Mosquito repellent circuit project

Last updated on July 12th, 2021 at 09:03 am

This is mosquito repellent circuit to generates a high sound frequency using transistors as bistable multivibrator.

It is economical and safer than using chemicals.

The mosquitoes are annoying. And, carriers the pathogens to humans.  Many ways to protect us from the mosquitoes.

Most people use chemicals because the chemicals are high efficiency. But using often chemicals no good for everyone.

Beware the mosquito bite

Why use the Mosquito repellent circuit?

This project uses the sound of mosquito repellents is the safest way for health. Because we generate a high-frequency sound wave that mosquitoes do not like.

According to the theory of scientists found that Mosquitoes do not like the high-frequency sound waves. So, it flies away because this sound interferes with its flying.

How Mosquito repellent circuit works

simple mosquito repellent circuit
Simple mosquito repellent circuit using transistors, bistable multivibrator

In the circuit, connects two transistors (Q1, Q2) into a bistable multivibrator oscillator to generate a sound frequency.

Which the signal of this circuit is determined by both resistors(R2, R3) and both capacitors(C1, C2).

The sound frequencies get out of a collector of Q2. Then, comes into the ceramic piezo buzzer.

It emits a high-frequency sound on a radius of under 5 square meters.

If an outdoor using, or mosquitoes disturb too much. You should place this project far from us around 1 meter.

Build Mosquito repellent circuit

The circuit is very easy to make.  As use a few components. To begin with, assemble them with the PCB layout as  Figure 2.


Figure 2 PCB an components layout of this projects.

It is a components layout, should solder them into the right position.

The value of the circuit should match with the circuit diagram. Then, cut the legs of devices.

After that, solder them to connects a 1.5V battery, a switch, and a piezo speaker with the wires.

The characteristics of the piezo speaker is a thin circular metal. One side coated with ceramic in different sizes are 15, 20, 25, 30, 35, 40 and 50 millimeters.

Testing and application

First of all, check your wiring and circuit for error.

Secondly, connect correctly a positive-negative voltage polarity from a common 1.5 volts battery.

Then, turn on S1-switch. We will hear the weak high frequency out of the piezo speaker.

Now, this project is working.

We turn on this circuit for about 30 minutes. Place this near an infestation mosquito.

After that, about 30 minutes, the mosquitoes should less. It indicates the circuit works great.

But if the mosquitoes are still too much.

Because your circuit may create the frequency, not effect to mosquitoes.

Thus, you have to adjust the new frequency by changing the capacitance of C2. From 0.002uF into 0.0022uF or lower 0.0015uF.

Then, observed changing of mosquitoes.

Components list

Resistors ¼ watts + 5%
R1, R4: 1.5 K
R2, R3: 100 K
C1: 560pF 50V polyester
C2: 0.002uF 50V polyester
Q1, Q2: 2SC9013-NPN type
P1: Piezo speaker 35mm.
S1: Switch ON-OFF
Battery 1.5V, PCB, Wires, Box, etc.
This is Circuit MOSQUITO REPELLENT. It can power a high-frequency Sound.

Bonus: MOSQUITO REPELLANT using IC-555, 4017, 4011

Circuit MOSQUITO REPELLANT by 555, 4017, 4011

This circuit uses an electronics parts. So easy to gets and inexpensive.

Look at the circuit. They include IC-555, 4017, 4011 and BC337, BC327.
The output is piezo Speaker.
The volt supply requires +12V or 9V

You may try to make it as PCB below:
pcb MOSQUITO REPELLANT by 555, 4017, 4011

Note: I never build it. But you can try it. Please share with me. When making it.

Have a good day for learning Electronics.


I always try to make Electronics Learning Easy.


  1. Leonard

    From where i can find piezo speaker? All i can find are piezo buzzers with fixed frequency.

    any links to products?

  2. Michael

    What type of sound will come from the speaker..?

  3. Totally a unique way to repel mosquitoes… Awesome thought… Really appreciable…

  4. Yesterday, while I was at work, my cousin stole my apple ipad and tested to see if it can survive a twenty five foot drop, just so
    she can be a youtube sensation. My iPad is now broken and she has
    83 views. I know this is entirely off topic but I had to share it with someone!


    I am working to make a mini project according to this simple CKT

  6. Hamid Hussain

    #MOSQUITO REPELLANT by IC 555, 4017, 4011

    i have read all the contents of your website its really cool website i appreciate your effort

  7. Hamid Hussain

    #MOSQUITO REPELLANT by IC 555, 4017, 4011

    can you please send me a circuit diagram of fm using 555 timer

  8. Rezaul Islam (NANTU)

    #MOSQUITO REPELLANT using IC 555, 4017, 4011

    I Make This ckt by IC 555,4017,4011. Frequincy IS about 13KHZ TO 65kHZ.but MOSQUITO not go.What I will do. pls tell me.

  9. Rezaul Islam (NANTU)


  10. #MOSQUITO REPELLANT using IC 555, 4017, 4011

    Hi Rezaul Islam (NANTU)
    Thanks for you feedback.

    I am sorry these circuits not sure mosquito go.
    Please check oscillator out at pin 3 at IC1 and IC3.

  11. Ming Kai

    After i finished the circuit. The sound wave that are produce by the speaker is very high pitch and it is very painful to hear it. Can u help me?

  12. Julia

    I am really very thankful to you for posting pcb layout. The circuit of your multivibrator works but sound is annoying for a person sits near it. So i just fixed it using resistor before piezo transducer.
    Thanks. But i don’t think that mosquitoes really gets repelled by it. Did any one try it and found useful.?

  13. zilan

    very easy …..and simple….also nice explanation description

  14. menace nditi



    Paragraph writing is also a excitement, if you be familiar with after
    that you can write otherwise it is complicated to write.

  16. khumalo mandhla

    what will happen if l use a 220pF capacitor instead of 56pF

  17. zuhair

    how do I get 0.002 uf and 560 pf. are they available in the market

  18. Nidhin babu

    #MOSQUITO REPELLANT using IC 555, 4017, 4011

    Can I get a circuit for driving 80 leds using bjt.

  19. Sumit Kailabag

    what frequency is needed to make sure that the mosquito should be away from mosquito repellent circuit

  20. Sujay Trivedi

    How to test this circuit is properly working or not? we cannot hear ultrasonic sound…so how to test it?

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