GB506128A - Gain control of valve amplifying systems - Google Patents

Gain control of valve amplifying systems

Info

Publication number
GB506128A
GB506128A GB24139/38A GB2413938A GB506128A GB 506128 A GB506128 A GB 506128A GB 24139/38 A GB24139/38 A GB 24139/38A GB 2413938 A GB2413938 A GB 2413938A GB 506128 A GB506128 A GB 506128A
Authority
GB
United Kingdom
Prior art keywords
bias
grid
output
valve
control
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
Application number
GB24139/38A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Publication of GB506128A publication Critical patent/GB506128A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G7/00—Volume compression or expansion in amplifiers
    • H03G7/02—Volume compression or expansion in amplifiers having discharge tubes

Landscapes

  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
  • Control Of Amplification And Gain Control (AREA)

Abstract

506,128. Automatic volume control. STANDARD TELEPHONES & CABLES, Ltd. Aug. 16, 1938, No. 24139. Convention date, Sept. 23, 1937. [Class 40 (v)] A volume compression system of the in which the rectified output of an amplifier is applied as variable bias to the grid of the valve includes also means to limit the output to a predetermined level by a rectified voltage applied to another grid of the same valve. The output from a microphone 1 is applied over amplifier 3 to the control stage 5 and thence over amplifier 4 to the loudspeaker 2. The output from 5 is also passed over amplifier 8 to a pair of rectifiers 9, 31, the former providing a control bias varying with input amplitude and applied to the grid 14 which has a variable-mu characteristic. This bias is superposed on a steady bias derived from tapping 33 on resistor 23 ; tapping 34 on this resistor provides also a steady bias on the second control grid 15 of valve 5 which has a linear characteristic with sharp cut-off and thus acts as a limiter. On this steady bias on grid 15 is imposed a bias variable with signal amplitude derived from rectifier 31. The time constants of the two rectifiers may be varied by means of condensers 35, 37 and resistors 36, 38 respectively. In a modification, Fig. 1 (not shown), the rectified output from a single rectifier is applied to both grids 14, 15 of valve 5.
GB24139/38A 1937-09-23 1938-08-16 Gain control of valve amplifying systems Expired GB506128A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US506128XA 1937-09-23 1937-09-23

Publications (1)

Publication Number Publication Date
GB506128A true GB506128A (en) 1939-05-23

Family

ID=21966284

Family Applications (1)

Application Number Title Priority Date Filing Date
GB24139/38A Expired GB506128A (en) 1937-09-23 1938-08-16 Gain control of valve amplifying systems

Country Status (1)

Country Link
GB (1) GB506128A (en)

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