ABSTRACT
Purpose of this
project is to control our domestic water pump set with the help of a digital
logic circuit. It automatically fill our water tank and we doesn’t bother about
to turn ON and OFF the pump set. The
circuit is build around a simple flip-flop, which automatically set and reset
with respect to the water level present in the water tank. Two probes are
dipped in the tank (one is on the top side and other is at bottom) to check the
presence of water and these probes are the input to the digital logic circuit.
It also contains some protection
mechanism in order to protect the motor from ‘Dry-run conditions’. For this purpose we are dipping a probe in
the water source (Well, Ponds, etc.) and the circuit detect the availability of
water in the source, when there is no water in the source, the whole system
will be shut down otherwise the motor may burn.
Another facility of this system is
that it can identify the purity of water. If the content of mud in the tank
increases, circuit not only indicates it but also turn OFF the motor.
Also to know the amount of water in
the tank, we are using a ‘Numeric Water
Level Display Circuit’ which indicates the amount of water numerically.
Table of Contents
List of figures……………………………………………….
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iv
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List of tables …………………………………………….
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v
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List of symbols, Abbreviations
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vi
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Chapters
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1
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Introduction ………………………………..
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1
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2
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Functional Blocks…………………………………………………..
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2
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3
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Circuit Diagrams ……………………...
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3
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3.1
Pump set controlling
Circuit ………………….
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4
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3.2
Numeric Water Level Display Circuit………………
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8
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3.3
Purity Checking Circuit …………………………
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11
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3.4
PCB Layout ………………………..
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12
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4
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Advantages………………………………....
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14
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5
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Disadvantages ……………...
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15
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6
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Conclusion and Future scope ………………
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16
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Bibliography ………………………….
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17
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Appendix: Data sheets ……………………..
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18
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LIST OF
FIGURES
2.1
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Complete
block diagram …………………………
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2
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3.1
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Pump set
controlling circuit ………………………...
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4
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3.2
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Transistor
switch ………………………………
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5
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3.3
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NE 555 Block
diagram ……………………………..
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6
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3.4
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Water level
display circuit………………………..
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8
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3.5
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IC 7447 and
display………………………………
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10
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3.6
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Purity
checking circuit ……………………………
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11
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3.7
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PCB layout
of pump set controller ………………
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12
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3.8
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PCB layout
of Numeric water level display …………
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13
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3.9
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PCB layout
of Purity checking circuit ………………
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13
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LIST OF
TABLES
3.1
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Function
table of 7411 Triple input AND gate ………
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5
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3.2
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Function
table of 74148 Encoder …………………….
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8
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3.3
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Function
table of 7447 BCD to 7-segment converter ………..
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9
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LIST OF
SYMBOLS AND ABBREVIATIONS
µ -
Micro
Ω -
Ohm
Vcc -
Voltage Source
A -
Ampere
V -
Volt
K -
Kilo
AC -
Alternating Current
DC -
Direct Current
LED -
Light Emitting Diode
LDR -
Light Depended Resistor
PCB -
Printed Circuit Board
IC -
Integrated Circuit
TO GET THIS COMPLETE MATERIAL
PRICE:
Pay #5,000 Naira, (i.e. the price
for this material) into our account.
ACCOUNT DETAILS:
Bank: Ecobank
A/c No: 2691085510
Name: Martins Chima
NEXT STEP:
Send your teller no, name and email
address to 07030722911. We will confirm your payment within 3hrs (working
hours) and you will receive the COMPLETE WORK immediately after
confirmation through your e-mail.
We will also send a text
message to your mobile phone number informing you that we have sent you the
COMPLETE MATERIAL.
Chapter 1
INTRODUCTION
1.1
Problem Definition
The present project
is about providing automation in the switching of water pump set. In additional
to this the project also includes the Water level indicating system and purity
checking facility. This project will definitely be useful in households.
1.2
scope of study
This project is
developed in order to provide the existing method in the switching of water
pump set much more better this also helps to detect the mud in the water and
informs the user accordingly
1.3 Project motivation
This project is developed
from the thought of getting automation in filling the water tank this will
helps to consume time and also the mud detection enhances the advantages of
this project.
Chapter 2
FUNCTIONAL
BLOCK DIAGRAM
2.1 Water
Level Determining Section
Fig 2.1 Fig 1. Complete Block diagram
This unit is the
input to digital control circuit. We already said that we have two levels top
and bottom. Two probes are placed at these levels. It senses the presence or
water at the corresponding levels. Inside this block two transistors (BC548)
functions as a switch and these probes are connected to the base of transistors.
2.2 Water Presence Checking Section
This section
protects our motor from ‘Dry run’
conditions. It checks whether water is present in the water source or not. The
source may be well, pond, etc. If the motor runs in the absence of water, may damage
the motor (Dry run).So this is a protecting mechanism.
2.3 Pump Set Control
Logic
It is the
controlling section of the whole system. It energizes the relay according to
the different inputs received by it. NE555 IC functions as the controlling
unit. Control flip-flop inside the NE555 IC do this job. We are giving some set
and reset conditions to the 555 IC.
2.4 Mud indicator
This section
indicates the purity of water in the tank. When the content of mud present
inside the tank reaches above a particular level, not only it indicates but
also the complete system may shut down.
2.5 Numeric Water
Level Display
It gives the
information about the amount of water present in the tank. It shows the present
level in a seven segment display.
Chapter 3
CIRCUIT
DIAGRAM
3.1 Pump set
controlling circuit
Fig 3.1 Pump set
controlling circuit
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Above fig shows the
controlling circuit. The probe connected to the 2nd pin of 555 is
used to switch the output to HIGH when the water level goes below the specified
level and it remain in the set state until we reset back the circuit. There are
three different conditions for resetting the control flip-flop. These three
conditions are fed to the circuit through a triple input AND gate. When anyone
of the input to AND gate goes LOW the output will be LOW, a LOW voltage at the
4th pin off 555 (Reset Pin) resets the internal control flip-flop.
The transistors decides when the circuit to be reset. These transistors act as
a switch operating mode.
3.1.1 Transistor act as a switch
Fig 3.2 Transistor
switch
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3.1.2 IC 74LS11 Triple input AND gate
The AND gate is a digital logic gate that implements logical conjunction
it behaves according to the truth
table to the right. A HIGH output (1) results only if both the inputs to
the AND gate are HIGH (1).If neither or only one input to the AND gate is HIGH,
a LOW output results. In another sense, the function of AND effectively finds
the minimum between two binary digits
. The 74LS11 IC package contains three
independent positive logic 3-input AND GATES. Pins 14 and 7 provide power for
all three logic gates. The output for a gate is HIGH only when all three inputs
are HIGH, otherwise output is LOW.
A typical 3 input AND gate works
according to the function table as shown in figure 3.4. Its output goes LOW
when anyone of the input goes LOW. This logic is utilized in our project. Here
the three inputs are the ‘reset’ conditions.
Table 3.1 Function table of
7411
3.1.3 NE 555 IC
NE555 is an 8 pin
IC, used for so many applications to produce square waves, Pulses, Bit storage,
etc. NE555 has three different operating modes.
Ø Astable :
Produce continuous square waves
Ø Mono-stable :
Produce a single pulse when triggered
Ø Bi-stable :
a simple memory which can be set and reset
Fig: 3.3 NE555
Block diagram
3.1.3.1 Inputs of 555
Trigger input: when < 1/3 Vcc ('active low') this makes the output high (+Vcc).
It monitors the discharging of the timing capacitor in an astable circuit. It
has high input impedance greater than 2 Mega ohm.
Threshold input: when
greater than 2/3 Vcc ('active high') makes the output low (0V). It monitors the
charging of the timing capacitor in astable and monostable circuits. It has
high input impedance greater than 10 Mega ohms. Providing the trigger input is
> 1/3 Vcc, otherwise the trigger input will override the threshold input and
hold the output high (+Vcc).
Reset input: when less than about 0.7V ('active low') makes the output low (0V),
overriding other inputs. When not required it should be connected to +Vcc. It
has an input impedance of about 10 kilo ohm.
Control input: this can be used to adjust the threshold voltage which is set
internally to be 2/3 Vcc. Usually this
function is not required and the control input is connected to 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.
3.1.3.2Outputs
of 555
The output of a
standard 555 can sink and source up to 200mA. This is more than other 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
+Vcc, especially if a large current is flowing. To switch larger currents you
can connect a transistor.
3.2 Numeric Water
level display circuit
Input to the encoder
is fed through transistors; Vcc is directly dipped in the water. When the water
level rises it come in to contact with the base of a particular transistor and
then the transistor become on and its collector voltage falls. The encoded
output is connected to BCD to 7 Segment converter which converts the encoded
values to display characters.
3.2.1 IC74148 Encoder
The 74148 provides
three bits of binary coded output representing the position of the highest
order active input, along with an output indicating the presence of any active
input. It is easily expanded via input and output enables to provide priority
encoding over many bits.
Table 3.2 Function
table of 74148 Encoder
Fig3.4 Water level
display circuit
3.2.2 IC 7447 Display Driver (BCD to 7
segment converter)
The DM74LS47 accepts
four lines of BCD (8421) input data, generates their complements internally and
decodes the data with seven AND/OR gates having open-collector outputs to drive
indicator segments directly. Each segment output is guaranteed to sink 24 mA in
the ON (LOW) state and withstand 15V in the OFF (HIGH) state with a maximum leakage
current of 250 µA. Auxiliary inputs provided blanking, lamp test and cascadable
zero-suppression functions.
Table 3.3 Function table of 7447 BCD to
7 segment converter
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3.2.2.1 Functional Description of 7447
The DM74LS47 decodes
the input data in the pattern indicated in the Truth Table and the segment
identification illustration. If the input data is decimal zero, a LOW signal applied
to the RBI blanks the display and causes a multidigit display. For example, by
grounding the RBI of the highest order decoder and connecting its BI/RBO to RBI
of the next lowest order decoder, etc., leading zeros will be suppressed.
Similarly, by grounding RBI of the lowest order decoder and connecting its
BI/RBO to RBI of the next highest order decoder, etc., trailing zeros will be
suppressed. Leading and trailing zeros can be suppressed simultaneously by
using external gates, i.e.: by driving RBI of a intermediate decoder from an OR
gate whose inputs are BI/RBO of the next highest and lowest order decoders. BI/
RBO also serve as an unconditional blanking input. The internal NAND gate that
generates the RBO signal has a resistive pull-up, as opposed to a totem pole,
and thus BI/RBO can be forced LOW by external means, using wired collector logic.
A LOW signal thus applied to BI/RBO turns off all segment outputs. This
blanking feature can be used to control display intensity by varying the duty
cycle of the blanking signal. A LOW signal applied to LT turns on all segment
outputs, provided that BI/RBO is not forced LOW.
3.2.3 Display driver
with display
Above fig shows how
the display system works. The binary inputs received by the 7447 IC converts it
in to appropriate display character. 7447 is a common anode display driver.
Fig 3.5 IC 7447 and display
3.3 Purity
checking circuit
It
make use of LDR (Light Depented Resistor). It has very low resistance in
presence of light and has very high resistance (MΩ) in absece of light. The
LEDand LDR is dipped in the water. If there is pure water the light fron LED
reaches the LDR and LDR offer very low resistance hence the voltage drop across
the LDR is also very low. So the transisteor become OFF. When the intensity of
mud in the tank increases, the light from LED doesn’t reaches the LDR then the
voltage drop across the LDR increases and hence the transistor become ON. Then
its collector voltage falls to Vce(sat) and the LED will glows.
3.4 PCB Layout (Pump set controlling circuit)
Fig 3.6 Purity
checking circuit
PCB Layout (Numeric Water Level Display Circuit)
Fig 3.8 PCB Layout (Numeric Water Level Display Circuit)
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PCB Layout (Purity checking circuit)
Chapter
4
ADVATEGES
Ø The main advantage of ‘Automated Water tank’ is that it provide complete automation for
the domestic pump set
Ø It is inexpensive
Ø Less man effort
Ø Awareness about amount of water inside the tank
Ø Indicates the purity of water
Ø Limits the usage of electricity
Ø Less wastage of water
Chapter
5
DISADVATEGES
Ø Continuous power supply required for the operation
Ø Limited sensitivity of Mud indicator
Chapter 6
CONCLUSION & FUTURE SCOPE
Here we are
developed an ‘Automated Water Tank’ circuit which could be used to control the
domestic water pump set, it also limit the exceeding electricity bill. The
circuit mainly consists of three parts such as Pump set controller, Numeric
Water Level display, Mud indicator. Pump set controller controls the motor.
Level Display circuit informs the amount of water inside the tank. Mud
indicator not only informs the presence of mud but also is shuts down the motor
when it detects the mud in the tank
The future scopes
are:
·
Use of Microcontrollers
for this job so that single chip can do all our needs
·
pH sensors can be used for Purity checking
·
Use of Solar
power for continuous DC supply
·
Introduction of a
cleaning arrangement in the tank, In order to clean water when
its purity less than certain limit
BIBILIOGRAPHY
·
Sedra & Smith,
Microelectronic Circuits, Oxford
University, 4th Edition
·
Floyd and Jain, Digital Fundamentals, 8th
Edition
·
Rashid, Power Electronics, University of West
Florida, 3rd Edition