Electronic Mosquito Repellent Circuit


ByJayant 38

Electronic Mosquito Repellent Circuit using 555 Timer IC

Various mosquito repellent solutions like coils, liquid vaporizers, and creams, all have possible adverse effects to health. Then there are electronic mosquito repellents available in market which are equally efficient and relatively safer. The concepts of these mosquito repellers are simple and we can build a simple mosquito repellent circuit at home easily by using 555 timer IC and few other commonly available components. Let’s see the concept of mosquito repellent circuit in detail.


The concept that we are going to use in out circuit is related to ultrasound. A sound with frequency higher than 20 kHz is termed as “Ultrasound”. For we humans a sound only ranging between 20 Hz to 20 kHz frequency is audible, and any sound with frequency below or higher than this range wouldn’t be audible for us. But there are various animals and insects (including mosquitos) that could hear the ultrasound. Generally ultrasound in a range of 20 kHz to 40kHz is transmitted by male mosquitoes and received by female mosquitoes, however after breeding female mosquitoes tend to avoid male mosquitoes and so they tend to avoid ultrasound in that range. As we know that only female breeding mosquitoes bites humans, we can use this concept and can design a circuit which produces the ultrasound in frequency range specified above.


So here we are going to design a simple mosquito repellent circuit which will be producing a sound of approximately 40 kHz.


Required Components

555 Timer IC


Resistors - 1k and 1.3k (variable resistor of 10k)

Capacitor - 0.01µF

Battery - 9v

Breadboard and connecting wires


Circuit Diagram and Explanation

Mosquito Repellent Circuit Diagram

As shown in the above diagram, we have designed a circuit using 555 timer IC in Astable mode to produce 40 kHz frequency sound. We have connected Buzzer at the output (PIN 3) of the 555 timer IC so that a sound of desired frequency can be generated. We should note here that we need a HIGH frequency Piezo buzzer, so that a high frequency sound can be generated. Also note that we might not be able to hear the sound, generated by the circuit as it is beyond our audible range.


We can calculate the value of resistors and capacitor to produce oscillation of 40KHz frequency by given formulae:

F = 1.44 / ((R1+R2*2)*C)

In our case we have used:

R1= 1K

R2(RV1) = 1.3 K (variable resistor of 10k, set at 1.3K with the help of multimeter)

C = 0.01uF

So now

F = 1.44 / {(1 + 2*1.3)*1000} * 0.01uF

F = 1.44 * 100000 / 3.6 = 40000 = 40KHz


We can increase the value of resistor R1 or R2 to decrease the frequency.

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  • noble's picture
    Mar 17, 2016

    can you suggest me how to trouble shoot this circuit, though i set everything properly i can listen the sound of my buzzer, please help me

  • Jayant's picture
    Mar 28, 2016

    What problem are you facing? Please, tell us precisely. You might feel a continuous very fine beep/sound.

  • Tasha 's picture
    Mar 22, 2016

    Where did you find a high frequency piezo buzzer?

  • Gurnoor singh brar's picture
    Gurnoor singh brar
    Mar 22, 2016

    What is the range of this system or how much area will it cover

  • taranjeet singh's picture
    taranjeet singh
    Apr 02, 2016

    Please tell that how to troubleshoot circuit as the sound from the buzzer is audible and circuit is unable to produce ultra sound so please clear the fault in the circuit as soon as possible .........

  • Baberullah khan's picture
    Baberullah khan
    Apr 16, 2016

    I connect component properly but there are not effect on mosquito?

  • Maddy's picture
    Apr 17, 2016

    @Baberullah @taranjeet: Try with some different frequencies and use high frequency Buzzer.

  • Ashwini s poojary's picture
    Ashwini s poojary
    May 31, 2016

    whats difference between killer and repellent?

  • meghana's picture
    Jul 05, 2016

    KILLER will kill the mosquito and repellent will repel them.

  • susi's picture
    Jul 07, 2016

    exclusive project it is very useful for us

  • Sidharth's picture
    May 30, 2017

    Susy,its working but mosquitoes are not going away. How did u put frequency of variable resister. Please answer this?

  • Aswin's picture
    Aug 21, 2016

    is the buzzer continious ?

  • Abhishek's picture
    Aug 22, 2016

    Yes, but you will not able to hear the sound, some times you can feel very fine buzzing sound.

  • Sharoj Al Hasan's picture
    Sharoj Al Hasan
    Sep 19, 2016

    Sir Will It Work?

  • sushma's picture
    Oct 07, 2016

    Sir, how we can know the range to which extent mosquitoes are repelled.Is there any way to improve the range

  • Lovnish's picture
    Dec 18, 2016

    The range should be in 20-40khz ..u can increase the range of frequency by cycloconverter

  • Rohan's picture
    Nov 24, 2016

    Please if this really worked for anyone

  • sreenej's picture
    Feb 25, 2017

    can i get the conclusion of the ckt

  • Rick's picture
    Mar 03, 2017

    In the circuit diagram the sign of the capacitor (0.01uF), it seems that it is polarized. Now my question is, is it really polarized? Because in the picture you have used a ceramic capacitor.

  • Soardr's picture
    May 11, 2017

    Though I set everything properly, I can hear a loud sound from the buzzer.

  • Rajidiot's picture
    May 26, 2017

    Sir !
    May i know the values of piezo buzzer value ...
    how can we set the exact potentiometer at "1.3k"

  • Sidharth's picture
    May 30, 2017

    Sir, i made it properly and when I change the frequency of variable resister lheard a small sound but mosquitoes didn't go far away. Why is it?

  • Abhishek's picture
    Jul 05, 2017

    Try increasing the frequency by using variable resistor.

  • unnikrishnan's picture
    Jun 04, 2017

    hi can you send circuit of radio freequency rc boat

  • Ukwu Godswill 's picture
    Ukwu Godswill
    Jul 05, 2017

    I real need come circuit

  • Mark Moritz's picture
    Mark Moritz
    Jul 11, 2017

    nice work

  • Hanzala Ibn Zahid's picture
    Hanzala Ibn Zahid
    Jul 13, 2017

    can i use a 0.01uf ceramic capacitor?

  • Dhairyarajsinh Jadeja's picture
    Dhairyarajsinh ...
    Aug 05, 2017

    Sir, I have proteus software and now I want to test the circuit after stimulating it.How can I determine errors if any in the circuit.Plz help sir

  • Raj H's picture
    Raj H
    Aug 21, 2017

    How to choose correct buzzer to emit 40KHZ signal and what are the requirement (spec) for it

  • Yogesh's picture
    Aug 25, 2017

    Can i use this for RAT repellent in car ?

  • RAMANJI's picture
    Dec 15, 2017


  • Rakesh Ramavath's picture
    Rakesh Ramavath
    Jan 25, 2018

    I'm Successful in making of Mosquito repellent as per the given Circuit diagram....thank you Circuit Digest

  • Bilal Zubairy's picture
    Bilal Zubairy
    Mar 06, 2018

    And is it effective as well?? I mean any reduction in mosquitos?

  • Afis's picture
    Mar 18, 2018

    The cct diagram is not explanatory enough, pls explain the cct diagram more

  • viral's picture
    Jan 28, 2019

    and if its effective then tell me please how much percentage u can say

  • Shumirai P Tsvanhu's picture
    Shumirai P Tsvanhu
    Apr 05, 2021

    I have been trying to simulate this using proteus. I cant hear the sound of the buzzer. is it becauseof the same reason that the frequency is very high.

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