FR2276756A1 - Automatic level control for microphone amplifier - uses series transistor with its base polarisation varying with output - Google Patents

Automatic level control for microphone amplifier - uses series transistor with its base polarisation varying with output

Info

Publication number
FR2276756A1
FR2276756A1 FR7421832A FR7421832A FR2276756A1 FR 2276756 A1 FR2276756 A1 FR 2276756A1 FR 7421832 A FR7421832 A FR 7421832A FR 7421832 A FR7421832 A FR 7421832A FR 2276756 A1 FR2276756 A1 FR 2276756A1
Authority
FR
France
Prior art keywords
output
base
level control
automatic level
transistor
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.)
Granted
Application number
FR7421832A
Other languages
French (fr)
Other versions
FR2276756B1 (en
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.)
AUDIBEL
Original Assignee
AUDIBEL
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 AUDIBEL filed Critical AUDIBEL
Priority to FR7421832A priority Critical patent/FR2276756A1/en
Publication of FR2276756A1 publication Critical patent/FR2276756A1/en
Application granted granted Critical
Publication of FR2276756B1 publication Critical patent/FR2276756B1/fr
Granted 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
    • H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
    • H04R25/35—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception using translation techniques
    • H04R25/356—Amplitude, e.g. amplitude shift or compression
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
    • H04R25/50—Customised settings for obtaining desired overall acoustical characteristics
    • H04R25/502—Customised settings for obtaining desired overall acoustical characteristics using analog signal processing

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Neurosurgery (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Control Of Amplification And Gain Control (AREA)

Abstract

An automatic level control audio circuit is for either a polarised or unpolarised microphone. The output of the microphone is connected to the collector of a transistor (Q) and the emitter is connected to an amplifier of appropriate gain. The transistor connections may be reversed. Its base is polarised in one direction by a fixed resistor (R1) and in the other direction by the rectified output (R3) of a potentiometer across the amplifier output. In this way the transistor has its transfer resistance varied as a function of the output level thus giving automatic gain control.
FR7421832A 1974-06-24 1974-06-24 Automatic level control for microphone amplifier - uses series transistor with its base polarisation varying with output Granted FR2276756A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7421832A FR2276756A1 (en) 1974-06-24 1974-06-24 Automatic level control for microphone amplifier - uses series transistor with its base polarisation varying with output

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7421832A FR2276756A1 (en) 1974-06-24 1974-06-24 Automatic level control for microphone amplifier - uses series transistor with its base polarisation varying with output

Publications (2)

Publication Number Publication Date
FR2276756A1 true FR2276756A1 (en) 1976-01-23
FR2276756B1 FR2276756B1 (en) 1980-04-25

Family

ID=9140426

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7421832A Granted FR2276756A1 (en) 1974-06-24 1974-06-24 Automatic level control for microphone amplifier - uses series transistor with its base polarisation varying with output

Country Status (1)

Country Link
FR (1) FR2276756A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3306441A1 (en) * 1982-03-01 1983-09-08 N.V. Philips' Gloeilampenfabrieken, 5621 Eindhoven AMPLIFIER SYSTEM WITH AUTOMATIC GAIN CONTROL AND HEARING AID WITH SUCH AN AMPLIFIER SYSTEM

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1161002A (en) * 1966-02-21 1969-08-13 Royal Industries Improvements in and relating to Hearing Aids
DE2452998A1 (en) * 1973-11-21 1975-05-22 Viennatone Hoergeraete HOE EQUIPMENT

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1161002A (en) * 1966-02-21 1969-08-13 Royal Industries Improvements in and relating to Hearing Aids
DE2452998A1 (en) * 1973-11-21 1975-05-22 Viennatone Hoergeraete HOE EQUIPMENT

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3306441A1 (en) * 1982-03-01 1983-09-08 N.V. Philips' Gloeilampenfabrieken, 5621 Eindhoven AMPLIFIER SYSTEM WITH AUTOMATIC GAIN CONTROL AND HEARING AID WITH SUCH AN AMPLIFIER SYSTEM

Also Published As

Publication number Publication date
FR2276756B1 (en) 1980-04-25

Similar Documents

Publication Publication Date Title
ES375554A1 (en) Signal translating stage
ES341641A1 (en) Gain controlled amplifier using field effect type transistor as the active element thereof
FR2276756A1 (en) Automatic level control for microphone amplifier - uses series transistor with its base polarisation varying with output
GB1289005A (en)
GB1161002A (en) Improvements in and relating to Hearing Aids
JPS524757A (en) Amplifier
SE7506200L (en) REINFORCEMENT CONTROL CIRCUIT
JPS5780813A (en) Amplifier
SU1589381A1 (en) Amplifyer with electronic control of gain
ES437513A1 (en) Monostable multivibrator
JPS5267547A (en) Transistor amplifying circuit
JPS5216952A (en) Transistor amplifying circuit
GB1030941A (en) Circuit arrangement for varying the level of a signal
JPS5786917A (en) Direct-current stabilized power source device
GB1312930A (en) Automatic gain control arrangements
GB1104132A (en) Improvements in or relating to limiter circuits
JPS5370480A (en) Photo agc system
JPS5357952A (en) Gain control circuit
JPS52139343A (en) Agc circuit
JPS51117856A (en) Automatic gain control circuit
JPS51132063A (en) Transistor amplifier
JPS5483744A (en) Transistor limiter circuit
JPS5442964A (en) Automatic gain control circuit
GB1509420A (en) Amplifier arrangement with automatic nonlinearity correction
JPS5354455A (en) Negative resistance amplifier

Legal Events

Date Code Title Description
ST Notification of lapse