Laboratory Report On Electronic Mosquito Repellent Circuit

Laboratory Report
On
Electronic Mosquito Repellent Circuit
(Electronics Circuit and Network Lab)
Submitted by
RISHIKA PAL -1704045
RIYA RANJAN -1704046
ROHIT MOHAPATRA -1704047
RUPAYAN BHATTACHARYA -1704048
B. Tech Programme in Electronics and Telecommunication
Engineering
School of Electronics Engineering
Kalinga Institute of Industrial Technology, Deemed to be University Bhubaneswar, India
October 2018
Objective
The main objective of the experiment is to do the Pspice simulation of Simple Electronic Mosquito Repellent Circuit.THEORY
Now a days, we have various solutions for mosquitoes repelling. Like liquid vaporizers, creams but problem is that all have some possible affects to health in adverse effect. And then there is an electronics mosquito repellent present. An electronics mosquito repellent’s function is to repel mosquitoes with the help of piezoelectric disc (speaker) to emit Ultrasounds. Sound with frequencies
Higher than 20KHz are ultrasounds which can’t be perceived by human ears. It’s also relatively safer. Also, we can build a simple Mosquito Repellent Circuit at home by using 555 timer IC easily.

REQUIREMENTS
NAME SPECIFICATIONS
Orcad capture cis lite(pspice) 555 timer
3;An electronic capacitor 0.01 micro farad
4;2 Resistors 760 ohms
1.5k
5;Piezo buzzer 6;A spst switch 7;A battery 5 volts
CIRCUIT DIAGRAM

Electronic Mosquito Repellent Circuit Diagram
This electronic circuit is basically a multivibrator ;used to generate a pulsed output signal.The multivibrators are arranged on the basis of stability of the output.The mulivibrator used is an Astable multivibrator which is used as an oscillator and doesn’t need external triggering. The stable multivibrator used in the circuit is 555 Timer IC.The 555 Timer IC used is an integrated chip used is basically a timer,pulse generation and oscillator.It mainly consists of eight pins.The functioning of each pin in the circuit is given as follows:
Pin 1: It is the Ground Pin.This pin is connected to the negative (-ve) terminal of the battery.

Pin 2:It is the Trigger Pin.Its a triggered active low pin.When the signal is lower than one third of the supply voltage ,only then ,the timer is triggered.This pin is connected to pin number 6 for a stable operation.

Pin 3:It is the Output Pin.

Pin 4:It is the Reset Pin.It is basically an active low pin.This pin is connected to the positive terminal of the battery.

Pin 5:It is the Control Pin.It is a seldom used pin.This pin is connected to the ground through a 0.01 microfarad ceramic capacitor ,for safety purposes.

Pin 6:It is the Threshold Pin.When the voltage at the pin is greater than or equal to two -thirds of the supply voltage,only then,the timer output is fed back to its stable state. The pin 6 is shorted to the pin 2 and connected pin 7 through a resistor for its stable operation.

Pin 7:It is the Discharge Pin.The pin provides the discharge path of the capacitor.

Design CALCULATIONS/
CODE DEVELOPMENT

Pspice Simulation of the Simple Electronic Mosquito Repellent Circuit
The main reason of developing this circuit is to develop a buzzer which would produce a ultrasound .The 555 Timer based a stable multivibrator circuit as the Oscillator circuit which is used to drive a buzzer.

The frequency of the astable multivibrator circuit is given by
F=(1.44(R1+R2*2)*C2)
Here,
R1 represents the resistance between Pin 7 and the voltage source(V1)
R2 represents the resistance between Pin 7 and Pin 6
C2 represents the capacitor between Pin 6 and ground
According to the circuit the value of C2= 0.01microFarads and the frequency of the buzzer is F=38kHz
As, the Duty cycle ,therefore D=60% (as practically it isn’t possible to get 555 timers with 50% duty cycle)
Therefore we get,
R1=1.44(2D-1)/(F*C2)
=0.756*10^-6 ohms
=0.75kohms
R2=1.44(1-D)/(F*C2)
=1515.12 ohms
=1.5 kohms
Hence a resistor R1 of resistance value of 0.75kohms and a potentiometer of 1,5kohms is being used in the circuit.

OBSERVATIONS
The main concept of the simple electronic mosquito repellent circuit is to produce continuous rectangular pulses at a specific frequency.It produces an output frequency of range of 31kHz to 100kHz.The frequency is perfect to repel of mosquitoes .The output buzzer produces sound of high pitch which when heard by a mosquito triggers their auditory senses which scares them away.Hence its a good method to repel the mosquito away.

DISCUSSION OF RESULTS
Reasons for limitations of the observations of the mosquito repellent circuit :
The circuit requires a lot of frequency setting.

As ultrasound signals travel at an angle 45 degrees of the source. As a result ,if there is any obstacles in the paths if traversal of the circuit then the signals gets diverted or reflected.

Often the circuit is applicable for less population of mosquitoes.

OBSERVATIONS
In this report, different aspects of Electronics Mosquito Repellent Circuit such as theory,working principle, diagram,formulas, and most importantly applications were studied to its depth.

REFERENCES
HYPERLINK ;https://www.electronicshub.org/electronics-projects-ideas/; https://www.electronicshub.org/electronics-projects-ideas/
HYPERLINK ;http://www.circuitstoday.com/electronic-mosquito-repeller; http://www.circuitstoday.com/electronic-mosquito-repeller
HYPERLINK ;https://www.electronicshub.org/electronic-mosquito-repellent-circuit/; https://www.electronicshub.org/electronic-mosquito-repellent-circuit/
STUDENT SIGNATURES
RISHIKA PAL (1704045) :
RIYA RANJAN (1704046) :
ROHIT MOHAPATRA (1704047) :
RUPAYAN BHATTACHARYA (1704048) :
SIGNATURE OF THE CONCERNED LAB FACULTY MEMBER
SUBMISSION DATE : 08.11.2018