NL25706C - - Google Patents
Info
- Publication number
- NL25706C NL25706C NL25706DA NL25706C NL 25706 C NL25706 C NL 25706C NL 25706D A NL25706D A NL 25706DA NL 25706 C NL25706 C NL 25706C
- Authority
- NL
- Netherlands
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
- H04R21/00—Variable-resistance transducers
- H04R21/02—Microphones
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/02—Constructional features of telephone sets
- H04M1/03—Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
- Telephone Set Structure (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB28960/27A GB304843A (en) | 1927-10-31 | 1927-10-31 | Improvements in or relating to telephone hand sets |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NL25706C true NL25706C (en:Method) |
Family
ID=10283971
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL25706D NL25706C (en:Method) | 1927-10-31 |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US1779490A (en:Method) |
| FR (1) | FR660479A (en:Method) |
| GB (1) | GB304843A (en:Method) |
| NL (1) | NL25706C (en:Method) |
-
0
- NL NL25706D patent/NL25706C/xx active
-
1927
- 1927-10-31 GB GB28960/27A patent/GB304843A/en not_active Expired
-
1928
- 1928-09-15 FR FR660479D patent/FR660479A/fr not_active Expired
- 1928-12-12 US US325614A patent/US1779490A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| FR660479A (fr) | 1929-07-11 |
| US1779490A (en) | 1930-10-28 |
| GB304843A (en) | 1929-01-31 |