I What can be used as a Frequency generator to make Chladni patterns?

[gavinthoms]

What can be used as a Frequency generator to make chladni patterns?

 

[Baluncore]

Welcome to PF.

Chladni figures form on the surface of a resonant plate.
Striking the plate with a small hammer, or using a violin bow, will excite the plate.

If you use an electronic oscillator, you will need to adapt a speaker coil, or some similar transducer, to shake the plate. You may then have trouble finding the critical resonant frequency.

You could mount a small electric motor below the plate, with an unbalanced shaft, that would shake the plate at the motor rotation speed.

 

[tech99]

For school we use a vibration generator, which is like a speaker, and a signal generator with an audio power amplifier.

 

[sophiecentaur]

For school we use a vibration generator, which is like a speaker, and a signal generator with an audio power amplifier.

I expect that transducer is the same as the ones I used to have in my lab. They are pretty heavy duty and link to a suitable waveform generator over several octaves (from very slow upwards). Natural resonances are more easy to induce, as you say but the re-arrangement of the sand when passing from one mode to another is impressive.

You could mount a small electric motor below the plate, with an unbalanced shaft, that would shake the plate at the motor rotation speed.

That's one approach (as with a water wave generator) but the frequency control of that method (motor speed) tends to be associated with big amplitude fluctuations.