JPS5711514A - Automatic level controller - Google Patents

Automatic level controller

Info

Publication number
JPS5711514A
JPS5711514A JP8543980A JP8543980A JPS5711514A JP S5711514 A JPS5711514 A JP S5711514A JP 8543980 A JP8543980 A JP 8543980A JP 8543980 A JP8543980 A JP 8543980A JP S5711514 A JPS5711514 A JP S5711514A
Authority
JP
Japan
Prior art keywords
circuit
output
amplifier
given
level 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.)
Pending
Application number
JP8543980A
Other languages
Japanese (ja)
Inventor
Kenji Fujibayashi
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.)
Olympus Corp
Original Assignee
Olympus Optic Co 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 Olympus Optic Co Ltd filed Critical Olympus Optic Co Ltd
Priority to JP8543980A priority Critical patent/JPS5711514A/en
Publication of JPS5711514A publication Critical patent/JPS5711514A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03GCONTROL OF AMPLIFICATION
    • H03G3/00Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/20Automatic control
    • H03G3/30Automatic control in amplifiers having semiconductor devices
    • H03G3/3005Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers
    • H03G3/301Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers the gain being continuously variable
    • H03G3/3015Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers the gain being continuously variable using diodes or transistors

Abstract

PURPOSE:To enable a stable level control by using a low voltage power supply such as dry batteries, by providing a detection circuit which can obtain a large DC output even with a comparatively smaller input signal, to a level control circuit used for a tape recorder. CONSTITUTION:An input signal is given to an input terminal 28, it is amplified through a level control circuit 29 at an amplifier 30, and outputted at an output terminal 34. Further, the output of an amplifier 30 is also given to the base point A of a transistor (TR)37 through a capacitor (C)36 of a detection circuit 35. A DC voltage according to the input from an amplifier 30 appears at the point B through the detecting operation of the TR37 and a C39, this DC voltage is given to a TR13 of the circuit 29, the base current of a TR14 is changed and the attenuation in the attenuation circuit consisting of resistors 8, 9 can be controlled. A diode 38 is connected forward between the points A and B of the circuit 35, the points A and B are biased to almost the same potential for DC positive feedback. Thus, a greater DC output is obtained with a comparatively small input and sure control can be made even with a low power supply voltage.
JP8543980A 1980-06-24 1980-06-24 Automatic level controller Pending JPS5711514A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8543980A JPS5711514A (en) 1980-06-24 1980-06-24 Automatic level controller

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8543980A JPS5711514A (en) 1980-06-24 1980-06-24 Automatic level controller

Publications (1)

Publication Number Publication Date
JPS5711514A true JPS5711514A (en) 1982-01-21

Family

ID=13858885

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8543980A Pending JPS5711514A (en) 1980-06-24 1980-06-24 Automatic level controller

Country Status (1)

Country Link
JP (1) JPS5711514A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58159008A (en) * 1982-03-16 1983-09-21 Matsushita Electric Ind Co Ltd Sound recording and amplifying circuit
CN102624344A (en) * 2012-03-22 2012-08-01 无锡士康通讯技术有限公司 Power amplifier

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58159008A (en) * 1982-03-16 1983-09-21 Matsushita Electric Ind Co Ltd Sound recording and amplifying circuit
CN102624344A (en) * 2012-03-22 2012-08-01 无锡士康通讯技术有限公司 Power amplifier

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