GB855997A - Improvements in or relating to electric control circuits - Google Patents

Improvements in or relating to electric control circuits

Info

Publication number
GB855997A
GB855997A GB40337/57A GB4033757A GB855997A GB 855997 A GB855997 A GB 855997A GB 40337/57 A GB40337/57 A GB 40337/57A GB 4033757 A GB4033757 A GB 4033757A GB 855997 A GB855997 A GB 855997A
Authority
GB
United Kingdom
Prior art keywords
bias
amplifier
rectifiers
input
shunt
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
GB40337/57A
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.)
SVENSKA RELAFABRIKEN AB
Original Assignee
SVENSKA RELAFABRIKEN AB
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 SVENSKA RELAFABRIKEN AB filed Critical SVENSKA RELAFABRIKEN AB
Publication of GB855997A publication Critical patent/GB855997A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)

Abstract

855,997. Automatic volume control. SVENSKA RELAFABRIKEN A.B. Dec. 30, 1957 [Oct. 31, 1957], No. 40337/57. Class 40 (4). A variable attenuation network comprises shunt non-linear resistances controlled from a bias source having two variable D.C. voltages of opposite sign superimposed thereon. The arrangement is used to condition a two-way amplifier in accordance with the amplitude and directions of speech currents received by it. As shown, terminals a, b and c, d are connected across the inputs to stages of amplifiers amplifying signals travelling in opposite directions. Thus the rectifiers D9, D10 and condensers C13, C14 constitute a shunt across the inputs of one of the stages. Rectifiers D9, D10 are normally partially conducting due to bias over resistors R13, R17. When the input to transformer T1 exceeds the bias, applied over resistors R12, R15, to rectifier D5 the condenser C10 charges with such a polarity as to decrease the D.C. through rectifiers D9, D10, thereby decreasing the shunt effect on the amplifier. Likewise a signal exceeding the bias on D3 charges C11 to increase the D.C. through D9, D10 and thereby increase the shunting effect. The upper controlling network operates in a similar manner. The latter is associated with the amplifier output which provides the input for T2. The lower network is associated with the amplifier whose output provides the input for T1. Thus the gains of the amplifiers in the two directions are arranged that when one rises the other falls, thereby preventing singing.
GB40337/57A 1957-10-31 1957-12-30 Improvements in or relating to electric control circuits Expired GB855997A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE855997X 1957-10-31

Publications (1)

Publication Number Publication Date
GB855997A true GB855997A (en) 1960-12-14

Family

ID=20362822

Family Applications (1)

Application Number Title Priority Date Filing Date
GB40337/57A Expired GB855997A (en) 1957-10-31 1957-12-30 Improvements in or relating to electric control circuits

Country Status (1)

Country Link
GB (1) GB855997A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0004054A1 (en) * 1978-03-10 1979-09-19 Siemens Aktiengesellschaft Circuit for automatically equalizing a signal

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0004054A1 (en) * 1978-03-10 1979-09-19 Siemens Aktiengesellschaft Circuit for automatically equalizing a signal

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