ABSTRACT

The passive infrared detector (PIR) is one of the most common detectors found in household and small business environments because it offers affordable and reliable functionality. The term passive refers to the fact that the detector is able to function without the need to generate and radiate its own energy (unlike ultrasonic and microwave volumetric intrusion detectors that are “active” in operation).

This system which is installed at the gate uses an IR transmitter sensor unit to identify the arrival of a person and makes a beep sound using a buzzer. This system also switches on the gate light when surrounding light is low. The light glows only for a designed time interval and thus it helps a lot in saving electricity. This is basically a detecting mechanism project.

INTRODUCTION

Burglary of residences, retail establishments, and other commercial facilities involves breaking and entering, and stealing property. Attempted forcible entry into a property is also classified as burglary, in the FBI's Uniform Crime Reports (UCR) definition.

As of 1999, there were 1.4 million residential burglaries reported in the United States, which was a record low number, not seen since 1966.[9] Though, up to 50% of burglaries are not reported to the police.

PIRs verify if an intruder or object is actually there. Creating individual zones of detection where each zone comprises one or more layers can achieve differentiation. Between the zones there are areas of no sensitivity (dead zones) that are used by the sensor for comparison.

The circuit may be used to automatically switch on a light at the entrance gate to the premises at night by sensing the presence of a person. In addition, it sounds an alarm to signify the presence of a person. Here we are using an IR Led as the transmitting unit and the TSOP as receiving unit. A monostable, multivibrator circuit is used for the purpose of getting time delay accordingly. Lamp is switched on only for a short interval to save electricity. The main application is its use in restricted areas to indicate the entry of trespassers. It can also be used for security purposes.

MOTIVATION:

In the present busy world cases may arise where we may not be able to keep a constant watch in certain areas. In such cases arises the application of our project. This actually serves as a detecting mechanism to indicate the presence of an object or person in undetected cases. This turned out to be our main motivation for us to do this project.

The necessity to find a solution of all these problems turned out to be the motivation; also we have succeeded in overcoming these difficulties by implementing this project.

PRINCIPLE

This circuit has two stages: Transmitting unit and receiving unit. Transmitting unit consists of IR LED and sensing unit consists of TSOP sensor. An IC 555 working in monostable mode gives the time delay. The circuit may be used to automatically switch on a light at the entrance gate to the premises at night by sensing the presence of a person. In addition, it sounds an alarm to signify the presence of a person. Here we are using an IR Led as the transmitting unit and the TSOP as receiving unit. A monostable, multivibrator circuit is used for the purpose of getting time delay accordingly. Monostable multivibrator often called a one shot multivibrator is a pulse generating circuit in which the duration of this pulse is determined by the RC network connected externally to the 555 timer. In a stable or standby state, the output of the circuit is approximately zero or a logic-low level. When external trigger pulse is applied output is forced to go high (» V_CC). The monostable circuit has only one stable state (output low) hence the name monostable. Astable Multivibrator is a two stage switching circuit in which the output of the first stage is fed to the input of the second stage and vice versa. The outputs of both the stages are complementary. This free running multivibrator generates square wave without any external triggering pulse. The circuit has two stable states and switches back and forth from one state to another, remaining in each state for a time depending upon the discharging of the capacitive circuit. Lamp is switched on only for a short interval to save electricity. An LDR based circuit is used to switch on the bulb at night only. The buzzer is connected such that it functions whenever the IR beam is interrupted.

LIST OF COMPONENTS:

1. IC’s (555)

2. Transformer (Step-down 6-0-6)

3. Transistor (BC 548)

4. Diode (1N4001)

5. Capacitor (100µF,1000µF,470µF)

6. Resistor (10K,1K,56K)

7. LDR

8. IR LED

9. TSOP 17

10. Buzzer

11. Relay (12V instantaneous)

ADVANTAGES

¨ High sensitivity

¨ Low cost

¨ Simple construction

¨ Easy to install and maintain

¨ Less power consuming

¨ Requires less space

¨ Reliable

CONCLUSION:

The project provides the detecting mechanism of objects or person at unexpected timings. The project is user-friendly and highly reliable. This project has the advantage of saving of electricity since the bulb glows in the dark only for a short interval of time. Another main advantage which we could point out is the height adjusting mechanism which we could implement.
With the use of high intensity alarms this can also be used for security purposes. Thus it turns out to be a domestic as well as security purpose project. System reliability can be a problem when it causes nuisance alarms, false alarms, or fails to alarm when called for. Nuisance alarms occur when an unintended event evokes an alarm status by an otherwise properly working alarm system or when there is an alarm system malfunction that results in an alarm state. It is easier to know when there are false alarms, because the system is designed to react to that condition. Failure alarms are more troublesome because they usually require periodic testing to make sure the sensors are working and that the correct signals are getting through to the monitor. Some systems are designed to detect problems internally, such as low or dead batteries, loose connections, phone circuit trouble, etc. While earlier nuisance alarms could be set off by small disturbances, like insects or pets, newer model alarms have technology to measure the size/weight of the object causing the disturbance, and thus are able to decide how serious the threat is, which is especially useful in burglar alarms.

Home and business owners can now choose a new type of keypad control panel designed to help reduce false alarms.

Based on a standard called CP-01-2000, developed by the American National Standards Institute (ANSI)[1] and Security Industry Association (SIA))[2] , the new generation of keypad control panels takes aim at user error by building in extra precautions that minimize unwarranted dispatch of emergency responders.
Some of the features of CP-01 keypads include a progress annunciation function that emits a different sound during the last 10 seconds of delay, which hastens exit from the premises. Also, the exit time doubles if the user disables the pre-warning feature.