GB998837A - Improvements in or relating to control of the transmission of electrical signals through networks - Google Patents
Improvements in or relating to control of the transmission of electrical signals through networksInfo
- Publication number
- GB998837A GB998837A GB506762A GB506762A GB998837A GB 998837 A GB998837 A GB 998837A GB 506762 A GB506762 A GB 506762A GB 506762 A GB506762 A GB 506762A GB 998837 A GB998837 A GB 998837A
- Authority
- GB
- United Kingdom
- Prior art keywords
- feed
- conducting
- transistors
- amplifier
- feb
- 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
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/04—Control of transmission; Equalising
- H04B3/10—Control of transmission; Equalising by pilot signal
- H04B3/12—Control of transmission; Equalising by pilot signal in negative-feedback path of line amplifier
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Control Of Amplification And Gain Control (AREA)
Abstract
998,837. Transistor amplifier circuits; automatic gain control. STANDARD TELEPHONES & CABLES Ltd. Feb. 8, 1963 [Feb. 9, 1962], No.5067/62. Headings H3T and H4R. An amplifier has a gain controlling negative feedback network which includes at least two resistive elements and two switching devices controlled by a unidirectional voltage so that operation of the switching devices varies the impedance of the feed-back network and hence the gain of the amplifier by two or more fixed amounts. Fig. 2 shows the preferred embodiment in which the amplifier transistors TR 3 and TR 4 have negative feed-back from output to the emitter circuit of transistor TR 3 via the feedback network R" R 2 and R 3 . Variation of the feed-back is accomplished by switching symmetrical transistors TR 1 and TR 2 . With TR 1 conducting the feed-back is zero, TR 1 non- conducting and TR 2 conducting the feed-back is at an intermediate value and with both TR 1 and TR 2 non-conducting the feed-back is a maximum. Capacitors Ca and Cb are D.C. blocking capacitors and resistor R 5 or R 5 <SP>1</SP> or R 5 <SP>11</SP> is inserted to prevent any D.C. surge on operation of transistors TR 1 or TR 2 . Transistors TR 1 and TR 2 . may be replaced by diodes.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB506762A GB998837A (en) | 1962-02-09 | 1962-02-09 | Improvements in or relating to control of the transmission of electrical signals through networks |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB506762A GB998837A (en) | 1962-02-09 | 1962-02-09 | Improvements in or relating to control of the transmission of electrical signals through networks |
Publications (1)
Publication Number | Publication Date |
---|---|
GB998837A true GB998837A (en) | 1965-07-21 |
Family
ID=9789129
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB506762A Expired GB998837A (en) | 1962-02-09 | 1962-02-09 | Improvements in or relating to control of the transmission of electrical signals through networks |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB998837A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2347833A1 (en) * | 1976-04-06 | 1977-11-04 | Int Standard Electric Corp | REMOTE CONTROL SYSTEM OF THE REPEATER GAIN OF A SUBMARINE CABLE |
-
1962
- 1962-02-09 GB GB506762A patent/GB998837A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2347833A1 (en) * | 1976-04-06 | 1977-11-04 | Int Standard Electric Corp | REMOTE CONTROL SYSTEM OF THE REPEATER GAIN OF A SUBMARINE CABLE |
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