Design And Construction Of A Mock Alarm With Call Bell
ABSTRACT
This work is on an automatic mock alarm to ward off any intruder to your house. The alarm becomes active at sunset and remains ‘on’ till morning. The flashing light-emitting diodes (LEDs) and beeps from the unit simulate the functioning of a sophisticated alarm system. Besides, the circuit turns on and off a lamp regularly at an interval of 30 minutes throughout the night. It also has a call bell facility.
The circuit is built around CMOS IC CD4060B (IC1), which has an internal oscillator and a 14-stage binary divider to provide a long delay without using a high-value resistor and capacitor. Press switch S2 to provide 9V power supply to the circuit. During daytime, light-dependent resistor LDR1 offers little resistance and transistor T1 conducts. This drives transistor T2 into the cut-off mode, as its base is pulled to ground via transistor T1. Reset pin 12 of IC1 remains high as long as transistor T2 is cut off. This keeps the oscillator of IC1 (comprising resistors R5 and R6 and capacitor C1) disabled and its outputs remain low. The sensitivity of LDR1 can be adjusted using preset VR1.
TABLE OF CONTENTS
COVER PAGE
TITLE PAGE
APPROVAL PAGE
DEDICATION
ACKNOWELDGEMENT
ABSTRACT
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE PROJECT
- PURPOSE OF THE PROJECT
- AIM OF THE PROJECT
- OBJECTIVE OF THE PROJECT
- PURPOSE OF THE PROJECT
- LIMITATION OF THE PROJECT
- ADVANTAGES OF THE PROJECT
- PROBLEM OF THE PROJECT
- APPLICATION OF THE PROJECT
- RESEARCH QUESTION
- PROJECT ORGANISATION
CHAPTER TWO
LITERATURE REVIEW
- OVERVIEW OF THE STUDY
- REVIEW OF THE RELATED STUDY
CHAPTER THREE
3.0 CONSTRUCTION METHODOLOGY
3.1 BASIC OF THE SYSTEM
3.2 BLOCK DIAGRAM OF THE SYSTEM
3.3 SYSTEM OPERATION
3.4 CIRCUIT DIAGRAM
3.5 CIRCUIT DESCRIPTION
3.6 DESCRIPTION OF COMPONENTS USED
3.7 POWER SUPPLY UNIT
CHAPTER FOUR
4.0 TESTING AND RESULTS
- CONSTRUCTION PROCEDURE AND TESTING
- INSTALLATION OF THE COMPLET DESIGN
- ASSEMBLING OF SECTIONS
- TESTING OF SYSTEM OPERATION
- COST ANALYSIS
CHAPTER FIVE
- CONCLUSION
- RECOMMENDATION
- REFERENCES
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Mock alarm circuit
The circuit is built around CMOS IC CD4060B (IC1), which has an internal oscillator and a 14-stage binary divider to provide a long delay without using a high-value resistor and capacitor.
Mock alarm circuit
Press switch S2 to provide 9V power supply to the circuit. During daytime, light-dependent resistor LDR1 offers little resistance and transistor T1 conducts. This drives transistor T2 into the cut-off mode, as its base is pulled to ground via transistor T1. Reset pin 12 of IC1 remains high as long as transistor T2 is cut off. This keeps the oscillator of IC1 (comprising resistors R5 and R6 and capacitor C1) disabled and its outputs remain low. The sensitivity of LDR1 can be adjusted using preset VR1.
Circuit operation
When the sunlight decreases in the evening, the resistance of LDR1 increases to cut off transistor T1. This drives transistor T2 into conduction mode and its collector voltage goes low. At the same time, reset pin 12 of IC1 goes low to enable the oscillator of IC1 and the oscillator starts oscillating. The O3 output (pin 7) of IC1 goes high every five seconds to light up the LEDs (LED1 and LED2) and activate the buzzer. Resistor R8 limits the tone produced from the buzzer.
At the same time, O13 output of IC1 (pin 3) goes high every 30 minutes to forward bias transistor T3 to energise relay RL1 and lamp L1 connected to the normally opened (N/O) contacts of relay RL1 glows. This cycle repeats till morning.
The call bell is built around IC 4822 (IC2). Its inbuilt musical tone generator generates different tones at each trigger. The frequency of the tone can be controlled through external components R11 and C2. The output at pin 11 of IC2 is amplified by transistor T4.
When push-to-on switch S1 is pressed once, trigger pin 4 of IC2 gets a positive trigger from the positive rail (reduced by zener diode to 3.3V) via resistor R10 and IC2 starts producing a melody. Resistor R10 limits the current to the trigger pin of IC2 and resistor R12 prevents any false triggering. Zener diode ZD1 provides the 3.3V required for IC 4822.
Construction & testing
The circuit works off 9V regulated power supply. Assemble the circuit on any general-purpose PCB and enclose it in a waterproof plastic box with holes for mounting LEDs on the rear and the LDR on the top of the box. Place the LDR such that sunlight falls on it directly. Mount the unit on the pillar of the entrance gate. To avoid unnecessary illumination of the LDR, install lamp L1 away from the unit in the porch of the house. Keep the speaker inside the room.
The Title Page should be the first section of your project “Design And Construction Of A Mock Alarm With Call Bell”, providing essential details like the project title, your name, your supervisor’s name, the institution, and the submission date. After that, the Abstract offers a brief summary of your project, touching on its purpose, methods, results, and conclusions in 150-300 words. The Acknowledgments section is where you can thank those who supported your research, such as your supervisor, peers, or organizations that provided resources.
Next, the Table of Contents organizes the Design And Construction Of A Mock Alarm With Call Bell by listing its chapters and sections, along with page numbers for easy reference. The List of Figures and List of Tables help guide readers to specific visual elements like graphs, charts, or tables included in the document. There should also be an Abbreviations and Glossary section to explain any specialized terms or acronyms, making the content clearer to readers unfamiliar with the technical language.
The main body of the Design And Construction Of A Mock Alarm With Call Bell should start with the Introduction, which provides background information, outlines the research problem, states your objectives, and gives a brief overview of your research methods. Following that, the Literature Review offers an in-depth look at previous research relevant to your project, identifying gaps your study aims to address. The Methodology section then explains the research design, tools, and data collection methods you used to conduct the project and analyze the data.
In the Results and Discussion section, you present your findings and discuss them in relation to the Design And Construction Of A Mock Alarm With Call Bell research questions or objectives, often using tables or charts to help explain the data. The Conclusion summarizes the key results, discusses their implications, and suggests possible directions for future research. You may also include recommendations based on your findings, offering practical advice for improvements or applications. Finally, the Design And Construction Of A Mock Alarm With Call Bell project should include a References or Bibliography section to list all the sources you cited, as well as Appendices for any additional material. A Statement of Originality is often included to confirm the authenticity of your work