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Showing papers on "Bimorph published in 1971"


Journal ArticleDOI
TL;DR: In this paper, a bending response is obtained from a sandwich-like structure of two properly oriented piezoelectric expander plates, referred to as a bender Bimorph®.
Abstract: Although flexurally responsive piezoelectric elements have been utilized for a few decades, interest in their utility remains high. This is a result of the ability of such structures to generate high output from sources of low mechanical impedance, or conversely, to develop large displacement at low levels of electrical excitation. Typically, a bending response is obtained from a sandwich-like structure of two properly oriented piezoelectric expander plates in which case the unit is referred to as a bender Bimorph®. However, other approaches to benders include the unimorph, the Multimorph®, and other specially treated single-plate elements. Numerous applications utilizing bender responsive elements exist. To aid in meeting the variety of requirements presented by these applications, the supplier has available to him many options. These variables include choice of materials, geometry, and electrode configuration. In terms of volume of usage, the phonograph cartridge remains the number one application. However, many other electroacoustical devices are made possible by the availability of the Bimorph or its modified alternates. Some of these are indicated. In addition, the utility of the equivalent circuit and its constants are described.

88 citations


Journal ArticleDOI
TL;DR: In this article, the utility of the equivalent circuit and its constants are described, as well as its utility in terms of volume of usage, the phonograph cartridge remains the number one application, and many other electroacoustical devices are made possible by the availability of the Bimorph or its modified alternates.
Abstract: Although flexurally responsive piezoelectric elements have been utilized for a few decades, interest in their utility remains high. This is a result of the ability of such structures to generate high output from sources of low mechanical impedance, or, conversely, to develop large displacement at low levels of electrical excitation. Typically a bending response is obtained from a sandwichlike structure of two properly oriented piezoelectric expander plates in which case the unit is referred to as a bender Bimorph. However, other approaches to benders include the Unimorph, the Multimorph, and other specially treated single plate elements. Numerous applications utilizing bender elements exist. To aid in meeting the variety of requirements presented by these applications, the supplier has available to him many options. These variables include choice of materials, geometry, and electrode configurations. In terms of volume of usage, the phonograph cartridge remains the number one application. However, many other electroacoustical devices are made possible by the availability of the Bimorph or its modified alternates Some of these are indicated. In addition, the utility of the equivalent circuit and its constants are described.

37 citations


Patent
Hugo W Schafft1
15 Apr 1971
TL;DR: In this article, the stiffness of the assembly varies in proportion to the magnitude of the bending force applied to the bender and by bending the wafers to conform to the shape of the center vane, increased coefficient of electromechanical coupling, strength, high frequency response, and linearity result.
Abstract: Bimorph benders comprised of a pair of piezoelectric wafers with a center vane of conductive material disposed therebetween or monomorph benders comprised of one piezoelectric wafer and one wafer of piezoelectrically inactive material with a center vane of conductive material disposed therebetween have one portion rigidly held in place and another portion coupled to move or be moved by a mechanical load thereby applying a distribution of bending forces to the bender. By selectively constructing the center vane so that the stiffness of the assembly varies in proportion to the magnitude of the bending force applied to the bender and by bending the wafers to conform to the shape of the center vane, increased coefficient of electromechanical coupling, strength, high frequency response, and linearity result.

17 citations


Journal ArticleDOI
TL;DR: In this article, the linear, three-dimensional, piezoelectric equations for a body in equilibrium are reduced to approximate, two-dimensional ones, treating the flexure of thin bimorphs, partly coated by electrodes (incomplete bimomorphs).
Abstract: In this paper the linear, three-dimensional, piezoelectric equations for a body in equilibrium are reduced to approximate, two-dimensional ones, treating the flexure of thin bimorphs, partly coated by electrodes (incomplete bimorphs). For that purpose two-dimensional equations are derived for piezoelectric plates and for bimorphs with completely coated faces. An assumption about the charge distribution on the inner electrode is given, stating that the charge vanishes on those parts where the outer faces are free of electrodes. This assumption allows the application of the mentioned, approximate equations for plates and bimorphs to the parts of incomplete bimorphs. By stating edge and continuity conditions, the approximate theory ls completed. The solution for a circular, incomplete, piezoceramic bimorph, loaded by a singular force in the centre, is given and compared with experimental results.

12 citations


Patent
A Moore1
03 Nov 1971
TL;DR: In this paper, an instrument for electrically measuring pressure changes having a circular bimorph and a thin flexure consisting of iron-nickel alloy supporting the circular Bimorph at its circumference and said flexure having its outer extremity adapted to support said bimomorph in a pressure cell comprising iron-Nickel alloy, whereby a high electrical output is obtained from the said bimmer in response to pressure being applied thereto.
Abstract: An instrument for electrically measuring pressure changes having a circular bimorph and a thin flexure comprising iron-nickel alloy supporting the circular bimorph at its circumference and said flexure having its outer extremity adapted to support said bimorph in a pressure cell comprising iron-nickel alloy, whereby a high electrical output is obtained from the said bimorph in response to pressure being applied thereto.

7 citations


01 Jan 1971
TL;DR: In this paper, a bending response is obtained from a sandwich-like structure of two properly oriented piezoelectric expander plates in which case the unit is referred to as a bender Bimorph@.
Abstract: Although flexurally responsive piezoelectric elements have been utilized for a few decades, interest in their utility remains high. This is a result of the ability of such structures to generate high output from sources of low mechanical impedance, or conversely, to develop large displacement at low levels of electrical excitation. Typically, a bending response is obtained from a sandwich-like structure of two properly oriented piezoelectric expander plates in which case the unit is referred to as a bender Bimorph@. However, other approaches to benders include the unimorph, the Multimorph@, and other specially treated single-plate elements. Numerous applications utilizing bender responsive elements exist. To aid in meeting the variety of requirements presented by these applications, the supplier has available to him many options. These variables include choice of materials, geometry, and electrode configuration. In terms of volume of usage, the phonograph cartridge remains the number one application. However, many other electroacoustical devices are made possible by the availability of the Bimorph or its modified alternates. Some of these are indicated. In addition, the utility of the equivalent circuit and its constants are described.