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<div class="moz-cite-prefix">Try a AD7822 for a start.</div>
<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">Here is an article from Maker Pro
talking about such a circuit:</div>
<div class="moz-cite-prefix"><i>How to Make a Circuit That Detects
High Frequencies: The Bat Detector!</i>:</div>
<div class="moz-cite-prefix"><a class="moz-txt-link-freetext" href="https://maker.pro/pcb/projects/how-to-build-your-own-bat-detector">https://maker.pro/pcb/projects/how-to-build-your-own-bat-detector</a></div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">Also check out: <i>A Simple Bat
Detector based shield for the Arduino Uno ...</i><br>
</div>
<div class="moz-cite-prefix"><a class="moz-txt-link-freetext" href="https://duino4projects.com/simple-bat-detector-based-shield-arduino-uno/">https://duino4projects.com/simple-bat-detector-based-shield-arduino-uno/</a></div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">Nuts & Volts Magazine explored bat
detector circuits:</div>
<div class="moz-cite-prefix"><i>Build A Bat Detector</i>:
<a class="moz-txt-link-freetext" href="https://www.nutsvolts.com/magazine/article/june2011_berber">https://www.nutsvolts.com/magazine/article/june2011_berber</a><br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">There was an article in Elektor
Magazine of such a circuit:<br>
</div>
<div class="moz-cite-prefix"><i>Bat detector with amplitude
recovery: The main features and specifications are:</i></div>
<div class="moz-cite-prefix"><i>hybrid analogue and digital
circuitry, low current consumption - less than 5 mA</i></div>
<div class="moz-cite-prefix"><i>in standby, selectable division
ratio, etc.</i>:</div>
<div class="moz-cite-prefix"><a class="moz-txt-link-freetext" href="https://www.elektormagazine.com/labs/bat-detector-with-amplitude-recovery">https://www.elektormagazine.com/labs/bat-detector-with-amplitude-recovery</a></div>
<div class="moz-cite-prefix">plus a user reviewing the circuit:
<a class="moz-txt-link-freetext" href="http://www.speleogroup.org/Bat_detector.html">http://www.speleogroup.org/Bat_detector.html</a><br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">and previously
<a class="moz-txt-link-freetext" href="https://www.elektormagazine.com/magazine/elektor-201607/29128">https://www.elektormagazine.com/magazine/elektor-201607/29128</a></div>
<div class="moz-cite-prefix">and an older version
<a class="moz-txt-link-freetext" href="https://www.elektormagazine.com/magazine/elektor-199504/33298">https://www.elektormagazine.com/magazine/elektor-199504/33298</a></div>
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<div class="moz-cite-prefix">The preamplifier circuit you would need
prior to the ADC is described here:</div>
<div class="moz-cite-prefix"><a class="moz-txt-link-freetext" href="https://www.elektormagazine.com/magazine/elektor-141/57147">https://www.elektormagazine.com/magazine/elektor-141/57147</a><br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">And they even made a kit available:
<a class="moz-txt-link-freetext" href="https://www.elektor.com/bat-detector-kit">https://www.elektor.com/bat-detector-kit</a></div>
<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">There's some thoughts in the All About
Circuits forums using the right ADCs:</div>
<div class="moz-cite-prefix"><i>Bat Detector Design</i>:
<a class="moz-txt-link-freetext" href="https://forum.allaboutcircuits.com/threads/bat-detector-design.33210/">https://forum.allaboutcircuits.com/threads/bat-detector-design.33210/</a><br>
</div>
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<div class="moz-cite-prefix">On 10/26/20 5:35 PM, Martin Brooke via
TriEmbed wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CALjzumroJmpeFF8aRh_9JCL52Vu+n-CY88_FDpprNYCA=O_-Sg@mail.gmail.com">
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<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small">I
wish for a high data rate 16-18 bit ADC module like this <a
href="https://www.adafruit.com/product/1085"
moz-do-not-send="true">https://www.adafruit.com/product/1085</a></div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small">maybe
using I2S to get the data rate up to where it would work for
ultrasound </div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small">192
ksps or higher would be ideal.</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small">If
it would work with a modern higher clock rate arduino or a RPi
that would be perfect.</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small">I
would deploy them to record sounds of bats in the rainforest
canopy and collect the data with WiFi.</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small">There
would be many other uses. Hydrophones, HiFi recording, </div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small">Right
now the gear to do this is really expensive </div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><a
href="https://www.wildmountainechoes.com/equipment/options-for-recording-ultrasounds/"
moz-do-not-send="true">https://www.wildmountainechoes.com/equipment/options-for-recording-ultrasounds/</a><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif;font-size:small"><br>
</div>
</div>
</blockquote>
<p><br>
</p>
<pre class="moz-signature" cols="80">--
Scott G. Hall
Raleigh, NC, USA
<a class="moz-txt-link-abbreviated" href="mailto:ScottGHall1@GMail.Com">ScottGHall1@GMail.Com</a>
<i>Although kindness is rarely a job, no matter what you do it's always an option.</i>
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