JPS5619214A - Agc circuit - Google Patents

Agc circuit

Info

Publication number
JPS5619214A
JPS5619214A JP9540079A JP9540079A JPS5619214A JP S5619214 A JPS5619214 A JP S5619214A JP 9540079 A JP9540079 A JP 9540079A JP 9540079 A JP9540079 A JP 9540079A JP S5619214 A JPS5619214 A JP S5619214A
Authority
JP
Japan
Prior art keywords
voltage
trq3
trq1
negative feedback
input
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
JP9540079A
Other languages
Japanese (ja)
Inventor
Yamato Okashin
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.)
Sony Corp
Original Assignee
Sony Corp
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 Sony Corp filed Critical Sony Corp
Priority to JP9540079A priority Critical patent/JPS5619214A/en
Publication of JPS5619214A publication Critical patent/JPS5619214A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3005—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers

Abstract

PURPOSE:To prevent occurrence of the distortion during the large input with a simple constitution, by securing the functions of the two transistors as a B-class push-pull amplifier each during the large input and at the same time varying the extent or the negative feedback. CONSTITUTION:In case the input level is high, AGC voltage E3 is small. And accordingly, DC voltage E5 applied to transistor (TR)Q5 is also reduced. Thus TRQ1, Q2 receive the B-class bias, and at the same time the working pont of TRQ3 reaches the saturation region to secure the function as an impedance element for TRQ3. And TRQ1, Q2 are turned into the B-class push-pull amplifiers with the current negative feedback applied. In this case, voltage E3 varies contrarily with change of the input level. Then the higher the input level the less collector current IS, and accordingly the collector current of TRQ13 is reduced to decrease the collector voltage. As a result, the impedance of TRQ3 is increased, and then the extent of the current negative feedback is increased to TRQ1, Q2 to decrease the gain. Thus the distortion occurring during the large input can be prevented.
JP9540079A 1979-07-26 1979-07-26 Agc circuit Pending JPS5619214A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9540079A JPS5619214A (en) 1979-07-26 1979-07-26 Agc circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9540079A JPS5619214A (en) 1979-07-26 1979-07-26 Agc circuit

Publications (1)

Publication Number Publication Date
JPS5619214A true JPS5619214A (en) 1981-02-23

Family

ID=14136603

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9540079A Pending JPS5619214A (en) 1979-07-26 1979-07-26 Agc circuit

Country Status (1)

Country Link
JP (1) JPS5619214A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59125109A (en) * 1982-12-30 1984-07-19 Rohm Co Ltd Gain variable amplifier

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59125109A (en) * 1982-12-30 1984-07-19 Rohm Co Ltd Gain variable amplifier

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