GB513529A - Improvements in or relating to telephone transmitters - Google Patents
Improvements in or relating to telephone transmittersInfo
- Publication number
- GB513529A GB513529A GB10565/38A GB1056538A GB513529A GB 513529 A GB513529 A GB 513529A GB 10565/38 A GB10565/38 A GB 10565/38A GB 1056538 A GB1056538 A GB 1056538A GB 513529 A GB513529 A GB 513529A
- Authority
- GB
- United Kingdom
- Prior art keywords
- mouthpiece
- sections
- equivalent
- values
- designed
- 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
Links
- 230000001419 dependent effect Effects 0.000 abstract 1
- 239000012528 membrane Substances 0.000 abstract 1
- 238000005192 partition Methods 0.000 abstract 1
- 230000009466 transformation Effects 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R21/00—Variable-resistance transducers
- H04R21/02—Microphones
-
- 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
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/222—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only for microphones
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R21/00—Variable-resistance transducers
- H04R21/02—Microphones
- H04R21/021—Microphones with granular resistance material
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Piezo-Electric Transducers For Audible Bands (AREA)
- Electric Double-Layer Capacitors Or The Like (AREA)
- Specific Sealing Or Ventilating Devices For Doors And Windows (AREA)
- Telephone Set Structure (AREA)
Abstract
513,529. Transmitters. STANDARD TELEPHONES & CABLES, Ltd., POCOCK, L. C., and LEMAN, H. S. April 6, 1938, No. 10565. [Class 40 (iv)] A mouthpiece assembly for a telephone transmitter comprises a plurality of chambers (including the mouthpiece chamber itself) separated by partitions or membranes through which -the sound waves travel in turn and which is divided acoustically into sections which are designed so that in the equivalent electrical network, they are equivalent to transformers at a given frequency near the upper limit of the band to be transmitted and the junction between the adjacent sections has the same acoustical resistance looking in both directions. As described in connection with Fig. 4, the sections to the right and left of the dotted line are shown to be equivalent to a transformer at a frequency dependent upon the values of the elements forming the section of the network. The values of some of the components are determined by the mouthpiece orifice and the shape, size, &c. of the diaphragm, and the values of the remaining parts are determined according to a frequency near the upper limit of the band to be transmitted. The terminating resistances of the sections are preferably arranged to form a geometrical progression and the impedance transformation ratio is less than 4 : 1. The mouthpiece chamber is designed and dimensioned to have a resonance of the same order, e.g., 3,000 cycles per sec. as the optimum frequency for which the sections of the equivalent network are designed. A preferred form of mouthpiece has a frustum-shaped cavity having an area of at least 15 sq. cms. at the mouth, an axial depth not exceeding 2.5 cms. and a ratio of front area to rear area of at least 4: 1. The transmitters shown in Figs. 11, 12 are generally similar to those described in Specification 494,293. The mouthpieces are shaped and dimensioned in accordance with the principles set forth in the Specification; in addition drainages holes DH are provided in the mouthpiece member MP. Specifications 243,321, [Class 40 (iv)], and 513,352 also are referred to.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB237518X | 1938-04-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB513529A true GB513529A (en) | 1939-10-16 |
Family
ID=10200725
Family Applications (5)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7816/39A Expired GB513561A (en) | 1938-04-06 | 1938-04-06 | Improvements in or relating to telephone transmitters |
| GB10565/38A Expired GB513529A (en) | 1938-04-06 | 1938-04-06 | Improvements in or relating to telephone transmitters |
| GB7815/39A Expired GB526212A (en) | 1938-04-06 | 1939-03-10 | Improvements in or relating to telephone transmitters |
| GB21035/45A Expired GB594116A (en) | 1938-04-06 | 1944-08-15 | Improvements in or relating to microphones |
| GB1277/45A Expired GB593082A (en) | 1938-04-06 | 1945-01-16 | Improvements in and relating to sliding bolts for doors and otherwise |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7816/39A Expired GB513561A (en) | 1938-04-06 | 1938-04-06 | Improvements in or relating to telephone transmitters |
Family Applications After (3)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7815/39A Expired GB526212A (en) | 1938-04-06 | 1939-03-10 | Improvements in or relating to telephone transmitters |
| GB21035/45A Expired GB594116A (en) | 1938-04-06 | 1944-08-15 | Improvements in or relating to microphones |
| GB1277/45A Expired GB593082A (en) | 1938-04-06 | 1945-01-16 | Improvements in and relating to sliding bolts for doors and otherwise |
Country Status (4)
| Country | Link |
|---|---|
| BE (1) | BE433695A (en) |
| CH (1) | CH237518A (en) |
| FR (1) | FR852567A (en) |
| GB (5) | GB513561A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1012641B (en) * | 1954-04-27 | 1957-07-25 | Akg Akustische Kino Geraete | Arrangement at sound transducers to smooth the frequency characteristics |
| DE1025452B (en) * | 1952-09-18 | 1958-03-06 | Standard Elektrik Ag | Electro-acoustic converter with Helmholz resonator |
| DE1147631B (en) * | 1960-08-16 | 1963-04-25 | Sennheiser Electronic | Electroacoustic converter |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2758861A (en) * | 1954-11-12 | 1956-08-14 | Arthur N Molloy | Bolt lock |
| US4205206A (en) * | 1975-10-31 | 1980-05-27 | Iwatsu Electric Co. Ltd. | Carbon granule microphone with molded resin-conductive carbon electrode |
| GB2203480A (en) * | 1987-04-15 | 1988-10-19 | Leslie Thomas Isaac | Sliding bolt assembly |
-
0
- BE BE433695D patent/BE433695A/xx unknown
- FR FR852567D patent/FR852567A/fr not_active Expired
-
1938
- 1938-04-06 GB GB7816/39A patent/GB513561A/en not_active Expired
- 1938-04-06 GB GB10565/38A patent/GB513529A/en not_active Expired
-
1939
- 1939-03-10 GB GB7815/39A patent/GB526212A/en not_active Expired
- 1939-04-06 CH CH237518D patent/CH237518A/en unknown
-
1944
- 1944-08-15 GB GB21035/45A patent/GB594116A/en not_active Expired
-
1945
- 1945-01-16 GB GB1277/45A patent/GB593082A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1025452B (en) * | 1952-09-18 | 1958-03-06 | Standard Elektrik Ag | Electro-acoustic converter with Helmholz resonator |
| DE1012641B (en) * | 1954-04-27 | 1957-07-25 | Akg Akustische Kino Geraete | Arrangement at sound transducers to smooth the frequency characteristics |
| DE1147631B (en) * | 1960-08-16 | 1963-04-25 | Sennheiser Electronic | Electroacoustic converter |
Also Published As
| Publication number | Publication date |
|---|---|
| GB526212A (en) | 1940-09-12 |
| CH237518A (en) | 1945-04-30 |
| GB593082A (en) | 1947-10-08 |
| BE433695A (en) | |
| GB513561A (en) | 1939-10-16 |
| FR852567A (en) | 1940-03-01 |
| GB594116A (en) | 1947-11-03 |
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