1

A

MINOR PROJECT REPORT

ON

“NUMERIC WATER LEVEL INDICTOR”

Submitted to Rajasthan Technical University in partial fulfillment

For the award of the degree

Of

BACHELOR OF TECHNOLOGY

IN

ELECTRICAL ENGINEERING

2016-2017

Submitted to: Submitted By:

Mr. Harish Rawal (H.O.D.) Narendra Kumar Parmar

Mr. Gopal Prajapat (Co-ordinator) Prakash Chandra Meghwal

Yogendra Singh Jhala

SUNRISE GROUP OF INSTITUTIONS, UDAIPUR

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CERTIFICATE

Date: - 10-11-2016

This is to certify that Mr. Narendra Kumar Parmar, Prakash Chandra Meghwal, Yogendra Singh

Jhala branch of Electrical Engineering Semester 7th had completed his minor project report on

“Numeric Water Level Indicator ” in partially fulfilment for the award of the degree “Bachelor Of

Technology” from Rajasthan Technical University, Kota (Rajasthan) under guidance of Mr. Harish

Kumar Rawal (Head of the Department, Electrical Engineering) at the Sunrise Group of Institution,

Udaipur (Raj).

Dr.Tarunshrimali Mr.Harish Kumar Rawal

(Principal) (Head of the Department)

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Candidate’s declaration

I hereby declare that the work, which is being presented in the report, entitled”NUMERIC

WATER LEVEL INDICATOR” in partial fulfilment for the award of Degree of “Bachelor of

Technology” in Dept. of Electrical Engineering and submitted to the Department of Electrical

Engineering, Sunrise Group Of Institutions, Udaipur, Rajasthan Technical University is a record

of my own investigations carried under the Guidance of Mr. Gopal Prajapat, Assistant Professor,

Sunrise Group Of Institutions, Udaipur.

I have not submitted the matter presented in this report anywhere for the award of any other

Degree.

Narendra Kumar

(Name and Signature of Candidate)

Enrolment No.: 13E1IUEEM4XP008 Counter Signed by:-

Mr. Harish Kumar Rawal

HOD(EE,ECE)

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ACKNOWLEDGEMENT

First and foremost, we would like to thank our supervisor of this project,

Mr. Gopal Prajapat for his valuable guidance and advice. He guided us greatly to

work in this project. His willingness to motivate us helped tremendously. Next we

thank Mr.Harish Kumar Rawal, for without his helping hand the project would be

incomplete. Besides, we would like to thank the authority of SUNRISE COLLEGE

for providing us with a good environment and facilities to complete this project. It

gave us an opportunity to participate and learn about the operation of Water Level

Controller. Finally, an honourable mention goes to our families and friends for their

understanding and support in completing this project. Without help of those

mentioned above, this project could not have been completed.

Narendra Kumar Parmar

Prakash Chandra Meghwal

Yogendra Singh Jhala

B.Tech (Electrical Engineering)

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ABSTRACT

The drinking water crisis in India is reaching alarming proportions. It might very

soon attain the nature of global crisis. Hence, it is of utmost importance to preserve

water. In many houses there is unnecessary wastage of water due to overflow in

Overhead Tanks. Automatic Water Level Controller can provide a solution to this

problem. The operation of water level controller works upon the fact that water

conducts electricity. So water can be used to open or close a circuit. As the water

level rises or falls, different circuits in the controller send different signals. These

signals are used to switch ON or switch OFF the motor pump as per our

requirements.

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CONTENTS

Acknowledgment 3

Abstract 4

Contents 5

Abbreviations and Acronyms 7

CHAPTER 1

INTRODUCTION

1.1 Motivation 8

1.2 Objectives 8

1.3 Organization of Thesis 8

CHAPTER 2

SYSTEM COMPONENTS

2.1 Introduction 9

2.2 Components used 9

2.2.1 Metallic Contacts 9

2.2.2 Transformer 9

2.2.3 Full-wave Rectifier 10

2.2.4 IC 74HC147 11

2.2.5 IC CD4511 14

2.2.6 Seven Segment Display 15

2.2.9 Transistor 18

2.2.10 Light Emitting Diode 19

7

2.3 Circuit Diagram 20

2.4 Circuit Layout 20

CHAPTER-3

LOGIC AND BASIC OPERATION

3.1 Step-by-step Operation 25

3.2 Truth Table of Water Level Controller 25

3.3Advantages of proposed water level controller 25

3.4 Cost Estimation 25

CHAPTER-4

CONCLUSION AND FUTURE WORK

4.1Results 26

4.2Conclusion 27

4.3Future Work 27

References 28

8

ABBREVIATIONS AND ACRONYMS

UGT - Under Ground Tank

OHT - Overhead Tank

IC - Integrated Circuit

BJT - Bi-polar Junction Transistor

LED - Light Emitting Diode

IC - 74HC147

IC – CD4511

Seven segment Display

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Introduction 1.1 MOTIVATION:

The total amount of water available on Earth has been estimated at 1.4 billion cubic

kilometers, enough to cover the planet with a layer of about 3 km. About 95% of the

Earth's water is in the oceans, which is unfit for human consumption. About 4% is

locked in the polar ice caps, and the rest 1% constitutes all fresh water found in rivers,

streams and lakes which is suitable for our consumption. A study estimated that a

person in India consumes an average of 135 litres per day.This consumption would

rise by 40% by the year 2025. This signifies the need to preserve our fresh water

resources.

1.2 THESIS OBJECTIVES:

The following objectives are likely to be focused and achieved at the end of the

project.

1) To create the most cost-effective and reliable water level controller using as less

resources as possible.

2) To study the controller model and observe its characteristics.

3) To compare the controller with the conventional controllers available in market

and find the advantages of the former over the latter.

4) To suggest any ideas or improvements that can lead to future development of the

controller.

1.3 Organization

The thesis is organized into six chapters including the chapter of introduction. Each

chapter is different from the other and is described along with the necessary theory

required to comprehend it.

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System Components

2.1 INTRODUCTION:

The water level controller we propose to make in our project depends on two

detection points in the OHT. The water level must be Controlled at these two points.

To facilitate this, we use sensors. In our case, these sensors are metallic contacts with

space between them present at each detection point. When water reaches a sensor, a

proper circuit must be present such that the presence of water is detected and a signal

is produced. This signal must pass through logic circuits to give the correct actuator

output. Also it must be strong enough to activate the actuator. A similar action must

take place when water reaches another sensor. Our circuit essentially uses the high

and low states.

2.2 COMPONENTS USED: The Water Level Controller has the following main components:-

-wave rectifier

2.2.1 Metallic Contacts These are L-shaped aluminium contacts which conduct electricity when the space

between them is bridged by water. For our project, we have used L-shaped brackets.

Two contacts at the bottom part of the tank form the indicator for low level of water.

Similarly two contacts at the upper part of the tank indicate that water is about to

overflow.

2.2.2 Transformer A centre-tapped step-down transformer is used to provide a suitable voltage to the

full-wave rectifier. We specifically selected this transformer so that the device could

be connected directly to the wall outlet. Also the centre tapping helps us to generate

a positive polarity voltage required for the circuit. Rating: 230/15 V AC, 50 Hz

11

2.2.3 Full-Wave Rectifier

(Full Wave Rectifier)

The full wave rectifier consists of four 1N4007 diodes and two 1000μF capacitors.

It is used to convert the AC supply of the wall outlet to DC supply which will run

majority of the circuit elements.

It converts an a.c. voltage into a pulsating dc voltage using both half cycles of the

applied ac voltage. For this purpose, it uses two diodes of which one conducts during

one half cycle while the other conducts during the other half cycle of the applied ac

voltage.

During the positive half cycle of the input voltage, the diode D2 becomes forward

biased and D4 becomes reverse biased. Hence D2 conducts and D4 remains OFF.

The load current flows through D2 and the voltage drop across the load will be equal

to the input voltage. Now during the negative half cycle of the input voltage, diode

D2 becomes reverse biased and D4 becomes forward biased. Hence D2 remains OFF

and D4 conducts. The load current flows through D4 and the voltage drop across the

load will be equal to the input voltage.

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2.2.4 IC 74HC147 The M54/74HC147 is a high speed CMOS 10 TO 4 LINE PRIORITY ENCODER

fabricated in silicon gate C

2 MOS technology. It has the same high speed performance of LSTTL combined

with true CMOS low power consumption. This device features priority encoding of

the inputs to ensure that only the highest order data line is en- coded. Nine input lines

are encoded to a four line BCD output. The implied decimal zero condition re- quires

no input condition as zero is encoded when all nine data lines are at high logic level.

All data input and outputs are active at the low logic level. All in-

puts are equipped with protection circuits against static discharge and transient

excess voltage. 1/10

Binary Encoders

Digital Electronics Module 1 (Number Systems) described a number of different

binary codes that are used to perform a range of functions in digital circuits.

Mathematics, graphics, data manipulation and physical control systems are among

many of the functions that are carried out using binary data, and each of these uses

may require binary data arranged in various forms of binary codes. For example text

may be represented by an ASCII code (American standard Code for Information

Interchange), in which each letter, number or symbol is represented by a 7-bit binary

code. Decimal numbers in a calculator may be sent to a numeric display using BCD

(Binary Coded Decimal). Notice that the word ‘code’ appears in each of these titles,

and a binary code differs from normal binary because it is arranged in a particular

way to suit a given purpose.

Priority Encoders

Binary Encoders generally have a number of inputs that must be mutually

exclusive, i.e. only one of the inputs can be active at any one time. The encoder

then produces a binary code on the output pins, which changes in response to the

input that has been activated.

Priority Encoding

Because it is always possible when using input switches that more than one input

may be active at a single time, most encoders of this type feature ‘priority encoding’

where, if more than one input is made active at the same time, the output will select

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only the most significant active input. For example, if 6 and 7 are pressed together

the BCD output will indicate 7. The Pinout diagram for the 74HC147 10-to-4-line

priority encoder from is illustrated in Fig.4.4.1.

Fig. 4.4.1 74HC147 10-to-4-Line Priority Encoder

Depending on the encoding purpose, each each different IC has its own particular

method for solving encoding problems. For example, a simple decimal to BCD (or

10-to-4 line) encoder would be expected to have ten input pins, but in fact the

74HC147 has only 9. The tenth condition (zero) is assumed to be present because

when none of the 1 to 9 input pins is active, this must indicate zero.

The input pins may be used to connect to switches on a decimal keypad, and the

encoder would output a 4-bit BCD code, (00002 to 10012) depending on which key

has been pressed, or simply to identify which one of ten input lines in a circuit is

active, by outputting an appropriate number in four bit BCD code.

Chip Enable Inputs

Some other encoder ICs also feature extra inputs and outputs that allow several ICs

to be connected together to achieve more flexibility in the numbers of input and

output lines available. These include ENABLE inputs, (typically labelled E), which

may consist of one or more input pins that need to have a particular logic level

applied (usually logic 0) in order to activate the encoding action. In the absence of a

correct ENABLE signal the output pins of the IC will remain in their inactive state.

Switch Bounce

One problem with combinational logic circuits is that unintended changes in output

data can occur during the times when the outputs of the IC are changing. This can be

due to problems such as switch contacts ‘bouncing’ as they close, creating rapid and

14

unpredictable changes in logic levels for a very short time, however logic IC operate

at high speed and will respond to these very fast changes.

Race Hazards

Problems can also occur due to ‘race hazards’ where different paths that digital

signals take through a logic circuit may have different numbers of gates. For example

two logic signals that change simultaneously at two circuit inputs may take different

routes through the circuit before being applied to some common gate later in the

circuit. However, if one signal passes through six gates for example, while the other

signal passes through seven gates, each of the signals will have encountered a

different total propagation delay due to the different number of gates they

encountered. Therefore they will each arrive at the common gate at slightly different

times, and so for a very short time an unexpected logic level may occur at that gate

output.

In using combinational logic ICs such as an encoder, problems like switch bounce

and race hazards must be allowed for, and one (though not necessarily the best)

solution can be to temporarily make the ENABLE pin high during times when data

is likely to change. This disables the encoder for a short time until the signal data has

settled at its new state, so that there is no chance of errors at the output during

changes of input signals.

2.2.5 IC CD 4511

Circuit Diagram

15

General Characteristics of CMOS IC CD4511

Supply: 3 to 15V, small fluctuations are tolerated.

Inputs have very high impedance (resistance). All unused inputs MUST be

connected to the supply (either +Vs or 0V), this applies even if that part of the

IC is not being used in the circuit!

Outputs can sink and source only about 1mA if you wish to maintain the

correct output voltage to drive CMOS inputs. If there is no need to drive any

inputs the maximum current is about 5mA with a 6V supply, or 10mA with a

9V supply (just enough to light an LED). To switch larger currents you can

connect a transistor.

Fan-out: one output can drive up to 50 inputs.

Gate propagation time: typically 30ns for a signal to travel through a gate with

a 9V supply, it takes a longer time at lower supply voltages.

Frequency: up to 1MHz, above that the 74 series is a better choice.

Power consumption (of the IC itself) is very low, a few µW. It is much greater

at high frequencies, a few mW at 1MHz for example.

IC DC4511

2.2.6 Seven Segment Display

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7 Segment Display

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Truth table

D C B A OUTPUT 0 0 0 0 0 0 0 0 1 1 0 0 1 0 2 0 0 1 1 3

0 1 0 0 4

0 1 0 1 5

0 1 1 0 6

0 1 1 1 7

1 0 0 0 8

1 0 0 1 9

1 0 1 0 a

1 0 1 1 b

1 1 0 0 c

1 1 0 1 d

1 1 1 0 e

1 1 1 1 f

CD4511 - CD4511 BCD to 7-segment Latch/Decoder/Driver

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Features

Contains a 4-bit Storage Latch, BCD-to-Seven Segment Decoder and Output

Drive

Suitable for LED, Incandescent, Fluorescent or LCD Readouts

Blanking Input

Lamp Test Provision

Low Power TTL

2.2.7 Transistor

FIGURE 2.11: A C547 TRANSISTOR

Transistors are semiconductor devices used to amplify and switch electronic signals

and electrical power. At least three terminals for connection to external circuit are

present. By applying voltage or current to one pair of the transistor the current

through other pair of terminal changes. Because the controlled (output) power can

be higher than the controlling (input) power, transistors can amplify a signal. In our

circuit, the output from the NOT gate is not strong enough to activate the relay.

Hence, we used transistor C547B to amplify it. IC 7809 provided the 9 volts Vcc to

the BJT which was connected in common base configuration.

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A diode and a capacitor are connected in parallel to the magnetizing coil terminals

of the relay. This is done because when the voltage input to the relay coil is removed

and its magnetic field collapses, a huge reverse voltage is produced. Without proper

protection, this voltage will cause the contact which is switching the relay coil to arc

and in time will destroy it. 15 2.2.10 Light Emitting Diode

2.2.8 LED

2.2.8 Light Emitting Diode

Three LEDs are used to indicate-

.

A resistance of 1 KΩ should be connected in series with the LED to protect it from

high voltages.

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2.3 CIRCUIT LAYOUT:

This is an unique water level indicator circuit which use 7 segment LED display to

show the current water level in the water tank. Most water level indicator circuits for

water tanks are based upon the number of LEDs that glow to indicate the current

level of water in the water tank / container. This circuit is the “digital version” of the

water-level indicator. It utilized a 7-segment LED display to show the water level in

numeric form from “0” to “9”. The circuit works off 5V regulated power supply. It

is built around priority encoder IC 74HC147 (IC1), BCD-to-7-segment decoder IC

CD4511 (IC2), 7-segment LED display LTS543 (DIS1) and a few discrete

components. Due to high input impedance, IC1 senses water in the water container

from its nine input terminals. The inputs are connected to +5V via 560-kilo-ohm

resistors.

The ground terminal of the sensor must be placed and maintain at the bottom of the

container (water tank). IC 74HC147 has nine active-low inputs and converts the

active input into active-low BCD output. The input L-9 has the highest priority. The

outputs of IC1 (A, B, C and D) are fed to IC2 via transistors T1 through T4. This

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logic inverter is used to convert the active-low output of IC1 into active-high for IC2.

The BCD code received by IC2 is shown on 7-segment display LTS543. Resistors

R18 through R24 limit the current through the 7 segment LED display.

When the water tank is empty condition, all the inputs of IC1 remain high. As a

result, its output also remains high, making all the inputs of IC2 low. Display

LTS543 at this stage shows “0”, which means the water tank is empty condition.

Similarly, when the water level reaches L-1 position, the display shows “1”, and

when the water level reaches L-8 position, the display shows “8”. Finally, when the

tank is full, all the inputs of IC1 become low and its output goes low to make all the

inputs of IC2 high. Display LTS543 now shows “9”, which means the water tank is

full condition.

Build this water level indicator circuit on a common-used PCB and enclose in a box.

Mount the 7-segment LED LTS543 on the front panel of the box. For sensors L-1

though L-9 and ground, you can use corrosion-free conductive-metal (stainless-steel)

strips.

2.5 Resistors

There is always some resistance in every circuit.

• A circuit is always made up of some wire, so there will be some resistance there.

• Even the battery has parts that offer resistance to the flow of electrons.

• The only circuits that come near to zero resistance are superconductors.

• This resistance that is from the parts of the circuit itself (especially the battery) is

called internal resistance.

• This internal resistance is usually drawn into a circuit diagram (schematic) as

shown in Figure.

• Notice the squiggly line just before the positive terminal of the battery? That’s to

show the internal resistance of the circuit.

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• That symbol, drawn any other place in the circuit, represents an actual resistor

placed in the circuit.

• A resistor is a device found in circuits that has a certain amount of resistance.

Why would you ever want to add resistance to a circuit by using a resistor?

• The most common reason is that we need to be able to adjust the current flowing

through a particular part of the circuit.

• If voltage is constant, then we can change the resistor to change the current.

I=V

R If “V” is constant and we change “R”, “I” will be different.

Actual Resistors: The resistors that you would most likely see if you opened up a CD

player, VCR, or other electronic device would look like the ones in Figure.

• They basically look like little cylinders with colored lines painted on them.

• The colored lines tell you the resistance and error range (tolerance) for a resistor

according to the following rules and table of numbers. You do NOT have to

memorize this table… it will be given to you if you need it.

To use the table you need to remember the following rules:

1. The first line is the first digit

2. The second line is the second digit

3. The third line is the multiplier

4. The last line (if any) is the tolerance

• Some resistors may have additional colored bands, but we will ignore them here.

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• They usually have something to do with measuring things like failure rates

temperature coefficients.

Figure 1: A schematic diagram showing internal resistance and a battery.

Methods of Making Resistors

There are two main methods that are used to make resistors.

• The most common is to just have a bunch of wire wound up inside that little

cylinder.

• Known as wire-wound resistors, they depend on the fact that a certain length of a

certain piece of wire will have a certain resistance.

• These resistors tend to be very reliable (with low tolerances), but cost more because

of the price of metals used in them and the machinery needed to carefully cut and

wind the wire.

• The other type of resistor is made of a piece of carbon.

• Known as a composition resistor, they depend on the size of the piece of carbon,

and the fact that carbon is a metalloid (has some metal-like properties) that does

conduct electricity.

• Because they are made from cheap carbon, composition resistors can cost much

less than similar wire-wound resistors. The drawback is that the carbon can be

24

cracked while making them, or become cracked in use. They have higher tolerances

because of the uncertainty in cutting the carbon.

In some cases it is necessary to have a circuit with resistors that you can adjust.

• These resistors are known as potentiometers or variable resistors.

• Often they are just a modified version of a wire-wound resistor, although newer

versions use advanced electronics instead.

• You’ve used one if you’ve ever used a dimmer switch for lights in a room, or played

with an electric race car set.

• Most variable resistors are designed so that by turning a dial or sliding a switch,

you change the amount of conducting material the current has to go through.

• The more conducting material the current has to go through, the higher the

resistance less material and the resistance is less

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Chapter -3 Logic and Operation

3.1 INTRODUCTION:

After assembling the system, what remains is to observe its operation and efficiency.

This can be done by breaking down the activity of the controller from the detection

of water to the working of the pump. We go over the responses obtained when water

reaches the sensors and the logic employed behind it. We also try to justify how a

system as simple as ours can compete with those available commercially.

3.2 STEP-BY-STEP OPERATION:

We placed metallic contacts both at the lower and upper area of the OHT. When

water filled the gap between them, the adjoining circuit closed and a signal (current)

flowed.

ignals were given to IC 74HC147 which produced an output signal Q.

de CD4511 IC. Also signal A was fed as the Seven

Segment IC.

3.3: Advantages of the proposed water level controller

A. Maintenance

It is an economical system that requires very less maintenance as compared to

conventional system as it has no complicated circuits and delicate mechanisms. This

saves the additional maintenance cost.

B. Cost

The main advantage of the water level controller is it has very low cost than the

conventional one available in markets. For example, some commercial controllers

use microcontrollers which alone costs around Rs.800. Some controllers even have

a price range of Rs.500-Rs. 1500. But for our system, the components used are less

in number and easily available. Hence losses will be less leading to a better

efficiency.

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C. Construction

The construction of a water level controller is very simple as it requires only a few

components. The circuit involved is also relatively simpler.

D. Skill Required

Since the system of water level controller is simpler than the ones conventionally

available, it can be easily made at home. The controller can also be easily operated

by anyone.

On a final note, the conventional controllers in market mostly use capacitive sensors

and microcontrollers. These increase the cost as well as the complexity of the system.

We have developed a rather simpler but efficient model of a water level controller.

27

Chapter – 4 Conclusion and Future Works UGT, actually has water or not. If no water source is present, then the submersible

pump would start running unnecessarily and overheat itself. This could be taken care

by implementing another sensor. Also, the rate of water input must always be equal

to or greater than the rate of water output. To make this happen we could use a speed

regulator. If these issues are taken care of then a more efficient and reliable

performance can be achieved.

4.1 RESULTS:

The experimental model was made according to the circuit diagram and the results

were as expected. The motor pump switched ON when the OHT was about to go dry

and switched OFF when the OHT was about to overflow.

4.2 CONCLUSION:

in rural as well as urban areas.

water for us and the future generations.

In these days, when Earth's reserve of consumable water is decreasing every

moment, every drop has its value. Water level controller is a simple yet effective

way to prevent wastage of water. Its simplicity in design and low cost components

make it an ideal piece of technology for the common man.

4.3 FUTURE WORK:

The water level controller designed in this project can be used to control water flow.

However, there is no way of knowing whether the source of water, which in this case

is the UGT, actually has water or not. If no water source is present, then the

submersible pump would start running unnecessarily and overheat itself. This could

be taken care by implementing another sensor. Also, the rate of water input must

always be equal to or greater than the rate of water output. To make this happen we

could use a speed regulator. If these issues are taken care of then a more efficient

and reliable performance can be achieved.

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REFERENCES

[1] Joydeep Kumar Chakraborty, “Water Level Controller”

[2] Rex Niedermeyer, "Aquarium Water Pumps"

[3] Kevin R. Sullivan, “Understanding Relays”, Professor of Automotive

Technology, Skyline College

[4] 74F00 Quad 2-input NAND gate datasheet, Philips Corporation

[5] Ward, Jack (2004), the 555Timer IC.

[6] Vardalas, John, Twists and Turns in the Development of Transistor,

IEEE-USA Today’s Engineer, May 2003.

29

CONCLUSION: Thus we have assembled a circuit which works on the conduction of electricity by

water. This circuit works using logic gates and the output obtained is in the form of

ON and OFF state of the centrifugal submersible pump.