Laporan Psm2 Final

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ii

“ I hereby declare that I have read this thesis and in my opinion this thesis is sufficient

in terms of scope and quality for the award of the Bachelor‟s Degree of Electrical

Engineering “

Signature : ………………………………………..…

Name of Supervisor : En. Camallil Bin Omar

Date : 30 April 2010

iii

AUTOMATIC TOILET VISITOR ON / OFF

LIGHT CONTROL

FADHIL LATIFFI BIN SHAHRUDDIN

A thesis submitted to the Faculty of Electrical Engineering in partial fulfillment

of the requirements for the award of the Bachelor’s Degree of Electrical

Engineering

Faculty Of Electrical Engineering

Universiti Teknologi Malaysia

APRIL 2010

iv

DECLARATION

“I declare that this thesis entitled “ Automatic Toilet Visitor On / Off Light

Control ” is the result of my own research except as cited in the references.

The thesis has not been accepted for any degree and is not concurrently

submitted in candidature of any other degree.”

Signature : ………………………………………..…

Name : Fadhil Latiffi Bin Shahruddin

Date : 30 April 2010

v

ACKNOWLEDGEMENT

The first I gracefully thank to gratitude to Allah S.w.t. for giving me the courage and

spirit to completing my study of the Degree in Bachelor of Electrical Engineering.

I would like to address my acknowledgment to several individuals, who had

been supporting and helping me during my study. I would not be able to complete my

study especially this report if it were from the first and foremost, my supervisor En.

Camallil Bin Omar. He had given me the courage to apply my writing skill and the

idea during the development of the project. I also would like to express my truthful

thank to all of the Space UTM Lecture that had been teaching me and the Space

Penang group especially, En Johari Kassim for his kindly advice to keep me on

continuing the study.

I would like to thank to all of my family especially both my parent, my father

Shahruddin Bonyamin and my mother Norsiah Bt. Othman for keep giving the

support to me on completing the study. Also to my aunty Kamariah Bonyamin and

my grandma Rahmah Mat Taib, for their greet support on my financial during the

study. To my lovely wife Zanariah Mohtar , her family and both of my children, for

giving back support and together to feel the hard life with me.

Also not forget to all my friend at Ittar Perai, especially my ex head of

electronic department En. Muhamad Zamri, En Saad Din and En Azman Rahimi for

their support. To all SmartLab Sdn. Bhd. Staff especially my ex manager En. Razali

Saad and Mohd Nor Abu Bakar for teaching me a lot knowledge and skill on circuit

design and testing .

At last I would like to thank to my head of electrical department En Ganesan

for giving me opportunity to use this innovation project also as my PSM project. And

all the electrical staff at ILP Nibong Tebal for a lot of giving an input and idea on the

problems occurs in the problems location.

vi

ABSTRACT

Electrical energy is the one of important required in our living live today. But

electrical energy mostly waste by user especially light in the toilet area. Most of the

time the light always remain on even the is no people in the toilet. For building or area

especially education institution like ILP Nibong tebal , toilet are most area use by

many people especially student ,and this area are the most waste of electrical energy.

Most of the time the toilet remain turn on until 8 hour/day and also a few times

found remain until 24 hour and 36 hour . This effected an electrical bill need to be pay

per/month , there where around RM100,00.00 per/month. In term of that , the main

objective of the project is to design and develop an automatic circuit to turn on / off

the light only when there is people in the toilet. By taking control of the light turn

on/off , the time of light use can be reduce into exactly when it needed.

The main component that will use in this project is a new type of detection

sensors called PIR Passive Infrared Sensors ). A passive Infrared sensor (PIR sensor)

is an electronic device which measures infrared light radiating from objects in its field

of view. PIRs are often used in the construction of PIR-based motion detector.

Normally it operates by motion that had been detected and the light will trigger to turn

On , depend on the timer setting.

In this project to turn on the light is not only depend on the PIR sensor where

its trigger by timer but it depend on existing of people inside the sub toilet area. By

using the device , human careless and undisciplined manner can be control. This will

help to reduce the total hour of the light to turn on , by this the total energy usage

reduce and electrical bills are also reduce.

vii

ABSTRAK

Tenaga elektrik adalah merupakan salah satu elemen keperluan yang penting

dalam kehidupan masa kini. Namun pembaziran tenaga elektrik sering di lakukan

oleh pengguna terutama di dalam tandas. Bagi banggunan terutamanya pusat

pendidikan seperti ILP Nibong Tebal, ruang tandas adalah merupakan tempat yang

sering digunakan oleh ramai orang terutamanya para pelajar, dan kawasan ini adalah

merupakan kawasan yang paling tinggi berlakunya pembaziran tenaga elektrik.

Pada kebanyakan masa lampu tandas di biarkan sentiasa terbuka malah kadang

kala mencecah sehingga 8 jam sehari dan kadangkala didapati berterusan selama 24

jam dan 36 jam. Ini menjejaskan jumlah bil yang perlu di bayar pada setiap bulan di

mana jumlah bil elektrik yang perlu di bayar adalah sebanyak RM 100,000.00

sebulan. Oleh yang demikian itu objektif utama projek ini adalah bagi merekabentuk

satu litar yang dapat mengawal tutup dan buka lampu tandas yang mana ia hanya di

buka apabila ketika terdapat penguna di dalam tandas sahaja. Dengan kaedah

pengawalan ini ia dapat mengurangkan kadar pengunaan tenaga elektrik dan

seterusnya mengurangkan kos bil bulanan.

Komponen utama yang digunakan di dalam projek ini adalah sejenis penderia

yang di panggil PIR – Passive Infrared Sensor. PIR Sensor andalah merupakan salah

satu alat elektronik yang mengukur perbezaan kadar pancaran cahaya infra merah

yang di pancarkan dari sesuatu objek. Kaedah yang di gunakan adalah melalui

pengesanan pergerakan dimana apabila terdapatnya pergerakan di kesan oleh PIR ia

akan memacu untuk lampu di buka.

Di dalam projek ini kawalan keatas lampu bukan hanya bergantung kepada

PIR sensor tetapi ia juga berdasarkan kepada kehadiran penguna di dalam tandas.

Dengan ini ia dapat mengatasi masalah pengguna yang tidak berdisiplin dan

seterusnya mengurangkan kos pembayaran bil bulanan.

viii

TABLE OF CONTENTS

CONTENT PAGE

CONFESSION ii

DECLARATION iv

ACKNOWLEDGEMENT v

ABSTRACT vi

ABSTRAK vii

TABLE OF CONTENTS viii

LIST OF FIGURES xi

LIST OF TABLE xiii

LIST OF SYMBOLS xiv

LIST OF ABBREVIATIONS xv

CHAPTER TITLE PAGE

1 INTRODUCTION

1.0 General.

1.1 Project Objective

1.2 Project Scope.

1.3 Project Problem Background.

1.4 Problem Area Location

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2 LITERATURE REVIEW

2.0 PIR – Passive Infrared Sensors.

2.0.1 Infrared Radiation

2.0.2 Pyroelectric Sensors

2.0.3 Fresnel Lens.

2.1 Digital System And Logic Gate

2.1.1 Digital Logic States

2.1.2 TTL Input & Output Voltage Levels

2.1.3 Digital Logic Gates

2.1.4 Pull-up and Pull-down Resistors

2.3 Bipolar Junction Transistor (BJT)

2.3.1 Transistor currents.

2.3.2 Functional model of an NPN transistor.

2.3.3 Using a transistor as a switch.

2.3.4 Protection Diode

2.3.5 Connecting a transistor to the output from an IC

2.3.6 Choosing A Suitable NPN Transistor

2.4 Relay

2.4.1 Reed Relays

2.4.2 Solid State Relay (SSR)

2.4.2.1 Advantages over mechanical relays

2.4.2.2 Disadvantages

2.5 Timer 555 / 556

2.5.1 Inputs Of 555/556

2.5.2 Output Of 555/556

2.5.3 Timer 555/556 Monostable Circuit.

2.5.3.1 Monostable Operation

2.5.3.2 Power-On Reset Or Trigger

2.5.3.3 Edge-Triggering.

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3 PROJECT METHODOLOGY

3.0 Introduction.

3.1 Project Development Stage.

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4 SYSTEM AND CIRCUIT OPERATION

4.0 Introduction.

4.1 Sensing Circuit.

4.1.1 Sensing Zone 1.

4.1.2 Sensing Zone 2.

4.2 Main Controller Circuit.

4.3 Light On/Off Controller.

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5 TEST AND RESULT

5.0 Introduction.

5.1 Light On/Off Controller Circuit Test.

5.2 PIR Sensor Testing.

5.3 Reed Switch Sensor Testing.

5.4 Main Controller Testing.

5.5 Full System Test.

5.6 On Location Test.

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6 CONCLUSION

6.0 Conclusion.

6.1 Suggestion And Future Development.

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REFFERENCES 68

APPENDIX 1 : Project Schematic And Component List 69

APPENDIX 2 : Component Data Sheet. 70

APPENDIX 3 : PSM2 Presentation Slide 71

xi

LIST OF FIGURES

FIGURE PAGE

Fig 1.0 : Toilet Floor Plan and Total Lamp Each Toilet.

Fig 2.1 : PIR Typical Configuration

Fig 2.2 : PIR Detecting Method and Signal Output.

Fig 2.3 : Murata IRA-E700 Series PIR Sensors Specification.

Fig 2.4 : Fresnel Lens Detection Angle And Lens Dimension.

Fig 2.5 : Fresnel Lens Construction

Fig 2.6 : TTL Digital Logic Voltage Level

Fig 2.7 : Ideal Digital Logic Voltage Level

Fig 2.8 : Input Pin Pull-up and Pull-down Resistor

Fig 2.9 : Transistor Circuit Symbols

Fig 2.10 : Transistor Current Flow

Fig 2.11 : NPN Transistor Functional Model

Fig 2.12 : Transistor As A Switch

Fig 2.13 : Protection Diode Across Inductive Load

Fig 2.14 : NPN and PNP Transistor Connection to Integrated Circuit (IC)

Fig 2.15 : Relay Schematic And Real Relay.

Fig 2.16 : Bi-Directional Solid State Relay With Opto-Isolation.

Fig 2.17 : Timer 555 and 556 Input/output Pin and Pin Assignment.

Fig 2.18 : Timer 555 Sinking And Sourcing Test.

Fig 2.18 : Timer 555 Output Protection Diode.

Fig 2.19 : Timer 555 Monostable Circuit With Manual Trigger

Fig 2.20 : Timer 555 Monostable Timing Diagram.

Fig 2.21 : Power-On Reset Or Trigger Circuit

Fig 2.22 : Edge-Triggering Circuit

Fig 3.1 : Project System Block Diagram.

Fig 3.2 : Project Development Flow Chart.

Fig 3.3.1 : Zone 1 Sensing Circuit

Fig 3.3.2 : Main Controller Simulation

Fig 3.4 : Light On/Off Controller Simulation.

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LIST OF FIGURES

FIGURE PAGE

Fig 3.5 : Main Controller Circuit Board.

Fig 3.6 : Light On/Off Controller Circuit Board.

Fig 4.1 : Project System Block Diagram.

Fig 4.2 : Sensing Zone Area.

Fig 4.3 : The PIR Sensors Module.

Fig 4.3 : The PIR Sensors Module Retriggering Jumper and Delay Adjust.

Fig 4.4 : The Reed Switch Condition During Door Open or Close.

Fig 4.5 : Zone 2 Sensing Circuit.

Fig 4.6 : Zone 2 Sensing Output Voltage.

Fig 4.7 : Main Controller Circuit.

Fig 4.8 : Zone 2 identification Circuit.

Fig 4.9 : Zone 2 Timer Circuit.

Fig 4.10 : Light On/Off Controller Circuit.

Fig 5.1 : Light On/Off Controller Circuit Test.

Fig 5.2 : PIR Sensor Circuit Test.

Fig 5.3 : PIR Sensor Detection Range.

Fig 5.4 : Reed Sensor Test.

Fig 5.5 : Main Controller Schematic And Test Point Location.

Fig 5.6 : Project Full System Integration.

Fig 5.7 :On Location Assembly And Test.

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xiii

LIST OF TABLE

TABLE PAGE

Table 1.0 : Energy usage data calculation table.

Table 3.1 : Automatic Toilet Visitor On/Off Light Control Component List.

Table 4.1 : The Main Controller Truth Table.

Table 5.1 : +12V And +5V Voltage Measurement Result.

Table 5.2 : PIR Sensor Response.

Table 5.3 : Reed Sensor Measurement Result.

Table 5.4 : Zone 1 Circuit Test Point Measurement Result.

Table 5.5 : Zone 2 Circuit Test Point Measurement Result.

Table 5.6 : Main Circuit Test Point Measurement Result.

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xiv

LIST OF SYMBOLS

IC Bipolar Transistor Collector Terminal Current

IB Bipolar Transistor Base Terminal Current

VBE Voltage In Between Base Terminal And Emitter Terminal

hfe Direct Current Gain Factor For Transistor

Rce Resistance In Between Collector Terminal To Emitter Terminal

IE Emitter Current

xv

LIST OF ABBREVIATIONS

PIR Passive Infred Sensor

DC Direct Current

AC Alternating Current

ILP Institut Latihan Perindustrian

PSM Final Year Project

MOSFET Metal Oxide Semiconductor Field Effect Transistor

IC Integrated Circuit

BJT Bipolar Junction Transistor

CMOS Complementary Metal Oxide Semiconductor

TTL Transistor – Transistor Logic

FET Field Effect Transistor

IR Infra Red

COMM Common Point

NC Normally Close

NO Normally Open

CHAPTER 1

INTRODUCTION

1.0 General.

Electrical energy is the one of important required in our living live today. But

electrical energy mostly wastes by user especially light in the toilet area. Most of the

time the light always remain on even there is no people inside the toilet. For building

or area especially education institution like ILP Nibong tebal , toilet are most area use

by many people especially student , and this area are the most waste of electrical

energy. Most of the times the toilets remain turn on until 8 hour/day and also a few

times found remain until 24 hour and 36 hour . This effected an electrical bill need to

be pay per/month , there where around RM100,00.00 per/month.

1.1 Project Objective.

The objective of this project is to build an automatic toilet visitor on/off light

controller for application at ILP Nibong Tebal.

1.2 Project Scope.

The main scope of the project are :

1. Design and develop a circuit to control the toilet a light automatically only

when there is visitor inside the toilet.

2. Using circuit simulation and assemble the project to develop the system.

3. Use knowledge that had been learn before during troubleshoot and solving any

project errors.

4. Test the circuit and analyze the project data and system response.

2

1.3 Project Problem Background.

Human undisciplined manner and careless are the main factor of an electrical

energy waste. It is because during the time when people came out after using the toilet

they doesn‟t turn off the toilet light, it make the light turn on even there is no people

inside the toilet. Most of the time toilets light always turn on until 8 hour per day, but

sometimes even worse the light turns remain turn on until 2 days where total hour is

around 48 hour.

These are the root cause of increasing the electrical bill. Because of this

problem, the Director of ILP Nibong Tebal had ask the electrical department to try

solve this problem by creating any device that can control the turn on / off the light.

Total number of toilet for workshop is around 24 toilet, where 4 toilet at electrical

department , 2 toilet at network department , 4 at multimedia department and 14 toilet

at printing department. All of this toilet are being use during class are running from

8.00am to 5.30pm.

1.4 Problem Area Location.

Figure 2.1 shows the floor plan of the toilet, where each floor has 2 toilets

each one for men and women. From the floor plan each toilet are using 4 double

florescent lamp, where each lamp using 40W electrical power.

Below is the calculation for total power usage on each toilet.

Quantity of Double 40w Florescent Lamp = 4

Total number of light / toilet = 8

Total power consumptions / toilet = 8 X 40W

= 320 Watt

3

Fig 1.0 : Toilet Floor Plan and Total Lamp Each Toilet.

From each toilet power consumption estimation can be done by estimate the

total hour usage per day in current situation and with using an automatic device. In

this estimation current hour usage per day is estimate as 8 hours and by using

automatic device total hours per day is estimate as 3 hours. Total usage per day will

be times with 20 days as a working day per month. By this we can get the total power

consumptions each toilet per month and the total bill need to pay for each month.

The calculation are using TNB web bill calculator, where the tariff is

Commercial C1 :0.25, 0.27, 0.34. Below are the tables of calculation in-between

current demand and after using an automatic device.

4

Table 1.0 : Energy usage data calculation table.

NO ITEM OF CALCULATIONS CURRENT USE AUTOMATIC DEVICE

1. ESTIMATE HOUR USE PER DAY 8 HOURS 3 HOURS

2. ESTIMATE NUMBER OF DAYS 20 DAYS 20 DAYS

3. ENERGY USAGE PER TOILET 320W 320W

4. ENERGY USAGE PER DAY 8 X 320 = 2.56KW 3 X 320 = 960W

5. ENERGY USAGE IN 20 DAYS 2.56KW X 20 = 51.20KW 960W X 20 = 19.2KW

6. COST EACH TOILET PER MONTH RM 1,274.68 RM 497.68

7. ENERGY USAGE 24 TOILET/MONTH 1,228.8KW 384KW

8. COST 24 TOILET/MONTH RM 29,759.08 RM 9,560.06

From the table we can view the different of total bill need to pay for every

month, where it can saved around RM 20,199.02 each month. From the data we can

conclude by reduce total energy usage by using an automatic light on/off device, we

also saved the cost to pay on electrical bills.

By implementing this project it might help ILP Nibong Tebal to reduce some

of electrical cost.

CHAPTER 2

LITERATURE REVIEW

2.0 PIR – Passive Infrared Sensors

Nowadays PIR sensors are the one most popular use in security alarm system

for motion detection, its also widely use in house hold as light control. Human body

also generated infra red signal that can be detected by this sensor, in that term its suite

table to use as human detection either motion or direction.

Infrared radiation enters through the front of the sensor, known as the sensor

face. At the core of a PIR sensor is a solid state sensor or set of sensors, made from an

approximately 1/4 inch square of natural or artificial pyroelectric materials, usually in

the form of a thin film, out of gallium nitride (GaN), caesium nitrate (CsNO3),

polyvinyl fluorides, derivatives of phenylpyrazine, and cobalt phthalocyanine. (See

pyroelectric crystals.) Lithium tantalate (LiTaO3) is a crystal exhibiting both

piezoelectric and pyroelectric properties.

The sensor is often manufactured as part of an integrated circuit and may

consist of one (1), two (2) or four (4) 'pixels' of equal areas of the pyroelectric

material. Pairs of the sensor pixels may be wired as opposite inputs to a differential

amplifier. In such a configuration, the PIR measurements cancel each other so that the

average temperature of the field of view is removed from the electrical signal; an

increase of IR energy across the entire sensor is self-cancelling and will not trigger the

device. This allows the device to resist false indications of change in the event of

being exposed to flashes of light or field-wide illumination. (Continuous bright light

could still saturate the sensor materials and render the sensor unable to register further

information.) At the same time, this differential arrangement minimizes common-

mode interference, allowing the device to resist triggering due to nearby electric

6

fields. However, a differential pair of sensors cannot measure temperature in that

configuration and therefore this configuration is specialized for motion detectors.

2.0.1 Infrared Radiation

Infrared radiation exists in the electromagnetic spectrum at a wavelength that

is longer than visible light. It cannot be seen but it can be detected. Objects that

generate heat also generate infrared radiation and those objects include animals and

the human body whose radiation is strongest at a wavelength of 9.4um. Infrared in

this range will not pass through many types of material that pass visible light such as

ordinary window glass and plastic. However it will pass through, with some

attenuation, material that is opaque to visible light such as germanium and silicon. An

unprocessed silicon wafer makes a good IR window in a weatherproof enclosure for

outdoor use. It also provides additional filtering for light in the visible range.

2.0.2 Pyroelectric Sensors

The pyroelectric sensor is made of a crystalline material that generates a

surface electric charge when exposed to heat in the form of infrared radiation. When

the amount of radiation striking the crystal changes, the amount of charge also

changes and can then be measured with a sensitive FET device built into the sensor.

The sensor elements are sensitive to radiation over a wide range so a filter window is

added to the TO5 package to limit detectable radiation to the 8 to 14mm range which

is most sensitive to human body radiation.

Typically, the FET source terminal pin 2 connects through a pulldown resistor

of about 100 K to ground and feeds into a two stage amplifier having signal

conditioning circuits. The amplifier is typically bandwidth limited to below 10Hz to

reject high frequency noise and is followed by a window comparator that responds to

both the positive and negative transitions of the sensor output signal. A well filtered

power source of from 3 to 15 volts should be connected to the FET drain terminal pin

1.

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Fig 2.1 : PIR Typical Configuration

The MURATA IRA-E700 SERIES PIR sensor has two sensing elements

connected in a voltage bucking configuration. This arrangement cancels signals

caused by vibration, temperature changes and sunlight. A body passing in front of the

sensor will activate first one and then the other element whereas other sources will

affect both elements simultaneously and be cancelled. The radiation source must pass

across the sensor in a horizontal direction when sensor pins 1 and 2 are on a

horizontal plane so that the elements are sequentially exposed to the IR source. A

focusing device called Fresnel Lens is usually used in front of the sensor. This lens

help to focus the infrared signal detected direct to sensor face opening.

Fig 2.2 : PIR Detecting Method and Signal Output.

The figure below shows the MURATA PIR IRA-E700 SERIES internal

specifications and layout in its TO5 package. Note the wide viewing angle without an

external lens.

8

Fig 2.3 : Murata IRA-E700 Series PIR Sensors Specification.

2.1.3 Fresnel Lens.

A Fresnel lens is a Plano Convex lens that has been collapsed on itself as in

figure 5 to form a flat lens that retains its optical characteristics but is much smaller in

thickness and therefore has less absorption losses.

The Fresnel lens is made of an infrared transmitting material that has an IR

transmission range of 8 to 14 µm that is most sensitive to human body radiation. It is

designed to have its grooves facing the IR sensing element so that a smooth surface is

presented to the subject side of the lens which is usually the outside of an enclosure

that houses the sensor.

The lens element is round with a diameter of 1 inch and has a flange that is 1.5

inches square. This flange is used for mounting the lens in a suitable frame or

enclosure. Mounting can best and most easily be done with strips of Scotch tape.

Silicone rubber adhesive can also be used to form a more waterproof seal.

The Fresnel Lens has a focal length of 0.65 inches from the lens to the sensing

element. Figure 4.4 below shows the lens dimensions and lens detection angle and

Figure 4.5 show the construction of the lens.

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Fig 2.4 : Fresnel Lens Detection Angle And Lens Dimension.

Fig 2.5 : Fresnel Lens Construction

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2.1 Digital System And Logic Gate

Standard commercially available Digital Logic Gates are available in two

basic forms, TTL which stands for Transistor-Transistor Logic such as the 7400

series, and CMOS which stands for Complementary Metal-Oxide-Silicon which is

the 4000 series of chips. This is refers to the logic technology used to manufacture the

Integrated Circuit, (IC) or "chip" as it is commonly called. Normally, TTL IC's use

NPN type Bipolar Junction Transistors while CMOS IC's use Field Effect Transistors

or FET's for both their input and output circuitry. As well as TTL and CMOS

technology, simple digital logic gates can also be made by connecting together diodes

and resistors to produce RTL, Resistor-Transistor Logic circuits but these are now

less common.

2.1.1 Digital Logic States

All digital electronic circuits and microprocessor based systems contain

hardware elements called Digital Logic Gates that perform the logical operations of

AND, OR and NOT on binary numbers. In digital logic only two voltage levels or

states are allowed and these states are generally referred to as Logic "1" or Logic "0",

High or Low, True or False and which are represented in Boolean Algebra and Truth

Tables by the numbers "1" and "0" respectively. A good example of a digital logic

level is a simple light as it is "ON" or "OFF".

Most logic systems use "Positive logic", in which a logic "0" or "LOW" is

represented by a zero voltage, 0v or ground and a logic "1" or "HIGH" is represented

by a higher voltage such as +5 volts, with the switching from one voltage level to the

other, from either a "0" to "1" or "1" to "0" being made as quickly as possible to

prevent any faulty operation of the logic circuit. There is also a complementary

"Negative Logic" system in which the values and the rules of a logic "0" and a logic

"1" are reversed.

In standard TTL (transistor-transistor logic) IC's there is a pre-defined voltage

range for the input and output voltage levels which define exactly what is a logic "1"

level and what is a logic "0" level and these are shown below.

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2.1.2 TTL Input & Output Voltage Levels

Fig 2.6 : TTL Digital Logic Voltage Level

There are a large variety of logic gate types in both the Bipolar and CMOS

families of digital logic gates such as 74L, 74LS, 74ALS, 74HC, 74HCT, 74ACT etc,

with each one having its own distinct advantages and disadvantages and the exact

voltages required to produce a logic "0" or logic "1" depends upon the specific logic

group or family. However, when using a standard +5 volt supply any TTL voltage

input between 2.0v and 5v is considered to be a logic "1" or "HIGH" while any

voltage input below 0.8v is recognized as a logic "0" or "LOW". The voltage region

between these two voltage levels either as an input or as an output is called the

Indeterminate Region. CMOS logic uses a different level of voltages with a logic "1"

level operating at between 3 and 15 volts.

Then from the above observations, we can define the ideal Digital Logic Gate

as one that has a "LOW" level logic "0" of 0 volts (ground) and a "HIGH" level logic

"1" of +5 volts and this can be demonstrated as:

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Fig 2.7 : Ideal Digital Logic Voltage Level

Where the opening or closing of the switch produces either a logic level "1" or

a logic level "0".

2.1.3 Digital Logic Gates

In this section of digital Logic Gates, we have seen that there are 3 main basic

types of digital logic gates, the AND gate, the OR gate and the NOT gate. We also

saw that each gate has an opposite or complementary form of itself in the form of the

NAND gate, the NOR gate and the Buffer respectively, and that any of these

individual gates can be connected together to form more complex Combinational

Logic circuits.

We also saw that both the NAND gate and the NOR gate can both be classed

as "Universal" gates as they can be used to construct any other gate type. In fact, any

combinational circuit can be constructed using only 2 or 3-input NAND or NOR

gates. We also saw that NOT gates and Buffers are single input devices that can also

have a 3-state High-impedance output which can be used to control the flow of data

onto a common Data Bus wire.

Logic Gates can be made from discrete components such as Resistors,

Transistors and Diodes to form RTL (resistor-transistor logic) or DTL (diode-

transistor logic) circuits, but today's modern digital 74xxx series integrated circuits are

manufactured using TTL (transistor-transistor logic) based on NPN bipolar transistors

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or the faster CMOS MOSFET transistor logic used in 74Cxx and 4000 series logic

chips.

The 8 individual "standard" Digital Logic Gates are summarized below along with

their corresponding truth tables.

a. The Logic AND Gate

Symbol Truth Table

B A Q

0 0 0

0 1 0

1 0 0

1 1 1

Boolean Expression Q = A.B Read as A AND B gives Q

b. The Logic OR Gate

Symbol Truth Table

B A Q

0 0 0

0 1 1

1 0 1

1 1 1

Boolean Expression Q = A+B Read as A OR B gives Q

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c. The NOT gate

Symbol Truth Table

A Q

0 1

1 0

Boolean Expression Q = not A or A Read as inverse of A gives Q

d. The Logic NAND Gate

Symbol Truth Table

B A Q

0 0 1

0 1 1

1 0 1

1 1 0

Boolean Expression Q = A.B Read as A AND B gives NOT Q

e. The Logic NOR Gate

Symbol Truth Table

B A Q

0 0 1

0 1 0

1 0 0

1 1 0

Boolean Expression Q = A+B Read as A OR B gives NOT Q

15

f. The Logic Ex-Or Gate

Symbol Truth Table

B A Q

0 0 0

0 1 1

1 0 1

1 1 0

Boolean Expression Q = A ⊕ B Read as A OR B but not BOTH

gives Q

g. The Logic Ex-Nor Gate

Symbol Truth Table

B A Q

0 0 1

0 1 0

1 0 0

1 1 1

Boolean Expression Q = A ⊕ B Read if A AND B the SAME gives

Q

h. The Buffer

Symbol Truth Table

A Q

0 0

1 1

Boolean Expression Q = A Read as A gives Q

16

2.1.4 Pull-up and Pull-down Resistors

One final point to remember, when connecting together digital logic gates to

produce logic circuits, any "unused" inputs to the gates must be connected directly to

either a logic level "1" or a logic level "0" by means of a suitable "Pull-up" or "Pull-

down" resistor ( for example 1kΩ resistor ) to produce a fixed logic signal. This will

prevent the unused input to the gate from "floating" about and producing false

switching of the gate and circuit.

Fig 2.8 : Input Pin Pull-up and Pull-down Resistor

2.3 Bipolar Junction Transistor (BJT)

There are two types of standard transistors, NPN and PNP, with different

circuit symbols. The letters refer to the layers of semiconductor material used to make

the transistor. Most transistors used today are NPN because this is the easiest type to

make from silicon. This page is mostly about NPN transistors and if you are new to

electronics it is best to start by learning how to use these first. The leads are labeled

base (B), collector (C) and emitter (E).

17

These terms refer to the internal operation of a transistor but they are not much

help in understanding how a transistor is used, so just treat them as labels! . A

Darlington pair is two transistors connected together to give a very high current gain.

2.3.1 Transistor currents

The diagram shows the two current paths through a transistor. We can build

this circuit with two standard 5mm red LEDs and any general purpose low power

NPN transistor (BC108, BC182 or BC548 for example). The small base current

controls the larger collector current.

Fig 2.10 : Transistor Current Flow

Fig 2.9 : Transistor Circuit Symbols

18

When the switch is closed a small current flows into the base (B) of the

transistor. It is just enough to make LED B glow dimly. The transistor amplifies this

small current to allow a larger current to flow through from its collector (C) to its

emitter (E). This collector current is large enough to make LED C light brightly.

When the switch is open no base current flows, so the transistor switches off

the collector current. Both LEDs are off. A transistor amplifies current and can be

used as a switch. This arrangement where the emitter (E) is in the controlling circuit

(base current) and in the controlled circuit (collector current) is called common

emitter mode. It is the most widely used arrangement for transistors so it is the one to

learn first.

2.3.2 Functional model of an NPN transistor

The operation of a transistor is difficult to explain and understand in terms of

its internal structure. It is more helpful to use this functional model:

Fig 2.11 : NPN Transistor Functional Model

The base-emitter junction behaves like a diode.

A base current IB flows only when the voltage

19

VBE across the base-emitter junction is 0.7V or more.

The small base current IB controls the large

collector current Ic.

Ic = hFE × IB (unless the transistor is full on and saturated) hFE is the current

gain (strictly the DC current gain), a typical value for hFE is 100 (it has no

units because it is a ratio)

The collector-emitter resistance RCE is controlled by the base current IB:

o IB = 0 RCE = infinity transistor off

o IB small RCE reduced transistor partly on IB

o increased RCE = 0 transistor full on ('saturated')

A resistor is often needed in series with the base connection to limit the base

current IB and prevent the transistor being damaged.

Transistors have a maximum collector current Ic rating.

The current gain hFE can vary widely, even for transistors of the same type!

A transistor that is full on (with RCE = 0) is said to be 'saturated'.

When a transistor is saturated the collector-emitter voltage VCE is reduced to

almost 0V.

When a transistor is saturated the collector current Ic is determined by the

supply voltage and the external resistance in the collector circuit, not by the

transistor's current gain. As a result the ratio Ic/IB for a saturated transistor is

less than the current gain hFE.

The emitter current IE = Ic + IB, but Ic is much larger than IB, so roughly IE =

Ic.

2.3.3 Using a transistor as a switch

When a transistor is used as a switch it must be either OFF or fully ON. In the

fully ON state the voltage VCE across the transistor is almost zero and the transistor is

said to be saturated because it cannot pass any more collector current Ic. The output

device switched by the transistor is usually called the 'load'. The power developed in

a switching transistor is very small:

20

In the OFF state: power = Ic × VCE, but Ic = 0, so the power is zero.

In the full ON state: power = Ic × VCE, but VCE = 0 (almost), so the power is

very small.

This means that the transistor should not become hot in use and you do not

need to consider its maximum power rating. The important ratings in switching

circuits are the maximum collector current Ic(max) and the minimum current gain

hFE(min). The transistor's voltage ratings may be ignored unless you are using a

supply voltage of more than about 15V.

2.3.4 Protection Diode

Fig 2.12 : Transistor As A Switch

Fig 2.13 : Protection Diode Across Inductive Load

21

If the load is a motor, relay or solenoid (or any other device with a coil) a

diode must be connected across the load to protect the transistor from the brief high

voltage produced when the load is switched off. The diagram shows how a protection

diode is connected 'backwards' across the load, in this case a relay coil.

Current flowing through a coil creates a magnetic field which collapses

suddenly when the current is switched off. The sudden collapse of the magnetic field

induces a brief high voltage across the coil which is very likely to damage transistors

and ICs. The protection diode allows the induced voltage to drive a brief current

through the coil (and diode) so the magnetic field dies away quickly rather than

instantly. This prevents the induced voltage becoming high enough to cause damage

to transistors and ICs.

2.3.5 Connecting a transistor to the output from an IC

Most ICs cannot supply large output currents so it may be necessary to use a

transistor to switch the larger current required for output devices such as lamps,

motors and relays. The 555 timer IC is unusual because it can supply a relatively large

current of up to 200mA which is sufficient for some output devices such as low

current lamps, buzzers and many relay coils without needing to use a transistor.

A transistor can also be used to enable an IC connected to a low voltage

supply (such as 5V) to switch the current for an output device with a separate higher

voltage supply (such as 12V). The two power supplies must be linked, normally this

is done by linking their 0V connections. In this case you should use an NPN

transistor.

A resistor RB is required to limit the current flowing into the base of the

transistor and prevent it being damaged. However, RB must be sufficiently low to

ensure that the transistor is thoroughly saturated to prevent it overheating, this is

particularly important if the transistor is switching a large current (> 100mA). A safe

rule is to make the base current IB about five times larger than the value which should

just saturate the transistor.

22

Fig 2.14 : NPN and PNP Transistor Connection to Integrated Circuit (IC)

2.3.6 Choosing A Suitable NPN Transistor

The circuit diagram above show how to connect an NPN transistor, this will

switch on the load when the IC output is high. If you need the opposite action, with

the load switched on when the IC output is low (0V) please see the circuit for a

PNP transistor

.

The procedure below explains how to choose a suitable switching transistor. The

transistor's maximum collector current Ic(max) must be greater than the load current

Ic.

Load Current (IC) = Supply Voltage (VS)

Load Resistance (RL)(2-1)

The transistor's minimum current gain hFE(min) must be at least five times the load

current Ic divided by the maximum output current from the IC.

hfe (Min) > 5 xLoad Current (IC)

Max IC Current(2-2)

23

1. Choose a transistor which meets these requirements and make a note of its

properties: Ic(max) and hfe(min).

2. Calculate an approximate value for the base resistor:

3.

RB =VCC - hfe

5 X IC

(2-3)

4. For a simple circuit where the IC and the load share the same power supply

RB = 0.2 x RL x hfe

(2-4)When VC = VS

5. Then choose the nearest standard value for the base resistor.

6. Finally, remember that if the load is a motor or relay coil a protection diode is

required .

2.4 Relay

Fig 2.15 : Relay Schematic And Real Relay.

A relay is an electrically operated switch. Current flowing through the coil of

the relay creates a magnetic field which attracts a lever and changes the switch

contacts. The coil current can be on or off so relays have two switch positions and

most have double throw (changeover) switch contacts as shown in the diagram.

Relays allow one circuit to switch a second circuit which can be completely separate

from the first. For example a low voltage battery circuit can use a relay to switch a

24

230V AC mains circuit. There is no electrical connection inside the relay between the

two circuits, the link is magnetic and mechanical.

The coil of a relay passes a relatively large current, typically 30mA for a 12V

relay, but it can be as much as 100mA for relays designed to operate from lower

voltages. Most ICs (chips) cannot provide this current and a transistor is usually used

to amplify the small IC current to the larger value required for the relay coil. The

maximum output current for the popular 555 timer IC is 200mA so these devices can

supply relay coils directly without amplification. Relays are usually SPDT or DPDT

but they can have many more sets of switch contacts, for example relays with 4 sets of

changeover contacts are readily available.

2.4.1 Reed Relays

Reed relays consist of a coil surrounding a reed switch. Reed switches are

normally operated with a magnet, but in a reed relay current flows through the coil to

create a magnetic field and close the reed switch.

Reed relays generally have higher coil resistances than standard relays (1000

for example) and a wide range of supply voltages (9-20V for example). They are

capable of switching much more rapidly than standard relays, up to several hundred

times per second; but they can only switch low currents (500mA maximum for

example).

2.4.2 Solid State Relay (SSR)

A solid state relay (SSR) is an electronic switch, which, unlike an

electromechanical relay, contains no moving parts. The types of SSR are photo-

coupled SSR, transformer-coupled SSR, and hybrid SSR. A photo-coupled SSR is

controlled by a low voltage signal which is isolated optically from the load. The

control signal in a photo-coupled SSR typically energizes an LED which activates a

photo-sensitive diode. The diode turns on a back-to-back thyristor, silicon controlled

rectifier, or MOSFET transistor to switch the load.

25

Fig 2.16 : Bi-Directional Solid State Relay With Opto-Isolation.

Voltage applied to the control line of an SSR causes the LED to shine on the

photo-sensitive diode. This produces a voltage between the MOSFET source and its

gate, causing the MOSFET to turn on. An SSR based on a single MOSFET, or

multiple MOSFETs in a paralleled array works well for DC loads.

There is an inherent substrate diode in all MOSFETs that conducts in the

reverse direction. This means that a single MOSFET can't block current in both

directions. For AC (bi-directional) operation, two MOSFETs are arranged back to

back with their source pins tied together. Their drain pins are connected to either side

of the output. The substrate diodes then are alternately reverse biased in order to block

current when the relay is off. When the relay is on, the common source is always

riding on the instantaneous signal level and both gates are biased positive relative to

the source by the photo-diode.

It is common to provide access to the common source so that multiple

MOSFETs can be wired in parallel if switching a DC load. There is also commonly

some circuitry to discharge the gate when the LED is turned off, speeding the relay's

turn-off.

26

2.4.2.1 Advantages over mechanical relays

SSRs are faster than electromechanical relays; their switching time is

dependent on the time needed to power the LED on and off, on the order of

microseconds to milliseconds

Increased lifetime due to the fact that there are no moving parts, and thus no

wear

Clean, bounce less operation

Decreased electrical noise when switching

Can be used in explosive environments where a spark must not be generated

during turn-on

Totally silent operation

Smaller than a corresponding mechanical relay.

Can continue to operate while subjected to severe vibration.

2.4.2.2 Disadvantages

Fail short more easily than electro-mechanical relays

Increased electrical noise when conducting

Higher impedance when closed (-> heat production)

Lower impedance when open

Reverse leakage current when open (µA range)

Possibility of false switching due to voltage transients

Isolated bias supply required for gate charge circuit

Higher Transient Reverse Recovery time (TRR) due to the presence of Body

diode .

27

2.5 Timer 555 / 556

The 8-pin 555 timer must be one of the most useful ICs ever made and it is

used in many projects. With just a few external components it can be used to build

many circuits, not all of them involve timing! A popular version is the NE555 and this

is suitable in most cases where a '555 timer' is specified. The 556 is a dual version of

the 555 housed in a 14-pin package, the two timers (A and B) share the same power

supply pins. The circuit diagrams on this page show a 555, but they could all be

adapted to use one half of a 556. Low power versions of the 555 are made, such as the

ICM7555, but these should only be used when specified (to increase battery life)

because their maximum output current of about 20mA (with a 9V supply) is too low

for many standard 555 circuits. The ICM7555 has the same pin arrangement as a

standard 555.

The circuit symbol for a 555 (and 556) is a box with the pins arranged to suit

the circuit diagram: for example 555 pin 8 at the top for the +Vs supply, 555 pin 3

output on the right. Usually just the pin numbers are used and they are not labeled

with their function. The 555 and 556 can be used with a supply voltage (Vs) in the

range 4.5 to 15V (18V absolute maximum). Standard 555 and 556 ICs create a

significant 'glitch' on the supply when their output changes state. This is rarely a

problem in simple circuits with no other ICs, but in more complex circuits a

smoothing capacitor (e.g. 100µF) should be connected across the +Vs and 0V supply

near the 555 or 556.

The input and output pin functions are described briefly below and there are fuller

explanations covering the various circuits:

Astable - producing a square wave

Monostable - producing a single pulse when triggered

Bistable - a simple memory which can be set and reset

Buffer - an inverting buffer (Schmitt trigger)

28

2.5.1 Inputs Of 555/556

Fig 2.17 : Timer 555 and 556 Input/output Pin and Pin Assignment.

Trigger input: when < 1/3 Vs ('active low') this makes the output high (+Vs). It

monitors the discharging of the timing capacitor in an astable circuit. It has a high

input impedance > 2M .

Threshold input: when > 2/3 Vs ('active high') this makes the output low (0V)*. It

monitors the charging of the timing capacitor in astable and monostable circuits. It has

a high input impedance > 10M .

* providing the trigger input is > 1/3 Vs, otherwise the trigger input will override the

threshold input and hold the output high (+Vs).

Reset input: when less than about 0.7V ('active low') this makes the output low (0V),

overriding other inputs. When not required it should be connected to +Vs. It has an

input impedance of about 10k .

Control input: this can be used to adjust the threshold voltage which is set internally

to be 2/3 Vs. Usually this function is not required and the control input is connected to

29

0V with a 0.01µF capacitor to eliminate electrical noise. It can be left unconnected if

noise is not a problem. The discharge pin is not an input, but it is listed here for

convenience. It is connected to 0V when the timer output is low and is used to

discharge the timing capacitor in astable and monostable circuits.

2.5.2 Output Of 555/556

Fig 2.18 : Timer 555 Sinking And Sourcing Test.

The output of a standard 555 or 556 can sink and source up to 200mA. This is

more than most ICs and it is sufficient to supply many output transducers directly,

including LEDs (with a resistor in series), low current lamps, piezo transducers,

loudspeakers (with a capacitor in series), relay coils (with diode protection) and some

motors (with diode protection). The output voltage does not quite reach 0V and +Vs,

especially if a large current is flowing. To switch larger currents you can

connect a transistor.

The ability to both sink and source current means that two devices can be

connected to the output so that one is on when the output is low and the other is on

when the output is high. The top diagram shows two LEDs connected in this way.

This arrangement is used in the Level Crossing project to make the red LEDs flash

alternately.

30

Fig 2.18 : Timer 555 Output Protection Diode.

Like all ICs, the 555 and 556 must be protected from the brief high voltage

'spike' produced when an inductive load such as a relay coil is switched off. The

standard protection diode must be connected 'backwards' across the relay coil as

shown in the diagram.

However, the 555 and 556 require an extra diode connected in series with

the coil to ensure that a small 'glitch' cannot be fed back into the IC. Without this

extra diode monostable circuits may re-trigger themselves as the coil is switched off!

The coil current passes through the extra diode so it must be a 1N4001 or similar

rectifier diode capable of biasing the current, a signal diode such as a 1N4148 is

usually not suitable.

31

2.5.3 Timer 555/556 Monostable Circuit.

Fig 2.19 : Timer 555 Monostable Circuit With Manual Trigger

A monostable circuit produces a single output pulse when triggered. It is called a

monostable because it is stable in just one state: 'output low'. The 'output high' state is

temporary. The duration of the pulse is called the time period (T) and this is

determined by resistor R1 and capacitor C1:

T = 1.1 x R1 x C1 (2-5)

T = time period in seconds (s)

R1 = resistance in ohms ( )

C1 = capacitance in farads (F)

The maximum reliable time period is about 10 minutes.

Why 1.1? The capacitor charges to 2/3 = 67% so it is a bit longer than the

time constant (R1 × C1) which is the time taken to charge to 63%.

Choose C1 first (there are relatively few values available).

Choose R1 to give the time period you need. R1 should be in the range 1k to

1M , so use a fixed resistor of at least 1k in series if R1 is variable.

Beware that electrolytic capacitor values are not accurate, errors of at least

20% are common.

32

Beware that electrolytic capacitors leak charge which substantially increases

the time period if you are using a high value resistor - use the formula as only

a very rough guide!

For example the Timer Project should have a maximum time period of 266s

(about 4½ minutes), but many electrolytic capacitors extend this to about 10

minutes!

Fig 2.20 : Timer 555 Monostable Timing Diagram.

2.5.3.1 Monostable Operation

The timing period is triggered (started) when the trigger input (555 pin 2) is

less than 1/3 Vs, this makes the output high (+Vs) and the capacitor C1 starts to

charge through resistor R1. Once the time period has started further trigger pulses are

ignored.

The threshold input (555 pin 6) monitors the voltage across C1 and when this

reaches 2/3 Vs the time period is over and the output becomes low. At the same time

discharge (555 pin 7) is connected to 0V, discharging the capacitor ready for the next

trigger.

33

The reset input (555 pin 4) overrides all other inputs and the timing may be

cancelled at any time by connecting reset to 0V, this instantly makes the output low

and discharges the capacitor. If the reset function is not required the reset pin should

be connected to +Vs.

2.5.3.2 Power-On Reset Or Trigger

It may be useful to ensure that a monostable circuit is reset or triggered

automatically when the power supply is connected or switched on. This is achieved by

using a capacitor instead of (or in addition to) a push switch as shown in the diagram.

The capacitor takes a short time to charge, briefly holding the input close to

0V when the circuit is switched on. A switch may be connected in parallel with the

capacitor if manual operation is also required. This arrangement is used for the trigger

in the Timer Project.

Fig 2.21 : Power-On Reset Or Trigger Circuit

2.5.3.3 Edge-Triggering.

If the trigger input is still less than 1/3 Vs at the end of the time period the

output will remain high until the trigger is greater than 1/3 Vs. This situation can occur

if the input signal is from an on-off switch or sensor.

34

The monostable can be made edge triggered, responding only to changes of

an input signal, by connecting the trigger signal through a capacitor to the trigger

input. The capacitor passes sudden changes (AC) but blocks a constant (DC) signal.

For further information please see the page on capacitance. The circuit is 'negative

edge triggered' because it responds to a sudden fall in the input signal. The resistor

between the trigger (555 pin 2) and +Vs ensures that the trigger is normally high

(+Vs).

Fig 2.22 : Edge-Triggering Circuit

CHAPTER 3

PROJECT METADOLOGY

3.0 Introduction.

From the figure 3.1, a block diagram of the project the system can be divided into four

major section . The main major section are :

a. PIR Sensor Circuit .

b. Reed Switch Sensor Circuit.

c. Main Controller Circuit.

d. Light on/off and Power Supply Circuit.

FL

OR

EC

EN

T L

IGH

T C

IRC

UIT

+5V DC L N

LOUT

6A

MC

B

AC

240V

PASIVE

INFRARED

SENSOR

( PIR 2 )

PASIVE

INFRARED

SENSOR

( PIR 1 ) LIGHT ON / OFF

CONTROL AND

POWER SUPPLY

CIRCUIT

12V DC

PIR1 IN

PIR2 IN

ELECTRICAL

DISTRIBUTION

BOARD

SWI TO SW6 SENSE

SIGNALREED SWITH

SENSOR

( SW1 TO SW6 )

CONTROLLER

LIV

E IN

LIVE

OUT

NEUTR

AL

AUTOMATIC TOILET LIGHT ON / OFF MAIN BLOCK DIAGRAM

Fig 3.1 : Project System Block Diagram.

36

3.1 Project Development Stage.

The development of the project are divided into a few major stage, where in

each stage have a specific job and testing to be done. In figure 3.2 shows the stage of

development for the project.

PROBLEM DISCRIPTION

AND ISUE

ANALYSE AND FINDING

SOLUTION METHOD

CIRCUIT DESIGN AND

SIMULATE EACH SUB

CIRCUIT

ASSEMBLE THE CIRCUIT

GET DATA AND SYSTEM

BEHAVIOR

PART AND COMPONENT

PROCUMENT

TEST EACH SUB CIRCUIT

ASSEMBLE AND TEST THE

CIRCUIT AT REAL

LOCATION

COMBINE AND TEST

CIRCUIT AS FULL SYSTEM

CIRCUIT

TROUBLESHOOTI

NG

START

END

YES

NO

NO

NO

YES

YES

YES

Fig 3.2 : Project Development Flow Chart.

37

The project are mainly are to solve the problems occurs that had been explain

detailed in chapter 1. From the problem the user ( ILP Nibong Tebal ) had define its

mains requirement of the project, where it was the light inside the toilet only turn on

during people exist inside the toilet and turn off automatically when user left the

toilet. The user also request to use as minimum cost for the project due to the number

of toilet that required to be installed for the whole ILP Nibong Tebal.

From the main objective of the project, a few solution had been develop for

solving the problem. The first solution is to use counting method to define and

identify if any people still exist inside the toilet. Where in this method the number of

user will be counted and light still remains on if the counter still not zero. This

method are possible to be done, but after some development process the result shows

that some errors exist on its operation and there are to many condition to take care on

human behavior. Due to this solution seems still have a lot of development and

research need to be done, especially in the controller firmware program. The

development time required will not fit with the psm2 schedule.

Because of the errors and development time , the project switch to the second

alternative , where the existing of toilet user will indentify by motion and when the

door are close at sub toilet area. When the alternative had been chosen, the design

stage of are begin. During the design stage of the circuit, the input of the sensing

circuit with the output of a controller will be define trough the truth table and

karnough map. Where in the truth table and karnough map , the equation for the

output can be seen clearly. The circuit will drawn and after that it will simulate to see

the output response. To simulate the circuit, the software that are using is Circuit

Simulator Ver1.7. Where this simulator software are free license type and using Java

programming. The reason of choosing this type of simulator because of :

1. It was open source type of software and there is no license required to run

the software.

2. Simple and easy to use , that did not required to many setting must be set

before the simulation can be run.

3. The output can be select either in voltage , logic high / low and using led

or light.

38

The simulation output can be seen in figure 3.3 shows the simulation output

for controller circuit and figure 3.4 shows the simulation output for light on/off

circuit.

Fig 3.3.1 : Zone 1 Sensing Circuit

Fig 3.3.2 : Main Controller Simulation

39

Fig 3.4 : Light On/Off Controller Simulation.

Procument process will start after all simulation circuit give the outputs as

desired. Most of the component can be found at local component seller, only for the

PIR are quite difficult to find. For this project I had use the complete PIR module

from Cytron Technology at Taman Universiti, Skudai Johor. Below are the table list

of all component that are using in the project.

After all component had complete it will assemble to a board. In this project , I

use the Vero board. This the fast method on develop the prototype circuit compared

with PCB, where some extra process required that will effect my schedule. After that

the circuit will test portion by portion and the data of the test result will be discuss

detail on Chapter 5 : Result And Discussion. Figure 3.5 & figure 3.6 show the

picture of the circuit that had been assembled.

40

Table 3.1 : Automatic Toilet Visitor On/Off Light Control Component List.

PROJECT BILL OF MATERIAL

NO. COMPONENT QUANTITY PRICE/UNIT TOTAL PRICE

1 RESISTOR 1/4W 10% 560Ω 8 RM 0.05 RM 0.40

2 RESISTOR 1/4W 10% 3.9KΩ 3 RM 0.05 RM 0.15

3 RESISTOR 1/4W 10% 10KΩ 1 RM 0.05 RM 0.05

4 RESISTOR 1/4W 10% 1KΩ 1 RM 0.05 RM 0.05

5 TRANSISTOR BC337 3 RM 0.30 RM 0.90

6 LED 3MM GREEN 8 RM 0.20 RM 1.60

7 ELECTROLITIC CAPASITOR 100uF , 16V 1 RM 0.30 RM 0.30

8 ELECTROLITIC CAPASITOR 10uF , 16V 1 RM 0.30 RM 0.30

9 ELECTROLITIC CAPASITOR 4.7uF , 16V 5 RM 0.20 RM 1.00

10 CERAMIC CAPASITOR 0.1uF , 16V 8 RM 0.50 RM 4.00

11 IC 74LS32 - QUAD OR GATE 2 RM 1.40 RM 2.80

12 IC 74HC14 - NOR GATE 2 RM 2.00 RM 4.00

13 IC LM555 - TIMER 1 RM 1.00 RM 1.00

14 IC LM7805 – REGULATOR +5V 1 RM 1.50 RM 1.50

15 IC LM7812 – REGULATOR +12V 1 RM 1.50 RM 1.50

16 BRIDGE RECTIFIER 5A 1 RM 3.00 RM 3.00

17 PIR SENSOR MODULE ( CYTRON TECH. ) 2 RM 38.00 RM 76.00

18 REED SWITCH SENSORS 6 RM 5.00 RM 30.00

19 TRANSFORMERS 240V – 12V , 7VA 1 RM 12.00 RM 12.00

20 201 SERIES CONNECTOR 3WAY 3 RM 1.00 RM 3.00

21 201 SERIES CONNECTOR 6WAY 3 RM 1.50 RM 4.50

22 IC SOCKET 14 PIN 4 RM 0.20 RM 0.80

23 IC SOCKET 8 PIN 1 RM 0.20 RM 0.20

24 SPACER 10MM SCREW NUT 15 RM 0.55 RM 8.25

25 VERO BOARD 2 RM 2.50 RM 5.00

26 PLASTIC CASING 1 RM 5.00 RM 5.00

TOTAL PROJECT COST RM 167.30

41

ZONE 2 INPUT AND

INDICATOR

ZONE 1 INPUT AND

INDICATOR

ZONE 2 CONTROLLER

ZONE 2 TIMER

LIGHT CONTROLLER

CIRCUIT

Fig 3.5 : Main Controller Circuit Board.

STEPDOWN

TRANSFORMER

POWER SUPPLY

CIRCUIT

LIGHT ON/OFF RELAYLIGHT ON/OFF

CONTROL CIRCUIT

Fig 3.6 : Light On/Off Controller Circuit Board.

When each sub module had given the required outputs result, latter it will be

assemble as a fully system. In each sub circuit the connector had been use to make

easier to disconnected in between the module. At full system, the circuit will be tested

again to check either it was fully functional. The system also had been assemble to the

real problems location and the operation of the system are monitored and the response

of the system can see clearly during this test.

CHAPTER 4

SYSTEM AND CIRCUIT OPERATION

4.0 Introduction.

From the figure 4.1, a system block diagram of the project, it can be divided

into four major section . The main major section are :

a. PIR Sensor Circuit .

b. Reed Switch Sensor Circuit.

c. Main Controller Circuit.

d. Light on/off and Power Supply Circuit.

FL

OR

EC

EN

T L

IGH

T C

IRC

UIT

+5V DC L N

LOUT

6A

MC

B

AC

240V

PASIVE

INFRARED

SENSOR

( PIR 2 )

PASIVE

INFRARED

SENSOR

( PIR 1 ) LIGHT ON / OFF

CONTROL AND

POWER SUPPLY

CIRCUIT

12V DC

PIR1 IN

PIR2 IN

ELECTRICAL

DISTRIBUTION

BOARD

SWI TO SW6 SENSE

SIGNALREED SWITH

SENSOR

( SW1 TO SW6 )

CONTROLLER

LIV

E IN

LIVE

OUT

NEUTRAL

AUTOMATIC TOILET LIGHT ON / OFF MAIN BLOCK DIAGRAM

Fig 4.1 : Project System Block Diagram.

43

The main operation of the circuit is to turn on/off the toilet light automatically

based on present of the toilet user. When user entering or inside the toilet, the light

will turn on automatically. When user left the toilet, the light will turn off

automatically after a few second he/she left the toilet.

The sensor that being use for the system are the PIR sensor, for motion

detector and the reed switch sensor for open or close of the sub toilet door. For the

PIR sensor it was detect the motion of visitor in the main toilet and the reed switch is

detect the door closing inside the sub toilet area. PIR sensor will giving high output

pulse (+5V) when it detected a motion, while the reed switch will giving low signal

(0V) when the sub toilet door are close.

The controller will read the signal from the sensing circuit and verify either it

need to turn on/off the light. When controller receive high signal from PIR sensor or

low signal from reed switch , it identify as a visitor are inside the toilet and will giving

high output voltage to light on/off controller to turn on the light.

The light on/off controller are the main interface to the lighting circuit of the

toilet. It was the main who control to turn on or off the light, by close or open the

relay that replace the light switch. When it receive the signal high from main

controller , it will turn on the relay from NC – normally close to NO – normally open

to turn on the light. This section also are the main who provided the supply voltage

for the main controller and the sensing circuit.

The whole operation of the system can be simplified as bellow:

a. When the visitor entering to the toilet , their motion and movement will

detected by the PIR sensor and the system will turn on the light.

b. When the visitor enter the sub toilet are it required to close the toilet door. The

reed switch sensor will turn on and the light will remain on until the sub toilet

door are open. But the light will not turn off just the reed switch become

open, there is the delay timer in controller will keep the light still on until a

few second.

44

c. When the visitor walk tough the main toilet area , it again detected by PIR

sensor. When the visitor left the toilet the light are still remain on a few second

before the light automatically turn off.

4.1 Sensing Circuit.

The figure 4.2 below shows the sensing circuit area for the toilet, where it was

divided into 2 sensing zone. The sensing zone 1 are the open area at the main toilet

and sensing zone 2 are the sub toilet are.

Fig 4.2 : Sensing Zone Area.

45

4.1.1 Sensing Zone 1.

This is the Sensing zone for the open area inside the main toilet, where the

user will use the mirror and the sink. Basically the sensor are purpose to detect any

movement or motion that exist in the area when the user walking or using the sink and

mirror. The sensor that being use in this area is the PIR – Passive Infra Red Sensors,

(PIR ) PASIVE INFRARED SENSOR

MODULE

FRESNELL LENS

Fig 4.3 : The PIR Sensors Module.

The PIR sensor has three wires, which should be connected to the main

controller circuit as follows:

- GND - Connects to Ground

OUT - Output Connects to an I/O pin set to INPUT mode (or

transistor/MOSFET)

+ VCC - Connects to Vcc (+5V to + 20V) @ ~100uA

The PIR sensor gives a simple on/off signal. When it is triggered, it will read

high for approximately one second. When the sensor is triggered for an extended

period of time, it will continue to read high until no movement is detected. This

module can set to be triggered in two modes.

46

H Retrigger - Output remains HIGH when sensor is retriggered repeatedly. Output

results in repeated HIGH/LOW pulses. Output is LOW when idle.

L Normal - Output goes HIGH then LOW when triggered. Continuous motion is

LOW when idle (not triggered).

In this project the sensor are set in H Retriggering because it required to

always remaining at high logic pulse when there is any motion detected. The PIR

Sensor requires a „warm-up‟ time in order to function properly. This is due to the

settling time involved in „learning‟ its environment. This could be anywhere from 10-60

seconds. During this time there should be as little motion as possible in the sensors field

of view. There is a variable resistor (Delay Time) on the PIR sensor to control the „ON‟

delay time for the sensor. Turning the variable resistor clockwise will give longer „ON‟

delay time while turning anticlockwise with reduce the „ON‟ delay time.

The PIR Sensor has a range of approximately 5 meters. The PIR sensor can

sense object up to 120° within 1 meter range. The sensitivity can vary with

environmental conditions. The sensor is designed to adjust to slowly changing

conditions that would happen normally as the day progresses and the environmental

conditions change, but responds by making its output high when sudden changes occur,

such as when there is motion.

Fig 4.3 : The PIR Sensors Module Retriggering Jumper and Delay Adjust.

The PIR Module output are connected directly to the PIR connector at the

main controller that labeled as PIR1 and PIR2.

47

4.1.2 Sensing Zone 2.

The zone 2 sensing are the area to detect the existing of visitor that using the

sub toilet area. The main component that being use to sensing the visitors inside the

sub toilet area is the reed switch. The reed switch sensor is the type of switch that

operates by the magnetic fields. The sensor it self are divided into two component, it

is the reed switch and the reed magnet. The reed magnet actually are the permanent

magnet and its is use to change the switch from open to close condition.

The type can be Single Pole Single Throw (SPST) or Single Pole Double

Throw (SPDT). In this project both type can be use as the sensing , because the

circuit only required to detect either the switch are turn on or off.

When there is no user, the door are open and the reed magnet is away from the

reed switch and the switch are open. When the door are close the reed magnet are near

to the reed switch and the magnetic field from the reed magnet change the switch

position to close. Figure 4.4 below show the both condition of the reed switch at the

sub toilet door.

REED MAGNET

REED

SWITCH

B. DOOR CLOSE

SWITCH CLOSE

REED

SWITCH

A. DOOR OPEN

SWITCH OPEN

Fig 4.4 : The Reed Switch Condition During Door Open or Close.

48

The reed switch pin COMM are connected to ground of the circuit and pin NC

connected to input sensing at the main controller. Figure 4.5 below shows the zone 2

schematic and the switch output voltage condition . The reed switch and reed magnet

are mounting at the sub toilet door , while the resistor and led are paced at main

controller board.

5

60

56

0

56

0

56

0

56

0

56

0

SW1

SW2

SW3

SW4

SW5

SW6

+5V

GND

RE

ED

SW

ITC

H 1

RE

ED

SW

ITC

H 2

RE

ED

SW

ITC

H 3

RE

ED

SW

ITC

H 4

RE

ED

SW

ITC

H 5

RE

ED

SW

ITC

H 6

Fig 4.5 : Zone 2 Sensing Circuit.

49

GNDGND

VCCVCC

SW1 SW1REED SWITCH

AT OPEN

CONDITION

WHEN THE

DOOR ARE

OPEN

REED SWITCH

AT CLOSE

CONDITION

WHEN THE

DOOR ARE

CLOSE

LED

INDICATOR

Fig 4.6 : Zone 2 Sensing Output Voltage.

When the door are open , the output of sensing are at logic high (+5v) , there

are no current trough the resistor and the led. When the door are close, the reed

magnet will cause the switch change to close position. The sensing output will

connected to ground and cause the output change to low (0v). The flow trough the

resistor and the led indicator will light up.

4.2 Main Controller Circuit.

The function of the main controller is to identify the existing of the visitor in

the toilet and command the light controller circuit to turn ON the light. Main

controller actually can be divided into tree main section, zone 1 identification circuits,

zone 2 identification circuits and main control circuit. Figure 4.7 below shows the

schematic circuit of the main controller.

REED MAGNET

REED SWITCH

SENSOR

50

Fig 4.7 : Main Controller Circuit.

Zone 1 identification circuit will read the input signal from both PIR sensor

and giving logic output high (+5v) at ZONE1 test point when either one are triggered.

The output at ZONE1 test point will at high (+5v) if the motion are detected by the

PIR sensor and this are identify there is a visitor inside the toilet and the light are turn

ON. This circuit also include the input led circuit , to visualize with PIR are active by

light up the led when receive high input signal.

Zone 2 identification circuit will read the input from the reed switch sensor,

and the output of the Zone 2 are at high (+1.2v) when there is no user at zone 2. When

there is a user at zone 2 toilet the signal will turn to low (0v), this signal will feed to

an inverter to invert back to high (+5v) by using 74HC14 ( Inverter Logic Gates). This

circuit are required to use the CMOS type of IC due to the leakage current when using

the TTL type IC. Figure 4.8 shows the full schematic circuit for the zone 2

identification circuit and figure 4.9 shows the zone 2 timer circuit.

51

U1C

U1A

U1B

U1D

U2A

U2B

ZONE 2

OUTPUT

TIMER

SW1

SW2

SW3

SW4

SW5

SW6

Z2A

ZONE2

U1 & U2 = 74HC32 ( QUAD OR

GATES )

Z2B

Fig 4.8 : Zone 2 identification Circuit.

Z2A

Z2B

Fig 4.9 : Zone 2 Timer Circuit.

The timer are using the 555 timer in monostable mode operation and the main

function is to provide the delay for the ZONE 2 output . When there is no user inside

the sub toilet are , the test point SW1 – SW6 are at logic high ( +1.2v) . The inverter

will change to the logic low (0v) at U1A, U1B and U1C input. When all input are

logic low it will give all the output also low and logic low at Z2A test point. This also

give low output at the Z2B after the timer circuit.

52

When there is a user go inside the sub toilet area, for an example at toilet no 3

and the reed switch signal at SW3. When user close the toilet door the reed switch

will change to close position and will giving an output logic low at SW3 signal. The

inverter will invert the logic level become logic high (+5v) at the input of U1B. When

there is logic high , the output of U1B, U1D and U2A will become logic high(+5v).

The output U2A at logic high also giving logic high at the input of the timer circuit.

The output of the timer circuit Z2B , will still at logic low because the circuit only

trigger when there is changes from logic high(+5v) to logic low(0v). When the input

Z1A at logic High(+5v) it will cause the ZONE 2 output at logic high(+5V) and the

controller will turn on the light.

When user left the sub toilet the SW3 signal will change to high (+1.2V) and

after the inverter will goes to logic low (0v). Its also cause the output U2A at test

point Z2A change to logic low(0v). When the timer detect the changes from

high(+5v) to low (0v) it will trigger the circuit and giving the high (+5v) output pulse

at Z2B. The high (+5v) output pulse will keep the ZONE 2 output remain at high

(+5v) until the pulse goes to low. This will keep the light remain on after user left the

sub toilet until a few second it will turn off automatically. The time of the pulse are

depend on the resistor 1K and the capacitor 100uF at the timer circuit. The time of the

timer are using the equation T = 1.1 X RXC , so the timer pulse in this project are

T = 1.1 x 1K x 100uF

= 0.11 second

The delay time can be adjust to make it more logger time by change the value

of the resistor and the capacitor.

The main controller output is depend on the input from ZONE 1 and ZONE 2

signal, this two input will attach to the OR gate that control the LIGHT ON/OFF

signal. When ZONE 2 and ZONE 1 at low (0v) the LIGHT ON/OFF signal also at

logic low (0v) and the light are turn OFF. When either one of the ZONE 1 or ZONE 2

at logic high (+5v) the LIGHT ON/OFF output will also at logic high (+5v) and the

light will turn ON. Table 4.1 below shows the truth table of the controller input and

output.

53

Table 4.1 : The Main Controller Truth Table.

NO. SW1 – SW6 PIR1 / PIR2 ZONE 1 ZONE 2 LIGHT

ON/OFF LIGHT

1 OPEN 0 0 0 0 OFF

2 CLOSE 0 0 1 1 ON

3 OPEN 0 0 1 UNTIL 0.1

SEC 1 UNTIL 0.1 SEC

ON UNTIL 0.1 SEC

4 OPEN 0 0 0 0 OFF

5 OPEN 1 1 0 1 ON

6 OPEN 0 0 0 0 OFF

4.3 Light On/Off Controller.

This part of the system are mainly the one that to control the ON/OFF of the

light. Due to the different voltage type and the value of the voltage where the output

of the main controller are in +5v DC but the lighting circuit are using the 240v AC, so

this circuit required to isolate and ensure the controller can control the lighting circuit.

This circuit are required to turn ON/OFF the relay that replace the light switch. In

this circuit are also include the power supply circuit to supply the DC for the

operating of the other circuit like the main controller and sensing circuit. The AC

supply for the light will be take as a input AC supply for the power supply circuit and

the circuit will provide two supply DC voltage, +5v DC and +12v DC. The +5v DC

are required for the most component in the system especially for the IC. The +12v DC

are required to supply an operating voltage for the PIR sensor and the Relay. Figure

4.10 shows the light on/off controller schematic circuit.

54

Fig 4.10 : Light On/Off Controller Circuit.

The main component that being use in the power supply circuit is the Bridge

Rectifier, 78XX series regulator IC and the Capacitors. The main component for the

light controller is using the general purpose transistor BC337 and the Relay.

When the Main Controller giving logic low (0v) at the LIGHT ON/OFF input

signal , there is no voltage for biasing the transistor to turn on. When the transistor are

off , there is no current flow trough the relay coil and the relay switch are remain at

NC position. The lighting circuit are in open condition and the light are OFF.

When the Main Controller giving logic high (+5v) at the LIGHT ON/OFF

input signal, the base of the transistor will get the biasing voltage (VBE) that will

turn ON the transistor. When the transistor turn ON , current will flow trough the

transistor to the ground and the current from VCC supply will flow trough the relay

coil. This will make the coil will energize and there is magnetic fields exist in the coil.

The magnetic fields will energize from NC position to NO position, this will make the

lighting circuit at close condition and the light will turn ON.

55

Because of the nature of the inductive relay coil, when the transistor turn OFF

, the voltage across the coil will rise rapidly. This is because of the energy stored in

the magnetic fields is returned to the circuit. A protection diode will required to be

connected across the relay coil to clamp the magnetic fields at 0.6v above the supply

rail. This will protect the transistor from over voltage breakdown and cause

permanent damage to it.

The relay that need to be use in this project the relay contact should be able to

handle the lighting current. It must be calculated carefully to chose the type of the

relay need to be use. If the current are bigger , the mechanicals relay can be replace

with a Solid State Relay type where it can handle more bigger current and more

reliable.

CHAPTER 5

TESTING AND RESULT

5.0 Introduction.

Testing of the circuit is an important part of development in this project ,

result of the testing will shows either the project functional or not and what other

modification are required. During the implementation of the project, testing process

are divided in to a few part it is :

a). Light On/Off Controller Circuit Test.

b). Sensing Circuit Test

c). Main Controller Circuit Test.

d). Full System Integrate Test.

e). On Location Test.

All the testing are done part by part is to ensure al the circuit are working and

functional as required. Before it was assemble as a system the, during each sub circuit

test got any modification and repair are required it can be known early. The first

circuit that being assemble ad test are the Light On/Off controller, it is because this

circuit are the one that control the lighting circuit and it also provide the DC supply

voltage to the other circuit.

Most of the result of the testing are the voltage level in each test point and also

indicator to the light either ON/OFF. The main equipment that are being use is a

Digital Multimeter.

57

5.1 Light On/Off Controller Circuit Test.

The requirement of the testing for this circuit is to identify the Power Supply

voltage and identify the capability of the On/Off circuit to control the AC load . For

the Power Supply Circuit, the test are to measure the supply voltage for +12V and

+5V supply. This are required to ensure the voltage that being supply to other circuit

are correct and will not damage the component especially the IC. Figure 5.1 below

shows the connection during the testing process.

LIGHT ON/OFF

CONTROLLER

+12V

+5V

GND

LIGHT

ON/OFF

1

2

3

L N

LIGHT

AC 240V

Fig 5.1 : Light On/Off Controller Circuit Test.

Table 5.1 Below show the test result 1 and 2 for the power supply voltage

measurement. From the result shows that the voltage level are same as the design.

Table 5.1 : +12V And +5V Voltage Measurement Result.

No. Voltage Supply Measurement Voltage Result

1 +12V +11.83V Ok

2 +5V +5.2V Ok

58

After supply voltage had been confirm correctly, next is the testing of the

On/Off control circuit. In this test the +5V supply will short to Light On/Off input

signal. This action are to simulate the controller output where in logic high (+5V)

when command to turn on the light. This is to make the transistor getting the biasing

voltage to turn on and energized the relay coil to close position.

From testing result shows, when +5V are attach to the Light On/Off input , the

light will turn ON. When it was remove from the input the light will turn OFF. From

the result, this circuit are functional as required.

5.2 PIR Sensor Testing.

In this PIR testing is to see the response of the PIR by the distance of

detection, angle of detection and material type of detection. Figure 5.2 below show

the connection of the PIR sensors are attach to the Light On/Off Controller for the

testing purposed.

LIGHT ON/OFF

CONTROLLER

+12V

+5V

GND

LIGHT

ON/OFF

L N

LIGHT

AC 240V

TARGET

MOVEMENT

PIR SENSORS

PIR OUTPUT

SIGNAL

Fig 5.2 : PIR Sensor Circuit Test.

59

When PIR are detected any motion in front of the lens, it circuit will giving

and high output pulse, it will trigger the Light On/Off Controller to turn ON the Light.

During then PIR was triggered the output pulse will be measured using multimeter

and the duration of triggered will be recorded. The subject also will be ask to move

until a few distance and angle from the PIR sensor to measured the maximum

detection angle and distance of the PIR.

The PIR also test for type of detection material, in this testing I was using the

plastic and metal move across the PIR lens. Table 5.2 below shows the result that had

been observe during the testing, and the figure 5.3 show the subject and the maximum

distance detection of the PIR sensor.

Table 5.2 : PIR Sensor Response.

No. Type Of Specification PIR Response

1 Triggering Voltage +3.3V

2 Max Delay Triggering Pulse 10 Second

3 Max Detection Range 6 Meters

4 Max Detection Angle 120 Degree

5

Type Of Object To Triggered

a. Plastic Not Triggered

b. Metal Triggered

c. Human Triggered

d. Insect Not Triggered

e. Mammals like Cats/Rats Triggered

60

Fig 5.3 : PIR Sensor Detection Range.

From the result above , the PIR sensor having a wide range of detection but

the problems is, it can be triggered by any material that having different heat from the

environment area and also by the small animal like rats or cat.

5.3 Reed Switch Sensor Testing.

The reed switch sensor are the one will mounted at the door of the sub toilet

area. During the testing its only to measured the voltage at the test point SW1 – SW6

during the door open and close. Figure 5.4 show the measuring point at the reed

switch sensor.

61

56

0

56

0

56

0

56

0

56

0

56

0

SW1

SW2

SW3

SW4

SW5

SW6

+5V

GND

RE

ED

SW

ITC

H 1

RE

ED

SW

ITC

H 2

RE

ED

SW

ITC

H 3

RE

ED

SW

ITC

H 4

RE

ED

SW

ITC

H 5

RE

ED

SW

ITC

H 6

Fig 5.4 : Reed Sensor Test.

From the testing the result show the sensor are at logic high (1.2V) during the

door open and low (0v) when the door close. Table 5.3 below the test result of the

reed switch sensor.

Table 5.3 : Reed Sensor Measurement Result.

No. Door Position Measurement Voltage Result

1 Open +1.2V Ok

2 Close 0V Ok

62

5.4 Main Controller Testing.

During the main controller testing, every test point will be measured the

voltage level. The sensor part are now connected to the main controller and the testing

done zone by zone. When testing the Zone 1 , the PIR are connected to the main

controller and the reed switch sensor at zone 2 all at open condition. When Zone 2

testing the PIR will take away from the main controller, and one of the reed switch are

in close condition. Table 5.4 – 5.6 show the test result of the main controller and

figure 5.4 show the test point on the main controller circuit.

Table 5.4 : Zone 1 Circuit Test Point Measurement Result.

Active PIR PIR1 Test Point PIR2 Test Point ZONE1 Test Point

PIR1 +3.3V 0V +5V

PIR2 0V +3.3V +5V

Table 5.5 : Zone 2 Circuit Test Point Measurement Result.

Active Switch

SW1 SW2 SW3 SW4 SW5 SW6 Z2A

Test Point Z2B

Test Point

ZONE2 Test Point

SW1 0V 1.2V 1.2V 1.2V 1.2V 1.2V +5V 0V +5V

SW2 1.2V 0V 1.2V 1.2V 1.2V 1.2V +5V 0V +5V

SW3 1.2V 1.2V 0V 1.2V 1.2V 1.2V +5V 0V +5V

SW4 1.2V 1.2V 1.2V 0V 1.2V 1.2V +5V 0V +5V

SW5 1.2V 1.2V 1.2V 1.2V 0V 1.2V +5V 0V +5V

SW6 1.2V 1.2V 1.2V 1.2V 1.2V 0V +5V 0V +5V

NONE 1.2V 1.2V 1.2V 1.2V 1.2V 1.2V 0V +5v

PULSE +5v

PULSE

Table 5.6 : Main Circuit Test Point Measurement Result.

ZONE 1 ZONE 2 LIGHT ON/OFF LIGHT

0V 0V 0V OFF

+5V 0V +5V ON

0V +5V +5V ON

63

Fig 5.5 : Main Controller Schematic And Test Point Location.

64

5.5 Full System Test.

After all subsystem already been verified functional, it will assemble as a full

system, during this stage it will be tested again to verified it was functional. In full

system all the above sub system will be connected together. In order to make the each

sun module easily to assemble and disconnected , in this project I use the connector

for the connection. Figure 5.5 below shows the picture of the project in fully system

integrated together.

Fig 5.6 : Project Full System Integration.

65

In the full system test , the project output result show same as desired

requirement. The PIR detect the motion until 6 meters around and when user close the

sub toilet door the light are remain ON. When user left the toilet, the light wait after a

few second to turn OFF. From the observation the maximum of delay time to turn off

the light is around 10 second.

5.6 On Location Test.

In order to see the real response of the project, it was assemble to the desired

location at one of the toilet in ILP Nibong Tebal. A Number of user had being ask to

become the test subject on testing the project.

ZO

NE

1 S

EN

SIN

GZ

ON

E 2

SE

NS

ING

MOTION DETECTION AREA

SWITCH SENSOR DETECTION AREA

REED

SWITCH

REED

MAGNET

SW1

PIR1

PIR2

PASIVE INFRARED MOTION

SENSOR

ZONE 2 SENSING AREAREED SWITCH SENSOR X 6

ANY SWITCH ON = PEOPLE EXIST

IN TOILET AREA AND LIGHT WILL

TURN ON UNTIL ALL SWITCH ARE

OFF.

ZONE 1 SENSING AREAPASIVE INFRERED SENSOR X 6

DETECT ON MOTION EXIST IN THE

AREA AND WILL TURN ON THE

LIGHT UNTIL THERE IS NO MOTION

DETECTED LIGHT WILL TURN OFF.

PIR SENSOR 1 PIR SENSOR 1 REED SWITCH SENSOR

Fig 5.7 :On Location Assembly And Test.

The result during the real testing shows the system is fully functional and

same as the full system testing. From the test result, the system are 100% functional

as desired application in the toilet of ILP Nibong Tebal.

CHAPTER 6

CONCLUSION

6.0 Conclusion.

During the development of the project, it was trained me on solving and

understand the system operation. The most critical in the project was during the

analyze the problems and to find the correct solution to solve the problem. During the

early stage of the project , I was proposed the different method to detect the existing

of the visitor in the toilet. Where in that time the existing of the visitor are detected by

direction of the movement either enter or leaving the toilet and counting the number

of visitor still exist to turn ON or OFF the toilet light.

But when the circuit had design for the solution are not working correctly, I

had found the method is not means impossible to apply but the time and budget are

limited me to continue on the method. There is still a lot of research and

developments need to be study to apply the solution especially on the microcontroller

programming.

Because of that the others solution are required to take place, and in the

second solution it was changing in the way of user detection. In the second solution I

was take the nature of the human behavior during using the toilet and divided the

detection area by two section based on the area of detection. For the main toilet area it

was an open space where it have the sink . By the nature user are always use the area

to wash hands and using the mirror to comb the hair. The movement during the

activities was detected by using the PIR sensor. The light will always on when the

PIR was triggered and will turn OFF if the PIR doesn‟t detect any motion in the area.

67

For the sub toilet area , by the nature during visitor using the toilet the toilet

door will be close. The closing of the toilet door will detect to identify the user are

exist in the area. So in all sub toilet area I was using the Reed switch sensor , where

the sensor switch will close condition when the door are close. But to ensure the door

keep open when there is no visitor inside the toilet it will required a devise that can

push the door remain open. For this application I had identify a mechanicals devise

by using spring to push back the door to remain open.

During the design stages , the simulation software had helping me a lot to

identify either the circuit are working and functional. It also help me a lot to identify

the circuit problem during trouble shooting stages of the project.

When the project had assemble to the problems location it was show the

positive response and functional as desired. But during the PSM2 demo , one of the

panel had asking about the men pee section area , where he had issue when user using

the area it required to move their head or hand to keep the light turn on. Because of

that I had suggest to using the other sensor to detect the existing of user in the area.

The sensor can be use is the IR Sensor that having an transmitter and receiver, when

the user place their self when using the area it will block the receiver to receive the IR

signal and this cause the receiver generate high logic output pulse to trigger on the

light.

6.1 Suggestion And Future Development.

From the result of the project I found that the PIR sensor are useful to solve a

lot of problem area especially to control the turn ON/OFF the light. It also can be use

to control the corridor light or the classroom light to make the electrical energy can be

safe. It also can be use to add in safety to the people when using the machine where in

one cased in the ILP one of the student hand had been cut bay the machine. There is a

lot of study and research can be done especially to make the PIR sensor on can be

triggered only by the human, because in current sensor its can be triggered by small

animals like cats or rats.

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REFFERENCES

1. Glolab Corpration. (2003). Direction Sensing Infrared Motion Detector Sensor.

2. Marty Brown . (2001). Power Supply Cookbook. 2nd

Edition. Newness.

3. Boylested, R. & Neleskey, L. (1996). Electronic Device And Circuit Theory.1st Ed.

New Jersey. Prentice-Hall International.

4. Robert A. Peace , (1993). Trouble Shooting Analog Circuit. National

Semiconductor. Newness.

5. Cyril W. Lander. (1992). Power Electronic. 3rd

Edition. McGraw Hill Book

Company.

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APPENDIX 1

Project Schematic

And

Project Component List

70

APPENDIX 2

Component Data Sheet

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APPENDIX 3

PSM2 Presentation Slide