RF BASEDHOME SECURITY SYSTEM

PRESENTED BY :

KESHARI NANDAN

MD. AAMIR KHURSHEED

MANU SINGH GAUR

ROHIT SHUKLA

CONTENTSINTRODUCTION

BLOCK DIAGRAM OF PROJECT

POWER SUPPLY

TYPES OF SENSORS

RF ENCODER & DECODER

ADVANTAGES

CONCLUSION

INTRODUCTION

The fear of theft and burglary always annoys many

people. When lock and keys become less safe, one can

seek the help of electronic security systems.

Such a portable security system is described here.

The system has two main parts: an intruder sensor

cum transmitter and a receiver. The intruder sensor

reacts to light, fire, gas and mechanical movements.

When the sensor detects a disturbance, the transmitter

gets triggered and begins to send wireless signals.

The receiver placed away from the transmitter receives

the signals and produces an audio alarm. At the same

time, a relay switch is turned on so that other security

systems can be energized through this relay.

WORKING

PROJECT BLOCK DIAGRAM

POWERSUPPLY

TXRF ENCODER

ALARM

Gas sensor

OP-AMP PIR

Fire sensor

LDR

RX RF DECODER

POWER SUPPLY

230 V AC 50 Hz

5V DC

12V step down transformer

Filter(470µf)

5v RegulatorBridge rectifier

A photoresistor or light-dependent resistor (LDR) or photocell is

a light-controlled variable resistor. The resistance of a

photoresistor decreases with increasing incident light intensity .

A photoresistor can be applied in light-sensitive detector

circuits, and light- and dark-activated switching circuits

Fire sensor is a fire sensing device. The moment it

senses heat, a loud alarm  is produced. Internal

resistance of these devices will decrease when

temperature rises.

A passive infrared sensor (PIR sensor) is an

electronic sensor that measures infrared (IR) light

radiating from objects in its field of view. They are

most often used in PIR-based motion detectors.

A gas detector is a device that detects the presence

of gases in an area, often as part of a safety

system.  These sensors usually employ an audible

alarm to alert people when a dangerous gas has

been detected.

RF Transmitter and Receiver

• RF modules are normally divided into three groups, RF transmitter

module, RF receiver module and RF transceiver module

• 433MHz ASK transmitter and receiver is used for the remote

control.

Fig : RF Transmitter

Features of RF

Range in open space(Standard

Conditions) : 100 Meters

RX Receiver Frequency : 433 MHz

RX Typical Sensitivity : 105 Dbm

RX Supply Current : 3.5 mA

RX IF Frequency : 1MHz

Low Power Consumption

Easy For Application

RX Operating Voltage : 5V

TX Frequency Range : 433.92 MHz

TX Supply Voltage : 3V ~ 6V

TX Out Put Power : 4 ~ 12 Dbm

Fig RF Receiver

HT 12 ENCODERFeatures

•Operating voltage is 2.4V~12V for the HT12A.

•Low power and high noise immunity CMOS technology

•Low standby current: 0.1_A (typ.) at VDD=5V

•HT12A with a 38kHz carrier for infrared transmission

medium

•Minimum transmission words are Four words for the

HT12E

•Built-in oscillator needs only 5% resistor

•Data code has positive polarity

•Minimal external components

•HT12A/E: 18-pin DIP/20-pin SOP package

HT12 DECODER

Features

Operating voltage: 2.4V~12V.

Low power and high noise immunity CMOS

technology.

Low standby current.

Capable of decoding 12 bits of information.

Binary address setting.

Address/Data number combination for HT12D: 8

address bits and 4 data bits.

Valid transmission indicator

Minimal external components

18-pin DIP, 20-pin SOP package

ADVANTAGES

• Track and alerts from unwanted and suspicious movements.

• Warn us against hazardous fire.

• The system has DC operated function with portable receiver

• Deters crime and protect valuables.

CONCLUSION

In this project we implemented Home security system comprising

Wireless alerts using RF signals as communication standards. The

hardware equipment is tested and result is obtained. This project is

cost effective. Implementation of this project in present day will

effectively provide a peace of mind to the residents. This project can

be implemented both in apartments and General stores as well.