BY

R.SURESH (16705A0426)B TECH II Year I Sem

ELECTRONICS & COMMUNICATION ENGINEERING

ANNAMACHARYA INSTITUTE OF TECHNOLOGY AND SCIENCES(AN AUTONOMOUS INSTITUTION)

(Approved by AICTE,NEW DELHI & Affiliated to J.N.T.U Anantapuramu)New Boyanapalli, RAJAMPET-516 126 (A.P)

ATECHNICAL SEMINAR

ON

MOBILE DETECTOR

CONTENTS INTRODUCTION

BLOCK DIAGRAM

POWER SUPPLYY

TRANSFORMER

BRIDGE RECTIFIER

CIRCUIT DIAGRAM

OP – AMPLIFIER

555 IC TIMER

PIZEO BUZZER

ADVANTAGES & DISADVANTAGES

APPLICATIONS

CONCLUSION

INTRODUCTION

The moment the bug detects RF transmission signal from an activated mobile

phone, it starts sounding a beep alarm and the LED blinks. The alarm continues

until the signal transmission ceases. An ordinary RF detector using tuned LC

circuits is not suitable for detecting signals in the GHz frequency band used in

mobile phones.

BLOCK DIAGRAM

POWER SUPPLY

TRANSFORMER

A transformer is a device that transfers

electrical energy from one circuit to another

through inductively coupled conductors —

the transformer's coils or "windings".

The transformer used here is a

230/(12V-0-12V) step down transformer.

BRIDGE RECTIFIER

CIRCUIT DIAGRAM

There are five major parts in the case of cell phone detector:AntennaLC tuner circuit Current to voltage converter 555 Timer circuitOutput stage

This IC is a 15 MHz Operational

amplifier with MOSFET inputs and

Bipolar output.

Gate-protected P-Channel MOSFET

(PMOS) transistors are used in the

input circuit to provide very-high-input

impedance, very-low-input current,

and exceptional speed performance.

We can also use this CA3130 as

voltage to current converter.

OP - AMP

555 IC TIMER

The NE555 IC is a highly stable controller

capable of producing accurate timing pulses.

For satiable multi vibrator operation as an

oscillator, the free running frequency and the

duty cycle are both accurately controlled with

two external resistors and one capacitor.

The NE555 Timer ic is also used for

Precision Timing, Pulse Generation, Time

Delay Generation and Sequential Timing.

TRANSISTOR

Transistor BC548 is a CMOS version using gate protected p-channel MOSFET

transistors in the input to provide very high input impedance, very low input

current and very high speed of performance.

PIZEO BUZZER

A buzzer is a signaling device, usually electronic, typically used in

automobiles, household appliances such as microwave ovens, or game shows.

PIZEO EFFECT:

Every day use of this phenomenon is used in load cells. Load cells are used on large weigh scales for trucks and large bin scales where materials need to be weighed. The signals from the cells are calibrated to compensate for the weight of the scale so that the scale can be zeroed out. The cell signal, because it is very small, is sent to an amplifier head where is can be read by the operator in units of weight. The head unit can be set to read in metric or imperial weights.

ADVANTAGES & DISADVANTAGES

The illegal use of cell phones is a growing and dangerous problem in institutions. Small in size.Detection of hidden cell phonesLong range –some RF can locate cell phones up to one mile away

DISADVANTAGES:

Cannot detect phones that are off or in airplane mode if a phone is powered off or not transmitting, it is invisible to the detector.

ADVANTAGES:

APPLICATIONS

Petrol pumps Gas station Historical places Religious places Court of laws Examination halls Spying and unauthorized video transmission Military bases Hospitals Theatres Conferences Embassies

CONCLUSION

This pocket-size mobile transmission detector or sniffer 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.

QUERIES ?