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Designing a variable-frequency ultrasonic wave generator

  1. Mar 6, 2015 #1
    Hello everyone! Seeing as this is my first post, I'll give you a basic background of who I am: My name is Andrew Raisbeck; I graduated from university with a Bachelor of Computing (Computer Science) degree a little over a year ago, and I now work full-time for the government of Canada. Since I am not an electronic engineer by trade, I apologize in advance if this question is a little more basic (or I'm a little more obtuse) then average!

    I love my current job, but I have the spirit of an entrepeneur... and I have come up with a product idea - one that requires I generate ultrasonic waves of a variable frequency (the variable frequency is just required for testing and development... the end product may vary well have a fixed frequency).

    Since I have very little knowledge of advanced electronics/circuits, I have had to do a lot of independent research; so far, I have determined that I will require the following (to complete a prototype for my idea):

    1. One or two Piezoelectric transducers (simply to generate ultrasonic waves... I do not require the ability to "listen" for their echo). Here is a set of transducers that I believe would work for my project.

    2. A variable-frequency wave generator (to send electronic signals of a controllable frequency to the piezoelectric transducer(s) in order to generate the ultrasonic waves). I believe this product is along the lines of what I am looking for, but I wouldn't mind something even more compact and stripped down.

    So! Basically, I just want to know if I am going about this the right way, or if I am completely misunderstanding the physics of what I am trying to do. I want to generate the ultrasonic waves with a piezoelectric transducer instead of a purpose-built ultrasonic transducer simply because it seems way more cost effective to buy the former instead of the latter. Will I be able to generate ultrasonic waves with the transducers that I linked to above? If not, how come? What issues (if any) might I run into by not using a purpose-built ultrasonic transducer? Finally, if I buy a piezoelectric transducer clocked at 3Mhz, is that simply the upper-limit of the wave frequencies it can produce? In other words, would I be able to product waves of a lower frequency with it by simply altering the frequency of the alternating current flowing to it?

    Thanks in advance for any advise and/or tips that you can provide me with! I really appreciate it. This is a totally new - and exciting - field of interest for me, and I want to really dive into this stuff head-on.
  2. jcsd
  3. Mar 6, 2015 #2
    Also, if anyone has any suggestions for better ways to procure the parts I need (and other electrical components for that matter), please let me know!
  4. Mar 6, 2015 #3


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    Staff: Mentor

    Welcome to the PF.

    What frequency range do you want to cover with your test prototype? Piezo transducers typically are narrow-band, working best at their resonant frequency. The one you linked to above looks to be a narrow-band transducer.

    I did a Google Images search on broadband piezoelectric transducer, and got some good hits. I think the first thing you should do (if you haven't already) is do some research into broadband piezo transducers, and see what they are typically driven by. How much output power are you thinking you will need? Have you done some reading on the human safety aspects of working with ultrasound? :smile:
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