GB832276A - Improvements in or relating to electro-acoustic transducers - Google Patents

Improvements in or relating to electro-acoustic transducers

Info

Publication number
GB832276A
GB832276A GB2138257A GB2138257A GB832276A GB 832276 A GB832276 A GB 832276A GB 2138257 A GB2138257 A GB 2138257A GB 2138257 A GB2138257 A GB 2138257A GB 832276 A GB832276 A GB 832276A
Authority
GB
United Kingdom
Prior art keywords
base
electrode
diaphragm
ring
porous
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
GB2138257A
Inventor
William Donald Cragg
Stuart Seymour Hill
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Publication of GB832276A publication Critical patent/GB832276A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
    • H04R1/38—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means in which sound waves act upon both sides of a diaphragm and incorporating acoustic phase-shifting means, e.g. pressure-gradient microphone
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R19/00—Electrostatic transducers
    • H04R19/01—Electrostatic transducers characterised by the use of electrets

Abstract

832,276. Capacitor transducers. STANDARD TELEPHONES & CABLES Ltd. July 4, 1958 [July 5, 1957], No. 21382/57. Class 40 (4). In a capacitor microphone or receiver an electrode comprises a coating on a rigid porous non-conductive body. As shown in Fig. 1, the electrode is the back electrode 9 of gold on a base 6 of sand, glass, or nylon particles bonded together by a polyester or epoxy resin so that the base is rigid but porous. Alternatively the base may be made from sintered ceramic particles. The base 6 is formed in a circular well of a metal casing 5 and its upper and exposed face is moulded or ground to be either flat or to have a number of high points. A front electrode 8 is deposited on a terylene, polystyrene, or polymethyl methacrylate foil 1 which is glued to a mounting ring 2 either while tensioned or so as to be shrunk and tensioned afterwards. A spacing ring 7 and a clamping ring 12 mount the front electrode. Electrical connections are taken from the ring 2 and from a conductor 10 passing through the base 6. Deposition of a gold layer over the porous base 6 produces portions of the layer which bridge the interstices of the base material and are said to provide diaphragm resonances up to 10 kc/s. Where the surface of the base has a number of high points these may bear against the diaphragm 1 and increase its resonances to a range between 10 and 20 kc/s. In the Provisional Specification it is explained that the dielectric diaphragm 1 is polarized by a D.C. voltage of from 300 to 1500 volts across the electrodes applied for ten to fifteen minutes. It is said to be probable that polarization of the base 6 also takes place. The invention may be made bi-directional by the back-to-back arrangement of two transducers shown in Fig. 2 in which apertures 13 provide communication between the back electrodes 9A and 9B. Specification 438,672 is referred to.
GB2138257A 1958-12-02 1957-07-05 Improvements in or relating to electro-acoustic transducers Expired GB832276A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3878758A GB881584A (en) 1958-12-02 1958-12-02 Improvements in or relating to electro-acoustic transducers

Publications (1)

Publication Number Publication Date
GB832276A true GB832276A (en) 1960-04-06

Family

ID=10405688

Family Applications (2)

Application Number Title Priority Date Filing Date
GB2138257A Expired GB832276A (en) 1958-12-02 1957-07-05 Improvements in or relating to electro-acoustic transducers
GB3878758A Expired GB881584A (en) 1958-12-02 1958-12-02 Improvements in or relating to electro-acoustic transducers

Family Applications After (1)

Application Number Title Priority Date Filing Date
GB3878758A Expired GB881584A (en) 1958-12-02 1958-12-02 Improvements in or relating to electro-acoustic transducers

Country Status (1)

Country Link
GB (2) GB832276A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3108162A (en) * 1960-04-11 1963-10-22 Schindler Mark Capacitor acousto-electric transducer and method of making the same
US3504137A (en) * 1965-12-10 1970-03-31 Tesla Np Condenser microphone with improved acoustical circuit
USRE28420E (en) * 1967-05-15 1975-05-13 Blbctret acoustic transducer
US3980838A (en) * 1974-02-20 1976-09-14 Tokyo Shibaura Electric Co., Ltd. Plural electret electroacoustic transducer
US4249043A (en) * 1977-12-02 1981-02-03 The Post Office Electret transducer backplate, electret transducer and method of making an electret transducer
WO2012130989A1 (en) * 2011-03-30 2012-10-04 Kaetel Systems Gmbh Electret microphone

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL295905A (en) * 1962-07-27 1900-01-01
US3654403A (en) * 1969-05-01 1972-04-04 Chester C Pond Electrostatic speaker
US3689709A (en) * 1969-10-31 1972-09-05 Non Acoustic Audio Corp Electrostatic electroacoustic transducer
US3787642A (en) * 1971-09-27 1974-01-22 Gte Automatic Electric Lab Inc Electrostatic transducer having resilient electrode
US3963881A (en) * 1973-05-29 1976-06-15 Thermo Electron Corporation Unidirectional condenser microphone
US3944756A (en) * 1975-03-05 1976-03-16 Electro-Voice, Incorporated Electret microphone
GB2003364B (en) * 1977-08-24 1982-03-03 Post Office Electroacoustic transducer for a microphone

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3108162A (en) * 1960-04-11 1963-10-22 Schindler Mark Capacitor acousto-electric transducer and method of making the same
US3504137A (en) * 1965-12-10 1970-03-31 Tesla Np Condenser microphone with improved acoustical circuit
USRE28420E (en) * 1967-05-15 1975-05-13 Blbctret acoustic transducer
US3980838A (en) * 1974-02-20 1976-09-14 Tokyo Shibaura Electric Co., Ltd. Plural electret electroacoustic transducer
US4249043A (en) * 1977-12-02 1981-02-03 The Post Office Electret transducer backplate, electret transducer and method of making an electret transducer
WO2012130989A1 (en) * 2011-03-30 2012-10-04 Kaetel Systems Gmbh Electret microphone
US9668038B2 (en) 2011-03-30 2017-05-30 Kaetel Systems Gmbh Loudspeaker
US10469924B2 (en) 2011-03-30 2019-11-05 Kaetel Systems Gmbh Method and apparatus for capturing and rendering an audio scene
US10848842B2 (en) 2011-03-30 2020-11-24 Kaetel Systems Gmbh Method and apparatus for capturing and rendering an audio scene
US11259101B2 (en) 2011-03-30 2022-02-22 Kaetel Systems Gmbh Method and apparatus for capturing and rendering an audio scene

Also Published As

Publication number Publication date
GB881584A (en) 1961-11-08

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