Design And Construction Of A Monostable Multivibrator

ABSTRACT

Multivibrators produce an output wave shape resembling that of a symmetrical or asymmetrical square wave and as such are the most commonly used of all the square wave generators. Multivibrators belong to a family of oscillators commonly called “Relaxation Oscillators”. Multivibrators have two different electrical states, an output “HIGH” state and an output “LOW” state giving them either a stable or quasi-stable state depending upon the type of multivibrator. One such type of a two state pulse generator configuration are called Monostable Multivibrators. Monostable Multivibrators have only ONE stable state, and produce a single output pulse when it is triggered externally. Monostable Multivibrators only return back to their first original and stable state after a period of time determined by the time constant of the RC coupled circuit.

The aim of this work is to design a monostable type of multivibrator.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• AIM OF THE PROJECT
• OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• APPLICATION OF THE PROJECT
• ADVANTAGES OF THE PROJECT
• STATEMENT OF THE PROBLEMS

CHAPTER TWO

2.0     LITERATURE REVIEW

2.1     OVERVIEW OF THE STUDY

2.2     HISTORICAL BACKGROUND OF THE STUDY

2.3      OPERATIONAL REVIEW OF MONOSTABLE

2.4     DESCRIPTION OF 555 TIMERS IC

2.5     HISTORICAL BACKGROUND OF 555 TIMER IC

CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1      BASICS OF THE SYSTEM

3.2      SYSTEM DIAGRAM

3.3      CIRCUIT DESCRIPTION

3.4     CIRCUIT WITH INTERNAL BLOCK DIAGRAM

3.5      THEORY OF RESISTOR

3.5      THEORY OF CAPACITOR

CHAPTER FOUR

RESULT ANALYSIS

4.0      CONSTRUCTION PROCEDURE

4.1      CASING AND PACKAGING

4.2      ASSEMBLING OF SECTIONS

4.3      TESTING OF SYSTEM OPERATION

4.4      PACKAGING

4.5      MOUNTING PROCEDURE

4.6      RESULT

4.7      COST ANALYSIS

CHAPTER FIVE

5.1      CONCLUSION

5.2      REFERENCES

The 555 timer gets its name from the three 5 kΩ resistors it uses to generate the two comparators reference voltage. It is a very cheap, popular and useful precision timing device that can act as either a simple timer to generate single pulses or long time delays, or as a relaxation oscillator producing stabilized waveforms of varying duty cycles from 50 to 100%. In this tutorial, the presenter will demonstrate how to setup 555 timer circuit in monostable mode. This will allow an LED to be turned on for a specific duration after pressing a button. The time the LED stays on can be changed by changing the resistance and capacitance in the circuit.

The 555 timer chip is extremely robust and stable 8-pin device. It can be operated either as a very accurate Monostable, Bistable or Astable multivibrator to produce a variety of applications. Some of the applications include one-shot or delay timers, pulse generation, LED and lamp flashers, alarms and tone generation, logic clocks, frequency division, power supplies and converters etc. In fact any circuit that requires some form of time control uses the timer IC as the list is endless.