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GB1350142A - Controllable attenuator - Google Patents

Controllable attenuator

Info

Publication number
GB1350142A
GB1350142A GB5073171A GB5073171A GB1350142A GB 1350142 A GB1350142 A GB 1350142A GB 5073171 A GB5073171 A GB 5073171A GB 5073171 A GB5073171 A GB 5073171A GB 1350142 A GB1350142 A GB 1350142A
Authority
GB
United Kingdom
Prior art keywords
attenuator
loud
emitter
nov
controlled
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
GB5073171A
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.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson 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
Priority claimed from SE16092/70A external-priority patent/SE337846B/xx
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Publication of GB1350142A publication Critical patent/GB1350142A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H11/00—Networks using active elements
    • H03H11/02—Multiple-port networks
    • H03H11/24—Frequency-independent attenuators
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G1/00—Details of arrangements for controlling amplification
    • H03G1/0005—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal
    • H03G1/0035—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements
    • H03G1/0082—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements using bipolar transistor-type devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Networks Using Active Elements (AREA)

Abstract

1350142 Volume control TELEFONAKTIEBOLAGET L M ERICSSON 1 Nov 1971 [27 Nov 1970] 50731/71 Heading H4R Controllable attenuator has two signal input terminals 1, 2, e.g. for a balanced input signal, connected to respective output terminals by resistors R2 and R3 with the emitter-base impedances of transistors V1, V2, connected in shunt to the output terminals and the emitter base impedances being varied by controlling the emitter current which is fed from a common variable current source V3, controlled by a control potential applied to terminal 5. The attenuator can be used in an echo suppressor for a loud-speaking telephone Fig. 2 (not shown), with the attenuator in the microphone path, and possibly the loud-speaker path, controlled by the signal fed to the loud-speaker.
GB5073171A 1970-11-27 1971-11-01 Controllable attenuator Expired GB1350142A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE16092/70A SE337846B (en) 1970-11-27 1970-11-27
FR7142363A FR2116072A5 (en) 1970-11-27 1971-11-26

Publications (1)

Publication Number Publication Date
GB1350142A true GB1350142A (en) 1974-04-18

Family

ID=26216737

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5073171A Expired GB1350142A (en) 1970-11-27 1971-11-01 Controllable attenuator

Country Status (5)

Country Link
CH (1) CH526234A (en)
DE (1) DE2157709A1 (en)
FR (1) FR2116072A5 (en)
GB (1) GB1350142A (en)
NL (1) NL7115909A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0742642A3 (en) * 1995-05-09 1997-11-05 Sony Corporation Level control circuit for receiver

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2638286C3 (en) * 1976-08-25 1979-03-01 Dasy Inter S.A., Genf (Schweiz) Circuit arrangement for a hands-free telephone

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0742642A3 (en) * 1995-05-09 1997-11-05 Sony Corporation Level control circuit for receiver
US5758270A (en) * 1995-05-09 1998-05-26 Sony Corporation Level control circuit for receiver
CN1064796C (en) * 1995-05-09 2001-04-18 索尼公司 Level control circuit for receiver

Also Published As

Publication number Publication date
NL7115909A (en) 1972-05-30
CH526234A (en) 1972-07-31
FR2116072A5 (en) 1972-07-07
DE2157709A1 (en) 1972-06-08

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee