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US4985926A Expired / Lapsed US ⏱️ 0.0 years remaining

High impedance piezoelectric transducer

Assignee: CTS Corp
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Filing: 1988-02-29
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Granted: 1991-01-15
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Expires: 2008-02-29
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Abstract

Abstract An improved bimorph piezoelectric transducer provides higher input impedance and allows operation at higher operating voltages. First and second piezoelectric elements have opposing electrode patterns which define a plurality of capacitors connected in series. This allows such transducers to be directly connected to high voltage audio distribution systems without the need for an impedance matching circuit.

Inventors

  • 👤 Richard G. Foster

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 16:23
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0607; B06B1/0622; B06B1/0625; H; H04; H04R; H04R17/00

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 96 words
A transducer comprising: a first piezoelectric element having first and second major surfaces; a second piezoelectric element having third and fourth major surfaces; means for forming at least two piezoelectric members having capacitance characteristics on each of said first and second piezoelectric elements so that all of said members on each of said elements are electrically in series; and means for connecting one of said members on said first element to one of said members on said second element to form an equivalent series electrical circuit, said members oriented to maximize physical deflection of said elements.
Claim 2
Dependent Claim 96 words
A transducer comprising: a first piezoelectric element having first and second major surfaces; a second piezoelectric element having third and fourth major surfaces; means for forming at least two piezoelectric members having capacitance characteristics on each of said first and second piezoelectric elements so that all of said members on each of said elements are electrically in series; and means for connecting one of said members on said first element to one of said members on said second element to form an equivalent series electrical circuit, said members oriented to maximize physical deflection of said elements.
Claim 3
Dependent Claim 30 words
The transducer according to claim 1 wherein said forming means comprises at least two annular separated electrodes on each of said major surfaces of said first and second piezoelectric elements.
Claim 4
Dependent Claim 33 words
The transducer according to claim 2 wherein at least one of the annular electrodes on the second and third surfaces overlap portions of said two electrodes on the first and fourth surfaces, respectively.
Claim 5
Dependent Claim 87 words
The transducer according to claim 3 wherein said at least one annular electrode on the second surface is disposed opposite said at least one annular electrode on said third surface, and said connecting means comprises a wafer disposed contiguously between said second and third surfaces, said wafer being nonconductive except for a conductive portion between said at least one electrode on said second and third surfaces thereby providing a direct connection between said one capacitor on said first element and said one member on said second element.
Claim 6
Dependent Claim 14 words
The transducer according to claim 1 further comprising a diaphragm coupled to said transducer.
Claim 7
Dependent Claim 162 words
An audio distribution system comprising: a source of audio signals for generating a predetermined audio voltage; and a plurality of piezoelectric audio transducers having a predetermined power handling rating connected in parallel to said source, each of said transducers comprising: a first piezoelectric element having first and second major surfaces; a second piezoelectric element having third and fourth major surfaces; means for forming at least two piezoelectric members having capacitance characteristics on each of said first and second piezoelectric elements so that all of said members on each element are electrically in series; and means for connecting one of said members on said first element to one of said members on said second element to form an equivalent electrical circuit of said at least four members, in series having an input impedance sufficient to limit the power to the transducer to not greater than said predetermined power handling rating of said transducer, said members oriented to maximize physical deflection of said elements.
Claim 8
Dependent Claim 162 words
An audio distribution system comprising: a source of audio signals for generating a predetermined audio voltage; and a plurality of piezoelectric audio transducers having a predetermined power handling rating connected in parallel to said source, each of said transducers comprising: a first piezoelectric element having first and second major surfaces; a second piezoelectric element having third and fourth major surfaces; means for forming at least two piezoelectric members having capacitance characteristics on each of said first and second piezoelectric elements so that all of said members on each element are electrically in series; and means for connecting one of said members on said first element to one of said members on said second element to form an equivalent electrical circuit of said at least four members, in series having an input impedance sufficient to limit the power to the transducer to not greater than said predetermined power handling rating of said transducer, said members oriented to maximize physical deflection of said elements.
Claim 9
Dependent Claim 30 words
The system according to claim 6 wherein said forming means comprises at least two annular separated electrodes on each of said major surfaces of said first and second piezoelectric elements.
Claim 10
Dependent Claim 35 words
The system according to claim 7 wherein at least one of the annular electrodes on each of the second and third surfaces overlap portions of said two electrodes on the first and fourth surfaces, respectively.
Claim 11
Dependent Claim 88 words
The system according to claim 8 wherein said at least one annular electrode on the second surface is disposed opposite said at least one annular electrode on said third surface, and said connecting means comprises a wafer disposed continuously between said second and third surfaces, said wafer being nonconductive except for a conductive portion between said at least one annular electrode on said second and third surfaces thereby providing a direct connection between said one capacitor on said first element and said one member on said second element.
Claim 12
Dependent Claim 16 words
The system according to claim 6 further comprising a diaphragm coupled to each of said transducers.
Claim 13
Dependent Claim 54 words
A transducer comprising: a first piezoelectric element having first and second major surfaces; and means for forming at least two piezoelectric members having capacitance characteristics on said first piezoelectric element so that all of said members on said element are electrically in series and all are oriented to maximize physical deflection of said element.
Claim 14
Dependent Claim 54 words
A transducer comprising: a first piezoelectric element having first and second major surfaces; and means for forming at least two piezoelectric members having capacitance characteristics on said first piezoelectric element so that all of said members on said element are electrically in series and all are oriented to maximize physical deflection of said element.
Claim 15
Dependent Claim 28 words
The transducer according to claim 11 wherein said forming means comprises at least two annular separated electrodes on each of said major surfaces of said first piezoelectric element.
Claim 16
Dependent Claim 27 words
The transducer according to claim 12 wherein at least one of the annular electrodes on the second surface overlaps portions of two electrodes on said first surface.
Claim 17
Dependent Claim 14 words
The transducer according to claim 11 further comprising a diaphragm coupled to said transducer.
Claim 18
Dependent Claim 25 words
The transducer according to claim 11 wherein said forming means comprises at least two separated electrodes on each of the major surfaces of said element.

References Cited (Backward Citations)

US3093775A Cited
US3253199A Cited
US3292063A Cited
US3548116A Cited
US3493825A Cited
US3745431A Cited
US3894198A Cited
US4078160A Cited
US4389548A Cited
US4401857A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-01-14 1994-07-16 1995-01-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-01-14 1998-07-16 1999-01-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-01-14 2002-07-16 2003-01-15 $7700.00 Window Closed / Lapsed

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