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Water level Indicator with

Numeric Display

A mini project submitted in

partial fulfilment of requirement of

Degree of Bachelor of Technology

A.Gnandeep Reddy

K.Gopi Vasanth Kumar

K.Varun Chowdary

J.Kowsik Sasthre

Department Of ECE

K L University

Vaddeswaram, Guntur District

NOV 2012

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Department of Electronics & Communication Engineering

CERTIFICATE

This is to certify that the project report entitled “WATER

LEVEL INDICATOR WITH NUMERIC DISPLAY” being

submitted by students mentioned below. In partial fulfilment for the

award of the Degree of Bachelor of Technology in ECE to the K L

University is a record of benefited work carried out by them under my

guidance and supervision. The results embodied in this project report

have not been submitted to any other University or Institute for the

award of any Degree or Diploma.

GROUP MEMBERS

A. Gnandeep Reddy 11004311

K. Gopi Vasanth Kumar 11004312

J. Kowsik Sasthre 11004325

K. Varun Chowdary 11004367

HEAD OF THE DEPARTMENT INTERNAL GUIDE

Dr. Habibulla Khan Abhishek Anchal

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ACKNOWLEDGEMENT

We are happy to take this opportunity to thank to people who helped us in

the making of our project. We acknowledge the influence and inspiration of

Rajnish Kumar, Asst. Professor and Dr G. SUMATI who made the entire

project an exciting and enjoyable experience.

At the outset, we thank God almighty for making our endeavour a

success. We also express our gratitude to our beloved principal Dr. A. Anand

Kumar, and Dr. Habibulla Khan Head of the Department, for providing us

with adequate facilities, ways and means by which we were able to complete this

project. We are also grateful to and all other teachers of Electronics &

Communication Engineering Department for their invaluable teaching, help

and support without which the successful completion of this project would not

have been possible.

We thank our Project Guide, Abhishek Anchal, Asst.

Professor in Electronics & Communication Engineering for assisting us in

variable ways.

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ABSTRACT

Water level indicator is an electronic device which senses water

level inside the water tank and indicates the level on the seven

segment display

This uses the conducting nature of water as tap water is good

conductor of electricity. Here we have we have used seven wires

which indicate seven different levels that are full, mid levels and

empty. The low, mid levels and full level are indicated on seven

segment displays 7, 6, 5, 4, 3, 2, 1, 0 respectively. The ground

potential is at the lowest level of the water tank. If water rises then

respective number will be displayed.

User can see present level of water on seven segment display.

He can become alert by the numbers on the seven segment display.

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CONTENT

CERTIFICATE ii

ACKNOWLEDGEMENT iii

ABSTRACT iv

LIST OF FIGURES vi

1. INTRODUCTION 1

2. CIRCUIT DIAGRAM AND ITS WORKING 3

2.1 CIRCUIT DIAGRAM 3

2.2 WORKING OF CIRCUIT 3

3. COMPONENT AND THEIR DESCRIPTION 5

3.1 Seven Segment Display 7

4. ADVANTAGES AND DISADVANTAGES 8

5. RESULT AND CONCLUSION 9

6. BIBLIOGRAPHY 11

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LIST OF FIGURES

Figure Title P.N.

Figure1 Circuit Diagram 3

Figure2 IC74148 5

Figure3 IC 7447 6

Figure4 Seven Segment Display 7

Figure6.1 Assembled circuit on breadboard 9

Figure6.2(a) &(b) Display output for various level of water 9

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1. INTRODUCTION

Now a day, there is large loss of water due to laziness of people.

We present here a very simple remedy for providing water level,

whenever water is being used or filled inside the tank at home offices

or at any place.

In this, we connect a circuit to water tank with wires inside

water to indicate the level up to which water is filled. We have used

here a seven segment display which gives an indication to the user by

showing*:

7 Indicates the tank is empty.

6 Indicates the very few amount of water is present in tank.

5 Indicates that water has increased to a level more than 6.

4 Indicates that water has increased to a level more than 5.

3 Indicates that water has increased to a level more than 4.

2 Indicates that water has increased to a level more than 3.

1 Indicates that water is going to reach its maximum level.

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0 Indicates the tank is full.

This reduces the human effort. Manual checking of water level

inside the tank is not required. This requires less power and is very

economical.

* These levels depend on the markings made by the user.

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2. CIRCUIT AND ITS WORKING

2. 1 CIRCUIT DIAGRAM

Fig. 1. Circuit Diagram of Water Level Indicator with Numeric Display

2.2 WORKING OF CIRCUIT

This circuit works mainly on conducting nature of water and

uses 7-segment display, to indicate the different water levels in the

tank. The circuit shows the water levels by displaying 7, 6, 5, 4, 3, 2,

1, and 0. Circuit uses seven wires to sense the different water levels

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in the tank. A wire is dipped into the tank which is grounded. When

there is a high voltage at the input pin of the IC74148 gate, it

outputs a high voltage. Similarly, for a low voltage at the input pin of

the IC74148 gate, it outputs a low voltage.

When the tank is empty, the input pins of IC 74148 are pulled

high via a 10KΩ resistor. So it outputs a high voltage as a result of

which there is a display 7 in the seven segment display. As water

starts filling the tank, a low voltage is available at the input pins of

the gate and it outputs a low voltage. When the water in the tank

rises to touch the marked levels, there is a low voltage at the

corresponding input pins of gate. When the water reaches to

maximum level then all the input pins of the gate is at the low

voltage.

The corresponding inputs produce corresponding outputs which

in turn are given to IC7447 which is a decoder IC. These inputs are

decoded and the corresponding outputs are given to a seven segment

display which displays the water level.

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3. COMPONENTS AND THEIR DESCRIPTION

Components required for this circuit are:

1. Power supply

2. Resistors (10kΩ x8, 100Ω x1)

3. IC 74148

4. IC 7447

5. Seven segment display

IC 74148

Fig. 2 IC74148 Pin Diagram

This is an encoder IC which encodes 8-datalines to 3-line binary. An

encoder is a digital circuit that performs the inverse operation of a

decoder. An encoder has (or fewer) input lines and n output lines.

The output lines generate the binary code corresponding to the input

value.

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This can also be used in the N bit encoding and in some code

generators and code convertors.

IC 7447

Fig. 3 IC7447 Pin Diagram

IC 7447 is a BCD to 7 segment decoder with active low outputs.

It accepts the BCD code and provides outputs to energize seven

segment display devices in order to produce a decimal read out.

LT stands for Lamp Test. When is low all the segments on the

7-segment display are lit regardless of AAAA 0123 .

BI stands for Blanking Input. When BI is low the display is

blank so all the segments on the 7segment display are off regardless

of AAAA 0123 .

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RBI stands for Ripple Blanking Input. When RBI is low and

AAAA 0123 =0000 the display is blank otherwise the number is

displayed on the display. This is used to remove leading zeroes from a

number (e.g. display 89 instead of 089). To use with more than one

display connect (Ripple Blanking Output) from most significant 7447

to the next 7447.

3.1 Seven Segment Display

The seven-segment display consists of seven elements that are

made of either LEDs or LCDs. These elements are labelled a-g.

Fig. 4 Seven-Segment Display

Depend on which elements are turned on, they display decimal

numerals 0 through 9.

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4. ADVANTAGES AND DISADVANTAGES

Advantages:

The circuit is very economical.

It can be employed anywhere.

It requires less power and easy in handling.

Disadvantages:

The circuit can’t stop overflow of water.

Water should be conducting then only the circuit works.

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5. RESULT AND CONCLUSION

We have assembled the components on breadboard as per our

design mentioned in 2.1 and tested the circuit for the various

level of water. The final assembled circuit is shown in the

figure 6.1 below:

Fig. 6.1 Assembled circuit on breadboard

Fig. 6.2 (a) & (b) display output for various level of water

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Figure 6.2 shows the display corresponding to different level of

water. So, we successfully designed, assembled and demonstrated the

working of our circuit.

There were few minor difficulties we experienced, because of

temporary wiring of circuit on breadboard. Further, we can improve

the reliability and easy handling of our circuit by making it on PCB.

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6. BIBLIOGRAPHY

Website Reference

1. www.wisc-online.com

2. www.wikipedia.org

3. www.circuitsgallery.com

Texted Reference

1. A. Anand Kumar, “Fundamentals of Digital Circuits”, Page337-

344, Chapter 7, PHI publication, June 2012