FR742731A - - Google Patents
Info
- Publication number
- FR742731A FR742731A FR742731DA FR742731A FR 742731 A FR742731 A FR 742731A FR 742731D A FR742731D A FR 742731DA FR 742731 A FR742731 A FR 742731A
- Authority
- FR
- France
- 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
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
- H04R21/021—Microphones with granular resistance material
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Details Of Audible-Bandwidth Transducers (AREA)
- Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
- Amplitude Modulation (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1107536A GB471270A (en) | 1936-04-17 | 1936-04-17 | Improvements in or relating to granular microphones |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| FR742731A true FR742731A (en:Method) | 1933-03-14 |
Family
ID=9979554
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FR742731D Expired FR742731A (en:Method) | 1936-04-17 |
Country Status (3)
| Country | Link |
|---|---|
| BE (1) | BE390588A (en:Method) |
| FR (1) | FR742731A (en:Method) |
| GB (2) | GB383348A (en:Method) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1061825B (de) * | 1954-02-26 | 1959-07-23 | Hans Widmaier | Kohlegriessmikrophon-Sprechkapsel |
-
0
- FR FR742731D patent/FR742731A/fr not_active Expired
- BE BE390588D patent/BE390588A/xx unknown
-
1931
- 1931-09-12 GB GB2563331A patent/GB383348A/en not_active Expired
-
1936
- 1936-04-17 GB GB1107536A patent/GB471270A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| BE390588A (en:Method) | |
| GB383348A (en) | 1932-11-17 |
| GB471270A (en) | 1937-09-01 |