Indian Institute of Technology Hyderabad MOBILE BUG 0 By: M. Pavan kumar(cs12b1025) P.V.Sairam(me12b1027) B.Naveen reddy(me12b1007) Siva Krishna(cs12b1038 )

CONTENTS CONTENTS INTRODUCTION CIRCUIT DIAGRAM PIN CONFIGURATION OF 1) IC CA3130 PIN CONFIGURATION OF 2) IC2 NE555 WORKING APPLICATIONS LIMITATIONS REFERENCES

INTRODUCTION 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 CIRCUIT DIAGRAM

PIN CONFIGURATION OF (1) IC CA 3130 PIN CONFIGURATION OF (1) IC CA 3130

PIN CONFIGURATION OF (2) IC NE 555 TIMER PIN CONFIGURATION OF (2) IC NE 555 TIMER

WORKING 0.22µF 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 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 LIMITATION RANGE OF CIRCUIT RANGE OF CIRCUIT The prototype has only limited range of two metres. Exact location of mobile phone cannot be detected REFERENCES REFERENCES