Operational Amplifier Final

TECHNOLOGICAL INSTITUTE OF THE PHILIPPINES#938 Aurora Blvd., Cubao, Quezon City

College of Engineering and ArchitectureDepartment of Electronics Engineering

The Application of Operational Amplifier in the Design of a LASER SECURITY ALARM

In Partial Fulfilment of the RequirementsNeeded for the completion of the subject Electronics Circuits Analysis and Design

(EC353L1)

Submitted By:Cabrera, Kristopher

De Guzman, Robert RyanGuzman, Loida Divina

Submitted To:Engr. Ryann Alimuin

Instructor

May 20, 2011

THE APPLICATION OF OPERATIONAL AMPLIFIER IN THE DESIGN OF A LASER ALARM SYSTEM

TABLE OF CONTENTS

CHAPTER 1| THE PROBLEM: RATIONALE AND BACKGROUND

Introduction 3

Objectives of the Project 3

Significance of the Study 4

Scope and Limitations 4

General and Specific Objectives……………………………………………………………………………………………5

CHAPTER 2 | REVIEW OF RELATED LITERATURE 6-7

CHAPTER 3| RESEARCH METHODOLOGY

Research Design 8-9

Data Collection 9

CHAPTER 4| PRESENTATION, ANALYSIS AND INTERPRETATION 10-13

CHAPTER 5| SUMMARY, CONCLUSION AND RECOMMENDATONS

Summary 12

Conclusion12-13

Recommendation 14

BIBLIOGRAPHY 15

Page 2CHAPTER I

THE PROBLEMS: RATIONALE AND


INTRODUCTION

Everywhere, especially in third world countries such as the Philippines, theft

contributes to one of the major crimes. One of the most dangerous forms of theft is

theft at home since you are not only endangered of losing valuable things but one

family’s life as well. The need for the installation then security alarms arises from the

basic concern of individuals living in such a hectic world – safety.

One form of such security system is the LASER security alarm. In essence, this security

system depends on the LASER beam being disrupted by a movement to trigger an alarm

– hence the name. Currently, there are already commercially available LASER security

systems but as mentioned in the previous paragraph, the affordability is limited. This

calls for the need of a relatively cheap but effective LASER security alarm system.

Such a security alarm system can be devised using an operational amplifier based LASER

security system. In order to create effective alarm systems, we need to have knowledge

in field of electronics. Developers need to adapt the modernization of technology. They

are simple to install and can be used effectively inside or outside a home. The systems

can be used as a highly effective perimeter alarm for property boundaries.

STATEMENT OF THE PROBLEM

Page 3


This project is conducted to respond to the following problems

1.) Design an effective gadget with the use of the idea regarding the operational

amplifier.

2.) Produce an affordable Laser Security Alarm System that would be cheap yet useful

for every household.

SIGNIFICANCE OF THE STUDY

This study is done by the researchers to come up with a process of creating a laser alarm

that is very useful to everyone, by using their knowledge about operational amplifier.

It also aims to make the process simple and the materials needed are affordable such

that the installation can be also done in houses without the help of the professional ones. Thus

targeting to provide extra protection most especially to the middle to low range income

families. Home security systems divert burglars who want to break in without complications.

This project would be a great help to those persons living in a crime prone area.

SCOPE AND DELIMITATIONS

This project is limited only for alarming the owner of a house or establishment if there is

a suspicious person roaming around and not more than that.

This is a movement dependent device. It is not concerned with the recognition of what

is the cause of the alarming.

Page 4


GENERAL AND SPECIFIC OBJECTIVES

It is the main objective of this project to construct an effective and low-cost device with

the use of an operational amplifier as one of its components.

Specifically, this project is conducted to help those who are financial incapable of buying

commercial security systems. Moreover, this project aims to inspire other students or

individuals who are fond of learning electronics.

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The operational amplifier got its name from the fact that it can be configured to

perform many different mathematical operations. Depending on its feedback circuit and

biasing, an op amp can be made to add, subtract, multiply, divide, negate, and,

interestingly, even perform calculus operations such as differentiation and integration. Of

course, aside from these operations, op amps are also found in a very large number of

applications. In fact, many consider the op amp as the foundation of many analogue

semiconductor products today.

An op amp has two inputs, one non inverting and one inverting, and one output.

When a signal goes into the non inverting input, the output is in phase with it; when a signal

goes into the inverting input, the output is 180 degrees out of phase with it. An op amp has

two power supply connections, one for the emitters of the transistors (Vee) and one for the

collectors (Vcc).

Because of the very high resistance exhibited by the inputs of an op amp, the

currents flowing through them are very small. The current flowing in or out of an op

amp's input pin, known as input bias current, is basically just leakage current at the base

or gate of the input transistor of that input, which is why it is very small. When solving

voltage/current equations for op amp circuits, the input currents are usually assumed to

be zero. For most of the commonly-used op-amp circuits, this means that the total output

current of the op amp is flowing through the feedback circuit between the output and the

Page 6

CHAPTER II REVIEW OF THE RELATED LITERATURE


inverting input (the feedback is usually connected to the inverting input for operation

stability).

The integrator is an operational amplifier circuit that performs the mathematical

operation of Integration that is we can cause the output to respond to changes in the input

voltage over time. The integrator amplifier acts like a storage element that "produces a voltage

output which is proportional to the integral of its input voltage with respect to time". In other

words the magnitude of the output signal is determined by the length of time a voltage is

present at its input as the current through the feedback loop charges or discharges the

capacitor as the required negative feedback occurs through the capacitor.

LASER is an acronym for “Light Amplification by Stimulated Emission of Radiation”

and a laser security system is a security system which use laser beam as a detector for

movements and to switch on security alarm.

Leveraging on the properties of the operational amplifiers (i.e. comparator capability)

one such LASER security system can be devised using these.

Page 7


RESEARCH DESIGN

In order for the researchers to build the project they used LM741 of operational

amplifiers. This operational amplifier is used as comparator not an amplifier. A ‘comparator’ is a

circuit that compares two input voltages. One voltage is called the reference voltage (Vref) and the

other is called the input voltage (Vin). A simple schematic diagram of the laser alarm system is

illustrated below:

Page 8

CHAPTER III RESEARCH METHODOLOGY


Followed by the PCB layout

DATA COLLECTION

For the construction of the prototype, the researchers first design the circuit for the device. It was then plotted at the PCB and was etched. Then, it was soldered. After then, it was placed in a casing.

Page 9

PROTOTYPING & DEVELOPING PCB

DESIGN

SOLDERED PCB

FINISHED PRODUCTS


This chapter would present the information that we have gathered on the experiment that we have performed to test the effectiveness of the device.

The picture above represents the testing of the device, the proponent test if the LDR react to the laser when it is in focus at this part of test the LDR stays at very low resistance so the output coming from the

Page 10

CHAPTER IV DATA PRESENTATION, ANALYSIS AND INTERPRETATION


471ic is low and the laser alarm is at waiting state.

Here the line has been broken and as the proponents expect the device goes loud and gave the warning sound that can call the attention of the person and as the laser returns to focus the device stays alarming until the reset button is pushed.

In here the proponents try to put a florescent lamp above of the device and the laser to test if it still works in case of day time, it is very important to test if ever the light from the environment affects the variation of resistance of LDR’s even when the Laser is at focus.

Page 11


As the line broke still the device still alarm and goes loud and stop after the reset button was pushed. Using the Proteus 7.4 the proponent try to simulate the circuit to minimize the error that can be encounter along making the prototype and in here as the Light Bulb is nearly focus to the LDR using virtual ohmmeter it is true that LDR become almost zero resistance as the meter reads 0.007Mohms and the 741ic is at the low state and the voltage is passing trough pin 3 of 4017 decade counter.And as the Light goes out the resistance of the LDR dramatically increased and become 85.685Mohms enough resistance to make the voltage off to the pin 3 of 4017ic and output 1 bit to the 4017ic in pin 3 along with this the op-amp 741ic output becomes high and trigger the clock of the 4017ic in pin 14 witch make the decade counter count from 0-9 so even the laser returns in focus the device stays at high output because of the pulse given by the clock and as long as the reset is not been pushed the clock will stay running along with the noise alarm.

DEVICE STATE ACTION RESET OUTPUT

Page 12


Laser Alarm ON No laser NO Alarming

Laser ON In focus NO No Alarm

Laser ON Line Broken NO Alarming

Laser ON Line Broken Yes Alarm Stopped

Laser OFF No laser NO Alarming

COMPONENTS PRICELIST

Components Unit Price Quantity Price

PCB 120 1 120.00

LM741 15.00 1 15.00

4017 decade counter ic 35.00 1 35.00

Resistors 2.00 5 10.00

IC Socket 10.00 2 20.00

Black Casing 20.00 1 20.00

Page 13


Slide Switch 9.00 1 9.00

9V Battery 60.00 1 60.00

Toggle Switch 9.00 1 9.00

LDR 15.00 1 15.00

2N3904 4.00 1 4.00

Connection Pins 20.00 1 20.00

Total Price 337.00

Page 14

CHAPTER V SUMMARY, CONCLUSION AND RECOMMENDATIONS


SUMMARY

The ability of the operational amplifier to magnify voltage values and act as comparator is taken advantaged and used as a platform to create a not only effective but also inexpensive LASER security alarm. The purpose which is to have an alarm triggered when motion is detected or disrupts a set LASER beam is efficiently attained with the current design.

CONCLUSION

Based from the different test conducted, it can be concluded by the researchers that an operational amplifier can be used for designing a LASER Security System. It is effective...

It can also be concluded that the project done is of great difference to the commercial one when it comes to the price of the components used.

RECOMMENDATION

The researchers recommend those persons who will use the product to make sure that it will be installed in a secret place for it to be more effective. Another reason is to make sure that stray light and objects does not falsely trigger the alarm.

Upon using the device, it is recommended to activate the security alarm under the following events:

1. At night, before the rest of the family go to sleep. 2. When leaving the house and no one will be left to look for it.3. It is also recommended to use mirrors to maximize the use of the security system.

For future researches, it is recommended to look into the possibility how they can incorporate digital camera or much better motion video recorder with this security system but still remain a cost effective device.

BIBLIOGRAPHY

Page 15


Petruzellis, Tom(2004). 41 Projects using IC741, 1st Edition. New delhi: Business Promotion Bureau.

Berlin, H. M. (1987). Design of Op-Amp Circuits. Samaploc, Manila: Philippine Reprint by JDIGIELECOM Publishers and Traders.,pp. 135-137

http://www.technologystudent.com/elec1/opamp3.htm

http://www.ecircuitcenter.com/circuits/op_comp/op_comp.htm

https://homepages.westminster.org.uk/electronics/4017.htm

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https://homepages.westminster.org.uk/electronics/4017.htm

http://www.ecircuitcenter.com/circuits/op_comp/op_comp.htm

http://www.technologystudent.com/elec1/opamp3.htm

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Operational Amplifier Final