BE484178A - - Google Patents
Info
- Publication number
- BE484178A BE484178A BE484178DA BE484178A BE 484178 A BE484178 A BE 484178A BE 484178D A BE484178D A BE 484178DA BE 484178 A BE484178 A BE 484178A
- Authority
- BE
- Belgium
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
- H04R1/22—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)
- Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH2572525X | 1947-08-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE484178A true BE484178A (de) |
Family
ID=4570209
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE484178D BE484178A (de) | 1947-08-06 |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US2572525A (de) |
| BE (1) | BE484178A (de) |
| CH (1) | CH269350A (de) |
| DE (1) | DE874019C (de) |
| FR (1) | FR969788A (de) |
| NL (1) | NL70171C (de) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE954967C (de) * | 1952-11-01 | 1956-12-27 | Standard Elek K Ag | Kohlemikrofon mit einer beweglichen und einer festen Elektrode, die in mehrere Teilelektroden unterteilt ist |
| DE1234267B (de) * | 1964-04-04 | 1967-02-16 | Telefonbau | Kohlemikrofon |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US557588A (en) * | 1896-04-07 | Telephony | ||
| US563395A (en) * | 1896-07-07 | Telephone-transmitter | ||
| US778409A (en) * | 1903-04-20 | 1904-12-27 | Oscar M Frykman | Telephone apparatus. |
| US1117231A (en) * | 1911-11-13 | 1914-11-17 | Western Electric Co | Loud-speaking transmitter. |
| US2179733A (en) * | 1934-11-27 | 1939-11-14 | Siemens Brothers & Co Ltd | Microphone |
| US2149628A (en) * | 1935-09-16 | 1939-03-07 | Associated Electric Lab Inc | Telephone transmitter |
| US2140859A (en) * | 1936-12-14 | 1938-12-20 | Siemens Ag | Telephone transmitter |
| GB513160A (en) * | 1938-03-01 | 1939-10-05 | Donald Mcmillan | Improvements in or relating to microphones |
| US2435920A (en) * | 1943-09-20 | 1948-02-10 | Electro Voice Mfg Co Inc | Balanced granular microphone |
-
0
- NL NL70171D patent/NL70171C/xx active
- BE BE484178D patent/BE484178A/xx unknown
-
1947
- 1947-08-06 CH CH269350D patent/CH269350A/de unknown
-
1948
- 1948-07-29 US US41371A patent/US2572525A/en not_active Expired - Lifetime
- 1948-07-30 FR FR969788D patent/FR969788A/fr not_active Expired
-
1949
- 1949-01-01 DE DEP29181A patent/DE874019C/de not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR969788A (fr) | 1950-12-26 |
| US2572525A (en) | 1951-10-23 |
| CH269350A (de) | 1950-06-30 |
| DE874019C (de) | 1953-04-20 |
| NL70171C (de) |