2
\$\begingroup\$

For example, if piezo disc has lowest resonant frequency of 4kHz. At that frequency, would the electrical impedance be at its maximum or minimum?

\$\endgroup\$

1 Answer 1

7
\$\begingroup\$

It's both. Just like regular crystals, piezo exhibits resonance and anti-resonance within a small part of the spectrum. See this for example. At one resonant point it will act like a series resonant circuit and appear like a short circuit and at the other point it will be a parallel (high impedance) circuit: -

enter image description here

See also this tutorial from Maxim - it contains the basic electrical model of a pizeo and note its similarity with a regular crystal: -

enter image description here

\$\endgroup\$
4
  • \$\begingroup\$ I see this graph alot , and I've never really understood it. Thanks , I'll have a good dig through the references you've given me. Thanks a lot. The reference you provided paper is fantastic. \$\endgroup\$
    – Saif
    Commented Nov 11, 2015 at 13:05
  • \$\begingroup\$ Is it possible to conclude from the paper referenced above that electrical impedance is in fact at minimum, when the piezo disc is vibrating at its fundamental resonant frequency (or any frequency of its resonance series for this matter). Anti-resonance = opposite of resonant frequency, where piezo disc vibrates least, therefore at its maximum electrical impedance. Have I gotten this wrong? this is what I got from your answer. \$\endgroup\$
    – Saif
    Commented Nov 11, 2015 at 22:29
  • \$\begingroup\$ both mechanically resonate. \$\endgroup\$
    – Andy aka
    Commented Nov 11, 2015 at 22:42
  • \$\begingroup\$ @Saif - have you put any music in the public domain yet? \$\endgroup\$
    – Andy aka
    Commented Nov 12, 2015 at 18:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.