GB797055A - Improvements in and relating to electrical communication systems - Google Patents
Improvements in and relating to electrical communication systemsInfo
- Publication number
- GB797055A GB797055A GB32549/55A GB3254955A GB797055A GB 797055 A GB797055 A GB 797055A GB 32549/55 A GB32549/55 A GB 32549/55A GB 3254955 A GB3254955 A GB 3254955A GB 797055 A GB797055 A GB 797055A
- Authority
- GB
- United Kingdom
- Prior art keywords
- over
- line
- controlled
- rectifier
- nov
- 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
- 230000006835 compression Effects 0.000 abstract 2
- 238000007906 compression Methods 0.000 abstract 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract 1
- 229910052799 carbon Inorganic materials 0.000 abstract 1
- 239000004020 conductor Substances 0.000 abstract 1
- 230000001419 dependent effect Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 abstract 1
- 238000001914 filtration Methods 0.000 abstract 1
- 239000008187 granular material Substances 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
Landscapes
- Transmitters (AREA)
Abstract
797,055. Volume controlling. SVENSKA RELAFABRIKEN AKTIEBOLAGET. Nov. 14, 1955 [Nov. 29, 1954], No. 32549/55. Class 40 (4). In a communication system in which the level of a transmitted signal is dependent on the intensity of a direct current supplied over the line to a transmitting apparatus (e.g. a system using a carbon granule microphone), the intensity of the D.C. applied to the line is controlled in dependence on the strength of signal voltages arriving at the receiving station. Direct current supplied to the " send " transistor amplifier F1, Fig. 1, over line L from a battery B is controlled by an opposed voltage produced in a rectifier LR by the received signals. The arrangement which produces amplitude compression may alternatively be modified to effect compression and hence limitation on high level signals, and expansion on low level signals. The source B and rectifier LR may be replaced by a single unit wherein the D.C. power is derived from a mains source and regulation of the output is effected directly by the received signals. In this arrangement the rate at which the current may increase may by the inclusion of filtering devices be made to differ from that at which it may be reduced. In a further embodiment described with reference to Fig. 2 (not shown), a push-pull transistor amplifier at the transmitter has its collectors fed with controlled D.C. over the line wires and the circuit is completed to their commoned emitters over a separate conductor.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE797055X | 1954-11-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB797055A true GB797055A (en) | 1958-06-25 |
Family
ID=20339792
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB32549/55A Expired GB797055A (en) | 1954-11-29 | 1955-11-14 | Improvements in and relating to electrical communication systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB797055A (en) |
-
1955
- 1955-11-14 GB GB32549/55A patent/GB797055A/en not_active Expired
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