This document describes a mosquito repellent device that uses ultrasonic frequency generation. It contains an introduction explaining how ultrasonic frequencies above 30 kHz can repel pests without harming humans. It then includes the system block diagram, list of components, circuit diagram, PCB layout, advantages and disadvantages. The device uses an IC555 timer chip in an astable configuration to generate ultrasonic pulses that are output through a piezo buzzer to create sound waves above the range of human hearing to repel mosquitoes in an affordable, simple and safe way.

1. MOSQUITO REPELLENT USING FREQUENCY GENERATOR
Acknowledgement
First and foremost, I would like to acknowledge my heartedly
thanks to respected Mr.N.B. HULLE, HOD(E&TC dept) for being a
source of perpectual inspiration and providing us such nice environment
for training nicely.
I would also like to express my most sincere gratitude to
our guide Mr.S.G.ITKALKAR for there valuable help during
development of this project. Without his priceless suggestion and timely
help, we would not have been able to complete this project.
Last but not the least I would express my regards for
Electronics And Telecommunication Department of our institute.
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INDEX
1. INTRODUCTION......................................5
2. LITERATURE SURVEY..........................7
3. ABSTRACT................................................8
4. SYSTEM MODEL
4.1 Block diagram of System........................9
4.2 List of Components…………………....10
5. HARDWARE DESCRIPTION
5.1 Circuit Diagram.......................................11
5.2 Pin description…………………….........12
6. PCB Layout ...............................................13
6.1 Simulation of the project………………14
6.1.1 PCB Designing……………………...14
6.1.2 Simulation………………………………..14
7. Advantages and Disadvantages…….…....15
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3. MOSQUITO REPELLENT USING FREQUENCY GENERATOR
8. Application of Project...............................16
9. References..................................................17
10. Cost of Project ……………..…………... .18
11. Conclusion……………………………......19
1.INTRODUCTION
It is possible that pests like insects, ants, rats, mice etc. are repelled by
ultrasonic frequency in the range of 30 kHz to 50 kHz. Human beings
can’t hear these high-frequency sounds. Our product repels pests by
emitting pulse ultrasonic waves. Using ultrasonic waves creates a noisy
and hostile environment which repels pests, whilst remaining absolutely
safe for humans and household animals. Unfortunately, all pests do not
react at the same ultrasonic frequency.
While some pests get repelled at 25 kHz, some others get repelled at
30KHz to 40 kHz or even higher frequencies.
Thus to increase the effectiveness, frequency of ultrasonic oscillator has
to be continuously varied between certain limits. Frequency of emission
of ultrasonic sound is continuously varied by our product in different
patterns to repel different insects.
Electronic Pest Repellent is the name given to the use of any of the
several types of electrically powered devices designed to repel or
eliminate pests such as rodents, Mosquito’s, etc.
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4. MOSQUITO REPELLENT USING FREQUENCY GENERATOR
There are usually two types of electronic mosquito repellent devices
widely used & available, these are Ultrasonic & Electromagnetic.
Ultrasonic devices operate by emitting short wavelength, high frequency
sound waves too high in pitch to be heard by the human ear (all
frequencies greater than 20,000 Hz). This is due to limitations in human
hearing. Humans cannot hear ultrasound because the eardrum
does not vibrate fast enough, but some animals such as dogs, bats and
rodents can hear
well into the ultrasonic range. Some insects, such as grasshoppers and
locusts can detect
frequencies from 50,000 Hz to 100,000 Hz, and moths and lacewings
can detect ultrasound
as high as 240,000 Hz produced by insect-hunting bats.
Insects detect sound by special hairs or sensilla located on the antennae
(mosquitoes) or genitalia (cockroaches), or by more complicated
tympanal organs (grasshoppers, locusts,
moths and butterflies).
"Ultrasound and Arthropod Pest Control" an extensive Kansas State
University study confirmed that ultrasonic sound devices do have both a
repellent effect as well as a reduction in mating and reproduction of
various insects. However, the results were mixed and ultrasonic sound
had little or no effect on some pests. Various ultrasonic devices where
highly effective on crickets while the same devices had little or no
repellent effect on cockroaches.
Additionally the results where mixed with some devices being effective
while others having no effect depending on the test subject.
The study also concluded there was no effect on ants or spiders in any of
the tests. They concluded, based on the mixed results, that more research
is needed to improve these devices.
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5. MOSQUITO REPELLENT USING FREQUENCY GENERATOR
2. Literature Survey
1. A test conducted in canada proved that DEET(N,N-
diethyl-3-methyalbenzamide) proved to provide max
protection against mosquito than Avon skin lotion &
special mixture chemicals.
2.But the drawbacks of it were, it was limited to particular
time, chemicals proved harmful for small children & some
lotions caused skin irritations to some people.
3.Mosquito Repeller using Frequency Generator overcomes
all this drawbacks & provide hazzle free protection from
mosquito’s.
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6. MOSQUITO REPELLENT USING FREQUENCY GENERATOR
3. ABSTACT
The purpose of the project is to design an ultrasonic pest
repellent. Such a device can be very useful to counter the
various problems caused by ants, insects, pests, rodents, etc.
The device is compact, cheap, and it does not cause any
pollution unlike the other chemical repellents.
We have used a RC oscillator circuit to generate a frequency of
ultrasonic range to keep the mosquito’s away.
The circuit has been experimentally tested on ants, bugs, and
small insects, and it has been successful in repelling them
through the generation of ultrasonic frequency sound.
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7. MOSQUITO REPELLENT USING FREQUENCY GENERATOR
4. SYSTEM MODEL
4.1 Block Diagram of system:-

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8. MOSQUITO REPELLENT USING FREQUENCY GENERATOR
4.2 List of Components:
1. Astable Timer IC- IC555
2. Diode 1N4007
3. Resistors: R1-68K ohms
R2-100 ohms
4. Capacitors: C1- 470 micro farad
C2- 0.2 pico farad
C3- 0.01 micro farad
5. Piezo-buzzer
6. 1 on/off switch
7. Battery supply – 12 Volts
8. 1 Red LED
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5. HARDWARE DESCRIPTION
5.1 Circuit Diagram of Project:-
Fig 5.1 Circuit Diagram
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5.2 Pin diagram
Fig 5.2.1 1Pin diagram
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6. PCB Layout of main circuit
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Fig 7. PCB Layout of main circuit
6.1 Simulation of the project
6.1.1 PCB designing:
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There are many software’s for the design of the PCB viz. express PCB,
Eagle PCB, Proteus, Circuit Wizard, Diptress, Protel, Ultiboard . Out of these
we have used Circuit Wizard for designing of our project’s PCB.
We have tested and checked our circuit and program using circuit
wizard software. It is very easy to use and understand the design of project
7. Advantages and Disadvantages:-
7.1 Advantages
1. Non Harmful to humans as frequency used is ultrasonic
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2. No ill odour generated
3. Simple construction
4. Handling is easy
5. Low Cost device
6. No need of AC mains supply
7. Battery can be replaced by solar charger
7.2 Disadvantage
1. Cannot be used for wide range
8. APPLICATION OF PROJECT:
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1.Mostly used in household applications
2.Can be used in Hospitals
3.Can be used in tents during trekking
4. In rooms with no electricity
9. References
1. Circuit garage
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2. Electronics for you
3. Datasheet of IC 555
4. Electronics magazine
5. Mosquito Repellent Effectiveness: A placebo controlled trial
comparing 95% DEET, Avon skin so soft, & a special mixture –
Richard Beever, MD.
6. International journal of Pharmaceutical, Biological &
chemical sciences
10. Cost of project
SR.NO COMPONENTS QUANTITY PRICE(Rs.)
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1
2
3
4
5
6
7
8
9
10
PCB Layout
IC1 7555 Timer
Diode 1N4007(Rectifier Diode)
Resistor1(R1=65k ohms)
Resistor2(R2=100 ohms)
Capacitor1(C1=470 micro F)Electro
Capacitor2(C2=0.2 pico F) Ceramic
Capacitor3(C3=0.01 micro F) Ceramic
Battery supply(12V)
Switch
1
1
1
1
1
1
1
1
1
80
10
1
1
1
1
1
1
40
5
11. Conclusion:-
Thus we have seen that the Resistors R1,R2 &
Capacitor C1 generates the desired frequency i.e., above 30K ohms
which is the suitable range for our project. Thus mosquito repellent
works efficiently as a frequency generator.
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