Tech Break 3764

Build an Arduino driven dog deterrent.​

-- Joseph LaBonde        
"Does anyone have a suggestion for an Arduino driven speaker that can produce 23Khz-40Khz?
I am setting up a motion sensor dog deterrent."    
        
What you need is NOT a speaker, but a Piezoelectric Transducer!        
* 40Khz (35 Watt)        
        
NB: The "Piezoelectric Effect" is the phenomenon that occurs when a mechanical stress is applied to certain materials, resulting in an electric charge.        
* Timing crystals (components) utilize this effect: They are "Crystal Oscillators" -- When a crystal (like quartz) is packaged in such a way as to compress the crystal, it will provide a stable "clock signal" for our digital IC projects.         
* The effect can be REVERSED: If I run an electrical charge through a piezoelectric material, it will create a mechanical stress.        
* In transducers, this mechanical stress become vibrations that in turn create sound waves.        

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