ELECTRONIC

SENTRY

1) •Used as guard system in entrance

2) •The circuit comprises a• Transmitter & receiver unit• Tracking device system

3)• Mounted face to face .• Raises alarm if someone

interrupts

INTRODUCTION

SETUP:

TRANSMITTER CIRCUIT

Wired as astable multivibratorBuilt around 555 timer

IR beam falls directly on the IR sensorsFor this align transmitter and receiver ckt

CIRCUIT DIAGRAM :

• Npn transistor BC548• IR sensor TSOP1738

Transistor &

Sensors • IC2 555 timer. Wired as

monostable multivibrator • Time period -30 s

IC

• IC3 UM66-melody generator

• 6V DC

Alarm generator

RECEIVER CIRCUIT

CIRCUIT DIAGRAM

Reflector behind IR LED for better directivity

When someone interrupts , sensor o/p goes high->T1 gets on

-> pin 2 of IC2 is low ,hence o/p at 3r

d

pin is high

In turn this makes produces sound at melody generator

WORKING

Sound lasts for 30 seconds, which stops then.

If someone interrupts continuously , it keeps ringing as IR beam is blocked

Using preset VR1, adjust the volume of the loudspeaker. This can be extended to outer walls also.

IMAGE LOCKING: persons image will be stored in the database

It alerts if any unknown person intrudes.System gets unlocked if image matches in database

ANTI THEFT CONTROL:

Reciever circuit

Tracking device

Analaysing circuit

Transmitting

antennaReceiver antenna

Database of residents

Amplfier and loud speaker

HomePolice

Station

Tracking device

CONCEPT:

Signaling :• If alarm

raises, then analog signal will be given to tracking device .

Tracking device:• Circuit

which stores the address in memory using controller

Transmitting circuit• The data is

sent to the nearby police station thro’ antenna after modulation

Receiver circuit:

• The obtained signal is demodulated and amplified like radio receiver.

Analyzing circuit:• Here obtained

signal is cross checked with the database.

• Database has details of residents.

Alarming unit:

• After analyzing, signal is amplified and it alerts the cops thro’ loud speaker.