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Better understanding of ultrasonic sounding

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fastline

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Basically working on a high power version of the ultrasonic distance tester commonly found online. I find emitters/receivers a little harder to find and I possible don't fully understand them right now as the demo circuit is hard to understand.

When an emmiter is rated for X frequency, do I need to provide a sine wave at that frequency to the emmiter? Or do you simply power them and they oscillate? Is this just a speaker and the frequency given is the same as any speaker which is the peak frequency response?

I am looking to use this to determine the length of a tube. I am hoping not to get false or inaccurate readings and trying to figure out the power requirements for say 100-200ft or so.
 
hi,
Do you have a link to the demo circuit.
E
 
Actually, looking at the data on that link kind of helps! I don't think I have that documentation. We sort of plugged all this in as a canned system to test it. From the looks if this, the emmiter/receiver operate with TTL signal or digital square wave? I am not yet sure how to know the rated power for these though. Maybe it is possible to simply boost the voltage to these little guys to get the distance required? No emitter/receiver data sheets to work from.

What I was hoping to do is dumb this down and use our function generator to run the emitter and maybe just a simple momentary switch and just plug the receiver into the scope. If I understand correctly, the receiver generates its own TTL output?
 
hi,
The transmitting transducer has to be driven with a square wave at the resonant frequency of transmit sensor.
A short burst.
E
 
The very first issue here is the power. This device has an effective range of 3 meters. I am curious what typical sonar might operate best at to be accurate at the receiver? Do we really just consider the power driven to the emitter and run the numbers to determine decay through air to determine power requirements? They only list the "supply current" at 30mA. So that might be .15W? Just curious how we will get from 3ft to 300ft? More power? I would think the receiver part would work just fine though? Just need to amp up the emitter?
 
If you are going to use one of those boards you linked to there are two issues :
1) If the Tx energy is confined within a tube rather than radiating spherically, the normal inverse square law of power reduction with distance won't apply, so you may get much more than 3m range with no Tx boosting :).
2) Since the board Rx outputs a variable-duration pulse to indicate range there may be a built-in limit to the duration, which would prevent the ranging being extended beyond 3m :(.
 
The very first issue here is the power. This device has an effective range of 3 meters. I am curious what typical sonar might operate best at to be accurate at the receiver? Do we really just consider the power driven to the emitter and run the numbers to determine decay through air to determine power requirements? They only list the "supply current" at 30mA. So that might be .15W? Just curious how we will get from 3ft to 300ft? More power? I would think the receiver part would work just fine though? Just need to amp up the emitter?
Hi,
I used to design and manufacture ultrasonic sounders for hydro graphic use as a product.
A range of 30mtrs ' in air' will require more powerful transducer than those in your link can deliver.

In a tube you should need less power, what is the diameter of the tube and what is the material.
Do you plan to bounce an echo from a closed end or have the TX and RX at opposite ends.?

The 'decay' in air is to the 4th power.!

Also you may have to consider using a higher frequency, say 150KHz or 200KHz.

E
 
I do not intend to use the board I links. Just using it as a reference for test. Tube diameters will vary from 4-12". I want to emit and receive signal from the same end. Basically send a pulse in the tube and receive the returned signal.

I sort of figured I would be pretty limited on the sounder in that board and I do think there is a timeout limit in it. I would plan to design and run directly from an MCU.

Where can I source sounders of this magnitude? No problem in a higher frequency, I was just looking at stuff I could find in the parts stores which might not work. I have some concerns of how sensitive it might be to little irregularities in the tube that might be able to reflect the signal and give a false reading. Just need to build one and test I suppose.
 
Conference halls use a very powerful Ultrasonic beam to play language translations to different people fairly far away (30m). The power is from an array of many ultrasonic transducers and a receiver is used. The new method below is also used for translations and the speech seems to come from inside your body.

There is a new method of using a powerful ultrasonic beam of specially modulated speech to bounce off an object in a museum or gallery. When the beam hits the object then it becomes de-modulated and heard to be coming from the object.

I cannot find a link that shows the many ultrasonic transducers in the array.
 
Tube diameters will vary from 4-12". I want to emit and receive signal from the same end. Basically send a pulse in the tube and receive the returned signal.
hi,

It would help if you posted more details about the problem rather than ask for help about ultrasonics.
eg:
Min/max pipe lengths.?
[you have posted the dia's]
Material.?
Is the pipe always straight.?
Is the pipe on the bench or underground.?
What is your location.?

Eric
 
Conference halls use a very powerful Ultrasonic beam to play language translations to different people fairly far away (30m). The power is from an array of many ultrasonic transducers and a receiver is used. The new method below is also used for translations and the speech seems to come from inside your body.

There is a new method of using a powerful ultrasonic beam of specially modulated speech to bounce off an object in a museum or gallery. When the beam hits the object then it becomes de-modulated and heard to be coming from the object.

I cannot find a link that shows the many ultrasonic transducers in the array.

I recall reading this, 2 or 3 years ago.
 
Look at https://en.wikipedia.org/wiki/Sound_from_ultrasound where the sound comes from "inside your head".
I could not find an uncovered photo of their speaker but I think it has an array of many ultrasonic transducers to handle the high power needed to travel a distance as far as 30m.

This array can be used to measure distances.
 
i believe you are referring to the Parametric Speaker ag.
https://technabob.com/blog/wp-content/uploads/2012/04/soundlazer_parametric_speaker_1.jpg
https://zao.jp/radio/soft66lc/P1010735.JPG

i don't get all that parallel speaker(transducer) stuff yet, so for learning purposes ima try this to see if it works, although i don't got the horn thing figured out yet: ) latest_attachment.jpg
 
i don't get all that parallel speaker(transducer) stuff yet
You need a LOT of power to send an ultrasonic frequency as far as 100-200ft. But an ultrasonic transducer (speaker) is fragile and has a low maximum allowed power rating so the array you posted uses 39 of them to increase the amount of power 39 times.

The array of transducers focusses the ultrasonics into a narrow beam so the tube might not be needed. They will not fit in a tube anyway.
 

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Eric, I will PM some specifics. At the moment I have a machine down so we are in critical mode around here.
hi,
I have replied to your PM, hope its helpful.
E
 
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