This is a 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 mosquitoes.
Most people use chemicals because the chemicals are high efficiency. But using often chemicals no good for everyone.
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 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
Capacitors
C1: 560pF 50V polyester
C2: 0.002uF 50V polyester
Semiconductor
Q1, Q2: 2SC9013-NPN type
Others
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
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:
Note: I never build it. But you can try it. Please share with me. When making it.
Have a good day for learning Electronics.
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I love electronics. I have been learning about them through creating simple electronic circuits or small projects. And now I am also having my children do the same. Nevertheless, I hope you found the experiences we shared on this site useful and fulfilling.
Very helpful
From where i can find piezo speaker? All i can find are piezo buzzers with fixed frequency.
any links to products?
What type of sound will come from the speaker..?
Totally a unique way to repel mosquitoes… Awesome thought… Really appreciable…
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
#MOSQUITO REPELLANT by IC 555, 4017, 4011
i have read all the contents of your website its really cool website i appreciate your effort
#MOSQUITO REPELLANT by IC 555, 4017, 4011
can you please send me a circuit diagram of fm using 555 timer
#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.
I BUILD THIS CIRCUIT BY 555, 4017, 4011. FREQUINCY ABOUT 13KHZ TO 65KHZ.BUT MOSQUITO DO NOT MOVE.WHAT I WILL DO NEXT.DETAILS KNOW TO ME ABOUT PIEZO SPEAKER WITH PICTURE.THANK.
#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.
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?
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.?
very easy …..and simple….also nice explanation description
I HAVE TRIED SO MANY CIRCUITS,DO YOU REALLY ASSURE ME IT WORKS????
Paragraph writing is also a excitement, if you be familiar with after
that you can write otherwise it is complicated to write.
what will happen if l use a 220pF capacitor instead of 56pF
how do I get 0.002 uf and 560 pf. are they available in the market
#MOSQUITO REPELLANT using IC 555, 4017, 4011
Can I get a circuit for driving 80 leds using bjt.
what frequency is needed to make sure that the mosquito should be away from mosquito repellent circuit
How to test this circuit is properly working or not?..as we cannot hear ultrasonic sound…so how to test it?