minor project on numeric water level indicator

1. 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)

3. 3
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

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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

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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

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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

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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

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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

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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.

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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.

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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.