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Electroacoustic transducer

  • US 4,751,418 A
  • Filed: 09/19/1986
  • Issued: 06/14/1988
  • Est. Priority Date: 09/20/1985
  • Status: Expired due to Term
First Claim
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1. An electroacoustic transducer, comprising:

  • a diaphragm which is vibrated by sound waves for producing an acoustic signal;

    a first piezoelectric element disposed on said diaphragm for converting said acoustic signal to an electric signal, said first piezoelectric element having a first electrode and a second electrode;

    a differential amplifier for amplifying said electric signal, said differential amplifier having a pair of input terminals;

    said first electrode being connected to first one of said input terminals;

    a reference voltage source connected to said second electrode; and

    a second piezoelectric element separate from said first piezoelectric element, and disposed on said diaphragm, said second piezoelectric element having a third electrode connected to said reference voltage soure, and a fourth electrode connected to a second one of said input terminals, said second piezoelectric element having substantially the same impedance as said first piezoelectric element, and said third electrode generating an electric potential of the same polarity as that of said first electrode in response to generation of said acoustic signal.

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