GREEN BEE Witout Moisture

7/27/2019 GREEN BEE Witout Moisture

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SMART PLOWING MACHINE WITH GREEN HOUSE SYSTEM

GREENBEE

Introduction:

Microcontroller Based GREENBEE Model project is an advanced and

innovative system for the automatic monitoring & controlling of the

GREENBEE Systems. In conventional method, the parameters like Soil

Moisture i.e., Water; Light Intensity & Temperature are manually controlled

to produce a food grains / vegetables or fruits. This process is time

consuming & requires man-power to study & control these physical

parameters.

Here, Automatic GREENBEE Model project is designed to measure &

control the above said parameters automatically and efficiently without the

manual attention & intervention. This project helps us to eliminate the

manpower requirement and also to use the resources like water & electricity

very efficiently.

Many electronic mosquito repellers are available in the market. These

usually consist of a small heating element that burns a chemical coated tablet

in order to produce chemical fumes which are meant to repel pests. But these

fumes not only affect pests but also have adverse effects on human beings.

Also, they prove to be considerably costly in operation and have a limited

life.

The fact that pests, especially pests, are sensitive to ultrasonic

frequencies, is quite well known. When exposed to ultrasonic frequencies,

they are unable to withstand them and tend to be repelled by them. Making

Dept. of Electrical & ElectronicPage 1



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use of this principle, the ultrasonic pest repeller described here uses

ultrasonic frequencies rather than chemical fumes for operation.

Robots today are being employed to release man from heavy, tedious,

monotonous work like arc welding or to work under conditions where

human beings cannot function effectively. The robot described here senses

the objects, picks it up and places it at a predefined distance. A wireless

device with a will control the functions of the robot.

Methodology:

The project consists of the following system elements / functional blocks.

The brief explanation for these section is also given below.

1) Sensors:

2) Buffer Amplifier

3) Filter 4) Amplifier / Signal Conditioner

5) DRIVER

6) Buffer

7) I/O Circuit / PC Port

1) Sensors:

Sensors are used to sense / detect the value of the physical parameter under

observation. Here numbers of sensors are used for analysing the parameters

like, Soil Moisture, Light Intensity & soil Conductivity.

2) Buffer Amplifier:

Buffer amplifier amplifies the faint electrical signals generated from the

sensors, so that the DRIVER (DRIVER) can process the data and converts

Dept. of Electrical & Electronic s



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them to digital format. If the input signals are not sufficiently high in

amplitude, the DRIVER circuit cannot perform the conversion.

3) Filter:

The job of the filter circuit is to eliminate all unwanted electrical noise

signals. This filter network is used to filter out the harmful signals from the

nearby electrical heavy devices like AC Motors, Pump sets etc.

4) Monostable :

Signal Conditioner is used to limit the incoming signal amplitude to a safe

limit in case the sensors operate in extreme conditions like Dry Soil or Over

temperature, so that, the remaining circuit components remain safe and

functional.

5) DRIVER:

DRIVER circuit is used to convert the incoming analogue signals in to

digital one. Since the Computer is a Digital Device, it cannot process or

sense Analogue Values. So the conversion of analogue signals to digital

format is very essential.

6) Buffer:

Buffer circuit is primly used to provide BUFFER of between the Input /

Output Device (I/O Device) like PC Parallel Port or COM Port. This

concept will help one to safeguard the relatively expensive computer fromelectrical damage in case the Project connected to it fails or gets damaged.

7) Ultrasonic: The system consists of an ultrasonic oscillator, a decade

counter, a clock pulse generator and a common regulated power supply.




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The ultrasonic oscillator generates an ultrasonic frequency which is

externally varied automatically in ten steps. The frequency has not been kept

constant because of two reasons. First a constant frequency after prolonged

use is unable to affect the pests effectively. Second, a particular frequency

affects only one specific kind of pests. So by utilizing various frequencies,

control can be exercised over various kinds of pests.

Applications:

1. Suitable for horticulture and agriculture fields.

2. With slight modifications can be used as Weather Station.

3. Frequency is varied continuously to affect larger number of pests.

4. The circuit has no operational expenditure.

APPLICATIONS

1) Used at homes, hospitals, etc.




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BLOCK DIAGRAM:

PEST CONTROLLER


BUFFER

DRIVER

FILTERS

PRE-

AMPLR

US RX

US TX LATCH

RF TX

LOAD

CONDUCTIVI

TY

FIRE

MULTIVIBR

ATOR



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RECEVING SECTION:


MICROCON

TROLLER

LCD

RF RX BUFFER &

DRIVER RELAY



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CHAPTER 4:

METHODOLOGY/DESIGN/FABRICATION/TESTS

4.1: HARDWARE DISCRIPTION

4.1.1: POWER SUPPLY UNIT:

The circuit needs two different voltages, +5V & +12V, to work. These dual voltages are

supplied by this specially designed power supply.

The power supply, unsung hero of every electronic circuit, plays very important role in

smooth running of the connected circuit. The main object of this ‘power supply’ is, as the

name itself implies, to deliver the required amount of stabilized and pure power to the

circuit. Every typical power supply contains the following sections:

1. Step-down Transformer: The conventional supply, which is generally available to

the user, is 230V AC. It is necessary to step down the mains supply to the desired level.

This is achieved by using suitably rated step-down transformer. While designing the

power supply, it is necessary to go for little higher rating transformer than the required

one. The reason for this is, for proper working of the regulator IC (say KIA 7805) it

needs at least 2.5V more than the expected output voltage

2. Rectifier stage: Then the step-downed Alternating Current is converted into Direct

Current. This rectification is achieved by using passive components such as diodes. If the

power supply is designed for low voltage/current drawing loads/circuits (say +5V), it is




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sufficient to employ full-wave rectifier with centre-tap transformer as a power source.

While choosing the diodes the PIV rating is taken into consideration.

3. Filter stage: But this rectified output contains some percentage of superimposed a.c.

ripples. So to filter these a.c. components filter stage is built around the rectifier stage.

The cheap, reliable, simple and effective filtering for low current drawing loads (say upto

50 mA) is done by using shunt capacitors. This electrolytic capacitor has polarities, take

care while connecting the circuit.

4. Voltage Regulation: The filtered d.c. output is not stable. It varies in accordance

with the fluctuations in mains supply or varying load current. This variation of load

current is observed due to voltage drop in transformer windings, rectifier and filter

circuit. These variations in d.c. output voltage may cause inaccurate or erratic operation

or even malfunctioning of many electronic circuits. For example, the circuit boards which

are implanted by CMOS or TTL ICs.

The stabilization of d.c. output is achieved by using the three terminal voltage regulator IC. This regulator IC comes in two flavors: 78xx for positive voltage output and 79xx for

negative voltage output. For example 7805 gives +5V output and 7905 gives -5V

stabilized output. These regulator ICs have in-built short-circuit protection and auto-

thermal cutout provisions. If the load current is very high the IC needs ‘heat sink’ to

dissipate the internally generated power.


1 2 3

KIA 78xx

Series



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Circuit Description: A d.c. power supply which maintains the output voltage

constant irrespective of a.c. mains fluctuations or load variations is known as regulated

d.c. power supply. It is also referred as full-wave regulated power supply as it uses four

diodes in bridge fashion with the transformer. This laboratory power supply offers

excellent line and load regulation and output voltages of +5V & +12 V at output

currents up to one amp.

CIRCUIT DIAGRAM OF +5V & +12V FULL WAVE REGULATED

POWER SUPPLY

Parts List:


230AC

X

1

C1

D2

1

C2 C3

IC1

7812

D1

19V

C4

IC1

7805+

+



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1. Step-down Transformer: The transformer rating is 230V AC at Primary and 12-0-

12V, 1Ampers across secondary winding. This transformer has a capability to deliver a

current of 1Ampere, which is more than enough to drive any electronic circuit or varying

load. The 12VAC appearing across the secondary is the RMS value of the waveform and

the peak value would be 12 x 1.414 = 16.8 volts. This value limits our choice of rectifier

diode as 1N4007, which is having PIV rating more than 16Volts.

2. Rectifier Stage: The two diodes D1 & D2 are connected across the secondary

winding of the transformer as a full-wave rectifier. During the positive half-cycle of

secondary voltage, the end A of the secondary winding becomes positive and end B

negative. This makes the diode D1 forward biased and diode D2 reverse biased.

Therefore diode D1 conducts while diode D2 does not. During the negative half-cycle,

end A of the secondary winding becomes negative and end B positive. Therefore diode

D2 conducts while diode D1 does not. Note that current across the centre tap terminal is

in the same direction for both half-cycles of input a.c. voltage. Therefore, pulsating d.c. is

obtained at point ‘C’ with respect to Ground.


SEMICONDUCTORS

IC1

IC2

7812 Regulator IC

7805 Regulator IC

1

1

D1& D2 1N4007 Rectifier Diodes 2

CAPACITORS

C1 1000 µf/25V Electrolytic 1

C2 to C4 0.1µF Ceramic Disc type 3

MISCELLANEOUS

X1 230V AC Pri,14-0-14 1Amp Sec Transformer 1



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3. Filter Stage: Here Capacitor C1 is used for filtering purpose and connected across

the rectifier output. It filters the a.c. components present in the rectified d.c. and gives

steady d.c. voltage. As the rectifier voltage increases, it charges the capacitor and also

supplies current to the load. When capacitor is charged to the peak value of the rectifier

voltage, rectifier voltage starts to decrease. As the next voltage peak immediately

recharges the capacitor, the discharge period is of very small duration. Due to this

continuous charge-discharge-recharge cycle very little ripple is observed in the filtered

output. Moreover, output voltage is higher as it remains substantially near the peak value

of rectifier output voltage. This phenomenon is also explained in other form as: the shunt

capacitor offers a low reactance path to the a.c. components of current and open circuit to

d.c. component. During positive half cycle the capacitor stores energy in the form of

electrostatic field. During negative half cycle, the filter capacitor releases stored energy tothe load.

4. Voltage Regulation Stage: Across the point ‘D’ and Ground there is rectified and

filtered d.c. In the present circuit KIA 7812 three terminal voltage regulator IC is used to

get +12V and KIA 7805 voltage regulator IC is used to get +5V regulated d.c. output. In

the three terminals, pin 1 is input i.e., rectified & filtered d.c. is connected to this pin. Pin

2 is common pin and is grounded. The pin 3 gives the stabilized d.c. output to the load.

The circuit shows two more decoupling capacitors C2 & C3, which provides ground path

to the high frequency noise signals. Across the point ‘E’ and ‘F’ with respect to ground

+5V & +12V stabilized or regulated d.c output is measured, which can be connected to

the required circuit.

Note: While connecting the diodes and electrolytic capacitors the polarities must be

taken into consideration. The transformer’s primary winding deals with 230V mains, care

should be taken with it.




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4.1.2: BUFFER, DRIVER & SWITCHING MODULE

When the user programs the schedule for the automation using GUI [Graphical User

Interface] software, it actually sends 5-bit control signals to the circuit. The present

circuit provides interfacing with the Microcontroller and the controlling circuitry. This

circuit takes the 5-bit control signal, isolates the MICROCONTROLLER from this

circuitry, boosts control signals for required level and finally fed to the driver section to

actuate relay. These five relays in turn sends RC5 coded commands with respect to their

relay position.

First the components used in this Module are discussed and

then the actual circuit is described in detail.

HEX BUFFER / CONVERTER [NON-INVERTER] IC

4050: Buffers does not affect the logical state of a digital

signal (i.e. logic 1 input results into logic 1 output where as

logic 0 input results into logic 0 output). Buffers are

normally used to provide extra current drive at the output,

but can also be used to regularise the logic present at an

interface. And Inverters are used to complement the logical

state (i.e. logic 1 input results into logic 0 output and vice

versa). Also Inverters are used to provide extra current

drive and, like buffers, are used in interfacing applications.

This 16-pin DIL packaged IC 4050 acts as Buffer as-well-

as a Converter. The input signals may be of 2.5 to 5V

digital TTL compatible or DC analogue the IC gives 5V

constant signal output. The IC acts as buffer and provides

isolation to the main circuit from varying input signals. The

working voltage of IC is 4 to 16 Volts and propagation

delay is 30 nanoseconds. It consumes 0.01 mill Watt power

with noise immunity of 3.7 V and toggle speed of 3

Megahertz.


1

2

6

3

5

4

7

Vcc

Vss8

IC 4050



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ULN 2004: Since the digital outputs of the some

circuits cannot sink much current, they are not

capable of driving relays directly. So, high-voltage

high-current Darlington arrays are designed for

interfacing low-level logic circuitry and multiple

peripheral power loads. The series ULN2000A/L

ICs drive seven relays with continuous load current

ratings to 600mA for each input. At an appropriate

duty cycle depending on ambient temperature and

number of drivers turned ON simultaneously,

typical power loads totalling over 260W [400mA x

7, 95V] can be controlled. Typical loads includerelays, solenoids, stepping motors, magnetic print

hammers, multiplexed LED and incandescent

displays, and heaters. These Darlington arrays are

furnished in 16-pin dual in-line plastic packages

(suffix A) and 16-lead surface-mountable SOICs

(suffix L). All devices are pinned with outputs

opposite inputs to facilitate ease of circuit board

layout.

The input of ULN 2004 is TTL-compatible open-collector outputs. As each of these

outputs can sink a maximum collector current of 500 mA, miniature

MICROCONTROLLER relays can be easily driven. No additional free-wheeling clamp

diode is required to be connected across the relay since each of the outputs has inbuilt

free-wheeling diodes. The Series ULN20x4A/L features series input resistors for

operation directly from 6 to 15V CMOS or PMOS logic outputs.

1N4148 signal diode: Signal diodes are used to process information (electrical signals) in

circuits, so they are only required to pass small currents of up to 100mA. General

purpose signal diodes such as the 1N4148 are made from silicon and have a

forward voltage drop of 0.7V.


1 1

6

2

3

4

5

6

7

8

11

12

14

15

13

10

9

IC ULN 2004



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CIRCUIT DIAGRAM OF BUFFER, DRIVER & SWITCHING STAGE

ept. of Electrical & Electronic s Page 14

5

3

9

7

8

1

11

4

2

10

6

12

1415

RL2 RL3 RL4 RL5

IC1

IC2

2

1

4

3

8

9

5

15

16

13

12

6 11

14

710

R1 TO R5

D1 TO D5

+5V

Gnd

+12

Commands

fromMICROCONTR

OLLER

D6-D10

R6-R10

RL1

N/C

COM-1

N/C

COM-2

N/C

COM-3

N/C

COM-4

N/C

COM-



SMART PLOWING MACHINE WITH GREEN HOUSE SYSTEM

Parts List:

Circuit Description:

The Hex Buffer/Inverter IC1’s working voltage of +5V is applied at pin-1 and five

control signals are applied at input pins 3, 5, 7, 9 & 11. Thus the signal supplying

circuit [i.e. MICROCONTROLLER] is isolated from this Buffer & Driver circuit.Further the grounding resistors R1 to R5 prevents the abnormal voltage levels passing

inside the IC1. The buffered outputs are acquired at pins 2, 4, 6, 10, & 12. Thus the

varying input is further stabilized and fed to signal diodes [D1 to D5]. As the load is

inductive, there is a chance of producing back e.m.f. So to cope with this back e.m.f,

signal diodes are used. But this signal level is not strong enough to drive the low

impedance relay. So, IC2 Darlington driver is used. Its working voltage is +12 V and

only five input/output pins are used. The output signal from the Darlington driver IC is

strong enough to actuate five relays.

These relays with +12V working voltage can be used to produce five command signals

with RC5 format. The N/O [Normally Open] contact of each relay produces one

Dept. of Electrical & Electronic

SEMICONDUCTORS

IC1 4050 HEX BUFFER/CONVERTER(NON-

INVERTER)

1

IC2 2004 DARLINGTON ARRY 1

RESISTORS

R1 to R5 220 Ohm ¼ Watt Carbon Resistors 5

R6 to R10 2.2 K Ohm ¼ Watt Carbon Resistors 5

DIODES

D1to D5 1N4148 SIGNAL Diodes 5

D6 to D10 Red Indicator LEDs 5

MISCELLANEOUS

RL1-RL5 12 V, 700 Ohm DPDT Reed Relays 5



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command signal with the help of RC5 Transmitter Circuit. The five relays activation

with their corresponding command signal production is tabulated as below:

RELAYCOMMAND

NUMBER COMMAND SIGNAL

RL1 COM-1 TURN LEFT

RL2 COM-2 TURN RIGHT

RL3 COM-3 MOVE BACKWARD

RL4 COM-4 MOVE FORWARD

RL5 COM-5SWITCH ON/OFF THE

SUCKING DEVICE

4.1.4: CIRCUIT DIAGRAM & ITS DESCRIPTION

Depend upon the circuit diagram this system is divided into following stages:

Monostable Multivibrator, Variable Power Supply and finally Power Supply.

Dept of Electrical & Electronics Page 16



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INTERNAL ARRANGEMENT OF 555 TIMER IC

The timer comprises two operational amplifiers (used as comparators) together with an

RS Bistable element. In addition, an inverting output buffer is incorporated so that a

considerable current can be sourced or sunk to/from a load. A single transistor switch,

TR1, is also provided as a means of rapidly discharging the external timing capacitor.

The standard 555 timer is housed in an 8-pin DIL package and operates from supply

rail voltages of between 4.5V and 15V. This encompasses the normal range for TTL

devices and thus the device is ideally suited for use in conjunction with TTL circuitry.

PIN OUT DIAGRAM OF TIMER IC 555

CIRCUIT DIAGRAM 555 MONOSTABLE MULTIVIBRATOR:


RESET

OUTPUT

TRIGGER

VCC

555

8

7

6

5

2

3

1

4

DISCHARGE

THRESHOLD

GROUND

CONTROL



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Parts List:

The circuit diagram shows how the timer IC 555 can be used as a Rising Light Level

Switch. In Monostable pulse generator mode, pin 4 is connected to pin 8 and that to

+Vcc. The threshold pin 6 and the discharge pin 7 are connected together to +Vcc by a

resistance R3. The control pin 5 is connected to ground via capacitor C2. The trigger


SEMICONDUCTORS

IC1 555 Timer IC 1

R1 33 K Ohm ¼ Watt 1

R2 1K Ohm ¼ Watt 1

R3 10K Ohm ¼ Watt 1

R4 470 Ohm ¼ Watt 1

D1 Red Light Emitting Diode 1

CAPACITORS

C1 & C3 10 µf / 25V Electrolytic 1

C2 0.1µF Ceramic Disc type 1

MISCELLENOUS

SENSOR LDR Sensor 1

C1

4 8

3

2

D1

GND

R1

R2

R4

470Ω

R3

C2C3

Output To Relay

+Vcc

67

1 5

IC1

input



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input pin 2 is connected to +Vcc using a pull-up resistor R1.Here the Light Detector,

R2 & C1 gives the triggering pulse needed for Multivibrator.

The current through Monostable Multivibrator will depend upon the light intensity

falling on LDR sensor. In full fall the reverse current flowing through Light Detector

will be very small. When the LDR has no light source falling on it, the capacitor C2 is

uncharged and the trigger input is low and that switching transistor TR1 (at pin-7) is in

the non-conducting state. Thus the output (at pin-3) is high. The capacitor C1 will begin

to charge toward +Vcc with current supplied by means of the series resistors R1 and

R2.

When LDR senses light on its surface, the reverse current flowing through LightDetector increases markedly. Thus Monostable timing period is initiated by a falling

edge (i.e. ‘High’ to ‘Low’ transition) applied to the trigger input (at pin 2). When such

an edge is received and the ‘trigger’ input voltage falls below ⅓ of Vcc, the output of

the lower comparator goes ‘high’ and the Bistable is placed in the ‘set’ state. The Q

output of the Bistable then goes low, switching transistor TR 1 is placed in the ‘OFF’

(non-conducting) state and the final ‘output’ (at pin-3) goes High. The circuit can be

readily adapted to drive a load with operating current less than about 150mA. So, the

indicator LED (D1) goes ‘ON’ stating the relay is in ON position.




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4.1.5: RF TRANSMITTER MODULE

RF TRANSMITTER

The RF transmitter is built around the ASIC and common passive and active

components, which are very easy to obtain from the material shelf. The circuit works

on Very High Frequency band with wide covering range. The Carrier frequency is 147

MHz and Data frequencies are 17 MHz, 19 MHz,22 MHz & 25 MHz. It should be

noted that ASIC or Application Specific Integrated Circuit is proprietary product and

data sheet or pin details or working principles are not readily available to the user.

ASIC:

Application Specific Integrated Circuit [ASIC] is another option for embedded

hardware developers. The ASIC needs to be custom-built for a specific application, so

it is costly. If the embedded system being designed is a consumer item and is likely to

be sold in large quantities, then going the ASIC route is the best option, as it

considerably reduces the cost of each unit. In addition, size and power consumption

will also be reduced. As the chip count (the number of chips on the system) decreases,

reliability increases.

If the embedded system is for the mass market, such as those used in CD players, toys,

and mobile devices, cost is a major consideration. Choosing the right processor,

memory devices, and peripherals to meet the functionality and performance

requirements while keeping the cost reasonable is of critical importance. In such cases,

the designers will develop an Application Specific Integrated Circuit or an Application

Specific Microprocessor to reduce the hardware components and hence the cost.

Typically, a developer first creates a prototype by writing the software for a general-

purpose processor, and subsequently develops an ASIC to reduce the cost.

Oscillator:

An electronic device that generates sinusoidal oscillations of desired frequency is

known as a sinusoidal oscillator. Although we speak of an oscillator as “generating” a

frequency, it should be noted that it does not create energy, but merely acts as an

energy converter. It receives d.c. energy and changes it into a.c energy of desired

frequency. The frequency of oscillations depends upon the constants of the device.




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A circuit which produces electrical oscillations of any desired frequency is known as an

oscillatory circuit or tank circuit. A simple oscillatory circuit consists of a capacitor (C)

and inductance coil (L) in parallel. This electrical system can produce electrical

oscillations of frequency determined by the values of L and C. The sequence of charge

and discharge results in alternating motion of electrons or an oscillating current. The

energy is alternately stored in the electric field of the capacitor and the magnetic field

of the inductance coil. This intercharge of energy between L and C is repeated over and

again resulting in the production of oscillations.

In order to obtain continuous undamped a.c. output from the tank circuit, it is necessary

to supply the correct amount of power to the circuit. The most practical way to do thisis to supply d.c. power to some device which should convert it to necessary a.c. power

for supply to the tank circuit. This can be achieved by employing a transistor circuit.

Because of its ability to amplify, a transistor is very efficient energy converter i.e. it

converts d.c. power to a.c. power. If the damped oscillations in the tank circuit are

applied to the base of transistor, it will result in an amplified reproduction of

oscillations in the collector circuit. Because of this amplification more energy is

available in the collector circuit than in the base circuit. If a part of this collector-circuit

energy is feedback by some means to the base circuit in proper phase to aid the

oscillations in the tank circuit, then its losses will be overcome and continuous

undamped oscillations will occur.

Hartley Oscillator is very popular and is commonly used as a local oscillator in radio

receivers. It has two main advantages viz., adaptability to a wide range of frequencies

and is easy to tune.

The RF transmitter is built around the common passive and active components, which

are very is to obtain from the material shelf. The circuit works on Very High Frequency

band with wide covering range.

CIRCUIT DESCRIPTION:

The ASIC Transmitter IC has four inputs and only one output pin. The four inputs are

for the frequency range of 17 KHz, 19 KHz, 22 KHz and 25 KHz and four switches are




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provided for each range. When any one switch is selected, that frequency is added to

the Transmitter circuit as data frequency and transmitted in the air. The Crystal X1 with

two coupling capacitor provides the working oscillator frequency to the circuit. The

Capacitors C6 and C7 are to stabilize the crystal oscillator frequency.

PARTS LIST

The ASIC output is added to the transmitter circuit’s oscillator transistor T1s base. The

data frequency is added with carrier frequency 147 MHz and aired for transmitting purpose. The transistor T1 is heart of the Hartely Oscillator and oscillates at carrier

frequency of 147 MHz along with tuned circuit formed by coil L1 and capacitor C4.

The Data frequency is fed to T1 on base through resistors R4 and R5. Capacitors C1

and C3 and for stabilizing the tuned circuit along with resistor R3.

To increase the range of the circuit, transmitting signals must be strong enough to travel

the long distance [i.e., upto 100 meters in this prototype]. So the generated signals are


SEMICONDUCTORS:

IC ASIC 1T1 BC 547 NPN Transistor 1

T2 BF 494 NPN Transistor 1

RESISTORS:

R1 & R2 2.7 K Ohm ¼ Watt 2

R3 & R6 330 K Ohm ¼ Watt 2



CAPACITORS:

C1, C2 0.001 Pico Farad Capacitor 2

C3 & C7 0.022 Pico Farad Capacitor 2

C4 4.7 Pico Farad Capacitor 1

C5 & C6 0.01 Micro Farad Capacitor 2

MISCELLANEOUS:

X1 1.44 MHz Crystal 1

S1 to S4 ON/OFF SWITCHES 4

L1 RF Coil 200mH 1

L2 Aerial or Telescopic Antenna 1



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made strong by amplifying to certain level with the help of Transistor T2 and

associated circuit.

The Radio frequency thus generated is fed to pre-amplifier transistor T2 on base

terminal. The resistor R6 provides the bias voltage to T2 and capacitors C5 & C7

removes the noise and harmonics present in the circuit. The antenna coil L2 transmits

the radio frequency in the air.




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CIRCUIT DIAGRAM OF RF TRANSMITTER

Dept. of Electrical & Electronics Page 24

R6

R4 C1 R5

C5

R3 330K

R2

2K7

C7

C2

0.00

1

T1

C3 C4

L1

L2

T2

R1

+Vcc

Gnd

17 KHz S1

19KHz S2

22 KHz S3

25 KHz S4ASIC

C6

C7X1



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4.1.6: RF RECEIVER MODULE

This circuit is built around the ASIC i.e., Application Specific Integrated Circuit, hence less

circuitry is observed. The Radio Frequency tuned circuit has 147 M Hz carrier frequency

with four options viz., 17Khz, 19Khz, 22KHz and 25KHz.

The transmitted signals are received on coil L1 which acts as receiver antenna. The

oscillator transistor removes the received signals from 147MHz carrier frequency and fed

to ASIC. The tank circuit formed by C1 and L1 gives the carrier frequency range. The

current limiting resistor R1 and bypass capacitor C5 stabilizes the oscillator. The resistor

R2, R3 and R4 provide the biasing voltage to the oscillator transistor T1. Capacitors C2 and

C3 are there to bypass the noise and harmonics present in the received signals. Through

coupling capacitor C7 output of the RF Receiver is fed to ASIC.

The ASIC manipulates the received signal and gives out four channels as output viz.,

17KHz, 19KHz, 22KHz and 25KHz. Each channel is amplified by pre-amplifier transistor

T2 along with bias resistor R9. The output of the pre-amplifier transistor is fed to relay

driver stage to activate the respective relay ON. The Darlington pair T3 and T4 are

arranged in driver stage to drive the low impedance relay.




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PARTS LIST:


SEMICONDUCTORS:

IC ASIC 1T1 BC 547 NPN Transistor 1

T2 BF 494 NPN Transistor 4

T3&T4 BC 548 NPN Transistor 8

RESISTORS:

R1 & R2 270 K Ohm ¼ Watt 2

R3 & R6 220 Ohm ¼ Watt 2

R4 2.2 K Ohm ¼ Watt 1

R5 2.2 M Ohm ¼ Watt 1

R7 10 K Ohm ¼ Watt 1R8 100 Ohm ¼ Watt 4

R9 560 Ohm ¼ Watt 4

CAPACITORS:

C1, C2 0.001 Pico Farad Capacitor 2C3 & C7 0.022 Pico Farad Capacitor 2

C4 4.7 Pico Farad Capacitor 1

C5 & C6 0.01 Micro Farad Capacitor 2L1 RF Coil 200mH 1



MART PLOWING MACHINE WITH GREEN HOUSE SYSTEM

CIRCUIT DIAGRAM OF RF RECEIVER

Dept. of Electrical & Electronic Page 27

T

T3

T3

T2

T2

C5

C3

L1

C2

C1

R1

R2

C4

T1

+Vcc

141312111098

1234567

ASIC

R8

RL1

R8

RL2

+Vcc

C6

C7R3

R4 R5

R6

R7R9

R9



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4.2: MICROCONTROLLER BASICS

The field parameters are monitored by this Microcontroller chip with the help of user written

program and generates alert message for LCD display and fault code for remote monitoringend transmission. The Microcontroller Chip has input port for getting fault condition of field

parameters and ‘Stop’ signal through RF Receiver and output port for sending fault code to

DTMF Encoder and switching Relay [MCB] for isolating power line from load.

INTRODUCTION OF MICRO-CONTROLLER

What is a microcontroller?

The general definition of a microcontroller is a single chip computer, which refers to the fact

that they contain all of the functional sections (CPU, RAM, ROM, I/O, ports and timers) of a

traditionally defined computer on a single integrated circuit. Some experts even describe

them as special purpose computers with several qualifying distinctions that separate them

from other computers.

Microcontrollers are "embedded" inside some other device (often a consumer product) so

that they can control the features or actions of the product. Another name for a

microcontroller, therefore, is "embedded controller."

Microcontrollers are dedicated to one task and run one specific program. The program is

stored in ROM (read-only memory) and generally does not change.

Microcontrollers are often low-power devices. A desktop computer is almost always plugged

into a wall socket and might consume 50 watts of electricity. A battery-operated

microcontroller might consume 50 mill watts.




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A microcontroller has a dedicated input device and often (but not always) has a small LED or

LCD display for output. A microcontroller also takes input from the device it is controlling

and controls the device by sending signals to different components in the device.

A microcontroller is often small and low cost. The components are chosen to minimize size

and to be as inexpensive as possible.

A microcontroller is often, but not always, ruggedized in some way. The microcontroller

controlling a car's engine, for example, has to work in temperature extremes that a normal

computer generally cannot handle. A car's microcontroller in Kashmir regions has to work

fine in -30 degree F (-34 °C) weather, while the same microcontroller in Gujarat region

might be operating at 120 degrees F (49 °C). When you add the heat naturally generated by

the engine, the temperature can go as high as 150 or 180 degrees F (65-80 °C) in the engine

compartment. On the other hand, a microcontroller embedded inside a VCR hasn't been

ruggedized at all.

Clearly, the distinction between a computer and a microcontroller is sometimes blurred.

Applying these guidelines will, in most cases, clarify the role of a particular device.




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ATmel 89C51 Technical Description

The ATmel 89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K

bytes of Flash programmable and erasable read only memory (PEROM). The ATmel 89C51

device is manufactured using Atmel’s high-density nonvolatile memory technology and is

compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash

allows the program memory to be reprogrammed in-system or by a conventional nonvolatile

memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip,

the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-

effective solution to many embedded control applications.

The ATmel 89C51 provides the following standard features: 4K Bytes of Flash, 128 bytes of

RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a

full duplex serial port, on-chip oscillator and clock circuitry. In addition, the 89C51 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 AT89C51

Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip

functions until the next hardware reset.

• Compatible with MCS-51 Products

• 4K Bytes of In-System Reprogrammable Flash Memory

• Fully Static Operation: 0 Hz to 24 MHz

• Three-level Program Memory Lock

• 128 x 8-bit Internal RAM 32

• Programmable I/O Lines

• Two 16-bit Timer/Counters

• Six Interrupt Sources Programmable Serial Channel

• Low-power Idle and Power-down Modes 40-pin DIP




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Parts List of Power Supply

X1 12-0-12V Transformer 1

IC1 7805 Regulator IC 1

D1 & D2 1N4007 Rectifier Diode 2

D3 Red Indicator LED 1

R1 100 KΩ Carbon Resistor 1

C1 1000MFD/25V

Electrolytic Capacitor 1

C2 & C3 0.1µF Ceramic Capacitor 2

COMPLETE CIRCUIT DIAGRAM [mother board] of 89c51

+VccP0.7 32

P0.6 33

P0.5 34

P0.4 35

P0.3 36

P0.2 37

P0.1 38

P0.0 39

P2.7 28

P2.6 27

P2.5 26

P2.4 25

P2.3 24

P2.2 23

P1.7 8

P1.6 7

P1.5 6

P1.4 5

P1.3 4

P1.2 3

P1.1 2

P1.0 1

1

19 XTAL1

18 XTAL2

30 pF

12 MHz

30 pF

89c51

vss

20

29 PSEN

30 ALE

31 EA

9 RST

+VCC

10 MFD/63V

20KΩ RESET

SWITCH

40

vcc

8 x 2.2 KΩ

ad7

ad6

ad5

ad4

ad3

ad2

ad1

ad0

rd

wr

t1

t0

int1

int0

txd

rxd

17 P3.7

16P3.6

15 P3.5

14 P3.4

13 P3.3

12 P3.2

a15

a14

a13

a12

a11

a10

a9

a8

230 AC

X1D1 & D2 IC1

R1

D3

C1 C2 C3

port 0

port 1

port 2 port 3



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CIRCUIT DESCRIPTION

The mother board of 89C51 has following sections: Power Supply, 89C51 IC, Oscillator, Reset Switch & I/O

ports. Let us see these sections in detail.

POWER SUPPLY:

This section provides the clean and harmonic free power to IC to function properly. The output of the full

wave rectifier section, which is built using two rectifier diodes, is given to filter capacitor. The electrolytic

capacitor C1 filters the pulsating dc into pure dc and given to Vin pin-1 of regulator IC 7805.This three

terminal IC regulates the rectified pulsating dc to constant +5 volts. C2 & C3 provides ground path to

harmonic signals present in the inputted voltage. The Vout pin-3 gives constant, regulated and spikes free +5

volts to the mother board.

The allocation of the pins of the 89C51 follows a U-shape distribution. The top left hand corner is Pin 1 and

down to bottom left hand corner is Pin 20. And the bottom right hand corner is Pin 21 and up to the top righthand corner is Pin 40. The Supply Voltage pin Vcc is 40 and ground pin Vss is 20.

OSCILLATOR:

If the CPU is the brain of the system then the oscillator, or clock, is the heartbeat. It provides the critical

timing functions for the rest of the chip. The greatest timing accuracy is achieved with a crystal or ceramic

resonator. For crystals of 2.0 to 12.0 MHz, the recommended capacitor values should be in the range of 15 to

33pf2.

Across the oscillator input pins 18 & 19 a crystal x1 of 4.7 MHz to 20 MHz value can be connected. The two

ceramic disc type capacitors of value 30pF are connected across crystal and ground, stabilizes the oscillation

frequency generated by crystal.

I/O PORTS:

There are a total of 32 i/o pins available on this chip. The amazing part about these ports is that they can be

programmed to be either input or output ports, even "on the fly" during operation! Each pin can source 20

mA (max) so it can directly drive an LED. They can also sink a maximum of 25 Ma current.

Some pins for these I/O ports are multiplexed with an alternate function for the peripheral features on the

device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. The

alternate function of each pin is not discussed here, as port accessing circuit takes care of that.

This 89C51 IC has four I/O ports and is discussed in detail: P0.0 TO P0.7

Source: Magnum Technologies.1

P2.0 21

1

11 P3.1

10 P3.0



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PORT0 is an 8-bit [pins 32 to 39] open drain bi-directional I/O port. As an output port, each pin can sink

eight TTL inputs and configured to be multiplexed low order address/data bus then has internal pull ups.

External pull ups are required during program verification.

P1.0 TO P1.7

PORT1 is an 8-bit wide [pins 1 to 8], bi-directional port with internal pull ups. P1.0 and P1.1 can be

configured to be the timer/counter 2 external count input and the timer/counter 2 trigger input respectively.

P2.0 TO P2.7

PORT2 is an 8-bit wide [pins 21 to 28], bi-directional port with internal pull ups. The PORT2 output buffers

can sink/source four TTL inputs. It receives the high-order address bits and some control signals during Flash

programming and verification.

P3.0 TO P3.7

PORT3 is an 8-bit wide [pins 10 to 17], bi-directional port with internal pull ups. The Port3 output buffers

can sink/source four TTL inputs. It also receives some control signals for Flash programming and

verification.

PSEN

Program Store Enable [Pin 29] is the read strobe to external program memory.

ALE

Address Latch Enable [Pin 30] is an output pulse for latching the low byte of the address during accesses to

external memory.

EA

External Access Enable [Pin 31] must be strapped to GND in order to enable the device to fetch code from

external program memory locations starting at 0000H upto FFFFH.

RST

Reset input [Pin 9] must be made high for two machine cycles to resets the device’s oscillator. The potential

difference is created using 10MFD/63V electrolytic capacitor and 20KOhm resistor with a reset switch.




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LCD MODULE

LCDs can add a lot to any application in terms of providing an useful interface for the user, debugging an

application or just giving it a "professional" look. The most common type of LCD controller is the Hitatchi

44780 which provides a relatively simple interface between a processor and an LCD. Using this interface is

often not attempted by inexperienced designers and programmers because it is difficult to find good

documentation on the interface, initializing the interface can be a problem and the displays themselves are

expensive.

The most common connector used for the 44780 based LCDs is 14 pins in a row, with pin centers 0.100"

apart. The pins are wired as:

Pins Description

1 Ground

2 Vcc

3 Contrast Voltage

4 "R/S" _Instruction/Register Select

5 "R/W" _Read/Write LCD Registers6 "E" Clock

7 - 14 Data I/O Pins

The interface is a parallel bus, allowing simple and fast reading/writing of data to and from the LCD.

The LCD Data Write Waveform will write an ASCII Byte out to the LCD's screen. The ASCII code to be

displayed is eight bits long and is sent to the LCD either four or eight


DATA

R/_S

R/_W

E

450 nSec

lcd data write waveform



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bits at a time. If four bit mode is used, two "nibbles" of data (Sent high four bits and then low four bits with

an "E" Clock pulse with each nibble) are sent to make up a full eight bit transfer. The "E" Clock is used to

initiate the data transfer within the LCD.

Sending parallel data as either four or eight bits are the two primary modes of operation. While there are

secondary considerations and modes, deciding how to send the data to the LCD is most critical decision to be

made for an LCD interface application.

The different instructions available for use with the 44780 are shown in the table below:

R/S R/W D7 D6 D5 D4 D3 D2 D1 D0 Instruction/Description

4 5 14 13 12 11 10 9 8 7 Pins

0 0 0 0 0 0 0 0 0 1 Clear Display

0 0 0 0 0 0 0 0 1 * Return Cursor and LCD to Home Position

0 0 0 0 0 0 0 1 ID S Set Cursor Move Direction

0 0 0 0 0 0 1 D C B Enable Display/Cursor

0 0 0 0 0 1 SC RL * * Move Cursor/Shift Display0 0 0 0 1 DL N F * * Set Interface Length

0 0 0 1 A A A A A A Move Cursor into CGRAM

0 0 1 A A A A A A A Move Cursor to Display

0 1 BF * * * * * * * Poll the "Busy Flag"

1 0 D D D D D D D D Write a Character to the Display at the Current

Cursor Position

1 1 D D D D D D D D Read the Character on the Display at the Current

Cursor Position

The bit descriptions for the different commands are:

"*" - Not Used/Ignored. This bit can be either "1" or "0"

Most LCD displays have a 44780 and support chip to control the operation of the LCD. The 44780 is

responsible for the external interface and provides sufficient control lines for sixteen characters on the LCD.

The support chip enhances the I/O of the 44780 to support up to 128 characters on an LCD. From the table

above, it should be noted that the first two entries ("8x1", "16x1") only have the 44780 and not the support

chip. This is why the ninth character in the 16x1 does not "appear" at address 8 and shows up at the address

that is common for a two line LCD.

The Character Set available in the 44780 is basically ASCII. It is "basically" because some characters do not

follow the ASCII convention fully (probably the most significant difference is 0x05B or "\" is not available).

The ASCII Control Characters (0x008 to 0x01F) do not respond as control characters and may display funny

(Japanese) characters.




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The last aspect of the LCD to discuss is how to specify a contrast voltage to the

Display.

Experts

typically use a potentiometer wired as a voltage divider. This will

provide an easily variable voltage between Ground and Vcc, which

will be used to specify the contrast (or "darkness") of the characters on the LCD screen. You may find thatdifferent LCDs work differently with lower voltages providing darker characters in some and higher voltages

do the same thing in others.

Liquid crystal panel service life 100,000 hours minimum at 25 oC -10 oC

3.3 definition of panel service life

Contrast becomes 30% of initial value

Current consumption becomes three times higher than initial value

Remarkable alignment deterioration occurs in LCK cell layer

Unusual operation occurs in display functions

Safety

If the LCD panel breaks, be careful not to get the liquid crystal in your mouth. If the liquid crystal touches

your skin or clothes, wash it off immediately using soap and plenty of water.

Handling

Avoid static electricity as this can damage the CMOS LSI.

The LCD panel is plate glass; do not hit or crush it.

Do not remove the panel or frame from the module.


LCD Contrast Circuit

+Vcc

Pin-3 Contrast

LCD10K pot

Shift Register LCD Data Write

R6

D0

D1

Dn

E

LCD

E Clock

S/R

Processor

Data

DataClock 00



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The polarizing plate of the display is very fragile; handle it very carefully

Mounting and Design

Mount the module by using the specified mounting part and holes.

To protect the module from external pressure; leave a small gap by placing transparent plates (e.g. acrylic or

glass) on the display surface, frame, and polarizing plate

Design the system so that no input signal is given unless the power-supply voltage is applied.

Keep the module dry. Avoid condensation; otherwise the transparent electrodes may break.

Storage

Store the module in a dark place, where the temperature is 25 oC - 10 oC and the humidity below 65% RH.

Do not store the module near organic solvents or corrosive gases.

ULTRASONIC MOTION DETECTOR (electronicsviaweb)

The ultrasonic motion detector is a project that uses an ultrasonic sensor as its base to detect movement or

moving object in small places. It is design to be a low cost ultrasonic motion detector. The transmitter sensor

use to generate signal in that area. When the signal is block by moving or movement the receiver will gets the

signal and amplifies the signal using transistor. The transistor is use as an amplifier to the receiver circuit.

The Led and buzzer in the circuit use to see if there is movement detect by the sensor. The relay use to trigger

another circuit when there is movement detects. The signal generate by the sensor is about ±40khz. This is a

fully hardware design project plus it is built to be a portable ultrasonic motion detector.




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INTRODUCTION

Human, animal or anything can produce sound. This sound is creating by the physical movement whether the

movement is fast or slow depends on the medium that create the sound. Eventually these movements can be

detected by using an ultrasound sensor. Ultrasonic sound waves are sound waves that are above the range of

human hearing and, thus, have a frequency above about 20,000 hertz. Any frequency above 20,000 hertz may

be considered ultrasonic.

An ultrasonic sensor typically comprises at least one ultrasonic transducer which transforms electrical energy

into sound and, in reverse, sound into electrical energy, a housing enclosing the ultrasonic transducer or

transducers, an electrical connection and, optionally, an electronic circuit for signal processing also enclosed

in the housing. Ultrasonic sensors have typically been used in applications such as detecting and identifying

solid objects, measuring the shape and orientation of a work piece, detecting possible collisions between

objects to avoid the collisions, room surveillance, flow measurement, and determining a type of material bymeasuring the absorption of sound.

By combining parts of electronic to the ultrasonic sensor it become an ultrasonic motion detector. A motion

detector is an electronic device that detects the physical movement in a given area and transforms motion into

an electric signal. The motion detector may be electrically connected to devices such as security, lighting,

audio 2 alarms. Motion sensors are used in a wide variety of applications. Motion detectors are mainly used

in for security systems.

Now days in the market there are many kind of ultrasonic motion detector sell, basically this project is to

design an ultrasonic motion detector use to detect physical movement of human, animal, or anything that

move. The design is to improving the use of sensor in detecting motion. Also to reduce the cost to built an

ultrasonic motion detector

The circuit consists of the following major blocks

1. Transmitter

2. Receiver

3. Transistor Amplifier Circuit

4. Opamp Amplifier

5. Opamp Comparator

6. Pi Filter

7. Schmitt Trigger

8. Darlington pair Amplifier




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1. Transmitter

The transmitter circuit consists of mainly an astable multivibrator circuit using IC 4093. The capacitor and

resistor values are adjusted to obtain a frequency of 40 kHz which is fed to the ultrasonic transmitter. The

transmitter produces ultrasonic waves of 40 kHz frequency which travel around the room, get reflected and

fall on the receiver.

2. Receiver

The receiver is an ultrasonic transducer. After transmission, the signal gets reflected from the surroundings.

This signal is received at the receiver transducer and is then sent to process for the presence of motion.

3. Transistor Amplifier Circuit

The first part of the receiver circuit consists of an amplifier section using a BC547. The ultrasonic waves

from the transmitter get reflected and fall on the receiver. The receiver is connected to an amplifier circuithaving a gain of 20. The amplitude of waves falling on the receiver is very small, the amplifier amplifies the

noise.

4. Opamp Amplifier

The LM741 series are general purpose operational amplifiers which feature improved performance over

industry standards like the LM709. They are direct, plug-in replacements for the 709C, LM201, MC1439 and

748 in most applications. The amplifiers offer many features which make their application nearly foolproof:

overload protection on the input and output, no latch-up when the common mode range is exceeded, as well

as freedom from oscillations. This is the second stage of the amplifier section. This part further amplifies the

noise received by the ultrasonic receiver. This also integrate the output of the amplifier

5. Opamp Comparator

One input consists of the shifted, negative clipped amplified output of the Opamp amplifier and the positive

clipped amplified output. The output of the comparator is by default high and when the positive clipped

portions exceed the negative clipped part due to noise, the Opamp inverts.

6. Pi-filter




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The capacitor-input filter, also called pi filter due to its shape that looks like the Greek letter pi, is a type

of electronic filter. The pi-filter converts the fluctuating ac noise into dc and feeds into the Opamp

comparator

7. Schmitt trigger

The next part of the receiver circuit is the Schmitt trigger. The Schmitt trigger is a comparator application

which switches the output negative when the input passes upward through a positive reference voltage. It

then uses negative feedback to prevent switching back to the other state until the input passes through a lower

threshold voltage, thus stabilizing the switching against rapid triggering by noise as it passes the trigger

point. In this circuit the motion caused by the object causes distortion at the receiver output. The comparator

output is by default high. When the noise levels detected are substantially high, the comparator inverts itself

and the trigger is triggered. The output is fed to a Darlington pair.

8. Darlington pair

This is a very high current gain section which when turned on by the trigger from the Schmitt trigger, starts

conducting and the buzzer and led goes on

CIRCUIT DIAGRAM


http://2.bp.blogspot.com/-pAJJvRsCrkI/T_SGWoI9xSI/AAAAAAAAAD0/iNS_IV6H4Zw/s1600/hj.bmp



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COMPONENTS LIST

R1 - 180 KOhm

R2, R12 - KOhm

R3, R8 - 47 KOhm

R4 - 3.9 KOhm

R5, R6, R16 - 10 KOhm

R7, R10, R12, R14, R17 - 100 KOhm

R9, R11 - 1 MOhm

R13, R15 – 3.3 KOhmC1, C6 - 10uF/16V

C2 - 47uF/16V

C3 - 4.7 pF

C4, C7 - 1 nF

C5 - 10nF

C8, C11 – 4.7 uF/16V

C9 - 22uF/16V

C10 - 100 nF

C12 - 2.2 uF/16V

C13 - 3.3nF

C14 - 47nF

TR1, TR2, TR3 - BC547 , BC548

P1 - 10 KOhm trimmer

P2 - 47 KOhm trimmer

IC1, IC2 - 741 OP-AMP

IC3 - 4093 C-MOS

R TRANSDUCER 40KHz

T TRANSDUCER 40KHz

D1, D2, D3, D4 - 1N4148




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Technical Specifications - Characteristics

Working voltage: 12V DC

Current: 30 mA




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WORKING OF THE CIRCUIT

As it has already been stated the circuit consists of an ultrasonic transmitter and a receiver both of which

work at the same frequency. They use ultrasonic piezoelectric transducers as output and input devices

respectively and their frequency of operation is determined by the particular devices in use.

The transmitter is built around two NAND gates of the four found in IC3 which are used here wired as

inverters and in the particular circuit they form a multivibrator the output of which drives the transducer. The

trimmer P2 adjusts the output frequency of the transmitter and for greater efficiency it should be made the

same as the frequency of resonance of the transducers in use. The receiver similarly uses a transducer to

receive the signals that are reflected back to it the output of which is amplified by the transistor TR3, and IC1which is a 741 op-amp. The output of IC1 is taken to the non inverting input of IC2 the amplification factor

of which is adjusted by means of P1. The circuit is adjusted in such a way as to stay in balance as long the

same as the output frequency of the transmitter. If there is some movement in the area covered by the

ultrasonic emission the signal

that is reflected back to the receiver becomes distorted and the circuit is thrown out of balance. The output of

IC2 changes abruptly and the Schmitt trigger circuit which is built around the remaining two gates in IC3 is

triggered. This drives the output transistors TR1, 2 which in turn give a signal to the alarm system or if there

is a relay connected to the circuit, in series with the collector of TR1, it becomes activated. The circuit works

from 9-12 VDC and can be used with batteries or a power supply.




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CHAPTER 5:

ADVANTAGES & DISADVANTAGES

ADVANTAGES:

• High water application efficiency.

•

• Levelling of the field not necessary.

•

• Ability to irrigate irregular shaped fields.

•

• Allows safe use of recycled water.

•

• Moisture within the root zone can be maintained at field capacity.

•

• Soil type plays less important role in frequency of irrigation.

•

• Minimized soil erosion.

•

• Minimized weed growth

DISADVANTAGES:

• Expense. Initial cost can be more than overhead systems.




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CHAPTER 6:

APPLICATIONS




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Source: Magnum Technologies.

1. Suitable for horticulture and agriculture fields.

2. With slight modifications can be used as Weather Station.

3. Frequency is varied continuously to affect larger number of pests.

4. The circuit has no operational expenditure.

7.1: CONCLUSION

In conclusion the greenhouse effect is a very controversial part in science.

It is part good and part bad. There are some things we need from it and

some things we don't, and until we find a way to block the bad part of the

greenhouse effect, I hope we (the countries and continents) continue to

help not pollute and ruin the atmosphere. After listing all the bad things

about the greenhouse effect I would like to say it is not just all bad,without it, it would be an average of -15 degrees Celsius every day. With it

15



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http://www.electronicsforu.com/

http://www.howstuffworks.com/

Documents

GREEN BEE Witout Moisture