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WATER LEVEL CONTROLLER USING EMBEDDED SYSTEM

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PROJECT REPORT ON:

WATER LEVEL CONTROLLER USING EMBEDDED SYSTEM.

Preface


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The electronic era started from mid of Second World War has almost completed its first step. The use of super computer in the 20th century has speeded up the network.

The electronic evolution has already entered India, as it is already sweeping the globe. A great significance is being attached with electronic industry in development of India. Therefore, it is necessary to disseminate this knowledge on water basis which can be attained by practical work theory. The project done by us serves the same purpose.

It was difficult task of coming to a conclusion on which project to undertake. There were many expectation from a project describe here under.

A project should have some industrial base so that experience gained while working on it will be useful in industries and it also should have some useful applications in residential areas. The project should rarely be found something different than other and something dynamic.

This work of hours was carried out through combined effort. Realization of expectations through co-ordination efforts has encouraged us to start our career with great hopes and expectations of bright future.

Our project, Water level controller using embedded system is the new upcoming technology in industries and in residential areas. This technology is used to save water and power using advance system and automation. Due to automation also reduces human time and provides more accuracy in this system.

INDEX


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SR. NO. TOPIC PAGE NO.I. Introduction 7

II. Block Diagram & Description

10

III. Circuit Diagram & Operation 13

IV. PCB Making & Designing The Layout

17

V. Soldering 23

VI. Component List & Layout 25

VII. Project Component Details 29

VIII. Project Programming 49

IX. Testing & Troubleshooting 55

X. Advantages & Disadvantages. 58

XI. Applications 60

XII. Modifications 62

XIII. Conclusion 65

XIV. Bibliography 67


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Chapter 1:

Introduction


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INTRODUCTION

Water Level Controller is a highly researched & important application used for controlling level of liquid. It’s used in every urban dwellers & an efficient system is vital for modern city. Our project developed a completely adaptive & self-evident. Water Level Controller is very economically in nature & devising a cost function, can be easily installed in every urban areas & each society’s in city. This project has devastated the earlier projects, so it’s seldom in today’s life.

This approach was found to reduce the overflow of water which used to happen in manual system which was used in earlier days. The advantage of embedded system based water level controller is that water can be controlled automatically.

Embedded Systems have become a ubiquitous part of day to day life in the modern world. From cell phones and digital watches to airplane control systems, specialized devices with the ability to adapt to their environment despite limited time, power, and / or space are necessary.

Water Level Controller is implemented in several ways, i.e. in each & every society & installing of this project is very easy as it’s an adaptive system offers significant advantages & performance improvement.

In early days, manual system was used. In that system we had start the pump. The pump used to suck the water from lower tank and


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it would supply it to overhead tank. When the overhead tank would fill to its maximum level then it would overflow and water would be wasted. Thus we would have to close the motor pump manually, when the water overflows. We would not know the time when the overhead tank fills. So this method has disadvantage that water gets overflowed and gets wasted. Thus in this system time, money is wasted.

The next system which is “Water Level Indicator”; has several advantages over the manual water control system. In this system sensors are placed in the lower tank to sense the level of water whether it is low or high. As the level of lower tank increases the respective LED will glow giving an indication that water is available in the lower tank, so we can turn on the motor. This will avoid the dry run of motor. Now when the overhead tank becomes full at predetermine level, it will glow the respective LED indicating that the overhead tank is full, so we can turn off the motor. The advantage of this system is that it senses the different levels of water in upper and lower tank.

In order to overcome the disadvantages of manual water level controller and water level indicator, we have introduced a new system which is more advanced than these above system. Our project describes about this advance “Water Level Controlling System Using Embedded System”. In this system we place various sensors at various level of upper and lower tank. These sensors are used for measuring the level of water in the tank and its level is indicated by the LED’s & controlling the water level with the help of motor which is automated by Embedded System.


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Chapter 2:

BLOCK DIAGRAM & DESCRIPTIO

N


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Block diagram:


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DESCRIPTION:


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The above diagram shows the block details of water level controller. It consists of embedded system. The upper tank i.e. Overhead tank is situated above the building. The lower tank i.e. sump is situated at the lower level. A motor is used to supply the water from lower tank to upper tank.

The microcontroller is programmed to detect the level of the upper and lower Tank. It also gives signal to relay to ON or OFF the pump depending on the level of lower & upper tank. It uses Embedded System as its ubiquitous part in day to day life of modern world.

Here microcontroller is used as small part of the embedded software is to be located in the internal memory and on-chip ports are required.

Here the pump supplied water from lower tank to upper tank (overhead tank).

It receives ON & OFF signal from Relay. The relay is operated by microcontroller.

The sensors connected in lower tank and upper tank are used to sense the level of water in both tank. The level is sensed by microcontroller.

In this block diagram as shown above the following LED’s indicate is given below:-

LED INDICATIONLED 1 Lower Tank Low Level LED 2 Lower Tank High LevelLED 3 Upper Tank Low LevelLED 4 Upper Tank High LevelLED 5 Pump ON/OFF


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Chapter 3:CIRCUIT

DIAGRA& OPERATION

CIRCUIT DIAGRAM


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CIRCUIT OPERATION:In this project a copper sensor is used to sense the level of water in both upper and lower tank. Here a 5 volts supply is given to one rod


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of sensors. Other rods of copper sensor are connected to transistor BC547. A current limiting resistor is used to limit current. When water is present in the tank then +5v is given to the base of BC547. Due to positive potential on the base of BC547 the transistor turns on and acts as closed switch. So the logic low input is given to the microcontroller. Earlier the logic level of the port-pin was high. So Micro-controller senses this changes in logic level and performs adequate operation. If there is no water in the tank then none of sensors will detect the level of water.

Case 1: LTLL (lower tank lower level)

Consider there is low level of water in lower tank (sump), and then the sump’s lower level sensors will detect the level of water. Now +5v supply will get connected to the base of BC547 (Q1) through sensors. Q1 turns on and act as closed switch. Due to this logic low level signal gets connected to P3.5 (pin no. 9) of microcontroller.

Now microcontroller senses a low signal through P1.6 (pin no. 18) to A2 pin of bidirectional buffer. The output pin B2 is connected to cathode of 4th LED. Through R13 resistor a +5v supply is applied to anode of 4th LED. So 4th Led glows which shows that there is low level of water in sump (lower tank).

Case 2: LTHL (lower tank higher level)

Consider there is high level of water in lower tank (sump), and then the sump’s higher level sensors will detect the level of water. Now +5v supply will get connected to the base of BC547 (Q2) through sensors. Q2 turns on and act as closed switch. Due to this logic low level signal gets connected to P3.4 (pin no. 8) of microcontroller.

Now microcontroller senses a low signal through P1.5 (pin no. 16) to A3 pin of bidirectional buffer. The output pin B3 is connected to cathode of 5th LED. Through R14 resistor a +5v supply is applied to


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anode of 5th LED. So 5th Led glows which shows that there is high level of water in sump (lower tank).

Case 3: UTLL (upper tank lower level)

Consider there is low level of water in upper tank, and then the upper tank’s lower level sensors will detect the level of water. Now +5v supply will get connected to the base of BC547 (Q3) through sensors. Q3 turns on and act as closed switch. Due to this logic low level signal gets connected to P3.3 (pin no. 7) of microcontroller.

Now microcontroller senses a low signal through P1.4 (pin no.16) to A4 pin of bidirectional buffer. The output pin B4 is connected to cathode of 6th LED. Through R15 resistor a +5v supply is applied to anode of 6th LED. So 6th Led glows which shows that there is low level of water in upper tank.

Case 4: UTHL (upper tank higher level)

Consider there is high level of water in upper tank, and then the upper tank’s higher level sensors will detect the level of water. Now +5v supply will get connected to the base of BC547 (Q4) through sensors. Q4 turns on and act as closed switch. Due to this logic low level signal gets connected to P3.7 (pin no. 11) of microcontroller.

Now microcontroller senses a low signal through P1.3 (pin no. 15) to A5 pin of bidirectional buffer. The output pin B5 is connected to cathode of 7th LED. Through R16 resistor a +5v supply is applied to anode of 7th LED. So 7th Led glows which shows that there is high level of water in upper tank.


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Chapter 4: PCB MAKING &

DESIGINIG THE LAYOUT

P.C.B. MAKING


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P.C.B. is printed circuit board which is of insulating base

with layer of thin copper-foil.

The circuit diagram is then drawn on the P.C.B. with

permanent marker and then it is dipped in the solution of

ferric chloride so that unwanted copper is removed from

the P.C.B. , thus leaving the components interconnection

on board.

The specification of base material is not important to know

in most of the applications, but it is important to know

something about copper-foil which is drawn to a thin slip.

The resistance of copper-foil will have an effect on the

circuit operation.

Base material is made of lamination layer of suitable

insulating material such as treated paper, fabric or glass

fibers an binding them with resin. Most commonly used

base materials are foamed paper bonded epoxy resin.

It is possible to obtain a range of thickness between

0.5mm to 3mm.

Thickness is the important factor in determining

mechanical strength particularly when the commonly used

base material is “Foamed” from paper assembly .


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Physical properties should be self supporting. These are

surface resistivity, heat dissipation, dielectric constant ,

dielectric strength.

Another important factor is the ability to withstand high

temperature.

DESIGNING THE LAYOUT: While designing a layout, it must be noted that sized of

the board should be as small as possible.


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Before starting, all components should be placed properly

so that an accurate measurement of space can be made.

The components should not be mounted very close to

each other or far away from one another and neither

should ignore the fact that some component need

ventilation.

The layout is first drawn on paper then traced on copper

plate which is finalized with a pen or permanent marker

which is efficient and clean with etching.

The resistivity also depends on the purity of copper, which

is highest for low purity of copper. The high resistance

path are always undesired for soldered connections.

The most difficult part of making an original printed circuit

is the conversion from, theoretical circuit diagram into

wiring layout without introducing cross over and undesirable

effect.

Although it is difficult operation, it provides greater amount

of satisfaction because it is carried out with more care and

skill.

The board used for project has copper-foil thickness in the

range of 25 40 75 microns.


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The soldering quality requires 99.99% efficiency.

It is necessary to design copper path extra large. There

are two main reasons for this,

i) The copper may be required to carry an extra large

overall current:

ii) It acts like a kind of screen or ground plane to

minimize the effect of interaction.

The first function is to connect the components together in

their right sequence with minimum need for interlinking i.e.

the jumpers with wire connections.

It must be noted, that when layout is done, on the next

day it should be dipped in the solution and board is

move continuously right and left after etching perfectly the

board is cleaned with water and is drilled.

After that holes are drilled with 1mm or 0.8mm drill. Now

the marker on the P.C.B. is removed. The Printed Circuit

Board is now ready for mounting the components on it.

PCB LAYOUT:


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Chapter 5:

SOLDERING

SOLDERING :


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For soldering of any joints first the terminal to be soldered

are cleaned to remove oxide film or dirt on it. If required

flux is applied on the points to be soldered .

Now the joints to be soldered is heated with the help of

soldering iron. Heat applied should be such that when

solder wire is touched to the joint, it must melt quickly.

The joint and the soldering iron is held such that molten

solder should flow smoothly over the joint.

When joint is completely covered with molten solder, the

soldering iron is removed.

The joint is allowed to cool, without any movement.

The bright shining soldering indicates good soldering.

In case of dry solder joint, a air gap remains in between

the solder material and joint. It means that the soldering is

done improper. This is removed and again soldering is done.

Thus is this the way all the component are soldered on

P.C.B.


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Chapter 6:COMPONEN

T LIST

&LAYOUTComponent List:


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Sr.no.

Component Description Quantity

Price in Rs.

1. Transformer 9V 1 50

2. Resistor 220 Ω, Fixed 6 2

3. Resistor 1K Ω, Fixed 2 1

4. Resistor 10K Ω, Fixed 8 2

5. Capacitor 1000µf,35V,Electrolytic

1 5

6. Capacitor 100µf,25V, Electrolytic

1 2

7. Capacitor 10µf,63V, Electrolytic

1 2

8. Capacitor 33pf, Ceramic

2 2

9. Capacitor 100pf, Ceramic

1 1

10. Relay JQC-3FC(T73), DC-12V, 50/60Hz,Electromagnetic

1 20

11. Diode 1N4007 P-N Junction Diode

4 4

12. Diode 1N4148 Zener Diode 1 2

13. LED 7 10

14. Crystal Oscillator

11.0592Mhz 1 5


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15. Transistor BC 547, BJT 6 12

16. IC Base 2 10

17. IC AT89C2051 Microcontroller 1 55

18. IC 7805 Regulator IC 1 10

19. IC 74245 Bi-directional Buffer

1 20

20. PCB Single sided with PCB Layout and Etching

1 1200

21. Mains Cord 1 20

22. Sensors Copper Electrode

4 16

23. Motor 1 350

24. Solder Wire 1 36

25. Connectors 4 20

26. Other Wires 2mtr. 6

Component layout:


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Chapter 7 :PROJECT

COMPONENT DETAILS

COMPONENT DETAILS:


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IC AT89C2051:-20-lead PDIP/SOIC:-

Features:- • Compatible with MCS®-51Products

• 2K Bytes of Reprogrammable Flash Memory – Endurance: 10,000 Write/Erase Cycles

• 2.7V to 6V Operating Range

• Fully Static Operation: 0 Hz to 24 MHz

• Two-level Program Memory Lock

• 128 x 8-bit Internal RAM

• 15 Programmable I/O Lines • Two 16-bit Timer/Counters

• Six Interrupt Sources

• Programmable Serial UART Channel


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• Direct LED Drive Outputs

• On-chip Analog Comparator

• Low-power Idle and Power-down Modes

• Green (Pb/Halide-free) Packaging Option.

Description:- The AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 2K bytes of Flash programmable and erasable read-only memory (PEROM). The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C2051 is a power-full microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications. The AT89C2051 provides the following standard features: 2K bytes of Flash, 128 bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In addition, the AT89C2051 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The power-down mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.

Block Diagram:-


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IC 74245:-PIN DIAGRAM:-


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FEATURES:- Wide Operating Voltage Range of 2 V to 6 V

High-Current 3-State Outputs Drive Bus Lines Directly or Up To 15 LSTTL Loads

Low Power Consumption, 80-µA Max ICC

Typical tpd = 12 ns

±6-mA Output Drive at 5

Low Input Current of 1 µA Max

DESCRIPTION:-

These octal bus transceivers are designed for asynchronous two-way


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communication between data buses. The control-function implementation minimizes external timing requirements. The devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (DIR) input. The output-enable (OE) input can be used to disablethe device so that the buses are effectively isolated.


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REGULATED POWER SUPPLY

A power supply (sometimes known as a power supply unit or PSU) is a device or system that supplies electrical or other types of energy to an output load or group of loads. The term is most commonly applied to electrical energy supplies.

The complete range of power supplies is very broad, and could be considered to include all forms of energy conversion from one form into another. Conventionally though, the term is usually confined to electrical or mechanical energy supplies. Constraints that commonly affect power supplies are the amount of power they can supply, how long they can supply it for without needing some kind of refueling or recharging, how stable their output voltage or current is under varying load conditions, and whether they provide continuous power or pulses.

The voltage regulation of power supplies is done by incorporating circuitry to tightly control the output voltage and/or current of the power supply to a specific value. The specific value is closely maintained despite variations in the load presented to the power supply's output, or any reasonable voltage variation at the power supply's input.

http://en.wikipedia.org/wiki/Current_(electricity)

http://en.wikipedia.org/wiki/Voltage

http://en.wikipedia.org/wiki/Load

http://en.wikipedia.org/wiki/Energy

http://en.wikipedia.org/wiki/Electrical


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Electrical power supplies: This term covers the mains power distribution system together

with any other primary or secondary sources of energy such as:.

Basic componenets used in `power supply as follows:

TRANSFORMER:It is an electrical device that transfers energy from one circuit to another by magnetic coupling with no moving parts. A transformer comprises two or more coupled windings, or a single tapped winding and, in most cases, a magnetic core to concentrate magnetic flux. An alternating current in one winding creates a time-varying magnetic flux in the core, which induces a voltage in the other windings. Transformers are used to convert between high and low voltages, to change impedance, and to provide electrical isolation between circuits simple transformer consists of two electrical conductors called the primary winding and the secondary winding. These two windings can be considered as a pair of mutually coupled coils. Energy is coupled between the windings by the time-varying magnetic flux that passes through (links) both primary and secondary windings.

http://en.wikipedia.org/wiki/Magnetic_flux

http://en.wikipedia.org/wiki/Electrical_conduction

http://en.wikipedia.org/wiki/Impedance

http://en.wikipedia.org/wiki/Voltage

http://en.wikipedia.org/wiki/Electric_current


http://en.wikipedia.org/wiki/Magnetic_core

http://en.wikipedia.org/wiki/Tap_(transformer)

http://en.wikipedia.org/wiki/Coil#Electromagnetic

http://en.wikipedia.org/wiki/Inductive_coupling

http://en.wikipedia.org/wiki/Electrical_network

http://en.wikipedia.org/wiki/Electricity


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A step-down transformer showing magnetizing flux in the core

If a time-varying voltage is applied to the primary winding of turns, a current will flow in it producing a magneto motive force (MMF). Just as an electromotive force (EMF) drives current around an electric circuit, so MMF tries to drive magnetic flux through a magnetic circuit. The primary MMF produces a varying magnetic flux

in the core, and, with an open circuit secondary winding, induces a back electromotive force (EMF) in opposition to . In accordance with Faraday's law of induction, the voltage induced across the primary winding is proportional to the rate of change of flux:

and

where

vP and vS are the voltages across the primary winding and secondary winding,

NP and NS are the numbers of turns in the primary winding and secondary winding,

http://en.wikipedia.org/wiki/Faraday's_law_of_induction

http://en.wikipedia.org/wiki/Electromotive_force


http://en.wikipedia.org/wiki/Electromotive_force

http://en.wikipedia.org/wiki/Magnetomotive_force

http://en.wikipedia.org/wiki/Image:Transformer3d_col3.svg


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dΦP / dt and dΦS / dt are the derivatives of the flux with respect to time of the primary and secondary windings.

Saying that the primary and secondary windings are perfectly coupled is equivalent to saying that . Substituting and solving for the voltages shows that:

where

vp and vs are voltages across primary and secondary,

Np and Ns are the numbers of turns in the primary and secondary , respectively.

Hence in an ideal transformer, the ratio of the primary and secondary voltages is equal to the ratio of the number of turns in their windings, or alternatively, the voltage per turn is the same for both windings. The ratio of the currents in the primary and secondary circuits is inversely proportional to the turns ratio. This leads to the most common use of the transformer: to convert electrical energy at one voltage to energy at a different voltage by means of windings with different numbers of turns. In a practical transformer, the higher-voltage winding will have more turns, of smaller conductor cross-section, than the lower-voltage windings.

The EMF in the secondary winding, if connected to an electrical circuit, will cause current to flow in the secondary circuit. The MMF produced by current in the secondary opposes the MMF of the primary and so tends to cancel the flux in the core. Since the reduced flux reduces the EMF induced in the primary winding, increased current flows in the primary circuit. The resulting increase in MMF due to the primary current offsets the effect of the opposing secondary MMF. In this way, the electrical energy fed into the primary winding is delivered to the secondary winding.

For example, suppose a power of 50 watts is supplied to a resistive load from a transformer with a turns ratio of 25:2.

P = EI (power = electromotive force × current)

http://en.wikipedia.org/wiki/Electric_power

http://en.wikipedia.org/wiki/Coil

http://en.wikipedia.org/wiki/Ratio


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50 W = 2 V × 25 A in the primary circuit

Now with transformer change:

50 W = 25 V × 2 A in the secondary circuit

Another component is diode as

RECTIFIER:

AC, half-wave and full wave rectified signals

A rectifier is an electrical device, comprising one or more semiconductive devices (such as diodes) or vacuum tubes arranged for converting alternating current to direct current. When just one diode is used to rectify AC (by blocking the negative or positive portion of the waveform) the difference between the term diode and the term rectifier is merely one of usage, e.g. the term rectifier describes a diode that is being used to convert AC to DC. Rectification is a process whereby alternating current (AC) is converted into direct current (DC). Almost all rectifiers comprise a number of diodes in a specific arrangement for more efficiently converting AC to DC than is possible with just a single diode. Rectification is commonly performed by semiconductor diodes. Before the development of solid state rectifiers, vacuum tube diodes were used. Early radios called crystal sets used a "cat's whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point contact rectifier or "crystal detector". In gas heating systems "flame rectification" can be used to detect a flame. Two metal electrodes in the outer layer of the flame provide a current path and rectification of an applied alternating voltage, but only while the flame is present

Full-wave rectification:Full-wave rectification converts both polarities of the input waveform to DC, and is more efficient. However, in a circuit with a non-center tapped transformer, four rectifiers are required instead of the one needed for half-wave rectification. This is due to each output polarity requiring 2 rectifiers each, for example, one for when AC terminal 'X' is positive and one for when AC terminal 'Y' is positive. The other DC

http://en.wikipedia.org/wiki/Center_tap

http://en.wikipedia.org/wiki/Center_tap

http://en.wikipedia.org/wiki/Crystal_detector

http://en.wikipedia.org/wiki/Galena

http://en.wikipedia.org/wiki/Cat's_whisker

http://en.wikipedia.org/wiki/Crystal_set

http://en.wikipedia.org/wiki/Vacuum_tube

http://en.wikipedia.org/wiki/Diode

http://en.wikipedia.org/wiki/Direct_current

http://en.wikipedia.org/wiki/Alternating_current

http://en.wikipedia.org/wiki/Wave





http://en.wikipedia.org/wiki/Semiconductor

http://en.wikipedia.org/wiki/Device

http://en.wikipedia.org/wiki/Electrical


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output requires exactly the same, resulting in four individual junctions (See semiconductors/diode). Four rectifiers arranged this way are called a bridge rectifier:

A full wave rectifier converts the whole of the input waveform to one of constant polarity (positive or negative) at its output by reversing the negative (or positive) portions of the alternating current waveform. The positive (negative) portions thus combine with the reversed negative (positive) portions to produce an entirely positive(negative) voltage/current waveform.

For single phase AC, if the AC is center-tapped, then two diodes back-to-back (i.e. anodes-to-anode or cathode-to-cathode) form a full wave rectifier.

In electronics, a diode is a component that restricts the direction of movement of charge carriers. Essentially, it allows an electric current to flow in one direction, but blocks it in the opposite direction. Thus,

http://en.wikipedia.org/wiki/Electric_current

http://en.wikipedia.org/wiki/Charge_carrier

http://en.wikipedia.org/wiki/Electronic_components

http://en.wikipedia.org/wiki/Electronics

http://en.wikipedia.org/wiki/Bridge_rectifier

http://en.wikipedia.org/wiki/Image:Gratz.rectifier.en.png

http://en.wikipedia.org/wiki/Image:Fullwave.rectifier.en.png

http://en.wikipedia.org/wiki/Image:VacRect2E.png


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the diode can be thought of as an electronic version of a check valve. Circuits that require current in only one direction will typically consist of one or more diodes in the circuit design.

Early diodes included "cat's whisker" crystals and vacuum tube devices (called thermionic valves in British English). Today the most common diodes are made from ultrapure semiconductor materials such as silicon or germanium.

A diode bridge or bridge rectifier (occasionally called a Graetz bridge) is an arrangement of four diodes connected in a bridge circuit as shown below, that provides the same polarity of output voltage for any polarity of the input voltage. When used in its most common application, for conversion of alternating current (AC) input into direct current (DC) output, it is known as a bridge rectifier. The bridge rectifier provides full wave rectification from a two wire AC input (saving the cost of a center tapped transformer) but has two diode drops rather than one reducing efficiency over a center tap based design for the same output voltage.

When the input connected at the left corner of the diamond is positive with respect to the one connected at the right hand corner, current flows to the right along the upper colored path to the output, and returns to the input supply via the lower one.

When the right hand corner is positive relative to the left hand corner, current flows along the upper colored path and returns to the supply via the lower colored path.

http://en.wikipedia.org/wiki/Current_(electricity)

http://en.wikipedia.org/w/index.php?title=Full_wave_rectification&action=edit

http://en.wikipedia.org/wiki/Rectifier




http://en.wikipedia.org/wiki/Bridge_circuit


http://en.wikipedia.org/wiki/Graetz_AG

http://en.wikipedia.org/wiki/Germanium

http://en.wikipedia.org/wiki/Silicon

http://en.wikipedia.org/wiki/Semiconductor

http://en.wikipedia.org/wiki/British_English



http://en.wikipedia.org/wiki/Cat's_whisker_diode

http://en.wikipedia.org/wiki/Check_valve

http://www.discoverprojects.com/


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AC, half-wave and full wave rectified signals

In each case, the upper right output remains positive with respect to the lower right one. Since this is true whether the input is AC or DC, this circuit not only produces DC power when supplied with AC power: it also can provide what is sometimes called "reverse polarity protection". That is, it permits normal functioning when batteries are installed backwards or DC input-power supply wiring "has its wires crossed" (and protects the circuitry it powers against damage that might occur without this circuit in place).

Prior to availability of integrated electronics, such a bridge rectifier was always constructed from discrete components. Since about 1950, a single four-terminal component containing the four diodes connected in the bridge configuration became a standard commercial

http://en.wikipedia.org/wiki/Battery_(electricity)




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component and is now available with various voltage and current ratings.

Output smoothing:For many applications, especially with single phase AC where the full-wave bridge serves to convert an AC input into a DC output, the addition of a capacitor may be important because the bridge alone supplies an output voltage of fixed polarity but pulsating magnitude (see photograph above).

The function of this capacitor, known as a 'smoothing capacitor' is to lessen the variation in (or 'smooth') the raw output voltage waveform from the bridge. One explanation of 'smoothing' is that the capacitor provides a low impedance path to the AC component of the output, reducing the AC voltage across, and AC current through, the resistive load. In less technical terms, any drop in the output voltage and current of the bridge tends to be cancelled by loss of charge in the capacitor. This charge flows out as additional current through the load. Thus the change of load current and voltage is reduced relative to what would occur without the capacitor. Increases of voltage correspondingly store excess charge in the capacitor, thus moderating the change in output voltage / current.

The capacitor and the load resistance have a typical time constant τ = RC where C and R are the capacitance and load resistance respectively. As long as the load resistor is large enough so that this time constant is much longer than the time of one ripple cycle, the above configuration will produce a well smoothed DC voltage across the load resistance.

http://en.wikipedia.org/wiki/Capacitor

http://en.wikipedia.org/wiki/Image:Diodebridge4.png


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Using a linear regulator:Linear regulators can be discrete as well as in integrated circuit form. The most common linear regulators are three-terminal integrated circuits in P1d packages/TO220 package. (The TO-220 package is the same kind that many medium-power transistors commonly come in: three legs in a straight line protruding from a black plastic molded case with a metal back plate which has a hole for bolting to a heat sink).

After one connects the appropriate pins to 0v and incoming power, the regulated output voltage appears on the output pin.

Common solid-state series voltage regulators are the LM78xx (for positive voltages) and LM79xx (for negative voltages), and common fixed voltages are 5 V (for transistor-transistor logic circuits) and 12 V (for communications circuits and peripheral devices such as disk drives). In fixed voltage regulators the reference pin is tied to ground, whereas in variable regulators the reference pin is connected to the centre point of a fixed or variable voltage divider fed by the regulator's output. A variable voltage divider (such as a potentiometer) allows the user to adjust the regulated voltage.

Fixed regulators:"Fixed" three-terminal linear regulators are commonly available to generate fixed voltages of plus 3 V, and plus or minus 5 V, 9 V, 12 V, or 15 V when the load is less than about 7 amperes.

The "78" series (7805, 7812, etc.) regulate positive voltages while the "79" series (7905, 7912, etc.) regulate negative voltages. Often, the last two digits of the device number are the output voltage; egg, a 7805 is a +5 V regulator, while a 7915 is a -15 V regulator.

http://en.wikipedia.org/wiki/Ampere

http://en.wikipedia.org/wiki/Potentiometer

http://en.wikipedia.org/wiki/Ground_(electricity)

http://en.wikipedia.org/wiki/Disk_drive

http://en.wikipedia.org/wiki/Disk_drive

http://en.wikipedia.org/wiki/Transistor-transistor_logic

http://en.wikipedia.org/wiki/TO220

http://en.wikipedia.org/w/index.php?title=P1d_package&action=edit

http://en.wikipedia.org/wiki/Integrated_circuit




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IC 7805:-PIN DIAGRAM:-

FEATURES:-• Output Current up to 1A

• Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V

• Thermal Overload Protection

• Short Circuit Protection

• Output Transistor Safe Operating Area Protection


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DESCRIPTION:-The KA78XX/KA78XXA series of three-terminal positive regulator are available in theTO-220/D-PAK package and with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents.


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RELAY:-

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism, but other operating principles are also used. Relays find applications where it is necessary to control a circuit by a low-power signal, or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits, repeating the signal coming in from one circuit and re-transmitting it to another. Relays found extensive use in telephone exchanges and early computers to perform logical operations. A type of relay that can handle the high power required to directly drive an electric motor is called a contactor. Solid-state relays control power circuits with no moving parts, instead using a semiconductor device triggered by light to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults; in modern electric power systems these functions are performed by digital instruments still called "protection relays".

ELECTROMAGNETIC RELAY:The core of the electromagnetic relay, naturally, is an electromagnet, formed by winding a coil around an iron core. When the coil is energized by passing current through it, the core in turn becomes magnetized, attracting a pivoting iron armature. As the armature pivots, it operates one or more sets of contacts, thus affecting the circuit. When the magnetic charge is lost, the armature and contacts are released. Demagnetization can cause a leap of voltage across the coil, damaging other components of the device when turned off.


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Therefore, the electromagnetic relay usually makes use of a diode to restrict the flow of the charge, with the cathode connected at the most positive end of the coil.

Contacts on an electromagnetic relay can take three forms. Normally opened contacts connect the circuit when the device is activated and disconnect it when the device is not active, like a light switch. Normally closed contacts disconnect the circuit when the relay is magnetized, and a change-over incorporates one of each type of contact. The configuration of the contacts is dependent upon the intended application of the device.

SPECIFICATION:


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Chapter 8 :

PROJECT PROGRAM

Program:-


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;***************************************************************************;VARIABLE DECLERATION

UPPFULL EQU P1.7

UPPLL EQU P1.6

LOWFULL EQU P1.5

LOWLL EQU P1.4

MOTOR EQU P1.1

PP EQU P1.3

POWER EQU P2.5

H2 EQU P3.7

L2 EQU P3.3

H1 EQU P3.4

L1 EQU P3.5

;***************************************************************************;MAIN PROGRAM

ORG 0000H

AJMP START

ORG 50H

START:MOV C,H2

MOV ACC.0,C

MOV C,L2

MOV ACC.1,C

MOV C,H1


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MOV ACC.2,C

MOV C,L1

MOV ACC.3,C

ANL A,#0FH

CJNE A,#00H,ST01

CLR UPPFULL

CLR LOWFULL

SETB UPPLL

SETB LOWLL

AJMP OFF

ST01:CJNE A,#01H,ST02

CLR LOWFULL

CLR UPPLL

SETB UPPFULL

SETB LOWLL

AJMP ON


CLR LOWFULL

SETB UPPFULLSETB UPPLL

SETB LOWLL

SJMP ON


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CLR LOWLL

CLR UPPFULL

SETB LOWFULL

SETB UPPLL

AJMP OFF


CLR LOWLL

CLR UPPLL

SETB LOWFULL

SETB UPPFULL

AJMP OFF


CLR LOWLL

SETB LOWFULL

SETB UPPLL

SETB UPPFULL

SJMP OFF


CLR LOWLL

SETB LOWFULL


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SETB UPPLL

SETB UPPFULL

SJMP OFF


CLR UPPFULL

SETB LOWFULL

SETB UPPLL

SETB LOWLL

SJMP OFF


CLR UPPLL

SETB LOWFULL

SETB UPPFULL

SETB LOWLL

SJMP OFF

ST09:CJNE A,#0CH,ST10

CLR UPPFULL

SETB LOWFULL

SETB UPPLLSETB LOWLL

SJMP OFF

ST10:CJNE A,#0DH,ST11


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CLR UPPLL

SETB LOWFULL

SETB UPPFULL

SETB LOWLL

SJMP OFF

ST11:CJNE A,#0FH,ST12

SJMP OFF

ST12:AJMP START

OFF:SETB MOTOR

SETB PP

AJMP START

ON:CLR MOTOR

CLR PP

AJMP START

END;****************************************************************************


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Chapter 9:

TESTING & TROUBLE

SHOOTINGTesting and troubleshooting


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Easy way of testing electronic components (resistor, capacitor, diode, transistor) using multi-meter.

How to test resistors?Read the indicated color code value then select the OHM-scale within but not way below the indicated value. A resistor is good if its resistance is close to the indicated. Tolerance should be considered with the ohmmeter reading. While, no resistance reading at all on the ohmmeter scale settings, the resistor is open. A zero resistance reading on all ohmmeter scale settings, resistor is shorted.

How to test capacitors?In most cases, a capacitor fails due to the deterioration of the dielectric material between its plate. Defective capacitors can have an internal shorted terminals, excessive leakage and degradation of capacitance meter. Momentarily, short the terminal of the electrolytic capacitor to discharge it.To test a capacitor, set the multi-tester to Rx 10 or Rx1K scale. Connect the tester negative probe to the capacitor positive terminal, the positive probe to the negative terminal. A good indication for electrolytic capacitor shows the meter needle deflecting towards zero and moves back again to infinite resistance position. For ceramic, Mylar and other capacitor with a capacitance with less than 1.0 uf, the meter will not deflect at all. A defective indication for an electrolytic capacitor shows that the meter will rest on zero and remain stationary at a point which is an indication that the capacitor is shorted.

How to test diodes?Set the multi-tester knob to any of the resistance position (x1, x10, x1K or 10K ohm ). Connect the positive probe to the anode and the negative probe to the cathode. Then connect the positive probe to the cathode and the negative probe to the anode of the diode. A good indication in the first procedure will show the meter deflected very little or may not deflect at all. And in the second procedure, the meter will deflect towards zero. The actual resistance reading is the forward resistance of the diode. A defective indication shows that the meter won’t deflect at all even when the probes are reversed. Or the meter deflects at the same time or almost the same resistance reading for both steps.

How to test transistors?Bipolar transistors are usually checked out of a circuit by means of an ohmmeter. When it is desired to check for the resistance across the transistor emitter and collector, NPN or PNP, ohmmeter probes may be connected either way. A good transistor will show above a reading above 1000 ohm.

How to determine if it is NPN or PNP transistor?To determine the correct terminal of the transistors, set the range selector to x 1 or 10 ohm. Connect the positive probe to the emitter and the negative probe to


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the base of the transistor. Note the reading interchange the connection of the probes to the leads of the transistor.

Base your conclusion on the table:

POSITIVE PROBE TO NEGATIVE PROBE TO RESISTANCE READING CONCLUSION:

Emitter Base Less than 150 ohm Transistor is NPN

Base Emitter Infinity Transistor is NPN

Emitter Base Infinity Transistor is PNP

Base Emitter Less than 150 ohm Transistor is PNP

Some defective indications of transistors:

Resistance between any pair of the terminals is less than 10 ohms. Transistor is shorted.

Resistance between base and emitter or base collector for both the forward and reverse application of ohmmeter probes is infinity (meter needle don’t deflect). Transistor is open.

Transistors overheats (except power transistors) during normal operating condition. Transistor is shorted.


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Chapter 10:

ADVANTAGES

ADVANTAGES: Compact elegant design

Fully automatic


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Saves water, motor, energy

Avoid seepage of roofs & walls due to overflowing tanks

Ideal for difficult to access overhead tanks.

Consume very little energy, ideal for continuous operation.

The Automatic Water Level Controller ensures no overflows or dry running of pump there by saves electricity and water.

Chapter 11:


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APPLICATION

APPLICATIONS1. Industrial applications of Liquid level controller are in:

Food processing , Beverage, dairy, Filtration, Effluent treatment, Water purification systems, Industrial chemical processing and spray coating, Boilers, Automatic liquid dispensing, Replenishment devices.


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2. It’s mainly used in societies(buildings) i.e. for home based applications.

3. It can also be implemented in rural areas.

Chapter 12:


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MODIFICATIONS

MODIFICATIONS:- Our project i.e. Water Level Controller is a household project which can be used in building.

With some modifications, our project can be used in Industrial application to control and detect the liquid levels. Following are some of modifications which can be done for Industrial application.

i) Boilers :- Boilers are large tanks used to heat or boil the liquids. They are used in various industries for various applications. The liquid in the boilers are of very high voltage. So utmost care should be taken to control the level of BOILER.Modification:- Here there will be two levels – high level and low level. Whenever low level is detected a low level alarm would be ON.


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Whenever high level is detected a high level a high level alarm would be ON. Here alarm are used in place of LED because as the liquid inside the boiler is of high temp so utmost care should be taken to prevent overflow of liquid. So alarm can be heard from long distance. So if a person who controls the boiler can hear the alarm and turn OFF the valve if there is any problem in controller. Also the sensors used here would be of different type which can work in high temperature.

Changes of mode:-1. Instead of LED Display – Level Alarm2. Instead of Copper sensor – Float sensor or IR-LED Sensor.

ii) In Beverage / Mineral Bottle Industries:-In above type there is a bottle in which has to be filled.So here a low level & high level sensor are used to detect the fluid level.The sensor used are IR-LED sensor in which LED sends light & is detected by the photodiode on other side of bottle.If the liquid is filled upto required level the LED sensor detects the level and closes the filling pump. If there is no liquid then the filling mechanism is turned ON.So in this way with some modification, the water level controller can be used in many industries for liquid level control.

Changes Mode:-1. Instead of Copper Sensors, IR-LED Sensor can be used.2. Instead of Motor, filling mechanism is interforced.


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Chapter 13:

CONCLUSION


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Conclusion:In this way WATER LEVEL CONTROLLER replaces older

systems and human efforts which were previously implied, and therefore this system is adopted in practical system.

At the end of this entire period of our, we came across many hardships and we tried to overcome them.

We could have still improved but the time was limited.

Thus, we conclude that-

The introduction of controlling techniques have changed the picture of this project, it becomes faster and accurate.

The advanced controlling system issued in any application was the operation water level has been controlled.

Finally, we conclude that this system is simpler and very economical and accurate.


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Chapter 14:

BIBLOGRAPHY


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WEBSITES:-

1. www.howstuffworks.com

2. www.wikipedia.com

3. www.altravista.com

4. www.electronicindia.com

BOOKS:-

1. Electronic for You

2. Mazidi

3. Kennith Ayla

http://www.electronicindia.com/

http://www.altravista.com/

http://www.wikipedia.com/

http://www.howstuffworks.com/


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