GB1454617A - Low-frequency amplifier - Google Patents

Low-frequency amplifier

Info

Publication number
GB1454617A
GB1454617A GB427874A GB427874A GB1454617A GB 1454617 A GB1454617 A GB 1454617A GB 427874 A GB427874 A GB 427874A GB 427874 A GB427874 A GB 427874A GB 1454617 A GB1454617 A GB 1454617A
Authority
GB
United Kingdom
Prior art keywords
frequency
resonant
potentiometer
adjust
peak height
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
GB427874A
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.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronic and Associated Industries Ltd
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 Philips Electronic and Associated Industries Ltd filed Critical Philips Electronic and Associated Industries Ltd
Publication of GB1454617A publication Critical patent/GB1454617A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/02—Circuits for transducers, loudspeakers or microphones for preventing acoustic reaction, i.e. acoustic oscillatory feedback
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/181—Low-frequency amplifiers, e.g. audio preamplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G5/00—Tone control or bandwidth control in amplifiers
    • H03G5/02—Manually-operated control
    • H03G5/025—Equalizers; Volume or gain control in limited frequency bands
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H11/00—Networks using active elements
    • H03H11/02—Multiple-port networks
    • H03H11/04—Frequency selective two-port networks
    • H03H11/12—Frequency selective two-port networks using amplifiers with feedback
    • H03H11/1217—Frequency selective two-port networks using amplifiers with feedback using a plurality of operational amplifiers

Landscapes

  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Power Engineering (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Networks Using Active Elements (AREA)
  • Amplifiers (AREA)

Abstract

1454617 Amplifiers PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 30 Jan 1974 [20 Feb 1973] 04278/74 Heading H3W A low frequency amplifier includes a number of identical equalizing filters which are independently adjustable in respect of Q, peak height and resonant frquency. Each filter comprises differential amplifiers 50, 51 interconnected by a frequency selective network 54, which may be a Wien Bridge, and having a feedback path via resistors 61, 62, 63. Potentiometer 56 adjusts the band width, potentiometer 59 adjust the peak height and ganged resistors 68, 69 adjust the resonant frequency. Either bandpass or notch responses can be obtained. Alternatively, Fig. 2, the frequency selective network may comprise a LC circuit 77, 76 the effective inductance and capacitance, and hence the resonant frequency being controlled by potentiometers 78, 79.
GB427874A 1973-02-20 1974-01-30 Low-frequency amplifier Expired GB1454617A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7302303A NL7302303A (en) 1973-02-20 1973-02-20

Publications (1)

Publication Number Publication Date
GB1454617A true GB1454617A (en) 1976-11-03

Family

ID=19818261

Family Applications (1)

Application Number Title Priority Date Filing Date
GB427874A Expired GB1454617A (en) 1973-02-20 1974-01-30 Low-frequency amplifier

Country Status (5)

Country Link
JP (1) JPS49115453A (en)
DE (1) DE2405783C2 (en)
FR (1) FR2219599B1 (en)
GB (1) GB1454617A (en)
NL (1) NL7302303A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4403201A (en) * 1980-03-24 1983-09-06 Nippon Gakki Seizo Kabushiki Kaisha Bandpass filter circuit

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4336501A (en) * 1978-09-26 1982-06-22 Nippon Columbia Kabushiki Kaisha Frequency characteristic adjusting circuit

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3657480A (en) * 1969-08-22 1972-04-18 Theodore Cheng Multi channel audio system with crossover network feeding separate amplifiers for each channel with direct coupling to low frequency loudspeaker

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4403201A (en) * 1980-03-24 1983-09-06 Nippon Gakki Seizo Kabushiki Kaisha Bandpass filter circuit

Also Published As

Publication number Publication date
DE2405783C2 (en) 1981-12-10
FR2219599B1 (en) 1982-05-07
DE2405783A1 (en) 1974-08-22
JPS49115453A (en) 1974-11-05
NL7302303A (en) 1974-08-22
FR2219599A1 (en) 1974-09-20

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Legal Events

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