GB526212A - Improvements in or relating to telephone transmitters - Google Patents
Improvements in or relating to telephone transmittersInfo
- Publication number
- GB526212A GB526212A GB7815/39A GB781539A GB526212A GB 526212 A GB526212 A GB 526212A GB 7815/39 A GB7815/39 A GB 7815/39A GB 781539 A GB781539 A GB 781539A GB 526212 A GB526212 A GB 526212A
- Authority
- GB
- United Kingdom
- Prior art keywords
- electrode
- graphite
- class
- coating
- electrode body
- 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
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract 6
- 229910002804 graphite Inorganic materials 0.000 abstract 5
- 239000010439 graphite Substances 0.000 abstract 5
- 239000011248 coating agent Substances 0.000 abstract 3
- 238000000576 coating method Methods 0.000 abstract 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 abstract 2
- 239000004020 conductor Substances 0.000 abstract 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 abstract 1
- 229910052799 carbon Inorganic materials 0.000 abstract 1
- 229910010293 ceramic material Inorganic materials 0.000 abstract 1
- 229910052802 copper Inorganic materials 0.000 abstract 1
- 239000010949 copper Substances 0.000 abstract 1
- 238000010438 heat treatment Methods 0.000 abstract 1
- 239000012535 impurity Substances 0.000 abstract 1
- 239000002904 solvent Substances 0.000 abstract 1
- 229910001220 stainless steel Inorganic materials 0.000 abstract 1
- 239000010935 stainless steel Substances 0.000 abstract 1
- 239000000725 suspension Substances 0.000 abstract 1
- 239000000057 synthetic resin Substances 0.000 abstract 1
- 229920003002 synthetic resin Polymers 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
Abstract
526,212. Microphones. STANDARD TELEPHONES & CABLES, Ltd., POCOCK, L. C., and LEMAN, H. S. March 10, 1939, No. 7815. Divided out of 513,529. [Class 40 (iv)] The active surface of an electrode for a telephone transmitter of the carbon granular type is formed by a coating of graphite on an electrode body of stainless steel, copper, ceramic material, synthetic resin or of a poor conducting or non-conducting material. The coating may be applied by heating the body to a temperature exceeding 300‹ C. and preferably up to 900‹ C. whilst in contact with fine graphite for a period of about one hour or by using a colloidal suspension of graphite in a volatile solvent such as acetone. The electrode may be sand-blasted or etched prior to the application of the coating and the graphite layer may be burnished and heated to remove impurities. When the electrode body is a poor conductor a graphite layer extends from the active surface of the electrode to a suitable contact or an accessible part of the electrode body. Specifications 1147/92, [Class 40], and 324,698, [ Class 40 (iv)], are referred to.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB237518X | 1938-04-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB526212A true GB526212A (en) | 1940-09-12 |
Family
ID=10200725
Family Applications (5)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB10565/38A Expired GB513529A (en) | 1938-04-06 | 1938-04-06 | Improvements in or relating to telephone transmitters |
| GB7816/39A Expired GB513561A (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 (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB10565/38A Expired GB513529A (en) | 1938-04-06 | 1938-04-06 | Improvements in or relating to telephone transmitters |
| GB7816/39A Expired GB513561A (en) | 1938-04-06 | 1938-04-06 | Improvements in or relating to telephone transmitters |
Family Applications After (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| 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) | GB513529A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4205206A (en) * | 1975-10-31 | 1980-05-27 | Iwatsu Electric Co. Ltd. | Carbon granule microphone with molded resin-conductive carbon electrode |
Families Citing this family (5)
| 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 |
| US2758861A (en) * | 1954-11-12 | 1956-08-14 | Arthur N Molloy | Bolt lock |
| DE1147631B (en) * | 1960-08-16 | 1963-04-25 | Sennheiser Electronic | Electroacoustic converter |
| 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 GB10565/38A patent/GB513529A/en not_active Expired
- 1938-04-06 GB GB7816/39A patent/GB513561A/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 (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4205206A (en) * | 1975-10-31 | 1980-05-27 | Iwatsu Electric Co. Ltd. | Carbon granule microphone with molded resin-conductive carbon electrode |
Also Published As
| Publication number | Publication date |
|---|---|
| FR852567A (en) | 1940-03-01 |
| GB513561A (en) | 1939-10-16 |
| GB513529A (en) | 1939-10-16 |
| GB593082A (en) | 1947-10-08 |
| GB594116A (en) | 1947-11-03 |
| CH237518A (en) | 1945-04-30 |
| BE433695A (en) |
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