Electronic mosquito repeller

Description.

Here is the circuit diagram of an ultrasonic mosquito repeller.The circuit is based on the theory that insects like mosquito can be repelled by using sound frequencies in the ultrasonic (above 20KHz) range.The circuit is nothing but a PLL IC CMOS 4047 wired as an oscillator working at 22KHz.A complementary symmetry amplifier consisting of four transistor is used to amplify the sound.The piezo buzzer converts the output of amplifier to ultrasonic sound that can be heard by the insects.

Circuit diagram with Parts list.

electronic-mosquito-repeller9

Notes.

  • Assemble the circuit on a general purpose PCB.
  • The circuit can be powered from 12V DC.
  • The buzzer can be any general purpose piezo buzzer.
  • The IC1 must be mounted on a holder.
Show Comments

161 thoughts on “Electronic mosquito repeller

  1. Åsmund Enget

    Hello, Im an norwegian engineer-student, and I am having your circuit as a project, both making and attempting to explain it. Making it wont be that much of a problem, but understanding it is a little more tricky. I wondered if you could explain a little bit how/why you have used 4 transistors, for example, and why this circuit will work the way it does.

    It would mean a lot to me!

    And, could you answer me by mail by some chance?
    On beforehand, thank you.

    Reply
    • Seetharaman

      Hi This is called bridged push pull output. This circuit will provide 4 times the normal 2 transistor push pull output connecting through a coupling capacitor. IC 4047 is an oscillator whose frequency is set by R1 & C1. The complimentary output of the IC which is available on pin no 10 & 11 are fed to the bridged output circuit. Since the frequency used for repelling mosquitoes is in the ultrasonic range a piezo transducer, which respond to Ultrasonic sound better is used for producing sound, instead of standard loud speaker.

      Reply
  2. manshass

    Dear sir also I used c1 as 4.7 but in true I’m not sure is it 4.7nd or 4.7pf
    Also the R1 I can’t find 1k ohm accuracy I connect one to the circuit but when I measure it I found it 7.8k ohm

    Reply
  3. manshass

    Hi dear sir
    The circuit it so good but
    I replaced the piezo buzzer to tweeter transducer 8 ohm
    Is this will work or not
    Other thing when I tested the circuit the Q1 and Q4 were so hot
    Is this normal or I have problems in circuit

    Reply
  4. nirmala

    Hai sir ! mosquito repeller project is nice ,circuit diagram is it here but how the circuit is working please explain it? what is the application of this circuit

    Reply
  5. santosh shah

    can we use transformer 12-12 v .or for 12 v supply dc,we use 12 v battry….what if we use 9 v dc battery..please send me answer…and help me out 2 make complete project

    Reply
  6. Terrence Banister

    We’re a group of volunteers and opening a brand new plan in our little local community. Your website offered us with beneficial info to work on. You have done a striking position and our complete community shall be thankful to you.

    Reply
  7. harsha

    sir,
    iam a second year student.does this project works well?
    what is the use of this circuit?
    could you please tell as early as possible

    Reply
  8. Electronics Projects

    CD4047 has very good applications. Oscillator function of Cd4047 is Damn good.My Suggestion is Better to use RPS with output 12V D.C for regular use at home because battery not stands for long time .

    Reply
    • roshan

      i think thr ll b some loose contacts …… better disconnect n try it again bcoz i got the result ……… try it once more

      Reply
  9. Priyadharshini

    hi.i used piezo buzzer and we didn’t hear any sound,is there any alternative?
    also instead of mosquito’s what can we use to test this experiment.
    very urgent please reply.

    Reply
  10. seetharaman

    Hi Zunnur there are so many makes available. you can use the one meant for car stereo add on tweeters two small one comes in a pack. clarion etc.

    Reply
  11. zunnur

    Thanks for the ckt diagram.Would u please inform me the model number of the piezo tweeter available most in market.

    Reply
  12. seetharaman

    Hi Susan connect 4.7nF in parallel to C1 the oscillator frequency will be in audible range. now check any out put is there if not check all the components and IC pin connections. if it gives audible sound, remove the capacitor connected in parallel, the circuit is ready for use. Piezotransducer will emit the in audible signal of the oscillator. sound level indicator is an equipment to measure the sound level (noise level) in an environment. they operate in human audible range only.

    Reply
  13. susan

    sir,we want a method to check the circuits. what about that piezo transducer or that sound level indicator?
    can you please explain this? can that be used to check the circuit?

    Reply
  14. Khurami_45

    hi
    this circuit is is a good achievement for insect specially mosquito if u will use the right component then no problem circuit will work i also checked it

    Reply
  15. jasmine

    hi.i used piezo buzzer and we didn’t hear any sound,is there any alternative?
    also instead of mosquito’s what can we use to test this experiment.
    very urgent please reply.

    Reply
  16. viyas

    already we knew that the human audio freq range is 20 to 20000 ..how can u say that ultra freq range wont affect human. .kindly please explain that

    Reply
  17. james Holy

    please can you list all the components that are use and their specification,my school approved this as my project.

    Reply
  18. shiva

    Electronic Mosquito Repellents Don’t Work, Say Researchers
    ScienceDaily (Apr. 18, 2007) — Electronic mosquito repellents — buzzing devices marketed to prevent malaria — don’t prevent bites and therefore don’t prevent disease transmission, according to a new review of studies. . . is this true

    Reply
  19. seetharaman

    If you use R1 as 22K and C1 as 10PF tha frequency out will be 1000kHz, similarly for 10 kHz C1 should be 100pF and R1 should be 220k or 22k and 1000pF. for 20kHz either you make C1 half (500pF) the value or R1 (11k)half the value(as the formula is inversely proportional)

    Reply
  20. Phuah

    Hi Seerharaman,
    May I know what is the formula calculation for this result as you mention? How we calculate it? Thanks. Seetharaman.
    A 1000 kHz 22k 10 pF
    B 100 kHz 22k 100 pF
    C 10 kHz 220k 100 pF
    D 1 kHz 220k 1000 pF

    Reply
  21. seetharaman

    Hi Phuah
    Freq R1 C1
    A 1000 kHz 22k 10 pF
    B 100 kHz 22k 100 pF
    C 10 kHz 220k 100 pF
    D 1 kHz 220k 1000 pF
    The above is the data for CD4047. From this you can calculate.

    Reply
  22. Phuah

    Actually what range of the output frequency can be generate by this circuit? How we calculate the output frequency? Got any calculation formula? Thanks.

    Reply
  23. admin Post author

    REPLY TO AZIM

    C2 is an electrolytic capacitor and they are available in different voltage ratings, from few volts to hundreds of volts and thats why its a common practice to represent the voltage rating of electrolytic capacitors in the circuit diagram.

    C1 is a ceramic capacitor and the commonly available ones are rated from 50V to 400V. Some manufacturers represent the voltage rating using some code while others not. Any way we can guess that a commonly available ceramic disc capacitor will be rated at least 50V or so.

    Here the working voltage is 12V and a 50V ceramic capacitor will be more than enough.

    Reply
  24. Phuah

    Hi Seetharaman, thanks for your respond. Can this circuit work with Piezo Tweeter with 98bd, 20khz. Is it workable to repel the mosquito?

    Reply
  25. Phuah

    Hi Seetharaman, may I know what type of the output speaker is most effective for pets repellent? How can I make a frequency for all range of pets include rat,mosquito, mice and spider? Thanks.

    Reply
  26. seetharaman

    Hi Bhaskardev piezo tweeters are the only inexpensive device which can respond to high end of sonic frequencies.

    Reply
  27. seetharaman

    Hi Zaman these small speakers may not respond beyond 11 to 12kHz. only hi-fi tweeters can respond they will be quite expensive. Hence Piezo tweeters are quite in expensive. this is normally used as additional attachment with car system speakers or part of portable sound system. you can use them.

    Reply
  28. kanni

    Hi it may repel the mosquito but does it affect the pets like cat and dogs becoz It shold not affect my doggy

    Reply
  29. vishwanath

    Dear sir,
    I am a chemical engr by profession. I need an electronic mosquito repellent which may be powered by 9 volt battery, for my personal use in travelling.
    I assembled mosquito repellent circuit. I am observing, mosquitoes are not affected by this. I don’t know whether the circuit is working or not. I used a piezo tweeter which works with 8000+ frequencies which I can hear (in other tests). I want to know where to be connected with No 2 leg of IC 4047. Can you please suggest me in this regard?
    If it works, I want to assemble few more for our use. Can you suggest me how to make a mosquito repellent with Variable Frequency (from 16 kHz to 45 kHz+) with sufficiently powerful output so that it should be sufficient to a 30 X 40 house. Or can you prepare me one such piece?
    regards
    Vishwanath

    Reply
  30. Ucheson

    Thanks alot for the cct! But my question instead of ic,can one use multivibrator circuit to generate the frequency! Since T(time const)=RC and we know that F(freqency)=1/T.We just make capacitor const and increase our resistor value to generate 20khz and above.Then connect output of our NPN collector with ultrasonic transmitter! Can it work that way?

    Reply
  31. fahad

    Hi Seetharaman,
    Thanks for reply. Can u do me another favour by telling the number of resisters used and the specifications of resistors.If there is any diode used please tell me the numbers and specs.
    thanks.

    Reply
  32. Seetharaman

    Hi Fahad the number of transistors are 4 and IC is one. The transistor are SK100 PNP general purpose transistor. SL100 NPN general purpose transistor. you can use the recent types 8050 for SL100 and 8550 for SK100.

    Reply
  33. fahad

    Hi Seetharaman.
    please tell me the number of transistors used in this circuit and value of these transistors.
    thanks.

    Reply
  34. Seetharaman

    Hi Badeekh you cannot use piezo buzzer they have built in electronics for producing music or sound. piezo transducer or piezo tweeter. you can use ultrasonuc transmitter (sender transducer), ensure that they are capable of reproducing from 20kHz.

    Reply
  35. Badeekh

    Hi Seetharaman, m going to assemble it, just confused about the sound source, shoud i use simple piezo buzzer or the ultrasonic transmitter available in market?

    Reply
  36. Seetharaman

    Hi Moon CD4047 is a standard CMOS digital chip freely available. For SL100 you can use BD135, BD137, BD139, 2N1711, 2N2219. For SL100 you can use BD136, BD138, BD140. 2N2905

    Reply
  37. Seetharaman

    Hi Hider since the frequency generated is beyond our hearing it will be difficult to hear, but you can make a sound level indicator using a condencer mic with suitable electronics.
    Piezo transducers can respond from around 1kHz to beyond audible range. they are normally used as tweeters in hifi loud speaker systems.
    Car reverse horns musical chime electronic music generators use them as they are wheather proof and they contain no moving parts like magnetic voice coil loud speakers
    http://www3.telus.net/chemelec/Projects/SPL/SPL-1.png

    Reply
  38. MUTHU

    HI IS THE COST OF MAKING THIS CIRCUIT WILL BE ECONOMICAL?AND IS THE EQUIPMENTS AVAILABLE IN ALL ELECTRONIC SHOPS!!!!!!!!

    Reply
  39. Seetharaman

    Hi Pooja the sound produced by this device irritates them and they become either sluggish or defunct or try to fly away. Thus they are driven away from the visinity.

    Reply
  40. zaipee

    another one question, if we remove 22 mf capacitor then what will happen? and is the piezo buzzer is the example of piezoelectric sensor?

    Reply
  41. zaipee

    thanks for the circuit… but i want to know how the ic cd4047 works in this circuit(does if change the electric signal to sound signal)…and does variable resistance change the output frequency..
    plz reply me.. as soon as possible….

    Reply
  42. Seetharaman

    Hi Senthil the ultasonic frequency range is just beyond human hearing range of 20KHz to 100KHz. There transducers available for sender and receiver. you can use them with amplification and detection and convert into signal strength with a DMM in Volt/mV range.

    Reply
  43. senthil

    very nice and useful circuit.can u pls tell me how to check the ultrasonic frequiency.is there any such circuits avilable?

    Reply
  44. Seetharaman

    Hi Biomer you can use NE555 timer IC with one transistor and tweeter. There is no equivallent for CD4047 it is a standard digital ic.

    Reply
  45. Seetharaman

    Hi Prakash you can use 16 ohms tweeter or two 8 ohms tweeters in series.
    Hi Firoz assemble this try using it near the group of mosquitos, you can see the reaction of them. you also see my aug 30th comment

    Reply
  46. Seetharaman

    Hi Isuru 4.7n will be written as 472 and voltage will be written in 63V etc if it is Japanese it will with J etc for voltage, here 16volt and above capacitor will do.

    Reply
  47. kesavan.b

    Sir,
    vanakkam,
    i happened to see your article in the site. i am 60 now. about more than 20 years back i was testing such articles as a hobby. now due to over age and due eye problems i am unable to do any work.

    will you kindly assemble one and send me for my household use, because we are suffering from heavy invasion of mosquitoes at our city. further the use of chemical repellents make my asthma problems more aggravated and throw me to admission to hospitals for emergency attention.

    i am ready to send the cost in advance if you can kindly mail me the details. rather if it is at market it may please be informed.

    thank you very much for your publication.
    i further wish you to develop many projects which are needed for the people’s welfare and publish such in the website.

    thank you one again and expecting your reply.
    kesevan. b

    Reply
  48. EASY

    pls i need full detail about this repeller and how it work and if i want to build it the capacity of the componet i wil use thank you GOD blessed you.

    Reply
  49. Mattew

    pls i urgently need a workable simplified circuit diagram for mosquito repellant without any ic. please forward it to my mail cashwot@yahoo.com. I will appreciate it better it many different circuit can be forwarded. Thank

    Reply
  50. Rohith

    hi…… thanks for this circuit but tell me what is the voltage of capacitor C1 4.7nF or else can use any other capacitor?

    Reply
  51. NIJU SASIDHARAN

    hi,I want to assemble it.is this really working.What is its renge?how many meters is its range?reply urgent pls.thank you

    Reply
  52. seetharaman

    Hi Vignesh This circuit is based on the simple principle that insects gets immobilised or driven away by using ultrasonic sound above 20KHz. The above circuit operates around 22KHz. You can try by assembling and try to direct it towards the group of mosquitos, you can see the results for yourself. K1 should be Phiezo tweeter (used in two in ones for hi frequency reproduction).

    Reply
  53. seetharaman

    Hi Wandera the cockroaches will not respond to electronic sounds. chemicals are the best solution for them, the combination of which should be changed regularly – immunity problem.

    Reply
  54. seetharaman

    Hi Pablo the transistor can be any medium power low frequency silicon transistor. Vceo 24 volt Ic 500mA Ptot around 1 watt hfe around 100 at 100mA Ft 1MHz

    Reply
  55. seetharaman

    Hi Sonny you can try to assemble a variable frequecy oscillator in the range of 16 to 20KHz with a suitable amplifier and a HF transducer(ceramic tweeters. This range will affect only mosquitos not other living things. You can find out at what frequecny the mosquitos flie away as your sounder approaches them.

    Reply
  56. sonny

    Thank you for the info, is there any alternative circuit(for mosquito repeller) that i can use in our piggery that will not affect my dog?

    Reply
  57. seetharaman

    Hi Sonny with pigs it should not be a problem with dog you will have lots of problem as they can hear it.

    Reply
  58. sonny

    Is this mosquito repeller can be use in our piggery? we noticed our pigs had several bites from mosquitos.
    Since this circuit is operated in sound frequency above 20khz range, would there be any side effects in our pigs?

    Reply
  59. seetharaman

    Hi Asad FOR SK100 2N2905, BD136, BC327 for SL100 2N1711, BD135, BC337,
    Hi Adnan for this low power radiation at 22KHz will not have any effect on human health.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>