GB1159337A - Piezoelectric Transducers - Google Patents

Piezoelectric Transducers

Info

Publication number
GB1159337A
GB1159337A GB1532667A GB1532667A GB1159337A GB 1159337 A GB1159337 A GB 1159337A GB 1532667 A GB1532667 A GB 1532667A GB 1532667 A GB1532667 A GB 1532667A GB 1159337 A GB1159337 A GB 1159337A
Authority
GB
Grant status
Application
Patent type
Prior art keywords
element
fig
diaphragm
apex
shown
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
Application number
GB1532667A
Inventor
Hugo Willy Schafft
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Motorola Solutions Inc
Original Assignee
Motorola Solutions Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00Piezo-electric transducers; Electrostrictive transducers

Abstract

1,159,337. Piezoelectric transducers; acoustic horns. MOTOROLA Inc. 4 April, 1967 [13 June, 1966], No. 15326/67. Headings H4J and H4X. An electro - acoustic transducer, e.g. a "tweeter" or microphone, has the apex 14 (Fig.2), of a compliant aluminium diaphragm 12 secured to a piezoelectric element 18, whereby in use the element 18 is subjected to undulations along its extent outwardly from its axis similar to vibrations of a mass in free space. The element mass is preferably greater than the diaphragm mass. The apex 14 extends into an aperture 16 of element 18 in the form of a bimorph crystal having outer electrodes 20, 22 connected together and to wire 26. Element 18 includes two piezoelectric wafers 28, 30 fastened together by a metal shim (32), Fig. 4 (not shown). Each wafer has inner electrodes (20A, 22A) and wire 34 connects shim (32) to a terminal 36. Epoxy adhesive 38 at aperture 16 mounts element 18 to diaphragm 12. Diaphragm 12 is mounted on a frame 10 and has a damping rubber ring 40. An alternating voltage across the electrodes causes the element 18 to oscillate (Fig. 3, not shown) and a nodal ring (72) Fig. 1 (not shown), occurs. Alternatively by applying sound waves in front, the diaphram 12 is stimulated to vibrate along axis 74 and produce a voltage gradient across wires 26, 34. Aperture 16 should be sufficiently small not to adversely affect the vibrational mode. Alternatively a non- apertured element 18 may be cemented to the apex 14, such apex 14 preferably having a flat end. In another embodiment a mass in the form of a ring (76), Fig. 5 (not shown), is attached to the outer periphery of the element 18 by clips (78). Ring (76) decreases the resonant frequency of the element 18, permits a heavier diaphragm 12, but increases mechanical losses. Alternatively, element 18 (Fig. 6), is attached to apex 14 through a rubber plug 80 adhesively attached to apex 14. Element 18 is resiliently held in an annular groove 84. The plug 80 dampens vibrations and reduces the coupling between diaphragm 12 and element 18. An element 18 of square (Fig. 7, not shown) or other shape may be used. In a further embodiment an exponential or hyperbolic horn body 100 (Fig. 11), has a plurality of passageways 102. A small diameter diaphragm 104 is closely spaced from the horn body 100 by an annular spacer 106. An annular clamp 108, bolted to body 100, holds the diaphragm 104 and spacer 106 against body 100. A piezoelectric wafer 110 is mounted on diaphragm 104, apex 112 extending through the wafer aperture. Embodiments in which the diaphragm is of elliptical cross-section or the apex is offcentre are envisaged . The element 18 may be freely mounted at its outer edge. Local circuit.-An inductance coil (44) ,Fig. 1 (not shown) may be inserted between a signal source and one terminal of the transducer to improve "tweeter" response. (Fig. 1, not shown).
GB1532667A 1966-06-13 1967-04-04 Piezoelectric Transducers Expired GB1159337A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US55712066 true 1966-06-13 1966-06-13
US85298569 true 1969-08-22 1969-08-22

Publications (1)

Publication Number Publication Date
GB1159337A true true GB1159337A (en) 1969-07-23

Family

ID=27071335

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1532667A Expired GB1159337A (en) 1966-06-13 1967-04-04 Piezoelectric Transducers

Country Status (3)

Country Link
US (1) US3548116A (en)
DE (1) DE1512729B2 (en)
GB (1) GB1159337A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2168396A1 (en) * 1972-01-18 1973-08-31 Siemens Ag
DE4135408A1 (en) * 1991-10-26 1993-04-29 Man Nutzfahrzeuge Ag Converting electric energy into vibrations - using piezoelectric effect to translate contraction or expansion to vibration of diaphragm
GB2443228A (en) * 2006-10-25 2008-04-30 Gary Paul Nicholson Piezo-electric loudspeaker

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3786202A (en) * 1972-04-10 1974-01-15 Motorola Inc Acoustic transducer including piezoelectric driving element
JPS4963860U (en) * 1972-06-26 1974-06-04
US3970987A (en) * 1972-08-17 1976-07-20 Signal Science, Inc. Acoustical switch
US3872470A (en) * 1973-04-18 1975-03-18 Airco Inc Audible signal generating apparatus having selectively controlled audible output
US4035672A (en) * 1975-02-06 1977-07-12 Cts Corporation Acoustic transducer with a dual purpose piezoelectric element
US4060741A (en) * 1975-12-29 1977-11-29 Motorola, Inc. High power piezoelectric bender
DE2705035C2 (en) * 1977-02-07 1984-05-03 Motorola, Inc., 60196 Schaumburg, Ill., Us
US4078160A (en) * 1977-07-05 1978-03-07 Motorola, Inc. Piezoelectric bimorph or monomorph bender structure
GB2018548B (en) * 1978-04-07 1982-06-16 Matsushita Electric Ind Co Ltd Piezoelectric speaker
US4240002A (en) * 1979-04-02 1980-12-16 Motorola, Inc. Piezoelectric transducer arrangement with integral terminals and housing
DE3009048C2 (en) * 1980-03-08 1983-04-21 Kuttruff, Heinrich, Prof. Dr., 5100 Aachen, De
JPS5753798U (en) * 1980-09-11 1982-03-29
US4454386A (en) * 1980-10-29 1984-06-12 Sumitomo Special Metal Co., Ltd. Piezoelectric transducer for piezoelectric loud speaker
GB8521410D0 (en) * 1984-09-05 1985-10-02 Sawafiji Dynameca Kk Vibrating elements
US4598177A (en) * 1985-01-16 1986-07-01 Sears, Roebuck, & Co. Hearing aid with self-contained battery compartment and volume control
US4985926A (en) * 1988-02-29 1991-01-15 Motorola, Inc. High impedance piezoelectric transducer
US5672929A (en) * 1992-03-03 1997-09-30 The Technology Partnership Public Limited Company Moving sensor using mechanical vibrations
US5450499A (en) * 1992-11-25 1995-09-12 Magnetic Resonance Equipment Corporation Audio speaker for use in an external magnetic field
US5727076A (en) * 1994-05-02 1998-03-10 Aura Systems, Inc. Audio transducer having piezoelectric device
US5652801A (en) * 1994-05-02 1997-07-29 Aura Systems, Inc. Resonance damper for piezoelectric transducer
US5828768A (en) * 1994-05-11 1998-10-27 Noise Cancellation Technologies, Inc. Multimedia personal computer with active noise reduction and piezo speakers
US5638456A (en) * 1994-07-06 1997-06-10 Noise Cancellation Technologies, Inc. Piezo speaker and installation method for laptop personal computer and other multimedia applications
US5901231A (en) 1995-09-25 1999-05-04 Noise Cancellation Technologies, Inc. Piezo speaker for improved passenger cabin audio systems
US6181797B1 (en) 1999-01-09 2001-01-30 Noise Cancellation Technologies, Inc. Piezo speaker for improved passenger cabin audio systems

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2168396A1 (en) * 1972-01-18 1973-08-31 Siemens Ag
DE4135408A1 (en) * 1991-10-26 1993-04-29 Man Nutzfahrzeuge Ag Converting electric energy into vibrations - using piezoelectric effect to translate contraction or expansion to vibration of diaphragm
GB2443228A (en) * 2006-10-25 2008-04-30 Gary Paul Nicholson Piezo-electric loudspeaker
GB2443228B (en) * 2006-10-25 2010-02-10 Gary Paul Nicholson Piezo-electric loudspeaker

Also Published As

Publication number Publication date Type
DE1512729A1 (en) 1969-07-10 application
US3548116A (en) 1970-12-15 grant
DE1512729B2 (en) 1972-09-21 application

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Legal Events

Date Code Title Description
PS Patent sealed
PLE Entries relating assignments, transmissions, licences in the register of patents
PE Patent expired