Ultrasonic transducer driver circuit

[busi]

I'm building a picocontroller based pest control unit that employs the transmission of ultrasonic sound. Could anyone help with the best driver circuit to use for the ultrasonic transducer?

 

[IRstuff]

Have you considered reverse engineering some of the products on the market? TTFN

 

[jbartos]

Suggestion: Visit

http://hamjudo.com/sonar/

http://www.dis.unimelb.edu.au/staff/Jon/pubs/motion/Measuring Motion.html

etc. for more info

 

[Thorn3]

One special note regarding such devices. Beasts of the world tend to develope an immunity to sounds that would initialy cause them to "flea" the area.. LOL.. If you wish to repel mosquitos, I would suggest you find out what the particular frequency the male emits. This sound, is not welcomed by the female. It is the female that bites you. Sorry ladies..but isn't that just typical? Anyway, mimic the sound of the male mosquito and you will have a device that will not allow immunity...to mosquitos that is. For other little nasties, I would suggest you try to eliminate quick immunity to your oscillator, by changing the frequency automaticaly at random intervals.

 

[busi]

Thorn3
My device will employ a microcontroller that should cause the generation a range of frequencies that are expected to repel a number of pests. This would make the timing more accurate aswell as reduce the possibility of the pests becoming immune to one frequency.
I have been trying to get information on the sound produced by the male mosquito but it seems no-one knows. Does anyone have a clue?

 

[Thorn3]

I know this sounds a bit much, but personaly, I would simply capture a male mosquito, and record its sound. More than likely, you will need to increase the gain on your pickup, but most importantly, you should use a frequency shifter circuit, to bring the sound within your range of hearing. This is not of course to make the pest repeller work at this modified frequency, but rather to assist you in determining if you have indeed captured its sound. If the shifter shows a sound present, you can then use the true recording of the mosquito in something like an ISD chip. I have used an ISD chip to keep pidgeons away, by recording the sound of a hawk. In reality, there is nothing quite like the real thing! It may be possible, that female mosquitos can tell the rather subtle differences between pure frequencies from an oscillator, and the recording of the real thing. I do not believe that anyone is presently using the "real thing". By using a frequency shifter circuit, you can hear the tonal differences occuring in the sound, that you would not otherwise know existed.
Since the output frequencies for mosquitos are different from a two tone pain generator that would deter other pests, your processor would have to create several "two tone" outputs, as well as play back the mosquito sound. Looks like you will be programming for quite a variety!
What I have done as an experiment, is to use two, tone generators, passed through a mixer. Set one frequency, then match the second to it. Then, slowly adjust the second frequency up or down. You will hear when the two tones create a most disturbing sound. This type of experiment will assist you in knowing better, the relationship between the two tones. Shifting such frequency groups up or down for different pests would then be quite easy, as the relationship between the two tones will always remain the same.
There is a difference between sounds that are anoying and ones that create pain. Discomfort can be filtered out, but two frequencies working together, cannot, as it creates a disruption on a cellular level.