Question on how to energize a air transducer

echoing Doug and anniel747,

First one I found:

https://www.ebay.co.uk/itm/290986012821

Needs serious drive to get full output (140V pk-pk).

They give no idea of impedance but it's common (but no essential) to drive these things with a transformer and to tune the inductance with the transducer capacitance.

If you will drive 72 of them it's going to be expensive if they all get different signals (and hard to see any point in 72 driven all the same.)

But as is sadly so often the case you haven't told us anything like enough to get good advice.

Explain your project in detail, with diagrams etc.

The more you tell us the better we can help - you can't lose by it.

This is an open forum - everybody learns or nobody learns.

MK

Not always easy to give all the details on the design with out giving out to much information. What I am trying to do is create anti gravity to prove it exists for new theories I have been trying to get the Physics world to take seriously on how the universe formed. I ask for verification of work done by Pakistan students to verify my theories  and have had no response. I am confident if I can create anti gravity that they would not be able to ignore me any longer.

   I only need to send 1 signal  to all of the transducers. I am good a making about anything, but I don't have a back ground in electronics need a design that will power the transducers and allow me to piggy back a sound wave.  Thanks for your help Ed

I have tried to send you the data sheet but not able to copy and past it in for SMART200H19XDA  AIR TRANSDUCER. 

I am confident that you will not be ignored if you can demonstrate anti-gravity.

I am equally confident that you will not do so.

Levitation using acoustics has been demonstrated but is no more anti-gravity than, for example, a drone with fans for lift.

https://en.wikipedia.org/wiki/Acoustic_levitation.

But I'm not interested in advising a secret project.

MK

Can be done with the right enclosure.

I can't tell from here, but that screw looks wrong - should be Pozidrive. Will never work with that one.

Nothing a roll of tape can't fix.

Ed2024 said:

SMART200H19XDA  AIR TRANSDUCER

Are you sure about that part number ?

SMATR200H19XDA
https://www.steminc.com/PZT/fr/air-transducer-200-khz

Where did you find the data sheet?

Thanks Dave - I took a look at the data sheet and as I suspected anti-gravity is not listed as one of the suitable applications for this part.

I think the pyramid thing might work if one of the fans was reversed.

MK

How that part can be a transmitter and a receiver at the same time with only 2 wires? 1-Wire or I²C protocol? 

How that part can be a transmitter and a receiver at the same time with only 2 wires? 1-Wire or I²C protocol? 

It's (probably) a piezoelectric disc, almost certainly operating in thickness resonance with some kind of coupling layer of different density to try an get a better mechanical impedance match with the air.

They work rather like the ultrasonic transducers on cars for reversing sensors but 200k ones a re harder to drive.

You usually need to drive it with a high voltage (single pulse or maybe short sine burst using a transformer) then you somehow isolate the drive and connect the receive amplifier. The 60dB or more difference between the TX and RX signal causes problems. There is always a minimum measurable distance because you need to allow things to calm down a bit in sensor and electronics before you can detect an echo signal.

MK

So why a regular piezo be so expensive?

$36 - that's pretty much free in some circles. Its a long time since I bought a Bruel and Kjaer Accelerometer but when were were selling them literally by the million as knock sensors at about £3 each a B&K part was £200 - 300. Much better than our knock sensor but very similar inside. Theirs cam in a little box (wooden in the 70s but changed to plastic later) and with a cal certificate.

I designed a tank level measuring system for a customer a long time ago and I researched (but didn't use) some 200kHz transducers. I'll have  a look later and see if I can find an more data and a picture of what's inside.

MK

Comparing a calibrated B&K accelerometer with a bare naked sensor? $36.00 plus $73.98 shipping, in my book that's not cheap. 

michaelkellett said:

The 60dB or more difference between the TX and RX signal causes problems. There is always a minimum measurable distance because you need to allow things to calm down a bit in sensor and electronics before you can detect an echo signal.

As others appear to have found out...

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/614398/pga460-q1-issues-while-using-200khz-transducer