Using piezoelectric transducer to ring singing bowl?

Projects General Guidance
1

Hi all,

Would love your help with a project I am working on. A while ago, I worked on using a solenoid to strike a singing bowl, controlled by an Arduino. This has worked well.

Now, I am trying to make the singing bowl ring by using a (series of) piezoelectric transducers. The idea being, that I should be able to make the singing bowl ring/vibrate by attaching the piezoelectric discs directly onto the singing bowl and then make them vibrate/ring with the right frequency and volume to stimulate the singing bowl sing.

I understand that I will be able to control the tone (and?) the volume of the piezoelectric disc(s) via the Arduino, but I am a little bit unsure about what type of piezoelectric transducer to buy.
Amazon etc. sell piezodiscs from 10mm to 27mm (e.g. this: https://www.amazon.co.uk/sourcing-map-Acoustic-Transducer-Microphone/dp/B07QNWXVF6/ref=sr_1_3?crid=H7UIUXXAB8C1&keywords=piezoelectric+disc&qid=1703760975&sprefix=piezoelectric+dis%2Caps%2C83&sr=8-3) but they all seem to have similar resonant frequencies of c. 3,000-5,000 herz, whereas the singing bowl rings more at a frequency of a couple hundred herz. What I am confused about is:

  • does this matter? i.e. do I need to buy a piezoelectric disc with a resonant frequency similar to the one of the singing bowl or will the singing bowl start vibrating just by having a (small) object vibrating next to it?
  • if the frequency does not matter, would it be better/possible to buy a piezoelectric transducer that has a resonant frequency in the ultrasound range, so that I can make it vibrate without creating sound that humans can hear?
  • if it does matter, what kind of piezodisc would I need to buy / where do I find this?
  • finally, I came across bone conductors - I understand that they turn objects into speakers, which is sort of what I am trying to do (but then would it still sound like the singing bowl being played?)

Thanks so much for your advice already!

Best

Tobias

2

Will a singing bowl with things glued on to it sing the same way as one without things glued onto it?

3

Yes I was thinking about this - it could potentially be glued to the bottom, so it would not be very different from the bowl standing/being held in the first place; alternatively there is a compromise: the higher up the 'easier' to make it vibrate, but also the more muted the sound.

4

If you are tying to simulate what the solenoid did, then I would try an audio exciter and ping it with short pulses. You will need an amplifier to drive the exciter.

5

Or …You might be better off with a small speaker , that way you can vary the frequency until it resonants .
If your piezo devices run at a different frequency you won’t hear anything.
Hitting it also excites the resonant frequency

6

Thank you Jim, this is great (and happy new year!), thank you so much for your guidance!

I have purchased a similar exciter to the one you recommended and also what I think a suitable amp is (https://www.amazon.co.uk/AZDelivery-amplifier-TPA3116D2-speakers-including/dp/B09PL6R1L7/ref=sr_1_12?crid=1CM4E6DY79WUL&keywords=class%2Bd%2Bamplifier%2B50watt&qid=1704556235&s=electronics&sprefix=class%2Bd%2Bamplifier%2B50watt%2Celectronics%2C49&sr=1-12&th=1)

Will report back once the parts arrive.

7

I joined just to see how this project was going.
I have the same ambition. I want to have singing bowls that are played by arduino.
Please let me know what you have discovered so far! : )

8

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