Question
Sun November 18, 2012 By: Juli
 

please give me some details for my physics project for boards on transducers.

Expert Reply
Sun November 18, 2012
You can analyze  tone from its conception through
amplification to understand how the mechanical vibrations created in guiter string become electrical signals which can be fed into  speaker.
Or can make your own electric guiter/musical instrument.
 
When its steel strings are plucked, their intense energy of vibration is absorbed by
the wood of the guitar at the bridge and headstock. The frequency of the vibrations is
preserved, and the guitar body accepts this energy with a strong frequency response. This
means that string vibrations that agree with the structural resonance frequencies of the
guitar body make the guitar’s wood components also vibrate with the same frequencies.
When these special resonance frequencies are excited, the air inside the body cavity
undergoes pressure changes and radiates a travelling pressure wave of said frequencies
from the guitar’s sound hole. Therefore, notes played within the resonant frequency
range will be fuller, richer, and louder than notes that do not excite the guitar body.
 
two experiments to investigate these resonant frequencies. The first
test used a piezoelectric transducer to excite the guitar bridge and then a second
piezoelectric to pick up those excitements elsewhere on the face of the guitar.
Piezoelectrics have the property that alternating currents cause the material to vibrate

with the frequency of those current alternations. This transducer was planted directly
onto the sound board beside the bridge with a small weight to attempt to couple the
vibration to the sound board.
can see:
http://courses.physics.illinois.edu/phys406/Student_Projects/Spring09/John_Alsterda/J_Alsterda_Phys498POM_Spring09_Final_Report.pdf
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