GB553935A - Improvements in or relating to voice-frequency signalling systems - Google Patents
Improvements in or relating to voice-frequency signalling systemsInfo
- Publication number
- GB553935A GB553935A GB5882/42A GB588242A GB553935A GB 553935 A GB553935 A GB 553935A GB 5882/42 A GB5882/42 A GB 5882/42A GB 588242 A GB588242 A GB 588242A GB 553935 A GB553935 A GB 553935A
- Authority
- GB
- United Kingdom
- Prior art keywords
- voice
- frequency
- amplifier
- cycles
- condenser
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
- H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Arrangements For Transmission Of Measured Signals (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
553,935. Voice - frequency signalling. STANDARD TELEPHONES & CABLES, Ltd. May 1, 1942, No. 5882. Convention date, April 19, 1941. [Class 40 (iv)] [Also in Group XL] A receiver for low frequency signals modulated on to voice frequency comprises a thermionic detector D coupled to a thermionic amplifier A through a resistance-condenser combination such as to ensure operation only after receipt of a number of low frequency pulses. In this way the amplifier is slowly unblocked at a rate which may be varied by varying the capacity of the condenser 11 and be such as to prevent unblocking of the amplifier by a transitory operation of the detector. The Specification gives data for a system operating at 1000 cycles interrupted at a frequency of 20 cycles. The secondary of the output transformer LF is tuned to 20 cycles by condenser 3 and retard coil 2 and the circuit completed by a rectifier 4 and relay 6.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US389335A US2299279A (en) | 1941-04-19 | 1941-04-19 | Signaling system |
Publications (1)
Publication Number | Publication Date |
---|---|
GB553935A true GB553935A (en) | 1943-06-10 |
Family
ID=23537833
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB5882/42A Expired GB553935A (en) | 1941-04-19 | 1942-05-01 | Improvements in or relating to voice-frequency signalling systems |
Country Status (2)
Country | Link |
---|---|
US (1) | US2299279A (en) |
GB (1) | GB553935A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2572814A (en) * | 1950-01-06 | 1951-10-23 | Marie K Laporte | Telephone shell and signal light |
-
1941
- 1941-04-19 US US389335A patent/US2299279A/en not_active Expired - Lifetime
-
1942
- 1942-05-01 GB GB5882/42A patent/GB553935A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US2299279A (en) | 1942-10-20 |
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