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  • Electronic Mosquito Repeller

  • Created: Feb 24, 2014

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This circuit is built to repel mosquito using high frequency sound. The design is comprised of LM555 timer which provides the pulse generation and precision timing. It is also a stable controller capable of monostable or astable operation. The 74HCT4017BQ device is a Johnson decade counter with 10 decoded outputs. It provides the signal to be fed into the 555 timer which is connected to the output piezo speaker. The piezo speaker generates the sound. The Bipolar Junction Transistors(BJT) BC337 and BC327 acts as the amplifier of the output sound. It forms the push-pull amplifier that is more efficient than a single-ended Class A amplifier.

The design is ideal for household application. It provides additional protection to the family against illness. It is also a suitable substitute to chemical based mosquito repellant.



Has anyone tried this? We have plenty of mosquitoes but seen too many things that claim to repel but do not.

Posted: May 30, 2014


I've never seen an VHF or UHF insect repeller that actually works (partly because they don't have ears). If I re-tune it for VLF it'll make a decent mammal repeller (raccoons, coyotes, neighbors Chihuahua) using infrasound, though. Have to put a cardboard cone around the piezo's to focus the output, so it doesn't drive my dog nuts.

Posted: May 30, 2014


I've tried to build these things since around 1970, when Popular Electronics published an article on one using a unijunction transistor. It worked when you whacked the mosquito with it.

Posted: May 31, 2014


This circuit will not work. Pin 8 is not connected and pin 5 is connected to the positive rail !!!!!!

Posted: Jun 28, 2014

Neil Mula

Hi Colin, I think the project has been updated already. I just email the designer about this. He is so busy building a lot of designs and I think he just fail to review this one. Any inputs and comments are very well appreciated according to him. Let us support schematics.com for social diagramming. This case is a great example that a collaboration between designers is better than designing alone.

Posted: Jul 21, 2014


I like his design but in the 80,s the Company I was in manufactured a similar unit to this and I did a lot of research at that time for our customer and the CSIRO in Australia tested it and found it did not work to repell. The current commercial designs on the market are multi-frequency and/or pulsed but there is no firm results proving to date that they work at all yet 1

Posted: Feb 12, 2015


what kind of speaker can effluence ultrasonic range?

Posted: May 02, 2015


clean schematic diagram bravo!

Posted: May 18, 2016


What is the point of the 1k resistors into the bridge??????

Posted: Sep 21, 2017



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