updated 2010-05-27.


Nifty things to do with ultrasonic transducers: ultrasonics and sonar

See also music.html

woefully incomplete ...

Acoustic stuff. Medical ultrasonics, simple distance measurement measurements ("sonar"), noise-cancellation, etc.


introductions to ultrasonics; beginner tutorials.

  • An Introduction to Ultrasonics Technology http://www.shahlimar.com/ultrasonics/ ``By Kathi Graham, September 1999''. Also has lots of links to more specific information.
  • Introduction to Ultrasonic Testing (UT) http://www.cnde.iastate.edu/ncce/UT_CC/ can get pretty technical.

    Interfacing to the Polaroid 6500 Sonar

    David Cary:

    I've been playing with some Polaroid sonar modules (including the 6500 Sonar Module). They work for me.

    I only needed to hooked up 4 wires to the module:

     +5V----->[1 TL851 ]
     -init--->[14     9]-----> +echo
     gnd----->[3       ]

    (all the relevant digital signals are on the "digital chip" TL851; I got the exact pin numbers from the free fax-back service Polaroid http://www.polaroid-oem.com has at 800 392 1170. . That chip is also in Texas Instruments _Data Book Volume 3: Linear Circuits:...Special Functions_. ) /* was some information at http://www.netwales.co.uk/ubiquity/polaroid/american/pdf.htm but this seems to be offline */

    I hooked a square-wave function generator to the /init line, set it to a couple of pulses per second, and looked at everything with my o'scope.

    When the box sees the -init line go high, the box sends out a pulse (I can hear the chirp). A short time later the box pulls the +echo line high. Then it is absolutely quiet. Then I pull -init low ... until the next time I pull -init high, telling it to chirp again.

    Is your +5V power supply working OK ? Perhaps the sonar module pulled a spike of power so large that your power supply couldn't handle it and shut down, resetting your cpu.... over and over. Perhaps your -init signal is not properly connected, causing lots of oscillations that continuously ping the transducer.

    A o'scope makes it a lot easier to debug any problems.

    magazine articles about ultrasonic stuff


    where to buy ultrasonic stuff.

    Includes "ultrasonic modules" (including drive circuit) and the raw transducers.

    DAV has played a little with the "Polaroid 6500 Series Module and 600 Series Transducer" kit, which seems to be the de-facto standard ultrasonic system for hobbyists. Note that besides the standard transducer, there are also lots of other 600 Series Transducers that can plug directly into that board (some are a lot more rugged, designed for outdoor in-the-rain applications).

    This is known to be incomplete; please help me complete it. Who sells the ultrasonic arrays used in medical applications ?


    noise cancellation






    Original Author: David Cary.

    This page started: 1996 Aug 8 and has backlinks

    known by AltaVista

    known by Yahoo!

    known by infoseek

    Send comments, suggestions, errors, bug reports to

    David Cary feedback.html

    Return to index // end http://rdrop.com/~cary/html/ultrasonic.html