Parameters to measure in ultrasonic transducer impedance analysis

In this webinar, I go over a power and under utilized method of measuring parameters from the resonance and anti-resonance response of a piezoelectric/ultrasonic transducer. The method is to use conductance and resistance for evaluation, which makes analysis simple and very accurate, especially in the present of strong damping.
To sign up for my next webinar, follow the link: www.ultrasonic...
Here are the topics:
0:59 - Outline
2:00 - About Ultrasonic Advisors
2:59 - What is impedance?
5:21 - How is impedance measured?
7:40 - Measurement of an ultrasonic cleaning transducer
20:00 - Measurement of Q-factor from impedance
24:50 - Measurement of Q-factor from conductance or real admittance
26:56 - Explanation of real impedance and admittance parameters
30:50 - Impedance measurement of piezo-unimorph
34:00 - Describing poor measurement when transducer is left on table
34:50 - Utilizing conductance and resistance to describe response of piezo-unimorph with great representation
37:10 - Calculation of Q-factor from conductance
41:40 - Measuring Q-factor accurately in the present of large damping on piezo unimorph
For more information about my consulting services on ultrasonic transducer simulation, please visit my website: www.ultrasonic...

[@ricksampson6780]

Excellent, most informative and concise information on this subject available in the public domain.

[@ultrasonicadvisors]

I really appreciate the comment from a long time fan!

[@ricksampson6780]

@@ultrasonicadvisors My pleasure, I acknowledge your determination in this subject area, cheers.

[@coucouj2781]

Excellent video !
Can you do a video on amplifiers please ?
Struggling between using opamp vs transformer.

[@ultrasonicadvisors]

Thanks for the suggestion!

[@ultrasonicadvisors]

***To sign up for my ultrasonic transducer webinars, follow the link: **www.ultrasonicadvisors.com/monthly-ultrasonic-webinar** ***

[@danielmccann2979]

This is awesome

[@gabrielbarrientos468]

Very nice demo!
Some questions though...
How do you calculate the Butterworth-van dyke parameters from what you measured?
And I see how you measure the impedance with a voltage differential over a known resistor, but how do you measure the phase?

[@ultrasonicadvisors]

I am uploading a video on that right now. Check my new videos.

[@loom5026]

Dr. Shekhani,
What is the device that says "A" and "B" on it that is between the PicoScope and the probes?

[@ultrasonicadvisors]

That is a box with a resistor in it.

[@cssa2893]

I have a basic question: in power ultrasonics, is the vibration amplitude controlled by voltage? How will the power be adjusted during the welding if I have set the power?

[@ultrasonicadvisors]

Voltage will be controlled to keep the power constant.

[@cssa2893]

@@ultrasonicadvisors Thanks for the answer! So it means the current is set a constant value. Controlling the voltage to control the power?

[@Pewpewlazorz112]

Thank you very much for the upload! Could not join the last Webinar.
Do you normally encounter nonlinear effects of the piezo in high power applications? Is it relevant?
Does it result in faster aging of the piezoceramic?
How would that be quantified?

[@ultrasonicadvisors]

Nonlinearity appears all the time in high power applications! It is relevant, but we use linear parameters to describe the conditions still. For example, measuring the impedance or quality factor for a certain power input.

[@UltralydvaskingLillehammer]

Question to you all: does the impedance of ultrasonic cleaning transducers get higher or lower after hundreds of hours of duty ??
Thx