US3716828A - Electroacoustic transducer with improved shock resistance - Google Patents
Electroacoustic transducer with improved shock resistance Download PDFInfo
- Publication number
- US3716828A US3716828A US00007606A US3716828DA US3716828A US 3716828 A US3716828 A US 3716828A US 00007606 A US00007606 A US 00007606A US 3716828D A US3716828D A US 3716828DA US 3716828 A US3716828 A US 3716828A
- Authority
- US
- United States
- Prior art keywords
- elements
- transducer elements
- transducer
- external peripheral
- plate members
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000035939 shock Effects 0.000 title description 8
- 239000000919 ceramic Substances 0.000 claims abstract description 43
- 230000002093 peripheral effect Effects 0.000 claims description 23
- 239000000463 material Substances 0.000 claims description 16
- 239000003365 glass fiber Substances 0.000 claims description 7
- 229910010293 ceramic material Inorganic materials 0.000 claims description 6
- 239000004593 Epoxy Substances 0.000 claims description 5
- 239000007767 bonding agent Substances 0.000 claims description 4
- 239000004020 conductor Substances 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 230000010355 oscillation Effects 0.000 claims description 4
- 241000557876 Centaurea cineraria Species 0.000 claims description 3
- 239000011152 fibreglass Substances 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 229920006333 epoxy cement Polymers 0.000 claims description 2
- 229910001220 stainless steel Inorganic materials 0.000 claims description 2
- 239000010935 stainless steel Substances 0.000 claims description 2
- 238000010276 construction Methods 0.000 description 4
- 239000004568 cement Substances 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 230000005226 mechanical processes and functions Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012811 non-conductive material Substances 0.000 description 1
- 238000004382 potting Methods 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0611—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements in a pile
- B06B1/0618—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements in a pile of piezo- and non-piezoelectric elements, e.g. 'Tonpilz'
Definitions
- An electromechanical transducer assembly comprises 'a stacked group of axially aligned piezoelectric ceramic rings. Plates, which have a larger diameter than the ceramic rings, are positioned between each of the adjoining faces of the ceramic rings. Therefore, the edges of the plates extend outwardly beyond the periphery of the ceramic rings. A tape or filament is tightly wound about the rim of each ceramic ring to maintain a radial stress upon the ceramic elements.
- transducers generally incorporate a number of electromechanical transducers elements interposed between a vibratile plate member of diaphragm or piston plate and an inertial support.
- the transducer elements are piezoelectric rings positioned in endto-end relationship. When an electrical oscillating signal is applied to these elements, they compress and expand to cause a corresponding vibratile movement of the piston member.
- This invention provides an additional degree of shock protection to the improved transducer construction described in U.S. Pat. No. 3,474,403.
- an object of the invention is to provide new and improved piezoelectric transducers with greatly improved shock resistant construction.
- an object is to provide such a transducer which is much more economical to build than those which were constructed heretofore.
- Another object of the invention is to provide a transducer using a plurality of piezoelectric ceramic elements.
- an object is to provide multi-element transducers having circumferentially compressive stressed ceramic elements.
- a transducer enclosed in a rigid housing terminating a waterproof cable.
- a transducer assembly having a plurality of axially aligned piezoelectric ceramic rings or disc-shaped elements separated by metallic plates.
- the plates extend radially beyond the rim surface of the ceramic, thereby forming flanges to make a bobbinlike structure.
- a tape or filament of material, such as fiberglass, is tightly wound upon the rims of the ceramic elements and between flanges formed by the plates. This way, the ceramic rings may be compressively stressed in a more uniform manner.
- FIG. 1 is a cross-sectional view of one embodiment of the invention which incorporates an underwater transducer incorporating .a stack of ring-shaped piezoelectric elements;
- FIG. 2 is a cross-sectional view of a bobbin-like structure comprising the stack of ring-shaped piezoelectric elements with a filament tape tightly wound between flange plates which project outwardly from the rims of the ceramic elements;
- FIG. 3 is a perspective view of a single piezoelectric element taken from the stack of FIG. 2;
- FIG. 4 is a cross-sectional view showing a second embodiment of the invention incorporating another type of polarized ceramic element.
- FIG. 5 is a perspective view of a single piezoelectric element taken from the stack of FIG. 4.
- FIG. 1 A fully assembled underwater transducer is shown in FIG. 1.
- the major elements of this transducer are a rigid housing 12, a stack of piezoelectric elements 13, a transformer 14, a waterproof covering 15 and a waterproof cable 16.
- the housing 12 encloses the nonradiating portions of the transducer assembly comprising the transducer assembly 13, an inertial element 17, and a stress bolt 18.
- Behind the housing 12 and inside the waterproof covering 15 is a chamber 21 housing the coupling transformer 14, which is suspended in a suitably rigid potting compound.
- the completed transducer assembly comprises a plurality of axially aligned, piezoelectric ceramic rings 25 separated by metal flange plates 26.
- a vibratile plate piston or diaphragm 27 is positioned against one end of the piezoelectric ceramic stack 13 and the inertial element 17 is positioned against the other end of the stack.
- a mechanical attachment is accomplished by passing the stress bolt 18 through one or more Belleville springs 31, the inertial element 17, the ceramic stack 13, and piston 27. The bolt 18 is tightened to a point where a predetermined axial compressive stress is applied to the entire assembly.
- the inventive transducer element 13 may become more apparent from a study of FIGS. 2 and 3, which include part of FIG. 1 enlarged to show greater detail.
- the assembly is here shown as including four ring-shaped piezoelectric ceramic elements 25.
- Any suitable, well known, ceramic material may be used, such as leadzirconate-titanate, for example.
- These ring-shaped elements are polarized with the electrical field applied along their axial or thickness dimension. This polarization is indicated in the drawing by and signs.
- An electrode 29 is formed on each side of each ceramic ring 25, as shown in FIG. 3.
- the four ceramic rings 25 are aligned and stacked in a side-by-side relationship.
- the orientation is such that similar polarities are positioned next to each other.
- two positive electrodes come together when the first two and last two elements are placed next to each other.
- Two negative electrodes come together at the center of the stack.
- the two electrodes at the outside ends of the stack are negative.
- ring or disc-shaped plates 26 are placed between each pair of common electrodes and against the outside two electrodes. Further, an insulating disc 28 is placed on each of the opposite ends of the stack.
- the plates 26 have a diameter which is larger than the diameter of the ceramic rings. Therefore, each pair of plates 26, and the intermediate ceramic ring forms a bobbin-like structure. Or stated another way, the plates form circular ridges projecting outwardly beyond the ceramic surface.
- the plates 26 may be made of any suitable electrically conductive material such as a metal or a metaland outer surfaces of the plates are rounded to avoid edges. Primarily, this rounding serves the electrical function of reducing corona which might otherwise form at sharp edges during high power operation. The rounding provides the mechanical function of making a smoother device which is less likely to cut other materials during fabrication or operation.
- the stack is completed by the insulating discs 28 attached to the outer ends of the assembly.
- these insulating discs may be formed on the inside surface of the vibratile plate member or piston 27 and mass element 17.
- an electrically conductive cement such as an epoxy with silver dust, is first applied to the electrodes 29, and the mating surfaces of the plates 26. Then, the ceramic and plate elements are placed in axial alignment within a fixture or jig. A suitable mechanical clamp holds the structure together until the cement becomes rigid.
- Means are provided for applying a compressive radial stress, uniformly to each of the ceramic elements.
- the assembly 13 is placed on a lathe, bobbin winding machine, or the like. Then the outer periphery of each ceramic ring is tightly wrapped with a non-conductive material 33.
- This wrapping material may be any suitable tape or filament, such as a glass fiber.
- a bonding agent (such as epoxy) coats this wrapping material to consolidate it into a solid mass.
- the plates 26 form projections or barriers which act as a bobbin or coil form to contain the wrapping material. Known techniques may be used to distribute the wrapping material uniformly over the entire exposed ceramic surface. Finally, the positive plates are electrically joined by the wire 35 and the negative plates are joined by the wire 36. These wires may be soldered in place, and led through holes in the rigid housing 12 to a primary winding on the transformer 14.
- FIGS. 4 and 5 A second embodiment of the invention is shown in FIGS. 4 and 5. This embodiment may be used interchangeably with the structure 13 of FIGS. 2 and 3.
- two tubular ceramic piezoelectric elements 41 are placed end-to-end, axially aligned relationship, and bonded together, as by epoxy, for example.
- An electrode 42 is formed about the inside circumference of the ceramic tube and an electrode 43 is formed about the outside circumference of the ceramic tube. While any of many known methods may be used to form these electrodes, I prefer to use a fired silver.
- positive and negative potentials are applied to the electrodes 42, 43. Therefore, the material is polarized at right angles with respect to the axis of the cylinder.
- polarized ceramic tube After the bonded, polarized ceramic tube is completed, electrical conductors 46, 47 are soldered to the electrodes 42, 43, respectively. Then a wrapping material 48 is tightly and uniformly wound about the outside periphery of the tube. Again, a suitable bonding agent may be used to consolidate the wrapping.
- FIG. 4 uses two separate cylindrical elements 41, instead of a single cylinder.
- the ad-' vantage of this arrangement is that the overall transducer characteristics are more uniform.
- the piezoelectric constants of polarized ceramic materials vary over relative wide ranges.
- the foregoing specification speaks of the use of a glass fiber for the wrapping material.
- This material is desirable in the embodiment of FIG. 2 since the nonconductivity does not interfere with the potential distribution along the surface which varies between the positive and the negative polarities.
- the electrode 43 has substantially the same potential over its entire surface. Therefore, the wrapping material may be conductive. Thus, a high tensile steel wire may be used to wrap the surface.
- An alternative wrapping for the embodiment of FIG. 4 involves a heating process. More particularly, a cylindrical stress tube is constructed to have a predetermined interference fit over the outside of the ceramic cylinder.
- the outside of the ceramic cylinder is preferably ground to close tolerances, and the inside of the cylindrical stress tube is held to similar close tolerances.
- By heating or otherwise temporarily expanding the stress tube it may be fitted over the outside of the ceramic cylinder.
- the stress tube then shrinks and applies the desired compressive stress to the outer periphery of the ceramic material.
- An electromechanical transducer assembly comprising at least two transducer elements for converting electrical oscillations to mechanical vibrations, each of said transducer elements having an external peripheral surface, said transducer elements being assembled together with said external peripheral surfaces held in a substantial alignment, a plurality of plate members each having an outer periphery, the periphery of said plate members being larger in radial dimension than the external peripheral surface of said transducer elements, said transducer elements being assembled between a pair of said plate members whereby the peripheries of said plate members project beyond the peripheries of said transducer elements to provide a bobbin-like form, and a continuous filament tightly wrapped on said bobbin from in direct physical contact with the external peripheral surfaces of said transducer elements for circumferentially applying a substantially uniform compressive stress directly to said external peripheral surfaces of said transducer elements throughout the entire ambient temperature range.
- An electromechanical transducer assembly comprising a plurality of ring-shaped piezoelectric elements, means for bonding said elements together in substantial axial alignment, and a continuous filament of material having a modulus of elasticity generally corresponding to the modulus of elasticity of glass fiber and stainless steel, said filament being tightly wrapped in direct physicahcontact with the outside perimeter of said piezoelectric elements for applying a substantially uniform compressive stress around the peripheries of said bonded elements, said means for applying said uniform compressive stress being characterized in that said compressive stress is uniformly maintained with the ceramic material.
- An electromechanical transducer assembly comprising at least two transducer elements for converting electrical oscillations to mechanical vibrations, each of said transducer elements having an external peripheral surface, said transducer elements being assembled together with said external peripheral surfaces held in a substantial alignment, a plurality of plate members each having an outer periphery, the periphery of said plate members being larger in radial dimension than the external peripheral surface of said transducer elements, said transducer elements being assembled between a pair of said plate members whereby the peripheries of said plate members project beyond the peripheries of said transducer elements to provide a bobbin-like form, and means on said bobbin form in direct physical contact with the external peripheral surfaces of said transducer elements for circumferentlally applying a substantially uniform compressive stress directly to said external peripheral surfaces of said transducer elements throughout the entire ambient temperature range, said stress applying means comprising a filament taken from the class of materials having a modulus of elasticity substantially as found in glass fiber and steel wire and said filament being in direct physical contact with the external
Abstract
Description
Claims (7)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US760670A | 1970-02-02 | 1970-02-02 |
Publications (1)
Publication Number | Publication Date |
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US3716828A true US3716828A (en) | 1973-02-13 |
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Family Applications (1)
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US00007606A Expired - Lifetime US3716828A (en) | 1970-02-02 | 1970-02-02 | Electroacoustic transducer with improved shock resistance |
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US (1) | US3716828A (en) |
Cited By (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3835340A (en) * | 1973-02-15 | 1974-09-10 | Edo Corp | Transducer corona shield |
US3870894A (en) * | 1972-02-19 | 1975-03-11 | Dynamit Nobel Ag | Electronic sensor for triggering safety devices during the crash of vehicles |
US3889166A (en) * | 1974-01-15 | 1975-06-10 | Quintron Inc | Automatic frequency control for a sandwich transducer using voltage feedback |
US3938072A (en) * | 1974-03-18 | 1976-02-10 | Charles Baird | Resonance earth structure logging |
US3992694A (en) * | 1975-02-20 | 1976-11-16 | Raytheon Company | Transducer with half-section active element |
US4011474A (en) * | 1974-10-03 | 1977-03-08 | Pz Technology, Inc. | Piezoelectric stack insulation |
US4017824A (en) * | 1975-06-06 | 1977-04-12 | The Bendix Corporation | Acceleration-insensitive hydrophone |
US4035761A (en) * | 1975-10-20 | 1977-07-12 | Raytheon Company | Sonar transducer having inertial inductor |
US4068209A (en) * | 1974-11-08 | 1978-01-10 | Thomson-Csf | Electroacoustic transducer for deep submersion |
US4183007A (en) * | 1978-02-22 | 1980-01-08 | Fischer & Porter Company | Ultrasonic transceiver |
US4223428A (en) * | 1971-11-24 | 1980-09-23 | The United States Of America As Represented By The Secretary Of The Navy | Method and apparatus for securing a ferroelectric stack to a weighted projection surface |
FR2544576A1 (en) * | 1983-04-13 | 1984-10-19 | Sintra Alcatel Sa | Electroacoustic transducer of the "Tonpilz" type subjected to hydrostatic pressures |
US4482834A (en) * | 1979-06-28 | 1984-11-13 | Hewlett-Packard Company | Acoustic imaging transducer |
DE3419256A1 (en) * | 1983-05-23 | 1984-12-13 | Raytheon Co., Lexington, Mass. | ELECTRIC-ACOUSTIC CONVERTER DEVICE |
US4545041A (en) * | 1982-10-27 | 1985-10-01 | The United States Of America As Represented By The Secretary Of The Navy | Shock-hardened hydrophone |
US4704709A (en) * | 1985-07-12 | 1987-11-03 | Westinghouse Electric Corp. | Transducer assembly with explosive shock protection |
US4737939A (en) * | 1983-05-23 | 1988-04-12 | Raytheon Company | Composite transducer |
US4821244A (en) * | 1985-11-30 | 1989-04-11 | Ferranti International Signal, Plc | Tubular acoustic projector |
US4823041A (en) * | 1986-07-02 | 1989-04-18 | Nec Corporation | Non-directional ultrasonic transducer |
US5101384A (en) * | 1989-05-29 | 1992-03-31 | Abb Atom Ab | Acoustic devices |
US5199004A (en) * | 1992-05-28 | 1993-03-30 | The United States Of America As Represented By The Secretary Of The Navy | Sealed acoustical element using conductive epoxy |
US5222049A (en) * | 1988-04-21 | 1993-06-22 | Teleco Oilfield Services Inc. | Electromechanical transducer for acoustic telemetry system |
US5229980A (en) * | 1992-05-27 | 1993-07-20 | Sparton Corporation | Broadband electroacoustic transducer |
US5305507A (en) * | 1990-10-29 | 1994-04-26 | Trw Inc. | Method for encapsulating a ceramic device for embedding in composite structures |
US5491671A (en) * | 1984-04-26 | 1996-02-13 | Alliant Techsystems Inc. | Sonar transducer with unitary isolator |
US5773915A (en) * | 1995-08-08 | 1998-06-30 | Murata Manufacturing Co., Ltd. | Vibrating gyroscope |
US6268683B1 (en) | 1999-02-26 | 2001-07-31 | M&Fc Holding Company | Transducer configurations and related method |
US6307299B1 (en) * | 1997-05-29 | 2001-10-23 | Seiko Instruments Inc. | Method of correcting a resonance frequency of a small rotary actuator |
US20100237748A1 (en) * | 2007-02-08 | 2010-09-23 | The Boeing Company | Spring disc energy harvester apparatus and method |
US20120069708A1 (en) * | 2010-03-23 | 2012-03-22 | Baker Hughes Incorporated | Apparatus and method for generating broad bandwidth acoustic energy |
WO2013060543A3 (en) * | 2011-10-28 | 2013-09-26 | Atlas Elektronik Gmbh | Electroacoustic converter |
CN106423810A (en) * | 2016-11-15 | 2017-02-22 | 陕西师范大学 | Performance parameter variable ultrasonic amplitude-change pole |
US10021492B1 (en) | 2017-10-06 | 2018-07-10 | Aga Ad Media, Llp | Electroacoustic transducer with axial electric field |
CN110355084A (en) * | 2019-07-17 | 2019-10-22 | 中北大学 | Axial ultrasonic energy converter |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3043967A (en) * | 1960-01-13 | 1962-07-10 | Walter L Clearwaters | Electrostrictive transducer |
US3328751A (en) * | 1966-03-28 | 1967-06-27 | Dynamics Corp Massa Div | Electroacoustic transducer |
US3360665A (en) * | 1965-04-15 | 1967-12-26 | Clevite Corp | Prestressed piezoelectric transducer |
US3396285A (en) * | 1966-08-10 | 1968-08-06 | Trustees Of The Ohio State Uni | Electromechanical transducer |
US3474403A (en) * | 1966-06-08 | 1969-10-21 | Dynamics Corp Massa Div | Electroacoustic transducer with improved shock resistance |
-
1970
- 1970-02-02 US US00007606A patent/US3716828A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3043967A (en) * | 1960-01-13 | 1962-07-10 | Walter L Clearwaters | Electrostrictive transducer |
US3360665A (en) * | 1965-04-15 | 1967-12-26 | Clevite Corp | Prestressed piezoelectric transducer |
US3328751A (en) * | 1966-03-28 | 1967-06-27 | Dynamics Corp Massa Div | Electroacoustic transducer |
US3474403A (en) * | 1966-06-08 | 1969-10-21 | Dynamics Corp Massa Div | Electroacoustic transducer with improved shock resistance |
US3396285A (en) * | 1966-08-10 | 1968-08-06 | Trustees Of The Ohio State Uni | Electromechanical transducer |
Cited By (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4223428A (en) * | 1971-11-24 | 1980-09-23 | The United States Of America As Represented By The Secretary Of The Navy | Method and apparatus for securing a ferroelectric stack to a weighted projection surface |
US3870894A (en) * | 1972-02-19 | 1975-03-11 | Dynamit Nobel Ag | Electronic sensor for triggering safety devices during the crash of vehicles |
US3835340A (en) * | 1973-02-15 | 1974-09-10 | Edo Corp | Transducer corona shield |
US3889166A (en) * | 1974-01-15 | 1975-06-10 | Quintron Inc | Automatic frequency control for a sandwich transducer using voltage feedback |
US3938072A (en) * | 1974-03-18 | 1976-02-10 | Charles Baird | Resonance earth structure logging |
US4011474A (en) * | 1974-10-03 | 1977-03-08 | Pz Technology, Inc. | Piezoelectric stack insulation |
US4068209A (en) * | 1974-11-08 | 1978-01-10 | Thomson-Csf | Electroacoustic transducer for deep submersion |
US3992694A (en) * | 1975-02-20 | 1976-11-16 | Raytheon Company | Transducer with half-section active element |
US4017824A (en) * | 1975-06-06 | 1977-04-12 | The Bendix Corporation | Acceleration-insensitive hydrophone |
US4035761A (en) * | 1975-10-20 | 1977-07-12 | Raytheon Company | Sonar transducer having inertial inductor |
US4183007A (en) * | 1978-02-22 | 1980-01-08 | Fischer & Porter Company | Ultrasonic transceiver |
US4482834A (en) * | 1979-06-28 | 1984-11-13 | Hewlett-Packard Company | Acoustic imaging transducer |
US4545041A (en) * | 1982-10-27 | 1985-10-01 | The United States Of America As Represented By The Secretary Of The Navy | Shock-hardened hydrophone |
FR2544576A1 (en) * | 1983-04-13 | 1984-10-19 | Sintra Alcatel Sa | Electroacoustic transducer of the "Tonpilz" type subjected to hydrostatic pressures |
DE3419256A1 (en) * | 1983-05-23 | 1984-12-13 | Raytheon Co., Lexington, Mass. | ELECTRIC-ACOUSTIC CONVERTER DEVICE |
US4737939A (en) * | 1983-05-23 | 1988-04-12 | Raytheon Company | Composite transducer |
US5491671A (en) * | 1984-04-26 | 1996-02-13 | Alliant Techsystems Inc. | Sonar transducer with unitary isolator |
US4704709A (en) * | 1985-07-12 | 1987-11-03 | Westinghouse Electric Corp. | Transducer assembly with explosive shock protection |
US4821244A (en) * | 1985-11-30 | 1989-04-11 | Ferranti International Signal, Plc | Tubular acoustic projector |
US4823041A (en) * | 1986-07-02 | 1989-04-18 | Nec Corporation | Non-directional ultrasonic transducer |
US5222049A (en) * | 1988-04-21 | 1993-06-22 | Teleco Oilfield Services Inc. | Electromechanical transducer for acoustic telemetry system |
US5101384A (en) * | 1989-05-29 | 1992-03-31 | Abb Atom Ab | Acoustic devices |
US5305507A (en) * | 1990-10-29 | 1994-04-26 | Trw Inc. | Method for encapsulating a ceramic device for embedding in composite structures |
EP0483955B1 (en) * | 1990-10-29 | 1998-03-04 | Trw Inc. | Encapsulated ceramic device and method for embedding in composite structure |
US5229980A (en) * | 1992-05-27 | 1993-07-20 | Sparton Corporation | Broadband electroacoustic transducer |
US5199004A (en) * | 1992-05-28 | 1993-03-30 | The United States Of America As Represented By The Secretary Of The Navy | Sealed acoustical element using conductive epoxy |
US5773915A (en) * | 1995-08-08 | 1998-06-30 | Murata Manufacturing Co., Ltd. | Vibrating gyroscope |
US6307299B1 (en) * | 1997-05-29 | 2001-10-23 | Seiko Instruments Inc. | Method of correcting a resonance frequency of a small rotary actuator |
US6268683B1 (en) | 1999-02-26 | 2001-07-31 | M&Fc Holding Company | Transducer configurations and related method |
US20100237748A1 (en) * | 2007-02-08 | 2010-09-23 | The Boeing Company | Spring disc energy harvester apparatus and method |
US8415860B2 (en) * | 2007-02-08 | 2013-04-09 | The Boeing Company | Spring disc energy harvester apparatus and method |
US9903971B2 (en) * | 2010-03-23 | 2018-02-27 | Baker Hughes, A Ge Company, Llc | Apparatus and method for generating broad bandwidth acoustic energy |
US20120069708A1 (en) * | 2010-03-23 | 2012-03-22 | Baker Hughes Incorporated | Apparatus and method for generating broad bandwidth acoustic energy |
WO2013060543A3 (en) * | 2011-10-28 | 2013-09-26 | Atlas Elektronik Gmbh | Electroacoustic converter |
CN106423810A (en) * | 2016-11-15 | 2017-02-22 | 陕西师范大学 | Performance parameter variable ultrasonic amplitude-change pole |
CN106423810B (en) * | 2016-11-15 | 2018-10-09 | 陕西师范大学 | The variable ultrasonic variable amplitude bar of performance parameter |
US10021492B1 (en) | 2017-10-06 | 2018-07-10 | Aga Ad Media, Llp | Electroacoustic transducer with axial electric field |
US10306373B2 (en) | 2017-10-06 | 2019-05-28 | Aga Ad Media, Llp | Electroacoustic transducer with axial electric field |
US10506350B2 (en) | 2017-10-06 | 2019-12-10 | Aga Ad Media, Llp | Electroacoustic transducer with axial electric field |
CN110355084A (en) * | 2019-07-17 | 2019-10-22 | 中北大学 | Axial ultrasonic energy converter |
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