Instructables
Picture of Mosquito repellent
schematic.bmp

The summer this year is too hot, the heat is not really a problem but mosquitoes ...! ,especially i camping.

So after i tried some solutions i got the idea to make an electronic mosquito repellent that i can take with me wherever i go. this circuit is just a transistor multivibrator that generates high frequency sound ,and mosquitoes don't like this sound.

I am not gonna use a PCB i will just solder components together to make it a simple and cheap

Update : here is the Kicad project + (the PCB , the schematic , the components view ) in PDF

Mosquito repellent.rar

 
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Step 1: Components

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  1. two BC548 transistors or equivalent
  2. two 100k resistors radio shack link
  3. two 1.5k resistors radio shack link
  4. one 4.7k resistor radio shack link
  5. one 2nF ceramic capacitor radio shack link
  6. one 560pF capacitor radio shack link
  7. 5mm Red led radio shack link
  8. Toggle switch radio shack link
  9. 9v battery radio shack link
  10. 9v battery snap connector radio shack link
  11. Piezo element radio shack link
  12. a small project enclosure radio shack link
  13. some wire

This components i salvaged them from my older projects ,but i put links to Radio Sack

Step 2: Tools

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  1. Cutting plier
  2. Needle nose plier
  3. Solder iron
  4. Some solder
  5. Philips screwdriver
  6. Hot or super glue

Step 3: Circuit soldring

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solder the components in order like in the pictures

  1. Bend the collector and base pin of each transistor
  2. Solder the emitter pins together
  3. Solder the 560 capacitor then 2nf one solder the two 100k resistances then the other 1.5k
  4. bend the free pins of 4 resistance and so

First thing, the details of your instructable are as clear and understandable as any instructable I've ever seen.

But do let us know the results of any testing you do with actual mosquitoes. I've read that mosquitoes don't even hear ultrasonic frequencies. Instead, male and female mosquitoes keep in touch with each other using audio frequencies around 400 Hz, NOT 40,000 Hz. Moreover, I've read that there have been more than a couple of tests of ultrasonic mosquito repellers that revealed that these repellers didn't work at all.

However, there is hope for your device as I've read that some shopkeepers in Dear Olde England have deployed devices like yours set to about 16000 Hz with the purpose of repelling unwanted teenagers who can hear these frequencies. Check out Howard Stapleton - teenager repellers. Note: the use of these devices has been challenged by some EU agencies that consider these devices "cruel to young humans and other creatures, treating them as unwanted birds or insects."

stubbsonic2 months ago

I'm like flavor-blasted Doritos to mosquitos. They bite me once, then they go find all their friends and come back for more. And DEET really is the only thing that works for me.

Have you tried your high-frequency device "in the field"?

I'm skeptical as to how well it will work in more intense circumstances.

amgworkshop (author)  stubbsonic2 months ago

yes i thinks it's working .but i can't stand those ultrasonics.

maybe i will increase the frequency or lower the operating voltage

there are all sorts of pest control devices using ultrasonic frequencies. like the above poster, unsure of how well it would work in this case.
Bashey2 months ago

Is it a 2nf or a 2.2 nf capacitor? 'cause i can't find some 2.2nf capacitors in my favorite electronic store.

Does operate on diferent voltages too?

And can i use some ultrasonic transmitter either (instead of the Piezo speakers)

very nice Project by the way! :)

amgworkshop (author)  Bashey2 months ago

it's 2nf ,yes it does operate on different voltage from 1.5v to the max voltage of the piezo buzzer and the transistors . i think you can use an ultrasonic transducer if that's what you mean.

thanks Bashey

Aleator7772 months ago

Now to deploy these in swamps everywhere! Mosquitos be-gone!