AT228283B - Electroacoustic transducer built into a capsule with a transistor amplifier, particularly for handsets in telephone stations - Google Patents
Electroacoustic transducer built into a capsule with a transistor amplifier, particularly for handsets in telephone stationsInfo
- Publication number
- AT228283B AT228283B AT97061A AT97061A AT228283B AT 228283 B AT228283 B AT 228283B AT 97061 A AT97061 A AT 97061A AT 97061 A AT97061 A AT 97061A AT 228283 B AT228283 B AT 228283B
- Authority
- AT
- Austria
- Prior art keywords
- transducer
- capsule
- sound field
- transistor amplifier
- handsets
- Prior art date
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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S181/00—Acoustics
- Y10S181/40—Wave coupling
Description
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In eine Kapsel eingebauter elektroakustischer Wandler mit einem Transistorverstärker, insbesondere für Handapparate von Fernsprechstationen
Die Erfindung betrifft einen in eine Kapsel eingebauten elektroakustischen Wandler mit einem Tran- sistorverstärker,'insbesondere für Handapparate von Fernsprechstationen, wobei der meist nach dem elektrodynamischen Prinzip ausgebildete Wandler in Miniaturausführung etwa im Mittelpunkt einer in- nerhalb der Kapsel sitzenden kreisförmigen Scheibe angeordnet ist, die als Montageplatte, gegebenen- falls auch als Schaltplatte, für einen Transistorverstärker dient.
Diese unter dem Namen "Transistormikrophon" bekanntgewordene Einrichtung besitzt die gleichen äusseren Abmessungen wie die bisher verwendeten Kohlemikrophone, so dass ein unmittelbarer Austausch möglich ist. Neben den den Transistormikrophonen eigenen Vorteilen, wie Verzerrungsfreiheit, grosse Lebensdauer usw., besitzen sie aber auch einen gewichtigen Nachteil gegenüber dem Kohlemikrophon, nämlich ihre grosse Empfindlichkeit gegenüber Störgeräuschen. Das Kohlemikrophon weist demgegenüber bekanntlich eine Art Reizschwelle auf, so dass akustische Signale (Schallwellen), deren Pegel einen gewissen Schwellenwert unterschreitet, vom Mikrophon nicht mehr aufgenommen werden.
Dies hat zur Folge, dass Störgeräusche, deren Schalldruckpegel im allgemeinen wesentlich niedriger ist als der Nutzpegel, nicht mehr übertragen werden, da der Schwingungsmechanismus eine gewissermassen selbsttätige Störaustauschtastung bewirkt.
Bei den üblichen dynamischen oder magnetischen Wandlersystemen ist dies hingegen nicht der Fall und sie übertragen daher, insbesondere wenn sie eine allseitig gleiche Empfindlichkeit aufweisen, auch sehr schwache Stoor- un Nebengeräusche, wodurch die Verständlichkeit der zu übertragenden Information ungünstig beeinflusst wird.
Die Erfindung zielt nun darauf ab, die Nachteile dieser bekannten Transistormikrophone unter Berücksichtigung der universellen Einbaumöglichkeit in den üblichen Fernsprechhandapparat zu beseitigen. Dies geschieht erfindungsgemäss dadurch, dass der Wandler, insbesondere elektrodynamische Wand- ler, als störschallkompensierter Gradientenempfänger ausgebildet ist, der im ebenen Schallfeld (Störschallfeld) eine nach den tiefen Frequenzen abfallende, im Kugelschallfeld (Nutzschallfeld) jedoch annähernd lineare Abhängigkeit der Empfindlichkeit von der Frequenz aufweist.
Ein geeigneter Wandler mit diesen Eigenschaften ist der an sich bekannte, auf die Schallschnelle ansprechende Empfänger, dessen Resonanzfrequenz in der Mitte des Übertragungsbereiches liegt und bei dem die Membranbewegungen durch eine überwiegende Reibungshemmung bestimmt wird. Man erhält dann im ebenen Schallfeld eine proportional mit der Frequenz ansteigende, auf die Membran wirkende Kraft, solange wenigstens, als die Abmessungen der Membrane kleiner als die Wellenlänge der höchsten zu übertragenden Frequenz sind. Praktisch ergibt sich im ebenen Schallfeld, wie es das Störschallfeld infolge seiner verhältnismässig grossen Entfernung vom Schallempfänger darstellt, unterhalb einer durch den Schallumweg fixierten Grenzfrequenz ein mit 6 db/Oktave abfallender Frequenzgang der Empfindlichkeit.
Bei Besprechung eines solchen Mikrophons aus der Nähe, also in einem Kugelschallfeld, in dem die Schallenergie mit dem Quadrat des Abstandes von der Schallquelle abnimmt, überwiegt der Antrieb der Membrane durch den direkten Schall. Der damit verbundene Anstieg der Druckdifferenz nach den tiefen
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Frequenzen hin bewirkt eine Linearisierung des Frequenzganges der Kapsel, welcher Effekt durch die als Schallwand dienende Schaltplatte für den Transistorverstärker wesentlich verbessert wird.
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Electroacoustic transducer built into a capsule with a transistor amplifier, particularly for handsets in telephone stations
The invention relates to an electroacoustic transducer built into a capsule with a transistor amplifier, in particular for handsets in telephone stations, the transducer, which is usually designed according to the electrodynamic principle, is arranged in miniature approximately in the center of a circular disk located inside the capsule, which serves as a mounting plate, possibly also as a circuit board, for a transistor amplifier.
This device, known under the name "transistor microphone", has the same external dimensions as the carbon microphones previously used, so that an immediate exchange is possible. In addition to the advantages inherent in transistor microphones, such as freedom from distortion, long service life, etc., they also have a major disadvantage compared to carbon microphones, namely their great sensitivity to interference. In contrast, the carbon microphone is known to have a kind of stimulus threshold so that acoustic signals (sound waves) whose level falls below a certain threshold value are no longer picked up by the microphone.
As a result, interfering noises, the sound pressure level of which is generally much lower than the useful level, are no longer transmitted, since the oscillation mechanism causes, to a certain extent, automatic interfering exchange control.
With the usual dynamic or magnetic transducer systems, however, this is not the case and they therefore also transmit very weak interference and background noises, especially if they have the same sensitivity on all sides, which has an adverse effect on the intelligibility of the information to be transmitted.
The aim of the invention is to eliminate the disadvantages of these known transistor microphones, taking into account the possibility of universal installation in the usual telephone handset. According to the invention, this is done in that the transducer, in particular electrodynamic transducer, is designed as an interference noise-compensated gradient receiver which, in the flat sound field (interference sound field), has a dependence of the sensitivity on the frequency that decreases towards the low frequencies, but in the spherical sound field (useful sound field) it is approximately linear .
A suitable transducer with these properties is the receiver, known per se, which responds to the speed of sound, whose resonance frequency is in the middle of the transmission range and in which the membrane movements are determined by a predominant friction inhibition. A force acting on the membrane is then obtained in the flat sound field, which increases proportionally with the frequency, as long as at least the dimensions of the membrane are smaller than the wavelength of the highest frequency to be transmitted. In practice, in the plane sound field, as represented by the interfering sound field due to its relatively large distance from the sound receiver, below a cutoff frequency fixed by the sound detour, there is a frequency response of the sensitivity that drops by 6 db / octave.
When discussing such a microphone at close range, i.e. in a spherical sound field in which the sound energy decreases with the square of the distance from the sound source, the diaphragm is driven by the direct sound. The associated increase in the pressure difference after the deep
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Frequencies causes a linearization of the frequency response of the capsule, which effect is significantly improved by the circuit board serving as a baffle for the transistor amplifier.
Claims (1)
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT97061A AT228283B (en) | 1961-02-06 | 1961-02-06 | Electroacoustic transducer built into a capsule with a transistor amplifier, particularly for handsets in telephone stations |
AT90762A AT234171B (en) | 1961-02-06 | 1962-02-03 | Electroacoustic transducer built into a capsule |
DEA39378A DE1186108B (en) | 1961-02-06 | 1962-02-05 | Directional microphone built into a capsule with a transistor amplifier, especially for handsets in telephone stations |
US194265A US3201516A (en) | 1961-02-06 | 1962-05-14 | Capsule-enclosed electro-acoustic transducer and transistor amplifier |
GB18588/62A GB961369A (en) | 1961-02-06 | 1962-05-15 | Improvements in electro-acoustic transducer which is incorporated in a capsule and comprises a transistor amplifier particularly for telephone handsets |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT97061A AT228283B (en) | 1961-02-06 | 1961-02-06 | Electroacoustic transducer built into a capsule with a transistor amplifier, particularly for handsets in telephone stations |
Publications (1)
Publication Number | Publication Date |
---|---|
AT228283B true AT228283B (en) | 1963-07-10 |
Family
ID=3503981
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AT97061A AT228283B (en) | 1961-02-06 | 1961-02-06 | Electroacoustic transducer built into a capsule with a transistor amplifier, particularly for handsets in telephone stations |
AT90762A AT234171B (en) | 1961-02-06 | 1962-02-03 | Electroacoustic transducer built into a capsule |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AT90762A AT234171B (en) | 1961-02-06 | 1962-02-03 | Electroacoustic transducer built into a capsule |
Country Status (4)
Country | Link |
---|---|
US (1) | US3201516A (en) |
AT (2) | AT228283B (en) |
DE (1) | DE1186108B (en) |
GB (1) | GB961369A (en) |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4401859A (en) * | 1981-05-29 | 1983-08-30 | Electro-Voice, Incorporated | Directional microphone with high frequency selective acoustic lens |
US4633045A (en) * | 1985-02-13 | 1986-12-30 | Crown International, Inc. | Differential microphone |
US4625828A (en) * | 1985-09-09 | 1986-12-02 | The Boeing Company | Acoustic reflector for ground plane microphone |
US20060147712A1 (en) * | 2003-07-09 | 2006-07-06 | Maxwell Technologies, Inc. | Dry particle based adhesive electrode and methods of making same |
US7791860B2 (en) * | 2003-07-09 | 2010-09-07 | Maxwell Technologies, Inc. | Particle based electrodes and methods of making same |
US7352558B2 (en) | 2003-07-09 | 2008-04-01 | Maxwell Technologies, Inc. | Dry particle based capacitor and methods of making same |
US20110165318A9 (en) * | 2004-04-02 | 2011-07-07 | Maxwell Technologies, Inc. | Electrode formation by lamination of particles onto a current collector |
US20070122698A1 (en) | 2004-04-02 | 2007-05-31 | Maxwell Technologies, Inc. | Dry-particle based adhesive and dry film and methods of making same |
US7920371B2 (en) * | 2003-09-12 | 2011-04-05 | Maxwell Technologies, Inc. | Electrical energy storage devices with separator between electrodes and methods for fabricating the devices |
JP4145769B2 (en) | 2003-10-20 | 2008-09-03 | 本田技研工業株式会社 | Forced open / close valve gear |
US7090946B2 (en) * | 2004-02-19 | 2006-08-15 | Maxwell Technologies, Inc. | Composite electrode and method for fabricating same |
US7440258B2 (en) * | 2005-03-14 | 2008-10-21 | Maxwell Technologies, Inc. | Thermal interconnects for coupling energy storage devices |
DE102013221752A1 (en) | 2013-10-25 | 2015-04-30 | Kaetel Systems Gmbh | EARPHONES AND METHOD FOR PRODUCING AN EARPHOR |
GB2527784A (en) * | 2014-07-01 | 2016-01-06 | Audiogravity Holdings Ltd | Wind noise reduction apparatus |
US11785375B2 (en) * | 2021-06-15 | 2023-10-10 | Quiet, Inc. | Precisely controlled microphone acoustic attenuator with protective microphone enclosure |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE912821C (en) * | 1935-11-13 | 1954-06-03 | Siemens Ag | Facility for voice transmission from noisy rooms |
US2299620A (en) * | 1938-08-19 | 1942-10-20 | Associated Electric Lab Inc | Acoustic apparatus |
US2228886A (en) * | 1938-10-31 | 1941-01-14 | Rca Corp | Electroacoustical apparatus |
US2463762A (en) * | 1941-11-14 | 1949-03-08 | Automatic Elect Lab | Electroacoustical transducer |
US2870255A (en) * | 1954-01-11 | 1959-01-20 | Remler Company Ltd | Microphone assembly |
DE1014595B (en) * | 1955-02-15 | 1957-08-29 | Lab Wennebostel | Directional microphone |
AT190988B (en) * | 1956-02-09 | 1957-07-25 | Henry Radio Heinrich & Co | Moving coil microphone |
US3048659A (en) * | 1959-03-30 | 1962-08-07 | Motorola Inc | Microphone preamplifier |
-
1961
- 1961-02-06 AT AT97061A patent/AT228283B/en active
-
1962
- 1962-02-03 AT AT90762A patent/AT234171B/en active
- 1962-02-05 DE DEA39378A patent/DE1186108B/en active Pending
- 1962-05-14 US US194265A patent/US3201516A/en not_active Expired - Lifetime
- 1962-05-15 GB GB18588/62A patent/GB961369A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
AT234171B (en) | 1964-06-25 |
GB961369A (en) | 1964-06-17 |
US3201516A (en) | 1965-08-17 |
DE1186108B (en) | 1965-01-28 |
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