Automatic Sprinkler Control System

Automatic Sprinkler Control System

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CHAPTER 1

INTRODUCTION

1. INTRODUCTION

Now days, water shortage is becoming one of the biggest problem in the world. Many

different methods are developed for conservation of water. We need water in each and every

field. In our day to day life also water is essential. Water is considered to be basic need of

human. Water is needed for everyone human beings, animals, plants, etc.

Agriculture is one of the fields where water is required in tremendous quantity. Wastage

of water is major problem in agriculture. Every time excess of water is given to the fields. There

are many techniques to save or to control wastage of water from agriculture.

Sprinkler System

In sprinkler or overhead irrigation, water is piped to one or more central locations within the

field and distributed by overhead high-pressure sprinklers or guns. A system utilizing sprinklers,

sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-

set irrigation system. Higher pressure sprinklers that rotate are called rotors and are driven by a

ball drive, gear drive, or impact mechanism. Rotors can be designed to rotate in a full or partial

circle. Guns are similar to rotors, except that they generally operate at very high pressures of 40

to 130 lbf/in² (275 to 900 kPa) and flows of 50 to 1200 US gal/min (3 to 76 L/s), usually with

nozzle diameters in the range of 0.5 to 1.9 inches (10 to 50 mm). Guns are used not only for

irrigation, but also for industrial applications such as dust suppression and logging.

Sprinklers can also be mounted on moving platforms connected to the water source by a hose.

Automatically moving wheeled systems known as traveling sprinklers may irrigate areas such as

small farms, sports fields, parks, pastures, and cemeteries unattended. Most of these utilize a

length of polyethylene tubing wound on a steel drum. As the tubing is wound on the drum

powered by the irrigation water or a small gas engine, the sprinkler is pulled across the field.

When the sprinkler arrives back at the reel the system shuts off. This type of system is known to

most people as a "water-reel" traveling irrigation sprinkler and they are used extensively for dust

suppression, irrigation, and land application of waste water. Other travelers use a flat rubber hose


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that is dragged along behind while the sprinkler platform is pulled by a cable. These cable-type

travelers are definitely old technology and their use is limited in today's modern irrigation

projects.

NEED OF AUTOMATIC IRRIGATION:-

Water conservation is the main reason for an auto-irrigation system. Every inch of your property

will have even coverage and distribution of water. The watering will be timed and calibrated so

there will be no wasted water, giving you a green lawn and saving you money.

Watering in the early morning allows for peak water pressure. The time of day is very important.

Our systems start around 3 a.m. and run until about 8 a.m. This eliminates evaporation of water

to the sun. Wind is at a day time low so all water lands “on target” saving you money. Proper

irrigation reduces soil temperatures. Many diseases are generated when soils go over 80 degrees.

During the late summer, these temperatures are many times exceeded.

The system can also be implemented on farms at large scale which would help in

increasing the per unit production, with less capital and manpower. It can be used in domestic

lawns and gardens also. In Poly and Green Houses also the technique seems beneficial. Thus,

they help in enhancing the beauty of a number of landscapes and lawns and also help in saving

gallons of water. It is the solution to the biggest hindrance i.e. water scarcity. The farmer can

even pass out specific amount of fertilizers and chemicals to the roots of the plant directly.


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CHAPTER 2

LITERATURE SURVEY

2.1 LITERATURE SURVEY

Water is essential for the existence and survival of any life form. Hence human

settlements the world over have thrived so long they had enough water for consumption and

growing crops that yield food for community. The Indian subcontinent has witnessed many such

early settlements that devised their own systems of water harvesting, which could be either from

surface water or ground water. In the medieval age areas dominated by feudal system, some of

these systems took more scientific form and surprisingly, many of these water extraction storage

and conveyance structures are still in use in some parts of the country. In other parts of the

country, especially in the hilly and mountainous terrains, the communities have devised certain

means of water tapping and transfer systems that have been used for generations to provide water

for drinking and agriculture. In fact, even today most of these hilly tracts do not enjoy the benefit

of modern irrigation systems and still depend on their age old practices.

In India, one may find regions varying in temperature, elevation and rainfall. As a result,

the climate is drastically varying from one place to another for example, when that of the

northern Himalayan regions is compared with that of the southern coastal regions or the dry

western and central regions are compared with the west eastern and north eastern regions. Hence,

the methods of traditional systems of water utilization have evolved very differently over the

years in different places. The main sources of water have generally been:

• Utilization of stream and river water

• Direct tapping of rain water (rain water harvesting)

• Ground water

In India, normal irrigation technique, which are manually operated are used widely due to its low

cost and high profits. Automatic irrigation techniques are not so prevalent here. But various

methods like the automatic sprinklers, which are used widely for domestic gardening purpose.

These are designed to supply water for a particular period of the day. They are time controlled

and therefore time controlled systems are still more popular due to its cheap value.


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In addition to the above there are two more methods they are closed loop and open loop

irrigation system. The closed loop type of system requires feedback from one or more sensors.

Therefore continuously we have to check the status of the sensors. Therefore closed loop systems

require a microcontroller based system which increases the cost of the system to a great extent.

But in an open loop system, the operator makes the decision on the amount of water that will be

applied and when the irrigation event will occur. This information is controlled y a timer circuit

and the water is applied according to the desired schedule. Open loop control systems use either

the irrigation duration or a specified applied volume for control purposes. The advantage of open

loop systems is their easy working and very less cost.

In conventional sprinkler systems the problem arises when we have to add some more

extra sprinkler valves. If you have an automatic sprinkler control system, chances are that you

are currently using all of its outputs controlling sprinklers. The problem arises when you want to

add another sprinkler control solenoid valve. Using this circuit, you can add an expansion

module to the controller without upgrading the controller or running new wiring. The circuit is

fitted in place of an existing solenoid and allows the controller to switch on two valves (hence

two sprinklers) instead of one.


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CHAPTER 3

BLOCK DIAGRAM AND DESCRIPTION

3.1 BLOCK DIAGRAM

Fig 3.1 Block Diagram

3.2 BLOCK DIAGRAM DESCRIPTION

The System is consists of mainly the following……

Power supply-

The whole circuit is divided into sections - one is timer circuit while other

one is control & isolation circuits.

The timer circuit requires 24V DC supply voltage while rest of the circuit

(for sprinkler valves) requires 24VAC supply voltage. For this purpose we

require a step down transformer which will step down 230V, 50Hz input

supply voltage to 24V AC.

Rectifier circuit -

At the output of transformer we get 24V AC voltage, but timer circuit

requires DC supply. Therefore we will use a rectifier to convert 24V AC to

24V DC. Here a filter is also required to filter out noise in the input voltage.


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Timer Circuit: - IC 555 is wired as an astable multivibrator producing

about 7Hz pulses.

14-Stage Binary Counter:- The 7Hz frequency is further divided by

IC CD4020, which is a 14-stage binary counter to generate 20 minute

time delay.

Control circuitry to switch between two the solenoid valves. The

optoisolation between control circuit and mains supply provid e extra

safety.


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CHAPTER 4

CIRCUIT DIAGRAM AND DESCRIPTION

4.1 CIRCUIT DIAGRAM

Fig.4.1 Circuit Diagram

4.2 CIRCUIT DIAGRAM DESCRIPTION

The whole circuit is divided into to three sections.

i . Power supply circuit

ii . Timer circuit to generate time delay

iii . Opto-isolation between control circuit & mains supply.

i . Power supply circuit : -

The circuit requires two type of supply voltage. 24V AC for the

optoisolation and relay circuit and 24V DC to power the timer circuit.


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a. To get the 24V AC we are using a step down transformer which wil l

convert 230V AC to 24V AC voltage.

b. The 24V AC from the controller is half-wave-rectified by diode D1 and filtered by

capacitors C1 and C2. The rectified DC is fed to the timer circuit through resistor R1

and zener diode ZD1 to produce 12 volts to enable the timer circuit.

ii . Timer circuit : -

In this circuit the two sprinkler valves have to be switched alternately

after 20 minutes. This time delay is achieved by the combination of

IC555 and 14-stage binary counter(CD4020BC). IC 555 (IC1) is wired as an

astable mutivibrator producing about 7Hz pulses. You can change this frequency by

changing the values of timing components R2, R3 and C4. The output of IC1 is fed to

clock pin 10 of IC2. The 7Hz frequency is further divided by IC2, which is a 14-stage

binary counter.

IC 555

The 555 Timer IC is an integrated circuit (chip) used in a variety of t imer,

pulse generation and oscillator applications. Depending on the manufacturer, the

standard 555 package includes over 20 transistors, 2 diodes and 15 resistors on

a si licon chip installed in an 8 -pin mini dual -in-line package (DIP-8).

Fig.4.2 internal block diagram of ic555

The 555 has three operating modes:


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Monostable mode: in this mode, the 555 functions as a "one -shot".

Applications include timers, missing pulse detection, bouncefree switches,

touch switches, frequency divider, capacitance measurement, pulse-width

modulation (PWM) etc

Astable - free running mode: the 555 can operate as an oscillator . Uses

include LED and lamp flashers, pulse generation, logic clocks, tone

generation, security alarms, pulse position modulation , etc.

Bistable mode or Schmitt trigger: the 555 can operate as a flip-flop, if

the DIS pin is not connected and no capacitor is used. Uses include

bouncefree latched switches, etc.

Pin Description of ic555

Fig. 4.3 Pin diagram of IC555


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Astable mode

In astable mode, the 555 timer puts out a continuous stream of rectangular

pulses having a specified frequency. Resistor R 1 is connected between VCC and

the discharge pin (pin 7) and another resistor (R 2) is connected between the

discharge pin (pin 7), and the trigger (pin 2) and threshold (pin 6) pins that

share a common node. Hence the capacitor is charged through R 1 and R2 , and

discharged only through R 2 , since pin 7 has low impedance to ground during

output low intervals of the cycle, therefore discharging the capacitor.

Fig. 4.4 Standard 555 astable circuit

In the astable mode, the frequency of the pulse stream depends on the

values of R1 , R2 and C:

f = 1/ [ln(2).1µF.(1kΩ+2*100kΩ) ]

= 7.17 Hz ……………….. (1)


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The high t ime from each pulse is given by

= ln(2) . (1KΩ+ 100KΩ) . 1µF

= 0.07 sec

and the low time from each pulse is given by

= ln(2) . 100KΩ . 1µF

= 0.069 sec

where R1 and R2 are the values of the resistors in ohms and C is the value

of the capacitor in farads.

NOTE: power of R1 must be greater than To achieve a duty cycle of less than 50% a diode can be added in parallel

with R2 towards the capacitor. This bypasses R2 during the high part of the cycle

so that the high interval depends only on R 1 and C.

Specifications of IC555

These specifications apply to the NE555. Other 555 timers can have

different specifications depending on the grade (military, medical, etc).

Supply voltage (VCC) 4.5 to 15 V

Supply current (VCC = +5 V) 3 to 6 mA

Supply current (VCC = +15 V) 10 to 15 mA

Output current (maximum) 200 mA

Maximum Power dissipation 600 mW

Power Consumption (minimum

operating)

30 mW@5V,

225 mW@15V

Operating temperature 0 to 70 °C


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14-Stage Ripple Carry Binary Counter (CD4020BC)

IC2 (CD4020BC) is reset through capacitor C6 and resistor R4 when

power switch S1 is closed. Output pin 3 of IC1 (LM555) goes low when i t

resets. Counter IC2 is then clocked at 7 Hz, with its final output (Q14) going

high after 20 minutes. This high output of IC2 activates the solenoid valves via

optocoupled triacs built around IC3 and IC4.

General description

The counters are advanced one count on the negative transition of each

clock pulse. The counters are reset to the zero state by a logical “1” at the reset

input independent of clock.

Features

Wide supply voltage range: 1.0V to 15V

High noise immunity: 0.45 VDD (typ.)

Low power TTL compatibility: Fan out of 2 driving 74 or 1 driving 74LS

Medium speed operation: 8 MHz typ. at VDD = 10V

Schmitt trigger clock input

Pin Diagram of CD4020BC

Fig. 4.5 Pin Diagram of CD4020BC


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Fig. 4.6 Schematic diagram of CD4020BC

iii. Opto-isolation between control and power circuit

In electronics, an opto-isolator, also called

an optocoupler, photocoupler, or optical isolator,

is "an electronic device designed to transfer

electrical signals by utilizing light waves to

provide coupling with electrical isolation between

its input and output". The main purpose of an

opto-isolator is "to prevent high voltages or

rapidly changing voltages on one side of the

circuit from damaging components or distorting

transmissions on the other side."Commercially

available opto-isolators withstand input-to-output Fig. 4.7 Pin description

voltages up to 10 kV and voltage transients with speeds up to 10 kV/μs.


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Hot-Line Switching Application Circuit

Fig. 4.8 Optocoupler circuit

Applications of Triac Drive Optocoupler

Solid state relays

Industrial controls

Lighting controls

Static power switches

AC motor starters

TRIAC Drive Optocoupler Advantage

Discrete TRIACs are often used to control motors, solenoids, relays and other power devices that

are driven by the AC mains (120VAC or 240VAC). The control signal that turns these loads on

and off comes from low voltage logic circuitry that needs to be isolated from the mains. This is

best achieved by use of an optocoupler. The TRIAC drive optocoupler consists of an infrared

LED on the input side and a silicon detector chip incorporating two inverse parallel silicon-

controlled rectifiers (SCRs). The logic signal drives the optocoupler’s LED. Light is transmitted

across the isolation barrier and activates the forward biased SCRs on the output side of the

optocoupler. Each SCR conducts one half cycle of the AC mains signal. Current from the mains

is then transmitted across the forward biased SCR which activates the gate of the power TRIAC.

The power TRIAC then drives the load for a majority of the duty cycle.


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The zero crossing versions of optocoupler inhibit switching until the mains voltage is close to

the zero crossing.

4.3 WORKING OF CIRCUIT

Working of the circuit is simple. When you power-on the circuit using switch S1, IC1 is

enabled and IC2 resets. Q14 of IC2 remains low, making transistor T1 cut-off. Transistor T2

conducts to forward-bias the internal LED of optocoupler IC3. Triac1 is controlled through IC3,

which provides gate current through resistor R12 to turn it on. As a result, solenoid valve-1

activates to provide path for water to flow. After 20 minutes, Q14 of IC2 goes high, making

transistor T1 conduct. Transistor T2 cuts off and the internal LED of optocoupler IC4 is forward-

biased. Triac2 is controlled through IC4, which provides gate current through resistor R9 to turn

it on. As a result, solenoid valve-2 activates to give path for water flow. Timer IC1 is disabled as

soon as the output of IC2 goes high, making its reset pin 4 low to stop clocking to IC2 and so its

output remains high. Triac2 has a snubber circuit built around R10 and C6. Triac1 too has a

snubber circuit built around R13 and C7. The snubber circuit is used to suppress any voltage

spike produced by switching the solenoid valve coils.


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CHAPTER 5

PCB MAKING DESIGN CONSODERATION

5.1 DESIGNING OF LAYOUT

The design part of the PCB is carried out with different softwares such as PROTEL99,

XILINX etc. The following are the steps for the design using these softwares.

1. Complete circuit diagram will be available with us.

2. Using this complete circuit diagram, a schematic document is prepared.

3. Designations & Footprints are given to all components.

4. A net list is prepared & the schematic is checked for errors.

5. If no errors found then the PCB document is created.

6. Border layers are selected accordingly, whether the PCB is a single side or a double sided

one.

7. Components are then loaded into the PCB.

8. The next step is the placement of components, which can be automatic or manual as per

requirement.

9. After the placement of components, next step is routing. There is an option for auto

routing.

10. Now the PCB document (layout) is ready. We can also view the 3D view of the PCB

using the software.

After this, the printout of layout is taken & a negative is prepared. Using this negative layout

is prepared on the PCB then the following process is carried out.

FABRICATION:-

PCB means Printed Circuit Board on which the circuit is made and the operation

depends on this circuit. The step requir ed for the PCB design for the circuit of a

two way intercom using mains is as explained below. Conductor materials

available are Silver, Brass, Aluminium and Copper. Copper is widely used. The


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thickness of conducting materials depends upon the current carr ying capability.

The printed circuit board serves three distinct functions.

1. It provides necessary interconnections.

2. It acts as a heat sink.

3. It provides a conduction path leading to removal of most of heat generate

in the circuit.

The various processes involved in the designing of PCB are:

CLEANING OF COPPER CLAD:-

First of all copper clad’s copper plated side is cleaned with the help of steel wool to remove the

dirt so that there are better copper connections.

ETCHING:-

Etching is the process to dissolve any exposed copper surface. For etching, the

board is held inside the etchant, which is placed inside a box of non -corrosive

material . In it takes water just enough to immerse the board and add required

amount of Ferric chloride without splashing. One may heat the solution to about

60 c for quicker results keep shaking the board in a see - saw motion. After

sometime the non shaded part of the copper starts changing i ts color and slowly

the base materials shows up, while the copper the copper protected by photo-

resist remains non-affected.

WASHING:-

The plate is then taken out ferric chloride solution and is washed under running water. The

developer on the pattern is removed by rubbing with steel wool until a good shine is obtained.

Now the printed circuit board is ready for soldering and components.


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VERNISHING:-

The printing ink should be removed from PCB. This can be removed with the help of turpentine

solution. With the help of pf and paper, copper is cleaned and varnish solution is applied on the

surface of PCB and it is allowed to dry.

DRILLING:-

Drilling is done on the marks on the board with the help of pin.

For drilling the board one can used high tensile steel pin of diameter 0.8 mm, 1mm and 3 mm.

one should check that how much pressure should not be applied on the bit as that will result in

bending or breaking of bits. While drilling one should again keep the following point in view:-

a) First of all the hole on the plate are drilled of diameter 0.8mm then this diameter can be later

increased whenever needed.

b) Always use IC sockets, as direct soldering of the IC may damage it. One can insert the IC in

the IC socket whenever needed.

c) The drilling the hole should be in such a manner so as to corresponds to IC sockets exactly

that is one faces no difficulty in inserting the pins of the sockets in the hole.

d) The lead of discrete components should also be properly inserted into holes.

e) The hole for the discrete components should also be so spaced that one not have bend the lead

of components much.

f) For external connections flexible wires should be used.

SOLDERING:-

Solder the components on the PCB with the soldering taking place on the copper side.

First of all the IC bases are carefully soldered, so as not to short of its legs & then solder the rest

of the components in their respective places.

For proper or better soldering flux should be used. Take care that the copper is not

removed while soldering. Now the instrument mounted PCB is ready for operation.


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Mounting Of IC’s:-

It never expected to put the IC’s directly on the PCB & the soldered. The IC sockets

are available in the market. These sockets are first mounted and leads of the sockets are soldered,

after completion, the transferred on the socket.

After the components mounting & soldering, the extra part of leads coming out must be cut with

a cutter. It is recommended that before soldering the leads, the extra portion of the leads must be

cut & then soldered. Lead cutting after soldering is used.

Functions Of Soldering Iron:-

It stores heat & transfers to the work piece.

It delivers molten solder to the piece.

It is used for removing excess solder. The bit is made of copper.

In the hand soldering every point is soldered at a time.

The component to be soldered is taken & the flux is applied to its lead for prominent

solder.

Following are the steps involved in the soldering.

1. Make the iron ready.

2. Apply flux to the two surfaces.

3. Heat the surface by iron bit positioned properly.

4. When the surface is hot then apply solder wire.

5. Let the solder be melted.

6. Lift the iron up along the component (after the wetting process is complete.)

7. Remove the iron, rub it against the pad and restore it.

8. Cut the extra lead.


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5.3 COMPONENT LIST

Sr. No. Component Name Value

1. IC1 LM555

2. IC2 CD4020BC

3. IC3, IC4 MC3030

4. Diode D1 1N4007

5. Zener Diode ZD1 12V, 1W

6. Triac TR1, TR2 BT136

7. Resistor R1 470Ω, 5W

R2 1KΩ

R3 100KΩ

R4 4.7 KΩ

R5, R6 10 KΩ

R7, R8 470 Ω

R9, R10 68 Ω

R11 1 KΩ

R12, R13 68 Ω

R14 1 KΩ

8. Capacitor C1 100µF, 50V

C2, C3 0.1 µF

C4 1 µF, 50V

C5 0.01 µF

C6 1 µF, 50V

C7, C8 0.01 µF

9. Transistor T1 (npn) BC548

T2 (pnp) BC558


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5.4 CIRCUIT SCHEMATIC

Fig. 5.1 Circuit Schematic drawn by ”ExpressPCB software”


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5.5 FINAL PCB LAYOUT


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CHAPTER 6

ADVANTAGES & DISADVANTAGES

6.1 ADVANTAGES

1. Simplicity. Save time and effort. Once an irrigation system is installed you’ll never

have to drag a hose all over the yard, never have to try and figure out if you’ve applied

enough (or too much) water, and you’ll never have to worry about watering the lawn

while you’re away.

2. Efficiency. Because the system is automatic, you don’t need to be there to physically

apply the water.

3. Saves water - Studies show that sprinkler systems use 30 - 50% less water than

conventional watering methods.

4. In this system we are using opto-isolation between timer circuit and mains supply.

Therefore protect the circuit from high voltage fluctuations.

5. Using this system we can set the time limit for the operation of individual sprinkler

valves located in different area in a farm or gardens.

6. This system can be easily implemented in small as well as large area.

7. The cost require to implement this system is very less (approx. Rs. 500 for the

controller).

8. As this system is automatic therefore it reduces the man power to a great extent.

9. Sprinkler irrigation does not require surface shaping of leveling of the area to be

irrigated.

10. Can be applied to areas of variable topography.

11. Suitable for most crops, not all, and are adaptable to most irrigable soils.

12. Flexibility is possible because sprinkler heads are available in a wide range of discharge

capacities.

13. Chemical and fertilizer applications are easily used with sprinkler systems.


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6.2 DISADVANTAGES

1. Disadvantages of Sprinkler systems. Water application efficiency under sprinkler

irrigation is strongly affected by wind.

2. Some crops are particularly sensitive and may suffer leaf scorch because of the salts

deposited on the leaves as the intercepted irrigation water evaporates.


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CHAPTER 7

APPLICATIONS AND FUTURE SCOPE

8.1 APPLICATIONS

1. This system can be used in agricultural farms and fields of small as well as large

areas.

2. This project can be used in automatic fire control sprinkler systems.

3. This project can be implemented in golf courses.

4. This system is ideal for garden lawns and landscaping areas.

8.2 FUTURE SCOPE

1. The system can be made fully automatic by the use of microcontroller.

2. By the use humidity sensor and volume controller we can control the amount of water

delivered to the plant.

8.3 CONCLUSION

The main goal of this project is to make a simple and cheap controller for the sprinkler

system. The system provides with several benefits and can operate with less manpower.

The system can switch between two sprinkler valves alternately after 20 minutes. The

optoisolation provides much more safety from the mains supply. Thus, the system is

efficient and compatible to the changing environment.


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CHAPTER 8

BIBILOGRAPPHY

1. http://en.wikipedia.org/wiki/555_timer_IC

2. http://en.wikipedia.org/wiki/Opto-isolator

3. http://www.fairchildsemi.com/products/opto/brochures/100004-002_FOD4XXX_EN.pdf

4. www.electronicsforu.com/EFYLinux/circuit/January2011/CI-04_Jan11.pdf

5. http://nptel.iitm.ac.in/courses/Webcoursecontents/IIT%20Kharagpur/Water%20Resource

%20Engg/pdf/m3l05.pdf


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CHAPTER 9

DATASHEETS

The datasheets attached are as follows:

1. LM555

2. CD4020BC

3. MCT2E

4. BT136

Documents

Automatic Sprinkler Control System