’ will how through the

resistor in direct proportion to that voltage. The reciprocal of the constant of

proportionality is known as the resistance R1,since with a given voltage V1

a larger value of R further “ resists” the flow of current I as given by Ohms

law.

I= V/R.

SI units of resistor is ohms (λ) – It is named after georg simon ohm.

An ohn is equivalent to a volt per ampere. Since resistors are specified and

manufactured over a very large range of values, the derived units of milli

ohms and 1 mega ohm are also in common usage. The reciprocal of

resistance R is called conductance, G = 1/R and is measured in siemen (SI

unit). Some times referred to as a ohm. Thus a siemen is the reciprocal of an

ohm; S= Λ-1

Some resistors are large enough in size to their resistance (ohms)

printed on the body. However there are some resistors that re too small in

size to have numbers printed on them therefore the system of cader coding is

used to indicate their values for their fixed moulded composition resistor 4

colour bands are printed one are one end of the other casing.

The colour bands are always read from left to right from the end that

as the bands close to it as shown in figure. The numerical value associated

with end colour is also shown. The 1st & 2nd bands represent the 1st & 2nd

significant digits the 3rd number is the multiplier and 4th number is tolerance

with 1,2,5,10 are brown, red, gold, silver colours respthy.

CAPACITORS

CAPACITORS

A capacitor is an energy strong passive compoenent which is found

nearly is every electronic circuit. A capacitor is basically a meant to store

electronic and electrical energy and release then whatever desired.

Capacitance is a measure of a capacitor ability to store electric

change.

UNITS: the units of capacitance is FARADS(F). However, parad is a large

unit. Practically, capacitors were specified in

(i) Micro farod (μ f)

(ii) PICO farad (pf)

A capacitor/condenser is a passive element, consisting of a pair of

conductors separated by a dielectric when voltage potential difference exists

b/w a conductors, an electric field is present in the dielectric. This field

stores energy and produces a mechanical force between the plates the effect

is greatest between wide, flat, parallel, narrowly separated conductors.

A capacitor formerly known as condenser is a device for strong

electric change. The forms of practical capacitor vary widely, but all contain

at least 2 conductors separated by a non-conductor capacitors are used as

parts of electrical systems for example, consisting of metal foils separated by

a layer of insulating film.

The capacitor is a reasonably general model for electric fields with

in the electric circuit. An ideal capacitor wholly characterized by a constant

capacitance ‘C’ defined as the ratio of charge ±Q, on each conductor to the

voltage ‘V’ b/w then.

C= Q/V

Sometimes, charge builtup affects the capacitor mechanically,

causing its capacitance to vary. In this case, capacitance is defined in terms

of incremental changes.

C= dQ/ dV

INDUCTOR

INDUCTOR

Inductor (or) coil (or) choke is an electromagnetic device consisting of a

conducting wire wound in cylindrical/ spiral form to obtain concentrated

magnetic flux. The base on which the coil is wound is known as core. The

core may be a magnetic material such as iron, ferrite (or) air.

DIODE

DIODE

PN junction conducts current easily when forward biased and practically

current flows, when it is reverse biased. This unidirectional conduction

characteristics of PN junction is similar to that of vaccum diode. Therefore

like a vaccum diode, a semiconductor can also accomplish. The job of

reflection change alternating to direct current. However semiconductor diode

have become more popular as they are smaller in size, cheaper and robust,

usually separated with greater efficiency.

A PN junction diode is also called as semiconductor (or) crystal

diode the outstanding property of a crystal diode, to conduct current in one

direction only. It can be used as rectifier. A crystal diode is usually

represented by schematic symbol. The arrow in the symbol indicates the

direction of easier conventional current flow.

The VI characteristics is drawn by taking voltage on x-axis and

current on Y-axis. The charactorists for toward and reverse bias of diode.

In towards bias the width of depletion layer decreases with increase

in applied voltage, the forward current remains Zero until the applied

voltage equals to potential barrier.

In reverse bias condition the potential barrier of PN junction diode

will increase. Therefore the junction resistance is very high and practically

no current flows through the circuit.

Applications of Diode

1. Rectifier

2. Switch

LED

LED

A light emitting diode (LED) is a semiconductor light source. LED’s are

used as indicator lamps in many devices and are increasing the used for

heightening. When a night emitting diode is forward biased (switched on),

electrons are able to recombine with holes with in the device, releasing

energy in the form of photons.

This effect is called as electro

luminescence and the cololurs of the light corresponding to the energy of the

photon is determined by the energy gap of the semiconductor. An Led will

offer an small area and integrated optical components may be used to shape

its prediction pattern. LED’s present many advantages over incandescent

light sources including lower energy consumption, longer life time,

improved robustness, smaller size faster switching and geater durability and

reliability.

LED’s are used in applications as diverse as replacements for

aviation lightning, automotive lightning as well as in traffic signals. The

compact size, the possibility of narrow band width, switching speed and

extreme reliability of LED’s has allowed new text and video display’s

sensors to be developed, while their high switching rates are also useful in

advanced communications technology.

Working

Charge carriers electons and flow into the junction from electrodes with

different voltages when an electron meets a hole, it fall into a lower energy

level and release energy in the from of a photon. The wave lehgth of light

emitted and there its colour, depends on the band gap energy of the national

forming the PN junction. The materials used for the Led have a direct band

gap with energies corresponding to near inferred, visible (or) near UV light.

TRANSISTOR

Transistor

A BC 547 transistor is a negative –positive negative (NPN) transistor that is

used for many purposes. Together with other electronic components such as

resistors, and capacitors. It can be used as the active component for switches

and amplifiers. Like all other NPN transistors, this type has an either

terminal, a base are control terminal and a collector terminal. In a typical

configuration, the current flowing from the base to the emitter controls the

collector current. A short vertical line, which is the base, can indicate the

transistor schematic for the NPN transistor and the emitter which is a

diagonal line connecting to the base, is an arrowhead pointing away from the

base.

The various types of transistors and BC 547 is a bipolar junction

transistor (BJT). The BC 547 transistors comes in one package. When

several are placed in a single package. It is usually referred to as a transistor

array. Arrays are commonly used in digital switching eight transistors may

be placed in one package to make layout much easier.

Transistors circuit design requires a thorough understanding of I-V

ratings of various components. Important such as in case of battery operated

devices.

Whenever base is high, the current starts flowing through base and

emitter and offer that only current will pass from collector to emitter. So,

that the Led which is connected to collector will glow to indicate the

transistor is ON.

TRANSFORMER

Transformer

Usually DC voltages are required to operate various electronic equipment

and these voltages are 5V , 9V (or) RV. But these voltages cannot be

obtained directly. Thus the AC input available at main supply ie., 230 v is to

be brought down transformer is employed to decrease the voltage to a

required level.

RECTIFIER

Rectifier

The output from the transformer is fed to the rectifier. It converts AC into

pulsating DC. The rectifier may be half wave (or)a full wave rectifier. In this

project, a bridge rectifier is used because of its merits like good stability and

full wave rectification.

The bridge rectifier is a circuit, which converts an AC voltage to DC

voltage using both Y2 cycles of I/p voltage. Bridge rectifier circuit is shown

in figure. The circuit has 4 diodes connecting to froms a bridge. The AC

voltage is applied to diagonally opposite ends of bridge. The load resistance

is connected b/w the other two ends of bridge.

For the ½ cycle, of input AC voltage , diodes D1 and D3 conduct,

where as diodes D2 and D4 remain in OFF state. The conducting diodes will

be in series with the load resistance ‘R1’ and hence the load current flows

through ‘R1’.

For – Ve Y2 cycle of input AC voltage, diodes D2 and D4 conduct

whereas D1 and D3 remains OFF. The conducting diodes D4 and D2 will be

in series the load resistance R1 and hence the current flows through ‘R1’ in

the same direction as in the previous ½ cycle. Thus a bi- directional wave is

converted in to a unidirectional wave.

FILTER AND VOLTAGE

REGULATOR

Filter

Capacitive filter is used in this project. It removes the ripples from

the output of rectifier and smoothens the DC O/p received from this filter is

constant until the mains voltage and load is maintained constant. However, it

either of two is varied DC voltage received at this pint changes. Therefore, a

regulator is applied at the output state.

Voltage Regulator:

As the name itself implies, it regulates the input applied to it. A

voltage regulator is an electrical regulator designed to automatically

maintain a constant voltage level.

In this project power supply of 5V and 12V are required. Inorder to obtain

these voltage levels, 7805 and 7812 voltage regulators are to be used. The 1 st

number 78 represents the supply and the numbers 05,12 represents the

required O/p voltage levels. The LM 78xx series of 3 terminal +Ve

regulators is available in TD – 220 , TO -220 FP, TO-3, D2 PAK and DPAK

packages and several fixed output voltages, making it useful in a wide range

of apps. These regulators can provide local on card regulation, eliminating

the distribution problems associated with single point regulation. Each type

employs a internal current limiting, thermal shut down and safe area

protection, making it essentially indestructible. It adequate heat sink is

provided, they can deliver over 1A output current, although designed

primarily as fixed voltage regulator.

PRINTED CIRCUIT

BOARD

PRINTED CIRCUIT BOARD

A printed circuit board is nothing but a prepared, worked inter

connecting system in which the active and passive components can be

inserted and soldered. It is the usually made o a copper clad laminate based

on epoxy resin or glass laminate.

A printed circuit board consists of acnducting coating o a based

material in the form of laminate. The bas material used in manufacturing of

copper clad or copper.

Laminations are

Paper phenoue

Glass epoxy

The PCB can also classified based on no of layers for conductors and

presence of hols. They are

1. Single sided board

2. Double sided board a) Non –plated through holes

b) Plated through holes

3. Multilayered board

4. Board for surface current devices

The following are the steps in which PCB will be made:

1. Preparation of layout of circuit and components

2. Tranferring layout on the copper

3. Transferring the copper from places where it isn’t required by using the

process of etching

4. Drilling of holes for components mounting.

5. Applications of protective coat to copper track

A PCB has to provide clean correct and easy means of

interconnecting of various components and devices relating to circuit of

subsystem. The interconnecting tracks of different components and devices

to be used in electronic circuits.

HEAT SINK

Heat Sink

In electronic systems a heat sink is passive heat exchanger that cools a

device by dissipating heat into the surrounding media. In computers, heat

sinks are used to cool control processing units (or) graphic processors. That

skinks are used with high power semiconductor devices such as power

transistor and opto electronics such as LASERS and LED, where the heat

dissipation ability of the device is insufficient to moderate its temperature.

A heat sink is designed to maximize its surface area in

contact with the cooling medium surrounding it such as air. Air velocity,

choice of material, protrusion design and surface treatment are factors that

affect the performance of heat sink. The most common heat sink materials

are aluminum alloys and copper. Diamond is another heat sink material.

Copper has excellent heat sink properties in terms of its thermal

conductivity corrosion resistance, bio fouling resistance. Its main

applications are industrial facilities, power plants, solar thermal water

system gas water heatests geothermal heating & cooling and electronic

systems. In this project the used a heat sinks which is made with aluminum.

Some of the heat sinks are shown .

WIRES

Wires

A wire is a single, usually cyclindrical, flexible stand (or) rod of

metal wires are used to bear mechanical loads or electricity and

telecommunication signal wires are commonly formed by drawing the metal

through a role in a die (or) draw plate wire guage cane in (variations) various

standard sizes as expressed in terms of guage no, the term is also used more

loosely to refer as a bundle of such standards as in multistand wire which is

move correctly turned a wire rope in mechanic or a cable in electricity.

Electrical wires are usually covered with installing materials such as plastic,

rubber, polymers etc., wire comes in solid core, stand board or braided

forms. Although usually circular in cross section, wires can be made in

square, hexagonal, hattered, rectangular (or) other cross sections.

SWITCHES

Switches

In elelctrical and electronic system, a switch is a device which can make (or)

break an electrical circuit (or) we can say that switch is a controlling device

which interrupt the flow of current on direct the flow of current in another

direction. Almost all the electrical and electronics systems contain at least on

switch which is used to make the device On (or) Off. In addition, a switch is

used to control the circuit operation and user may able to activate (or) de

activate the whole (or) certain parts of the connected circuit.

Generally switches are of 2 types. They are

1. Mechanical switches

2. Electrical/ electronic switches

Mechanical switches are again classified into 5 types , they are

1. SPST [ Single pole single throw switch]

2. SPDT [ single pole double throw switch]

3. DPST [Double pole single throw switch]

4. DPDT [ double pole double throw switch]

5. 2P6T [2 plle, 6throw switch]

A single pole single throw [SPST] switch is a switch that only has a

single I/P and can connect only to one output. This means that it has one I/P

terminal and one O/p terminal.

A single pole single throw switch serves in circuits as on off

switches. When the switch is closed, the circuit is on . when the switch is

open, the circuit is off.

SPST switches are thus every simple in nature.

SPST Switch Circuit

Below, is an example of a circuit which utilizes a SPST switch.

When the SPST is closed, the circuit open and light from the lamp

switches ON. When the SPST is then opened, the light from the lamp goes

out and the CKT is off.

Electrical/switches, are again classified into 3 types. They are

1. Transistor\

2. MOSFET’S

3. RELAYS

CIRCUIT DIAGRAM

WORKING

The diagram shown, is the circuit diagram of mobile signal jammer.

Constructional details:

The circuit diagram of mobile signal jammer comprises of the

following components. Thus are

1. 555 timer (output of fixed frequency)

2. MRF 94751 (RF power amplifier)

3. Antenna.

Whenever a power supply is given, the adopter converts the 230V AC

supply into a low DC supply. This low DC supply is about 5V. Then this 5V

Dc supply given to the mobile signal jammer circuit. This mobile signal

jammer can block the GSM, CDMA, DCS.PHS, 3G frequencies. For this

purpose, each application (DCS/CDMA/GSM/3G) contains a circuit

consisting of a 555 timer producing a definite frequency for each

application. If the supply is given to the circuit, the LED glows, whenever

the SPST switch is turned ON and vice versa.

Working:

Whenever the SPST switch is turned ON and the input supply is

given, then the IC 555 timer generates an output signal depending upon the

frequency used in it. Since the mobile signal jammer can isolate (or) jam

GSM,CDMA,DCS, 3G signals. For each application, different 555 IC timers

of different turned frequency is used.

The IC 555 timer present in mobile jammer produces frequency of

desired range, the output of the 555 timer is then given to the RF power

Amplifier [MRF947T1]. Since the O/p from the IC 555 timer is of low

power, it is given to the RF power Amplifier. This Amplifier strengthens the

signal in power range and then it is given to the tuning circuit. This tuning

circuit is used for impedance matching with the RF Antenna. So that the

frequency obtained from IC 555 timer with gets matched with the frequency

produced by the tuning circuit. This produces resonance, so that the

maximum output can be obtained from the Antenna.

The RF Antenna used here is an collinear Antenna, which is an

array of dipole Antenna. Which strengthens the signal so that it can be

transmitted to long distances.These Antenna are highly directional Antenna.

Therefore, the signals will travel long distance.

INSTALLATION

Installation Of Mobile Jammer

1 .Install this device at a height about 1.5m-1.7m will get the best jamming result, keep all the antennas in vertical.

2. Never install this device close to the wall, wall will affect the interference signals .Put this device 30-50cm away from the wall.

3. One set of this device can block all types of cellular systems including analog(AMPS,TACS,NIM) and digital (GSM,DCS,PDC,TDMA,PHS,PCS,IDEW,CDMA,WCDMA)signals up to 30 cm radius, covers an individual room of around 2800 square meters.

4. To cover an area bigger than 2800 square meters .Please install multiples of this device to ensure better jamming effect.EG. . in an individual space of 3500 square meters, you should need to install 2 or more devices working together.

5. This device is not able to cover different spaces divided with walls, install

individual jammers in different positions of a building to ensure the best

jamming effect.

SPECIFICATIONS

SPECIFICATIONS

OUTPUT FREQUENCY AVERAGE OUTPUT POWER

CHANNEL OUTPUT POWER

CDMA

GSM

DCS

3G

800-850MHz

850-900MHz

1800-1900MHz

2000-2100MHz

35dB

35dB

33dB

33dB

4dB/30khz(min)

3dB/30KHz(min)

1dB/30KHz(min)

1dB/30KHz(min)

Power supply : AC : 110-240V

DC : 5V/8A

Energy consumption : 30W

Dimension: 451 241 8.5cm

Running temperature : -100 to +550 C

Weight : 3 Kg

Output power : 10 W

Jamming range : 2.50m

ADVANTAGES

Advantages of Cell Phone Jammers

Cell phones offer great conveniences to people all over the world. It arouses new challenge on the safety of secret work. Now a day, copying in examination, wiretap, gas station outburst, and medical negligence are taking place due to mobile phones. Probably, it is one of the major reasons behind the emergence of   jammers. Advantages of cell phone jammers are vast.Basically, jammers function under specific frequency and connect to the main station throughelectromagnetic wave. It transmits sound and data through intonation and baud rate. The devicecreates an unrecognizable code hindrance to jam a cell phone. Most jamming devices can jam only one frequency .Only advanced devices can block multiple frequencies. Now, it is being used in prison, theater ,conference centre, library, church, gas station, school campus, government hospitals, and military site. Under the security of the device you do not have to worry about outburst and information safety. The new models are highly portable in nature. Diverse types of jammers are readily available in the market. Advantages of cell phone jammers are immense. The portable devices are particularly designed for small, safe and private places like mobile cars, discussion room and confidential office. Nevertheless, it can successfully  block cellular phone communication in the range of 50-80 sq meters.

APPLICATIONS

APPLICATIONS

To maintain the complete silence in library and lecture hall.

To avoid fraud in examination hall.

For, providing security in business conference, board of directors rooms ,

seminars, etc.

For providing calm and peaceful atmosphere in Hospitals.

Church/Mosques/Cathedral/Temple/Religious establishment

During a hostage situation, police can control when and where a captor can

make a phone call. Police can block phone calls during a drug raid so

suspects can't communicate outside the area.

jammers can be used in areas where radio transmissions are dangerous,

(areas with a potentially explosive atmosphere), such as chemical storage

facilities or grain elevators.

Corporations use jammers to stop corporate espionage by blocking voice

transmissions and photo transmissions from camera phones.

FUTURE SCOPE

FUTURE SCOPE

This project is more compatable and reliable.Therefore,this can be further

implemented in so many ways as follows;

1.This project can be accessed by using remote.

2.This can br automated using a gsm module.

3.The range of mobile jammer can be further extended by using some

special antennas.

CONCLUSION

CONCLUSION

Hence, we made the project mobile signal jammer. It is

very useful in avoiding disturbance during important conferences. It is very

much useful for VIP’s for security purposes.

Finally this project enabled us to improve our practical and

technical knowledge. That is why good grounding of communication theory

is achieved on completion of this project.

BIBLIOGRAPHY

BIBLIOGRAPHY

Websites Referred

www.tele communications.com

www.wikpedia.com

www.seminar projects.org

Books referred

Principles of electronics,

Electronic communication systems,

Electronics devices and circuits

ANTENNA

POWER SUPPLY

ADAPTER

BLOCK DIAGRAM OF MOBILE SIGNAL JAMMER

RF POWER AMPLIFIER555 TIMER

TUNING CIRCUIT (FIXED)