Is anybody working in this area?

I notice that one can buy two ultrasound transmitters, pitched at 40khz, and a driving board for around £35.

The snag is that one needs to examine the board, see what it takes to adjust the existing fixed frequency.

https://www.ebay.co.uk/itm/2X-50W-40...AAAOSwrFxbbP8L

But typing the number on the board, 13913887466 100W, does get us to what purports to be a circuit diagram - but without any 555 or similar chips.

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that sort of transducer only works at resonance,
changing the frequency would just make it not work very well.
the driving board likely seeks resonance to drive the part at
so, if you want to change the frequency, you likely have to make mechanical changes to the ultrasonic transducer

edit:
also, without looking at any of the details on this one,
the 42.8Khz was likely just what his 40khz ultrasonic transducer happened to resonate at.

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spacecaseO

Any ideas on how to make an adjustable/tune-able transducer ?

the water will most likely always be a moving target and need either
a brute force heavy power [wasteful]

or some way to sense the reaction and adjust ??

some interesting water fuel experiments are in the wind for a few of the open source venues.
this might be a nice addendum.

respectfully
Chet K

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physical resonance has to do with how much metal and the geometry
you can weld on more metal,
you can cut off metal
not sure how well bolting on metal with work. would have to try it.

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If there were cones within cones [or pyramids !;} ..perhaps adjustable ? or could oscillate to adjust the gap or space between them.

tricky stuff .
the beauty of these experiments is they can be small table top [itty bitty]
we are after all effecting the micro micro world.

one thing is certain ,the hardware to play with and manage these experiments is available as never before.

thanks
Chet

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What do these transducers actually consist of?

Somewhere I discovered a loudspeaker "super top" which said it went up to that level. I'll try and find it.

The impression I get from Keely circles is that the frequency that works is very precise. One would need to adjust +/-a couple of places in the second decimal place position, using 42.79khz or thereabouts.

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Small rodin coil w magnet attached to membrane

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I have done some experiments with it and it is very interesting. I used a Function Generator some diodes and a few ultrasonic speakers.

Leads into Bubble Fusion.

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the one linked is a piezoelectric materiel inside an aluminum block
https://en.wikipedia.org/wiki/Piezoelectricity

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I built an ultrasonic transmitter about 50 years ago. I believe you can get ultrasonic transducers from places like mouser.com and others sources like that. I downloaded data sheets on several there and while they state the center frequency is 40 KHz plus or minus 1 KHz I would think they could still operate at 42.8 KHz by just plugging them onto a frequency generator. They would not be as efficient but I'm fairly certain they would generate the 42.8 KHz. I might be wrong on that but if so it would seem you could contact the manufacturer of these transducers to see if they can produce them in the range or if they have some ideas on how it may work with the existing 40 KHz units.

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There is no important work, there are only a series of moments to demonstrate your mastery and impeccability. Quote from Almine

This unit would probably do the trick:
https://www.ebay.com/itm/High-qualit...wAAOSwft9csEw9

20 to 40 KHz and 40 to 120 KHz frequency ranges and 1500 watt output ! Unfortunately not cheap - about $1100 with shipping. Maybe they have a lower output unit that can do the job for less.

Also look at this eBay item number:323709703394 as the seller has a lot of different transducers and your choice of many different frequencies. Write them a request and maybe they can do one specific to 42.8 KHz. If they think there is a market for it I'll bet they would produce them. Same seller as the on for the unit above.

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There is no important work, there are only a series of moments to demonstrate your mastery and impeccability. Quote from Almine

Hey guys, I looked into building a device for doing this a while back but have focused my resources on other projects that were working.

Driver
You dont need to spend insane amounts of money. You can drive the ultrasound transducer using 2 mosfets/igbts in a full/half bridge configuration. You can basically pump as much power as you want to into it from a dc power source. The thing with a lot of these ultrasound transducers is that they sometimes run at a few hundred volts and a small current so igbts are better.
Would cost around 30 dollars depending on voltage.

Transducers
So there are the ultrasound horns on ebay that youve found. There are also piezoelectric transducers which are actually whats inside the horn. So if you look up piezoelectric transducer you will start to find discs and rings etc that will resonate very close to 42.8kHz, but they wont take much power so you will have to parallel them together.

Impedance
To massively reduce the input power needed to make it oscillate youll need to impedance match your frequency generator to the horn or transducer. Also if you impedance match it will reduce reflected power to your source so it doesnt blow up lol.

Anyway if i have free time and somebody wants help designing the system. Let me know

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What about this item? One pcb with an unfamiliar look and two transducers:

https://www.ebay.co.uk/itm/2X-50W-40...AAAOSwrFxbbP8L

Putting 13913887466 100W into Google Images gets a number of circuit diagrams which may or may not be correct - to enable the circuit to be tuned.

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I believe we should pay attention here too !

https://overunity.com/7030/stanley-m...msg540014/#new

respectfully
Chet K

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