mosquito repeller demo

[denccj]

I have done a circuit on mosquito repeller, but have no idea how to demo it to show that it is workable. since it generates >20kHz frequency, our human ears will not be able to hear the ultrasonic sound.

any advice?

 

[Oznog]

Sounds like you need some mosquitoes?

Actually from what I hear no reputable test has ever shown ultrasonic gadgets to be of any value. It would be difficult to show it repelling them or causing them not to bite in a reasonably sized box even if the principle were effective.

 

[Nigel Goodwin]

I have done a circuit on mosquito repeller, but have no idea how to demo it to show that it is workable. since it generates >20kHz frequency, our human ears will not be able to hear the ultrasonic sound.

any advice?

There have been a number of circuits published for 'bat detectors', these down convert the bat's ultrasonic sonar to be audible. Presumably a similar system could be used to make your ultrasonics aucible?.

You should be able to find deatails via google?.

As already suggested though, it doesn't prove that it will repel mosquito's.

 

[denccj]

thank you Oznog and Nigel!!

to be true, the bat detector circuit looks quite complicated to me. i'm new to engineering, still in my first year. i'm not good in practical. after this project, i'll try to DIY a lot.

is there any other method ( besides using a system similar to bat detector ) to show that there is actually an ultrasonic sound produced?

or any other good method to demo the mosquito repeller system?

 

[chemelec]

Ultrasonics devices will Repel Male Mosquitos, but male mosquitos Don't Bite.

Female mosquitos Bite, but they are Deaf so the sound doesn't bother or repel them at all.

 

[denccj]

thank you Chemelec.

from my reading, the mosquito repeller will create a sound of frequency similar to the frequency of the wing beat of a male mosquito.

and female mosquito will always fly away from male mosquito ( except during mating period ).

 

[denccj]

and seriously, female mosquitoes are Deaf?

dead, i have to show this thing works.

 

[Nigel Goodwin]

You can use an oscilloscope to show that's it's producing an ultrasonic output - would that be enough?.

 

[chemelec]

and seriously, female mosquitoes are Deaf?

dead, i have to show this thing works.

YES

 

[audioguru]

Some electret microphones pick-up "sounds" a little above 20kHz. An electret microphone will need to be properly powered and would show the output on a 'scope.

 

[Dr.EM]

Yeah, I think you'd need either a very quiet location or some steep roll off high pass filter for that to work well though, as the high frequency bat calls will be picked up as much quieter than any ambient noise.

 

[audioguru]

With an electret mic directly in front of the "mosquito repeller", its output would be pretty high if the 25kHz ultrasonic transducer worked. It could feed a preamp and show its output on an LM3915 driving a bar-graph of LEDs.

Maybe the mosquito repeller would repel mosquitos if it had a bat installed inside, if mosquitos can hear the bat's sonar and know that they will be eaten. You would need to trick the bat so it thinks it is hungry and is flying.

 

[Oznog]

and seriously, female mosquitoes are Deaf?

dead, i have to show this thing works.

Next project, very teeny tiny mosquito hearing aids.