Acoustic magnetic generator.

[verpies]

I used my PA in the following clip (changed the setup a little too), but this limits the frequency range till about 60KHz which could be a problem.

Since your fundamental standing wave frequency is around 12kHz you might be fine within this limit.

I was able to input >300V pp into the piezo without seeing anything special.

My 120W ultrasonic cleaner has 200V_RMS across its piezo element and it can do a lot of damage.
BTW: The piezo predominantly is a voltage device but a regular speaker predominantly is a current device.  This distinction is not applicable to this experiment but is important to keep in mind for the future.

With the PA (>300V pp) there was a noticeable ac field which i could feel with my finger when touching the piezo.
This touching caused a greater response in the pickup coil, also when touching the pickup coil (to move it), there is a big influence on the amplitude of the signal (increase), which somehow does not seem right.

The piezo and its wires are working as a transmitter antenna and interfering with your sensors.  Change the driving wires to a flexible coax and shield the piezo with copper foil (all grounded bur not dampening acoustic vibrations of the piezo or the rods).

[verpies]

Just because Milehigh said radial does not change the polarization from axial as it is. What are trying to pull? You sound like some kind of nut case.

Just because I understood you differently from what you had in mind does not warrant you making Ad Hominem remarks about my sanity.

You do not express yourself precisely and your frequent use of colloquialisms and loose grammar leads to such confusion.
In this case, you should have directly stated that the magnetization of the disks is axial - not that he was "looking at" axial.  There is a difference.

I welcome criticism of my actions, analysis and ideas but personal statements as to what I am (Ad Hominem) are overboard.
One more remark about my person instead of my actions, analysis or ideas and you will be ad-blocked and completely ignored.
This is your only warning.

[synchro1]

@Verpies,


Listen Bub, I have a M.F.A in Professional writing from USC, I have a published book in all the world's libraries and am extremely literate. You can't understand what you read, and I'll be the one doing ad blacking smart guy! You're just another stinking know it all like those other conceited jerks. You can shove it!

[synchro1]

@Itsu,


         Very nice improvised soloution. Removing material from the ferrite rod would be senseless. Thanks for the video link:  Magnetostrikció ? I wonder what frequency he's vibrating his transducer at?


That turns Verpies admonition against attaching the transducer to the rod end into rubbish too!

[verpies]

Removing material from the ferrite rod would be senseless.

That statement has no justification.
I have stated the reason for a shallow groove in the previous posts clearly: A friction-maximizing sand holder, that does not involve dampening materials.  Also, extensional l.waves are reflected from the surface of the rod and are much weaker above the surface than under the surface.

That turns Verpies admonition against attaching the transducer to the rod end into rubbish too!

This statement demonstrates your lack of discernment between qualitative and quantitative objections.

You're just another stinking know it all like those other conceited jerks. You can shove it!

Note, that I have never called you names.
I will filter out your posts from now on - you've been warned.