Indian Institute of TechnologyHyderabad

MOBILE BUG

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By: M. Pavan kumar(cs12b1025) P.V.Sairam(me12b1027) B.Naveen reddy(me12b1007) Siva Krishna(cs12b1038)

CONTENTS

INTRODUCTION CIRCUIT DIAGRAM PIN CONFIGURATION OF 1) IC CA3130 PIN CONFIGURATION OF 2) IC2 NE555 WORKING APPLICATIONS LIMITATIONSREFERENCES

INTRODUCTION

AIM:TO CONSTRUCT A CIRCUIT WHICH GIVES WARNING INDICATION IF MOBILE PHONE IS USED IN CONFIDENTIAL AREAS

WHAT IS AN ORDINARY LC CIRCUIT ?

WHY ORDINARY LC CIRCUIT DOESNOT SUIT FOR CELL PHONE DETECTOR CIRCUIT ?

WHAT IS THE BASIS FOR THIS CIRCUIT ?

CIRCUIT DIAGRAM

PIN CONFIGURATION OF (1) IC CA 3130

PIN CONFIGURATION OF (2) IC NE 555 TIMER

WORKING0.22µF Disk capacitor(C3) along with the leads acts as a small antenna

to collect the RF signals from the mobile phone

This capacitor creates a field, stores energy and transfers the stored energy in the form of minute current to the inputs of IC CA3130

Op-amp IC CA3130 converts the current to corresponding voltage output

Capacitor C4 and resistor R1 keeps the non-inverting input (3) stable

Resistor R2 provides the discharge path for capacitor C4

Resistor R3 acts as a feed back resistor

C5 is connected for phase compensation

Depending on the signal frequency detected by the C3,output of the IC1 becomes high and low alternatively, indicated by LED1 and beeping of buzzer

Mono-stable timer IC2 is triggered through capacitor C7

Capacitor C6 maintains the base bias of transistor T1

R6 and C9 reduce time delay

APPLICATIONS It can be used to prevent the use of mobile phone in Examination halls,

confidential rooms etc. It is also useful for detecting the use of mobile phone for spying and

unauthorized video transmission.Range of the detector also plays a important role: EXAMPLE will be explained It can detect the information receiving mobile phone even if it is in silent mode.

LIMITATION RANGE OF CIRCUIT The prototype has only limited range of two metres.Exact location of mobile phone cannot be detected

REFERENCES www.google.com

www.googleimages.com

www.pdfmachine.com

www.Wikipedia.com