Abstract: An insulated sounder assembly may include: a) a sounder cup having a bottom and a sidewall; b) a piezoelectric element positioned in the bottom of the cup; c) a potting layer within the sounder cup and spaced apart from the piezoelectric element so that the potting layer contacts the cup sidewall for a distance of at least 3 mm around the entire circumference of the cup, and so that a gap exists between the piezoelectric element and the potting layer, with the gap being sufficient to allow vibration of the piezoelectric element in the sounder cup without restriction by the potting layer; and d) an electrical contact wire attached to the piezoelectric element to provide a voltage to the piezoelectric element, wherein the electrical contact wire passes through the potting layer so that at least 3 mm of bare wire is completely embedded in said potting layer.

Abstract: A buzzer includes a piezoelectric diaphragm and a housing enclosing the diaphragm and defining a resonating chamber. The chamber includes a sound port and has an optimal resonating frequency fHt at a temperature T defined by fHt=(vt/2?)(?(A/voL)) were vt is the velocity of sound waves in air at a temperature T, A is the effective area of the sound port, vo is the volume of the resonating chamber, and L is the effective length of the sound port. A temperature compensating member moves in response to changes in temperature to change the value of ?(A/voL) at a rate and in a manner that balances the change in 1/vt across that same temperature range, thereby reducing changes in the product (vt/2?)(?(A/voL)) and consequently reducing any changes that would otherwise occur in fHt across that temperature range, thereby holding the value of fH substantially constant across the temperature range.

Abstract: A PZT-type piezoelectric ceramic material having a perovskite structure of the ABO3 type. The stoichiometric ratio of AB is 1:1, with the “A” component being Pb1-zSrz and the “B” component being (Mn1/3Sb2/3)x(ZryTi1-y)1-x. Z is between 0.02 and 0.03, x is between 0.03 and 0.07, and y is between 0.40 and 0.60. The material further comprises dopants, with the dopants comprising Ce, Cu, and Nb dopants, with each of the Ce, Cu, and Nb dopants being provided in an amount of up to 2 wt. %, with the combined amount of the Ce, Cu, and Nb2 dopants being between 1 wt. % and 4 wt. %. Methods for preparing the PZT ceramic materials by combining oxides of Pb, Sr, Mn, Sb, Zr, Ti, Nb, Cu, and Ce and calcining the combined oxides so as to produce a PZT composition of the stated formula are also disclosed.

Abstract: A pressure-compensated transducer assembly has an inner housing with a closed transducer end and an outer housing with an open transducer end. A piezoelectric assembly is in the closed transducer end of the inner housing. A liquid-filled inter-housing space is between the outer housing and the inner housing, and has a transducer end open to the environment and a connection end open to the piezo assembly space. A blocking member separates the transducer end of the inter-housing space from the connection end, and prevents fluids from flowing between the two ends. The blocking member is movable within the inter-housing space in response to pressure differences the environment and the interior space.

Abstract: A class of ceramic compositions according to the formula Pb(1-z)Mz(Mn1/3Sb2/3)x(ZryTi1-y)1-xO3 where M is selected to be either Sr or Ba, x is selected to be between 0.01 and 0.1, y is selected to be between 0.35 and 0.55, and z is selected to be between 0.01 and 0.10. In some embodiments of the above composition, one or more dopants is added to the compositions. The dopant(s) may be selected from the group comprising: PbO, CeO2, SnO2, Sm2O3, TeO2, MoO3, Nb2O5, SiO2, CuO, CdO, HfO2, Pr2O3, and mixtures thereof. The dopants can be added to the ceramic composition in individual amounts ranging from 0.01 wt % to up to 5.0 wt %. The preferred ceramic compositions exhibit one or more of the following electromechanical properties: a relative dielectric constant (?) of between 1200 and 2000, a mechanical quality factor (Qm) of between 1500 and 2800; a piezoelectric strain constant (d33) of between 250-450 pC/N, a dielectric loss factor (tan ?) of between 0.002-0.

Abstract: Piezoelectric ceramics of the formula Pb(1-z)Mz(Mg1/3Nb2/3)x(ZryTi1-y)1-xO3 where M can be either Sr or Ba or both, and x is between 0.3 and 0.6, y is between 0.2 and 0.5, and z is between 0.04 and 0.08, wherein y=0.551?0.539x?0.593x2. The piezoelectric ceramic is provided as a composite perovskite structure, and may additionally include materials or dopants such as: PbO, HfO2, TeO2, WO3, V2O5, CdO, Tm2O3, Sm2O3, Ni2O3, and MnO2. The piezoelectric ceramics can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.

Abstract: A piezoelectric buzzer includes a vibrating layer capable of withstanding temperatures in excess of 260° C. for at least five minutes while still maintaining its ability to vibrate and produce a buzzing sound at a level of at least 80 dB, and a high temperature piezoelectric material having a Curie temperature in excess of 260° C. and one or more of the following properties: a planar coupling coefficient (kp) of at least about 0.5; a longitudinal coupling coefficient (k33) of at least about 1500; and a mechanical quality factor (Qm) of at least about 2000. The piezo material may have a combination of these properties such that the product (kp2)(k33)(Qm) is at least about 1.5×106. The piezoelectric material may have a base formula of PbxSr(1-x)(Mn1/3Sb2/3)(1-y)(ZrzTi1-z)yO3 with x ranging from 0.95 to 0.99, y ranging from 0.92 to 0.97, and z ranging from 0.45 to 0.55, and may further include dopants in the amounts of about 0.4% CeO2, about 1% CuO, and about 4% Nb2O5.

Abstract: Piezoelectric compositions of the formula Pb(1-z)Mz(Mg1/3Nb2/3)x(ZryTi1-y)1-xO3 where M can be either Sr or Ba or both, x is between about 0.35 and about 0.40, y is between about 0.36 and about 0.42, and z is between about 0.04 and about 0.08. The piezoelectric ceramic is provided as a composite perovskite structure. Additional materials or dopants can be added to the piezoelectric ceramic of the present invention. Example of dopants that can be added to the piezoelectric ceramic include, but are not limited to: MnO2, Ni2O3, TeO3, TeO2, MoO3, Nb2O5, Ta2O5, CoCO3, and Y2O3. The piezoelectric ceramics of the present invention can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.

Abstract: A class of ceramic compositions according to the formula Pb(1-z)Mz(Mn1/3Sb2/3)x(ZryTi1-y)1-xO3 where M is selected to be either Sr or Ba, x is selected to be between 0.01 and 0.1, y is selected to be between 0.35 and 0.55, and z is selected to be between 0.01 and 0.10. In some embodiments of the above composition, one or more dopants is added to the compositions. The dopant(s) may be selected from the group comprising: PbO, CeO2, SnO2, Sm2O3, TeO2, MoO3, Nb2O5, SiO2, CuO, CdO, HfO2, Pr2O3, and mixtures thereof. The dopants can be added to the ceramic composition in individual amounts ranging from 0.01 wt % to up to 5.0 wt %. The preferred ceramic compositions exhibit one or more of the following electromechanical properties: a relative dielectric constant (?) of between 1200 and 2000, a mechanical quality factor (Qm) of between 1500 and 2800; a piezoelectric strain constant (d33) of between 250-450 pC/N, a dielectric loss factor (tan ?) of between 0.002-0.

Abstract: Piezoelectric ceramics of the formula Pb(1-z)Mz(Mg1/3Nb2/3)x(ZryTi1-y)1-xO3 where M can be either Sr or Ba or both, and x is between 0.3 and 0.6, y is between 0.2 and 0.5, and z is between 0.04 and 0.08. The piezoelectric ceramic is provided as a composite perovskite structure, and may additionally include materials or dopants such as: PbO, HfO2, TeO2, WO3, V2O5, CdO, Tm2O3, Sm2O3, Ni2O3, and MnO2. The piezoelectric ceramics can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.

Abstract: This invention relates to a piezoelectric ceramic of the formula Pb(1?z)Mz(Mg1/3Nb2/3)x(ZryTi1?y)1?xO3 where M can be either Sr or Ba or both and x is in between about 0.1 and about 0.7, y is between about 0.2 and about 0.7, and z is between about 0.02 and about 0.1 and to method for preparing the piezoelectric ceramic. The piezoelectric ceramic is provided as a composite perovskite structure. Additional materials or dopants can be added to the piezoelectric ceramic of the present invention. Example of dopants that can be added to the piezoelectric ceramic include, but are not limited to: MnO2, Ni2O3, TeO3, TeO2, MoO3, Nb2O5, Ta2O5, CoCO3, and Y2O3. The piezoelectric ceramics of the present invention can be used to fabricate piezoelectric elements for a wide variety of devices that can be fabricated to exhibit high power applications including miniaturized displacement elements, buzzers, transducers, ultrasonic sensors and ultrasonic generators, and the like.