GB2201318A - Electromechanical transducer - Google Patents
Electromechanical transducer Download PDFInfo
- Publication number
- GB2201318A GB2201318A GB08703217A GB8703217A GB2201318A GB 2201318 A GB2201318 A GB 2201318A GB 08703217 A GB08703217 A GB 08703217A GB 8703217 A GB8703217 A GB 8703217A GB 2201318 A GB2201318 A GB 2201318A
- Authority
- GB
- United Kingdom
- Prior art keywords
- transducer
- output
- piezoelectric material
- layer
- oscillatory
- 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.)
- Granted
Links
- 239000000463 material Substances 0.000 claims abstract description 23
- 230000003534 oscillatory effect Effects 0.000 claims abstract description 19
- 229920003023 plastic Polymers 0.000 claims abstract description 5
- 239000004033 plastic Substances 0.000 claims abstract description 5
- 239000004593 Epoxy Substances 0.000 abstract description 2
- 238000003491 array Methods 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 5
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 1
- 238000010276 construction Methods 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
- 230000001419 dependent effect 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
- 238000001465 metallisation Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- -1 polyvinylenedifluoride Polymers 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000004506 ultrasonic cleaning Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
An electromechanical transducer comprises an oscillatory body (1) having a piezoelectric oscillatory element (2) with associated electrodes (5, 6), sandwiched between filled epoxy matching elements (7). The output face of the body (1) carries a layer (9) of plastics piezoelectric material with associated electrodes (10, 11). The layer (9) provides a signal which is supplied as a feedback signal to control the output of the transducer, whereby the transducer can be self-regulating making it ideally suited for use in transducer arrays. <IMAGE>
Description
ELECTROMECHANICAL TANSDUCER This invention relates to an electromechanical
transducer.
Many forms of electromechanical transducer are
known and they are used for many purposes, for
example medical ultrasonic scanning, non-destructive
testing using sound waves, underwater sonar,
ultrasonic cleaning of workpieces, and many other
purposes.
Some known transducers comprise an oscillatory
body having an output face from which sound waves are
derived, the body being formed of an oscillatory
element, for example an element of piezoelectric
material with associated input electrodes, and one or
more matching elements carried by the oscillatory
element and serving in use to match the output of the
transducer to the medium at the output face thereof.
The oscillatory element can be of piezoelectric
material having the electrodes in the form of metal -layers deposited thereon.
In underwater sonar apparatus a plurality of
such tranducers are often used in any array, it then
being necessary for the output of each transducer to
be set relative to the outputs of all the other
transducers in the array in order for an intelligable
picture to be obtained with the apparatus. Such
setting of the transducers is generally carried out
using a detector arranged to receive the output of
the transducer array, each transducer in the array
being operated individually and its output determined
with the detector, the transducer being adjusted
until the required output is obtained.
Clearly this is a laborious, time consuming and
thus expensive operation to carry out.
According to this invention there is provided an electromechanical transducer comprising an oscillatory body having an output face and a layer of piezoelectric material with associated electrodes at said output face and serving in use to provide an output signal indicative of the output of the transducer.
With the transducer of this invention the layer of piezoelectric material at the output face will give an output signal directly indicative of the output of the transducer, which output signal can be usea to control the transducer, possibly automatically, to give the required output.
The layer of piezoelectric material is preferably thin so as to have minimal effect on the output of the transducer. However, with transducers as described above having matching elements the layer of piezoelectric material can itself constitute the or the outer matching element, in which case its thickness will be dependent upon the effect it is required to have on the output of the transducer.
The piezoelectric material used is preferably a plastics material, for example polyvinylenedifluoride (PVDF) since such materials are less brittle than ceramic materials.
An electromechanical transducer according to this invention will now be described by way of example with reference to the drawing which is a diagrammatic sectional side view of the transducer with associated components.
The transducer comprises an oscillatory body 1 having an oscillatory element 2 formed of a pair of piezoelectric material members 3 and 4 having metal electrodes 5 and 6 between them and on their outer surfaces. The members 3 and 4 can be of piezoelectric ceramic material such as lead-zirconate-tintanate as sold as PZT 4 or PZT 5.
The electrodes 5 and 6 can be provided in known manner by any suitable metal deposition technique.
The outer electrodes 6 are commoned and an input signal applied between electrodes 5 and 6 effects oscillation of the members 3 and 4. Although the oscillatory element 2 shown comprises two members 3 and 4, a single member element of known form can otherwise be used.
The members 3 and 4 are arranged in a stack with a plurality of matching elements 7 formed of filled epoxy material, there being a single element 7 on one side of the element 2 and serving to mount the transducer on a support surface 8 and two elements 7 on the other side of the element 2. The matching elements 7 serve in known manner to match the output of the transducer to the medium, for example water, at the output face 8 thereof in order to achieve effective coupling between the transducer and the medium.
As thus far described the transducer is of conventional construction.
As shown, the output face of the transducer is covered with a layer 9 of plastics piezoelectric material, for example PVDF, having output electrodes 10 and 11 on its opposite surfaces. The layer 9 is relatively thin and dimensioned to have minimal effect on the output of the transducer. The layer 9 is responsive to oscillation of the body 1 caused by the element 2 and provides an output electric signal between its electrodes 10 and 11 indicative of the output of the transducer. This output signal is supplied as a feedback signal to the energizing circuit 100 for the transducer where it is used to control energisation of the transducer in order to obtain a required output.
The transducer can thus be self regulating, although if required the output signal from the layer 9 can be used to give an indication to an operator so that manual control of the transducer can be effected.
The transducer described above has the advantage that when a plurality thereof are used in an array as used for underwater sonar, each transducer can be self-regulating simultaneously with all the other transducers, there being no need for sequential individual setting to obtain a required composite output.
Although in the transducer described above the layer 9 is relatively thin, as previously discussed the layer 9 can otherwise constitute a matching element for the transducer in which case it will be relatively thick in order to have the desired effect on the output of the transducer.
Claims (7)
1. An electromechanical transducer comprising an oscillatory body having an output face and a layer of piezoelectric material with associated electrodes at said output face and serving in use to provide an output signal indicative of the output of the transducer.
2. A transducer as claimed in Claim 1, in which the body comprises an oscillatory element with associated input electrodes and one or more matching elements carried by the oscillatory element and serving in use to match the output of the transducer to the medium at the output face thereof.
3. A transducer as claimed in Claim 2, in which the layer of piezoelectric material constitutes the or the outer one of the matching elements.
4. A transducer as claimed in Claim 2 or Claim 3, in which the oscillatory element is of piezoelectric material.
5. A transducer as claimed in Claim 4, in which the oscillatory element is of plastics piezoelectric material.
6. A transducer as claimed in any preceding claim, in which the output signal from the piezoelectric material layer is used for automatic control of the output of the transducer.
7. 'A transducer array comprising a plurality of transducers each as claimed in any preceding claim.
7. An electromechanical transducer substantially as hereinbefore described with reference to the drawing.
8. A transducer array comprising a plurality of transducers each as claimed in any preceding claim.
Amendments to the claims
have been filed as follows
CLAIMS
1. An electromechanical transducer in the form of an oscillatory body comprising an oscillatory element of piezoelectric material with associated input electrodes and having an output face with a layer of piezoelectric material with associated electrodes at said output face and serving in use to provide an output signal indicative of the output of the transducer.
2. A transducer as claimed in Claim 1, including one or more matching elements carried by the oscillatory element and serving in use to match the output of the transducer to the medium at the output face thereof.
3. A transducer as claimed iFs Claim 2, in which the layer of piezoelectric material constitutes the or the outer one of the matching elements.
4. A transducer as claimed in any preceding claim, in which the oscillatory body is of plastics piezoelectric material.
5. A transducer as claimed in any preceding claim, in which the output signal from the piezoelectric material layer is used for automatic control of the output of the transducer.
6. An electromechanical transducer substantially as hereinbefore described with reference to the drawing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8703217A GB2201318B (en) | 1987-02-12 | 1987-02-12 | Electromechanical transducer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8703217A GB2201318B (en) | 1987-02-12 | 1987-02-12 | Electromechanical transducer |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8703217D0 GB8703217D0 (en) | 1987-07-08 |
| GB2201318A true GB2201318A (en) | 1988-08-24 |
| GB2201318B GB2201318B (en) | 1990-10-24 |
Family
ID=10612167
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8703217A Expired - Fee Related GB2201318B (en) | 1987-02-12 | 1987-02-12 | Electromechanical transducer |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2201318B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2223377A (en) * | 1988-09-30 | 1990-04-04 | Dornier Gmbh | Piezoelectric transducer |
| GB2238120A (en) * | 1989-10-21 | 1991-05-22 | British Nuclear Fuels Plc | Corrosion monitoring using a piezo-electric crystal on a solid probe |
| EP0589648A1 (en) * | 1992-09-21 | 1994-03-30 | Ngk Insulators, Ltd. | Ultrasonic transducers |
| EP1440738A2 (en) | 2003-01-23 | 2004-07-28 | ROLLS-ROYCE plc | Method of monitoring the performance of an ultrasonic transducer |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1016115A (en) * | 1963-06-21 | 1966-01-05 | Philips Electronic Associated | Improvements in or relating to loudspeaker arrangements |
| GB1031145A (en) * | 1963-06-26 | 1966-05-25 | Philips Electronic Associated | Improvements in or relating to audio-frequency amplifiers |
| GB1534842A (en) * | 1976-06-01 | 1978-12-06 | Mcmullen R | Loudspeakers and associated circuitry |
| GB2148504A (en) * | 1983-09-28 | 1985-05-30 | Pennwalt Corp | Force transducer |
| GB2157914A (en) * | 1984-01-25 | 1985-10-30 | Kirksaeter Vertrieb | A device for reducing distortion in a loudspeaker |
-
1987
- 1987-02-12 GB GB8703217A patent/GB2201318B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1016115A (en) * | 1963-06-21 | 1966-01-05 | Philips Electronic Associated | Improvements in or relating to loudspeaker arrangements |
| GB1031145A (en) * | 1963-06-26 | 1966-05-25 | Philips Electronic Associated | Improvements in or relating to audio-frequency amplifiers |
| GB1534842A (en) * | 1976-06-01 | 1978-12-06 | Mcmullen R | Loudspeakers and associated circuitry |
| GB2148504A (en) * | 1983-09-28 | 1985-05-30 | Pennwalt Corp | Force transducer |
| GB2157914A (en) * | 1984-01-25 | 1985-10-30 | Kirksaeter Vertrieb | A device for reducing distortion in a loudspeaker |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2223377A (en) * | 1988-09-30 | 1990-04-04 | Dornier Gmbh | Piezoelectric transducer |
| GB2223377B (en) * | 1988-09-30 | 1993-06-02 | Dornier Gmbh | A hydrophone and a piezoelectric hydrophone transducer |
| GB2238120A (en) * | 1989-10-21 | 1991-05-22 | British Nuclear Fuels Plc | Corrosion monitoring using a piezo-electric crystal on a solid probe |
| GB2238120B (en) * | 1989-10-21 | 1993-09-08 | British Nuclear Fuels Plc | Corrosion monitoring |
| EP0589648A1 (en) * | 1992-09-21 | 1994-03-30 | Ngk Insulators, Ltd. | Ultrasonic transducers |
| US5446333A (en) * | 1992-09-21 | 1995-08-29 | Ngk Insulators, Ltd. | Ultrasonic transducers |
| EP1440738A2 (en) | 2003-01-23 | 2004-07-28 | ROLLS-ROYCE plc | Method of monitoring the performance of an ultrasonic transducer |
| GB2397719A (en) * | 2003-01-23 | 2004-07-28 | Rolls Royce Plc | Ultrasonic transducer structure with performance monitoring arrangement |
| GB2397719B (en) * | 2003-01-23 | 2006-04-19 | Rolls Royce Plc | Ultrasonic transudcer structures |
| US7069786B2 (en) | 2003-01-23 | 2006-07-04 | Rolls-Royce Plc | Ultrasonic transducer structures |
| EP1440738A3 (en) * | 2003-01-23 | 2008-06-11 | ROLLS-ROYCE plc | Method of monitoring the performance of an ultrasonic transducer |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8703217D0 (en) | 1987-07-08 |
| GB2201318B (en) | 1990-10-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19970212 |