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ELECTRONIC WATCHDOG A Minor Project Report Submitted in Partial fulfillment for the award of Bachelor of Engineering in Electronics & Communication Department
Submitted to RAJIV GANDHI PROUDYOGIKI VISHWAVIDYALAYA BHOPAL(M.P.)
MINOR PROJECT REPORT Submitted by
*Himanshu Meshram(0105EC081 Meshram(0105EC081041) 041) * Mahesh Gaur(0105EC081054) *Sumit Kapse(0105EC081109 Kapse(0105EC081109))
Under The Supervision of
Prof.S.G KERHALKAR(H.O.D KERHALKAR (H.O.D .E C Department) Mr.ABHISHEK MISHRA (Lecturer, E.C Department)
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
ORIENTAL INSTITUTE OF SCIENCE & TECHNOLOGY BHOPAL
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ORIENTAL INSTITUTE OF SCIENCE & TECHNOLOGY, BHOPAL DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
CERTIFICATE This This is to cert certif ify y that that the the work ork embo embodi died ed in this this minor inor proj projec ectt work work enti entitl tled ed “ ELECTRONIC ELECTRONIC WATCHDOG WATCHDOG”” has has been been sati satisf sfac acto tori rily ly comp comple lete ted d by
Himanshu
Meshram, Mahesh Gaur, Sumit Kapse. It is a bona-fide piece of work, carried out under the guidance in the Department of Electronics And Communication Engineering,Oriental Institute Of Science & Technology, Bhopal for the partial fulfillment of the Bachelor of Enginee Engineering ring in ELECTRONICS ELECTRONICS AND COMMUNICATIO COMMUNICATION N ENGINEERING ENGINEERING during during the academic year 2010-2011.
Approved by
Project Guide
Prof.S.G KERHALKAR (Prof. & Head of Department Dept. of Electronics & Communication)
Mr.ABHISHEK MISHRA
(Lecturer, E.C Department)
Forwarded by
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ORIENTAL INSTITUTE OF SCIENCE & TECHNOLOGY, BHOPAL
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
DECLARATION We Himanshu Meshram, Mahesh Gaur, Sumit Kapse are student of Bachelor of Engineering, Electronics And Communication Engineering,Oriental Institute Of Science & Technology, Bhopal hereby declare that the work presented in this Minor project is outcome of our own work, is bonafide, correct to the best of our knowledge and this work has been carried out taking care of Engineering Ethics. The work presented does not infringe any patented work and has not been submitted to any University for the award of any degree or professional diploma.
Date: Place: Bhopal
Himanshu Meshram Mahesh Gaur Sumit Kapse
Table of Contents
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Acknowledgement
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Introduction
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Component list
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About the circuit
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Circuit diagram
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How the circuit works?
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About BC548
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About IC NE555
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About IC UM66
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Applications
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Limitations
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Scope for further improvements
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Merits over other watchdogs
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References
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ACKNOWLEDGEMENT
We owe great many thanks to great many people who helped and supported us during making of this project. Our deepest thanks to Abhishek Mishra Sir, the guide of the project for guiding and correcting various documents of ours with attention and care. He has taken pain to go through the project and make necessary correction as and when we needed. Thanks and appreciation to helpful people for their support. We would also thank our institution and our faculty members without whom this project would have been a distant reality.We also extend our heartfelt thanks to our family and well wishers.
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INTRODUCTION
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Here’s an electronic watchdog for your house that sounds to inform you that somebody is at the gate.
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The circuit comprises a transmitter unit and a receiver unit, which are mounted face to face on the opposite pillars of the gate such that the IR beam gets interrupted when someone is standing at the gate or passing through it.
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This circuit can also be used as a doorbell or burglar alarm.
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COMPONENT LIST
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IC NE555(2) RESISTORS IR LED 6V BATTERY TRANSISTOR BC548(2) CAPACITOR S
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IR RECEIVER
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IC UM66(Melody Generator)
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ZENER DIODE(3.3V)
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SPEAKER(8 OHM,0.5W)
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ABOUT THE CIRCUIT •
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The transmitter circuit (see Fig. 1) is built around timer NE555 (IC1), which is wired as an astable multivibrator producing a frequency of about 38 kHz. The infrared (IR) beam is transmitted through IR LED1. The receiver circuit is shown in Fig. 2. It comprises IR sensor TSOP1738 (IR RX1), npn transistor BC548 (T1), timer NE555 (IC2) and some resistors and capacitors. IC2 is wired as a monostable multivibrator with a time period of around 30 seconds. The melody generator section is built around melody generator IC UM66 (IC3), transistor T2 and loudspeaker LS1. Fig. 3 shows pin configurations of IR sensor TSOP1738 and melody generator IC UM66.
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The power supply for the transmitter is derived from the receiver circuit by connecting its points A and B to the respective points of the receiver circuit. The receiver is powered by regulated 6V DC.
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For the purpose, you can use a 6V battery.
CIRCUIT DIAGRAM
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Transmitter:
Receiver:
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HOW THE CIRCUIT WORKS?
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The transmitter and receiver units are aligned such that the IR beam falls directly on the IR sensor. As long as IR beam falls on the sensor, its output remains low, transistor T1 does not conduct and trigger pin 2 of IC2 remains high. When anyone interrupts the IR beam falling on the sensor, its output goes high to drive transistor T1 into conduction and pin 2 of IC2 goes low momentarily. As a result, IC2 gets triggered and its pin 3 goes high to supply 3.3V to melody generator IC3 at its pin 2, which produces a sweet melody through the speaker fitted inside the house. Output pin 3 of IC2 remains high for around 30 seconds. Fig. 4 shows mounting arrangement for both the transmitter and receiver units on the gate pillars. To achieve a high directivity of the IR beam towards the sensor, use a reflector behind the IR LED. After both the units have been built, connect 6V power supply to the receiver circuit. You should hear a continuous melody from the speaker.
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Now connect 6V power to the transmitter also and orient IR LED1 towards IR receiver. The melody should stop after about 30 seconds. Now the transmitter and the receiver units are ready for use. When somebody enters through the door, the IR beam is interrupted and the alarm sounds for 30 seconds. The alarm keeps sounding as long as one stands between the transmitter and receiver units. Using preset VR1, you can set the volume of the loudspeaker. This circuit can also be used as a doorbell or burglar alarm.
ABOUT BC 548
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The BC548 is a member of a larger group of similarly numbered transistors.
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Its complement is the BC558, which is similar to the North American 2N3906 and the Japanese 2SA1015.
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The BC548 is flanked by two similar transistors, the BC547 and the BC549. These are similar to the BC548 but the 547 has a greater Vcbo of 50 volts and the 549 has the same Vcbo of 30 volts but a lower noise figure.
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The 547 and 549 have complementary PNP versions numbered 557 and 559.
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A 556 device also exists with a Vcbo of 80 volts, which device finds extensive use in the current mirror input stages of medium quality audio amplifiers with relatively high rail voltages.
ABOUT IC NE 555
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Internal block diagram
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The 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and multivibrator applications. The IC was designed by Hans R. Camenzind in 1970 and brought to market in 1971 by Signetics (later acquired by Philips).
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The original name was the SE555 (metal can)/NE555 (plastic DIP) and the part was described as "The IC Time Machine".
It has been claimed that the 555 gets its name from the three 5 kΩ resistors used in typical early implementations, but Hans Camenzind has stated that the number was arbitrary. The part is still in wide use, thanks to its ease of use, low price and good stability. As of 2003, it is estimated that 1 billion units are manufactured every year. The 555 has three operating modes: Monostable mode: in this mode, the 555 functions as a "one-shot". Applications include timers, missing pulse detection, bouncefree switches, touch switches, frequency divider, capacitance measurement, pulse-width modulation (PWM) etc.
Astable - free running mode: the 555 can operate as an oscillator. Uses include LED and lamp flashers, pulse generation, logic clocks, tone generation, security alarms, pulse position modulation, etc.
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Bistable mode or Schmitt trigger - the 555 can operate as a flip-flop, if the DIS pin is not connected and no capacitor is used. Uses include bouncefree latched switches, etc.
ABOUT IC UM66
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UM66T is a melody integrated circuit. It is designed for use in bells, telephones, toys etc.
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It has an inbuilt tone and a beat generator. The tone generator is a programmed divider which produces certain frequencies.
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These frequencies are a factor of the oscillator frequency.
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The beat generator is also a programmed divider which contains 15 available beats. Four beats of these can be selected.
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There is an inbuilt oscillator circuit that serves as a time base for beat and tone generator.
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It has a 62 notes ROM to play music. A set of 4 bits controls the scale code while 2 bits control the rhythm code.
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When power is turned on, the melody generator is reset and melody begins from the first note.
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The speaker can be driven by an external npn transistor connected to the output of UM66.
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Many versions of UM66T are available which generate tone of different songs.
APPLICATIONS
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Electronic watchdog can be used as a door bell or burglar alarm. It can also be used in houses, offices, jewellery shops for security and anti-theft purpose.
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LIMITATIONS AND SCOPE FOR FURTHER IMPROVEMENT
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It uses the concept of IR transmission and reception. So only when anyone interrupt the IR beam the bell will ring.
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But if motion sensor is used in the watchdog the it will detect anyone in the radius of 5-10 metres
MERITS OVER OTHER WATCHDOGS
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Low power consumption
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Small in size
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Low cost
REFERENCES •
Electronics projects Vol 8 (3rd edition )
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Power Electronics Printed circuit boards design and technology (Walter C. Bosshart)
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Integrated circuits (Millman & Halkias) Wikipedia
