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A DESIGN OF AN AIR IONIZER USING THE COCKCROFT – WALTON

VOLTAGE MULTIPLIER

SUZI BINTI MUHAMAD

This report is submitted in partial fulfillment of requirements for the award of Bachelor

of Electronic Engineering (Industrial Electronics) With Honours

Faculty of Electronic and Computer Engineering

Universiti Teknikal Malaysia Melaka

30 APRIL 2009

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UNIVERSTI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER

BORANG PENGESAHAN STATUS LAPORAN

PROJEK SARJANA MUDA II

Tajuk Projek : A DESIGN OF AN AIR IONIZER USING THE

COCKCROFT-WALTON VOLTAGE MULTIPLIER Sesi

Pengajian : 2008/2009

Saya SUZI BINTI MUHAMAD

mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-

syarat kegunaan seperti berikut:

1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.

2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.

3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi

pengajian tinggi.

4. Sila tandakan ( √ ) :

SULIT*

(Mengandungi maklumat yang berdarjah keselamatan atau

kepentingan Malaysia seperti yang termaktub di dalam AKTA

RAHSIA RASMI 1972)

TERHAD*

(Mengandungi maklumat terhad yang telah ditentukan oleh

organisasi/badan di mana penyelidikan dijalankan)

TIDAK TERHAD

Disahkan oleh:

__________________________ ___________________________________ (TANDATANGAN PENULIS) (COP DAN TANDATANGAN PENYELIA)

Alamat Tetap: KG PERMATANG MACHANG JELAWAT,16070 BACHOK

KELANTAN

Tarikh: ……………………….. Tarikh: ………………………..

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“I hereby declare that this report is the result of my own works except for quotes as cited

in the references.”

Signature :…………………………

Name : SUZI BINTI MUHAMAD

Date :…………………………

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

terms of scope and quality for the award of Bachelor of Electronic Engineering

(Electronic Industrial) with Honours”

Signature : ……………………………….

Supervisor‟s Name : EN.ZULKARNAIN BIN ZAINUDIN

Date : ……………………………….

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Special dedicated to my beloved parent, family, lecturer, friends, who had strongly

encouraged and supported me in my entire journey of learning.

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ACKNOWLEDGEMENT

I have completed my thesis which is a partial fulfillment of requirement for the

degree of Bachelor in Electronic Engineering (Industrial Electronic).

On this opportunity, I would like to express my gratitude to the Faculty of

Electronic Engineering, Universiti Teknikal Malaysia Melaka generally and especially

to my supervisor En.Zulkarnain Bin Zainudin for her help, advice and guidance

throughout the process of searching, collecting information, analyzing and completing

the report.

To my parent, I would like to express million of thanks to them for their support

and always understanding in everything. Hence, I would like to thanks to all my friends

especially 4 BENE student for their great cooperation and supports and also to everyone

who involve in this project either direct or indirect.

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ABSTRACT

Air Ionizer is a project that required design by using the Cockcroft-Walton

Voltage Multiplier to generate negative ion. The air ionizer will produced negative ions

in the air for a small room such as the tutorial room in FKEKK. This project will

develop an air ionizer which can produce the negative ions to the air. The development

of the air ionizer will involve electronic circuit. The Cockcroft-Walton design is based

on the Half-Wave Series Multiplier. By using only capacitor and diodes, these voltage

multipliers can step up relatively low voltage to extremely high value. This project will

focus on the generation of a massive amount of negative ions. The advantages of this

project will using a low cost component and easy to insulate. The problem statements

are the quality of air is reducing and causing many health problems to mankind. Beside

that, now there is green house effect that will cause the damage to a human such as skin

effect, asthma and other illness related to the air. This circuit is design to solve the

problem related to the low quality air in a small room. The main objectives of this

project are to generate negative ions by exposing air to a high negative voltage and to

converts AC or pulsing DC electrical power from a low voltage level to a higher DC

voltage level. Through this project, the characteristic of the Cockcroft-Walton Multiplier

circuit will discussed and the related circuit will be design and simulated.

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ABSTRAK

Projek ini dibuat bagi mereka satu litar yang boleh digunakan untuk

menghasilkan ion negative didalam udara dengan menggunakan pendarab voltan

Cockcroft-Walton. Pengion negative ini akan digunakan bagi menghasilkan ion negative

untuk kawasan yang kecil seperti bilik tutorial di FKEKK. Pengion yang direka ini akan

menghasilkan ion negative di dalam udara. Projek ini memerlukan rekaan dan binaan

litar elektronik keseluruhannya. Dengan hanya menggunakan capacitor dan diod akan

menaikkan voltan yang rendah kepada voltan yang tinggi. Kebaikan projek ini adalah

ianya menelan belanja yang murah bagi kos komponen dan mudah untuk di reka.

Pengion ini direka berdasarkan teori Cockcroff-Walton yang membuktikan bahawa ion

negative dapat dipisahkan daripada udara sekiranya voltan yang tinggi dialirkan pada

satu konduktor pada udara. Pengion negative ini penting bagi mengurangkan ion-ion

positif dalam udara yang mana sekiranya terlalu banyak ion akan memberi kesan

negative kepada kesihatan manusia. Pernyataan masalah bagi projek ini adalah kualiti

udara yang semakin berkurang dan kesan rumah hijau yang akan mendatangkan

kemudaratan kepada manusia seperti masalah kulit, lelah dan lain-lain penyakit. Objektif

utama projek ini adalah untuk mereka satu litar pengion yang dapat menghasilkan ion-

ion negative dalam udara yang dapat mendedahkan udara kepada negative voltan yang

tinggi berdasarkan teori Cockcroft-Walton. Melalui projek ini, ciri-ciri pengganda

Cockcroft-Walton dapat dikenalpasti dan dibincangkan manakala litar yang terlibat akan

dibuat simulasi bagi memperoleh voltage keluar yang memenuhi syarat teori tersebut.

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TABLE OF CONTENT

CHAPTER TITLE PAGE

PROJECT TITLE i

REPORT STATUS CONFIRMATION FORM ii

DECLARATION iii

SUPERVISOR CONFIRMATION iv

DEDICATION v

ACKNOWLEDGEMENT vi

ABSTRACT vii

ABSTRAK viii

CONTENTS ix

LIST OF FLOW CHART xiii

LIST OF TABLE xiv

LIST OF FIGURE xv

LIST OF SHORTFORM xi

I INTRODUCTION

1.1 Introduction of the Project 1

1.2 Objective of Project 2

1.3 Problem Statement 3

1.4 Scope of Project 4

1.5 Project Methodology 5

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II PROJECT BACKGROUND

2.1 Literature Study on Air Ionizer 7

2.2 Literature Study on Cockcroft-Walton Voltage

Multiplier 9

2.2.1 Cockcroft-Walton Application 11

2.2.2 Voltage Multiplier 12

2.2.3 How it works 16

2.2.4 How Negative Ions Purify the Air 17

2.2.5 About Air Ion 18

2.4 Literature Study on Ionizer Technology 20

2.4.1 AC Ionizers 21

2.4.2 DC Ionizers 22

III METHODOLOGY

3.1 Introduction 23

3.2 Block Operation of Circuits 25

3.2.1 Power Supply 25

3.2.2 Cockcroft-Walton Voltage Multiplier 25

3.2.3 Output Voltage 25

3.3 Design of Cockcroft-Walton Voltage Multiplier 26

3.3.1 Regulation and Ripple Calculation 27

3.4 Analyzed of Voltage Multiplier Circuit 28

3.4.1 Example of Air Ionizer Circuit 33

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IV RESULT

4.1 Calculation Result 34

4.2 Simulation Result 37

4.2.1 Simulation circuit, where 0Vdrop

under no load condition 38

4.2.2.1 Graph for Simulation Circuit 47

4.2.2 Simulation circuit, based on Frequency

Value 50

4.2.3 Design a Cockcroft-Walton Voltage

Multiplier 67

4.2.4 Output Waveform 70

4.3 Measuring Result 70

4.3.1 Measuring Result for Output Voltage 70

4.3.2 Measuring Result after Charging Capacitor 73

4.4 Component Layout 74

4.5 Design of Air Ionizer 75

4.5.1 Air Ionizer Circuit Diagram 75

4.5.2 Air Ionizer Circuit Model 78

4.6 Measuring the Negative Ions 79

V CONCLUSIONS AND DISCUSSION

5.1 Discussion 82

5.2 Conclusion 84

REFERENCES 85

APPENDIX 87

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LIST OF TABLE

TABLE TITLE PAGE

2.1 Application of the Cockcroft-Walton Voltage

Double circuit 11

4.1 Simulation result, where 0Vdrop under no load

Condition 48

4.2 Simulation result using a difference frequency 65

4.3 Measuring Results for Output Voltage 70

4.4 The Output Voltage for Charging Capacitor 73

4.5 Output Voltages and Sum of Ions Per Cubic Centimeter 80

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LIST OF FIGURE

FIGURE TITLE PAGE

2.1 Cockcroft-Walton Voltage Multiplier 10

2.2 Voltage Multipliers circuit 12

2.3 Cascade Voltage Multipliers 12

2.4 Positive and Negative Cockcroft-Walton

Multiplier circuit 13

2.5 Cockcroft -Walton x8 voltage multiplier 14

2.6 Cockcroft-Walton (x8) waveforms. Output is v(8). 15

2.7 Two Stage of Cockcroft Walton Multiplier 16

2.8 The curve showing CW output voltage 17

2.9 Schematic diagram of an AC-type ionizer 21

2.10 Schematic of a DC-type ionizer. 22

3.1 Flow chart of Project Progress 24

3.2 Block Diagram of Air Ionizer 25

3.3 Simulation of a 3 stage CW multiplier 26

3.4 Cascade circuit according to Cockcroft Walton 29

3.5 Waveform of potentials at the nodes, no load 30

3.6 Loaded cascade circuits, definitions of voltage drop

Vo and ripple V2 32

3.7 Negative Ionic Generator Circuit 33

4.1 Simulation for 8 stages CW circuit using pF10 capacitor 38

4.2 Simulation for 8 stages CW circuit using pF300 capacitor 39

4.3 Simulation for 8 stages CW circuit using nF3.3 capacitor 40

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4.4 Simulation for 8 stages CW circuit using nF10 capacitor 41

4.5 Simulation for 8 stages CW circuit using nF51 capacitor 42

4.6 Simulation for 8 stages CW circuit using nF100 capacitor 43

4.7 Simulation for 8 stages CW circuit using nF300 capacitor 44

4.8 Simulation for 8 stages CW circuit using nF750 capacitor 45

4.9 Simulation for 8 stages CW circuit using uF1 capacitor 46

4.10 Simulation for 8 stages CW circuit using uF10 capacitor 47

4.11 Graph for Capacitor (Farad) versus Output Voltage (Volt) 49

4.12 Simulation for 8 stages of CW circuit using

HZV 10240 Input Voltage 50

4.13 Simulation for 8 stages of CW circuit using

HZV 20240 Input Voltage 51

4.14 Simulation for 8 stages of CW circuit using

HZV 30240 Input Voltage 52

4.15 Simulation for 8 stages of CW circuit using

HZV 40240 Input Voltage 53

4.16 Simulation for 8 stages of CW circuit using

HZV 50240 Input Voltage 54

4.17 Simulation for 8 stages of CW circuit using

HZV 60240 Input Voltage 55

4.18 Simulation for 8 stages of CW circuit using

HZV 70240 Input Voltage 56

4.19 Simulation for 8 stages of CW circuit using

HZV 80240 Input Voltage 57

4.20 Simulation for 8 stages of CW circuit using

HZV 90240 Input Voltage 58

4.21 Simulation for 8 stages of CW circuit using

HZV 100240 Input Voltage 59

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4.22 Simulation for 8 stages of CW circuit using

HZV 200240 Input Voltage 60

4.23 Simulation for 8 stages of CW circuit using

HZV 400240 Input Voltage 61

4.24 Simulation for 8 stages of CW circuit using

HZV 600240 Input Voltage 62

4.25 Simulation for 8 stages of CW circuit using

HZV 800240 Input Voltage 63

4.26 Simulation for 8 stages of CW circuit using

HZV 1000240 Input Voltage 64

4.27 Graphs for Frequency (Hz) versus Output Voltage (Volt) 66

4.28 Simulated of 8 Stage CW Voltage Multiplier Circuit 67

4.29 Simulated 8 stage of CW Voltage Multiplier Circuit

(Output Voltage with load 20MΩ) 68

4.30 Ionizer circuit using uF1 450Vcapacitors and IN4007 69

4.31 Output Voltage Waveform 70

4.32 Measured Voltage value for 1 minutes first 71

4.33 Measured Voltage value for 2 minutes first 71

4.34 Measured Voltage value for 3 minutes first 71

4.35 Measured Voltage value for 4 minutes first 72

4.36 Measured Voltage value for 5 minutes first 72

4.37 Component layout of the circuit 74

4.38 Layout of positive type PCB board 74

4.39 Air Ionizer Circuit Diagram 75

4.40 Fan12V DC circuit 77

4.41 Input Signal Circuit 77

4.42 Air Ionizer Top View 78

4.43 Air Ionizer Front View 78

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4.44 Air Ionizer Model Design 79

4.45 Negative Ion Measured in the 3130m room 81

4.46 The Handheld Air Ion Counter 81

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LIST OF ABBREVATION

CW - Cockcroft – Walton

FKEKK - Fakulti Kejuruteraan Elektonik dan Kejuruteraan Komputer

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LIST OF APPENDIX

NO TITLE PAGE

A Datasheet Diode IN4001-IN4007 88

B Datasheet Ceramic Disc Capacitor 91

C Journal Air Ion Counter 94

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CHAPTER 1

INTRODUCTION

This chapter is about to brief introduction of the „ Projek Sarjana Muda (PSM)

thesis. This thesis will introduce what the whole project is all about. The project is to

design an air ionizer using the Cockcroft-Walton Multiplier. Chapter 1 is about the

introduction of the project, the objective of the project, problem statement, scope of

project and simple explanation of methodology. It will give the overview on about this

project.

1.1 INTRODUCTION OF THE PROJECT

This project is about design of an Air Ionizer by using Cockcoft-Walton Voltage

Multiplier is to generate negative ions by exposing air to a high negative voltage. This

circuit is design to solve the problem related to the low quality air in a small room. The

ionizer will produce negatives ions and neutralize the ions in the air.

The negative ions work by producing the negative output which exceeding 5kV

at the end of the Cockcroft-Walton Voltage Multiplier circuit. The Cockcroft-Walton

circuit is one of the cheaper ways of generating high voltage at relatively low current is

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the classic multistage diode/capacitor voltage multiplier. By using only capacitors and

diodes, these voltage multipliers can step up relatively low voltages to extremely high

values. The Cockcroft-Walton is design based on the Half-Wave Series Multiplier, or

voltage doublers. The biggest advantage of such circuit is that the voltage across each

stage of this cascade is only equal to twice the peak input voltage.

The development of the air ionizer will involve mechanical and electronic

circuit. An air ionizer is a device which used high voltage to ionize, or electrically, air

molecules. Ionizers create ions by either adding electrons to atoms/molecules or

stripping electrons from atoms/molecules. The basic part of this project is to generating

high voltage from a low voltage AC. This project will focus on the generation of a

massive amount of negative ions.

1.2 OBJECTIVES OF PROJECT

The objectives of this project are:

1. To converts AC or pulsing DC electrical power from a low voltage level to a

higher DC voltage level.

2. To generate negatives ions by exposing air to a high voltage.

3. To solve the problem related to the low quality of air in a small area such as a

lecture room.

The first objective is to converts AC or pulsing DC electrical power from a low

voltage level to a higher DC voltage level. To achieve the objective, this project is used

some basic electronic knowledge and Cockcroft Walton theories to design an air ionizer

which will produce negative ion. The Cockcroft Walton is basically a voltage multiplier

that converts AC or pulsing DC electrical power from a low voltage level to a higher

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DC voltage level. The second objectives are to generate negatives ions by exposing air

to high voltage. To achieve this objective, the fundamental of the voltage multiplier such

as the principle, concept, types and characteristics of each type and the output waveform

of each circuit is study. To solve the problem related to the low quality of air in a small

room such as a lecture room, the suitable circuit by using Cockcroft Walton voltage

multiplier is design, simulate and construct to prove the theoretical that has been

covered.

1.3 PROBLEM STATEMENT

Nowadays, the quality of air is reducing many health problems to the mankind.

Before the issues of air pollution became a hit, many scientists and researchers had

noticed that the ionizations of even clean air can improve the quality of air. Basically,

the clean air is consists of 78% nitrogen and 21% of oxygen, typically contain negative

and positives ions in approximately 4-to-5 ratio. Those researchers found that whenever

this ratio is charging, it will affect the biological system especially human.

The idea about the negative ions effect on human was popularized by a scientist

named Fred Soyka, whom in 1970‟s had written a book title „The ion effect‟. In this

book, he discussed about the natural occurrence of negative and positive ionized air.

From his finding, he demonstrated that negatively ionizer air had substantial health

benefits. He summarized hat the negatives ions helps elevate mood, enhance physical

performance and training, and sterilized harmful airborne bacteria. On the other hand,

the abundance of positives ions causing numbers of low grade medical problem, such as

fatigue, headache and anxiety.

According to the research, many other scientists try to see other effect of the

negative and positive ions to human and all the results showed that negatives ions give

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many benefits compare to positives ions which give more bad effect to human. Here,

this report tried to discuss about developing the negatives ions in a very practical method

using Cockcroft-Walton voltage regulator circuit. The reason of this circuit is deign is to

solve the problem related to the low quality air in a small area such as in a tutorial room

or an office.

1.4 SCOPE OF WORK

The scope of work is very important for the execution of a project or a thesis. In

this project, this section is divided into four sections.

1. To analyzed the fundamental of multiplier

i. Search for information in books, internet sources and other.

ii. To study about advantages and disadvantages of multiplier.

iii. Analyze the information and make problem solving for the project

development.

iv. To study about the output waveform based on theory.

2. Design the related circuit for Cockcroft Walton Voltage Multiplier

i. Change the value of component

ii. Calculated the expected output.

3. Simulate the design circuit

i. Using the Pspice and Multisim or other simulation programming.

ii. The connection of each component will be checked.

iii. Get the output value.

iv. Determine the advantage and the disadvantage of the circuit.

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4. Construct the circuit

i. Construct the prototype of the circuit.

ii. Compared the output with the simulation result.

iii. Calculate the percentage different

5. Overall Test

i. To make sure the air ionizer can operate as planned.

ii. To make modification and development to the air ionizer if any

problems occurred.

To achieve the objective of this project, the scope of work above must be

follow. The simulation circuit and other source are use is based on Voltage Multiplier

and Cockcroft-Walton Voltage Multiplier.

1.5 PROJECT METHODOLOGY

Firstly, search a literature review to collect more information about this project.

The literature review will take journal, report, internet and books as it reference. To

design a negative ionizer using the Cockcroft-Walton Voltage Multiplier circuit, the

theory and all application about CW Voltage Multiplier circuit has been studies and

understanding. Make a research about circuit theory and the characteristic of each

component to redesign the CW circuit. Later, some literature review will used to

compare this project with previous experiment and related project for this title.

Then, the circuit of CW Voltage Multiplier has been design by refer the literature

review have found. To design the circuit, make sure the capacitor and diodes will used is

more suitable for CW circuit to generate a high voltage. The design circuit will be

simulated using the Pspice and Multisim software. The output voltage will be

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measured and the calculated of the voltage is very important because it will determine

the sum of component and stage that the circuit required to get the right output voltage.

After the design is successful, the circuit will be constructed on strip board.

Make sure all connection of component at strip board is right. Then, check the circuit

output voltage by using the multimeter and the value is compared with simulation output

value. Then, the circuit has been constructed on PCB board. All connection in circuit is

confirmed right before the soldering process. For last inspection, test the hardware if

function or not. If not function, the circuit will be troubleshooting. If the circuit already

functions, the model has been designed.

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