BE499477A - - Google Patents
Info
- Publication number
- BE499477A BE499477A BE499477DA BE499477A BE 499477 A BE499477 A BE 499477A BE 499477D A BE499477D A BE 499477DA BE 499477 A BE499477 A BE 499477A
- Authority
- BE
- Belgium
Links
Classifications
-
- 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
- H04M1/21—Combinations with auxiliary equipment, e.g. with clocks or memoranda pads
- H04M1/215—Combinations with auxiliary equipment, e.g. with clocks or memoranda pads by non-intrusive coupling means, e.g. acoustic couplers
- H04M1/2155—Acoustic coupling
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
- H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
- H04M1/62—Constructional arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Details Of Audible-Bandwidth Transducers (AREA)
- Coils Or Transformers For Communication (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1427050A GB684633A (en) | 1950-06-08 | 1950-06-08 | Improvements in or relating to amplifying devices for use with telephone apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE499477A true BE499477A (xx) |
Family
ID=10038122
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE499477D BE499477A (xx) | 1950-06-08 |
Country Status (3)
| Country | Link |
|---|---|
| BE (1) | BE499477A (xx) |
| CH (1) | CH288283A (xx) |
| GB (2) | GB646589A (xx) |
-
0
- BE BE499477D patent/BE499477A/xx unknown
-
1948
- 1948-01-23 GB GB207648A patent/GB646589A/en not_active Expired
-
1950
- 1950-06-08 GB GB1427050A patent/GB684633A/en not_active Expired
- 1950-11-22 CH CH288283D patent/CH288283A/de unknown
Also Published As
| Publication number | Publication date |
|---|---|
| CH288283A (de) | 1953-01-15 |
| GB684633A (en) | 1952-12-24 |
| GB646589A (en) | 1950-11-22 |