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JPS56149807A - Agc circuit - Google Patents

Agc circuit

Info

Publication number
JPS56149807A
JPS56149807A JP5282680A JP5282680A JPS56149807A JP S56149807 A JPS56149807 A JP S56149807A JP 5282680 A JP5282680 A JP 5282680A JP 5282680 A JP5282680 A JP 5282680A JP S56149807 A JPS56149807 A JP S56149807A
Authority
JP
Japan
Prior art keywords
output
amplifier
band
circuit
inputted
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
JP5282680A
Other languages
Japanese (ja)
Inventor
Hiroshi Igarashi
Minoru Kidena
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP5282680A priority Critical patent/JPS56149807A/en
Publication of JPS56149807A publication Critical patent/JPS56149807A/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
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3036—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers
    • H03G3/3042—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers

Landscapes

  • Television Receiver Circuits (AREA)
  • Control Of Amplification And Gain Control (AREA)

Abstract

PURPOSE:To maintain a transmission output at a prescribed value based on the radio law, by taking a difference between the output which has detected a picture and sound signal of the transmission wave band for television repeating broadcast, and the output which has extracted and detected only a voice signal from the signal of IF band. CONSTITUTION:A picture and voice signal Sin of IF band is inputted to the terminal 11, and is led to the gain control circuit 12. An output of the circuit 12 passes through the frequency converting circuit 13 having the overall gain coefficient K3, the local oscillator 14 and the amplifier 15, and an output signal Sout of VHF or UHF band is outputted from the terminal 16. A part of the signal Sout is inputted to the differential amplifier 22 through the directional coupler C1 (coupling amount K1) and the peak detector (detection efficiency K21). On the other hand, a part of the output of the circuit 12 is inputted to the directional coupler C2 (coupling amount K2) and the IF band BPF23, and a voice signal component is extracted. This component is inputted to the amplifier 22 through the peak detector 24 (detection efficiency K24) and the DC amplifier 25 (gain coefficient K25). It is fed back to the circuit 12 from the amplifier 22 by setting said constants as shown in the expression.
JP5282680A 1980-04-23 1980-04-23 Agc circuit Pending JPS56149807A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5282680A JPS56149807A (en) 1980-04-23 1980-04-23 Agc circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5282680A JPS56149807A (en) 1980-04-23 1980-04-23 Agc circuit

Publications (1)

Publication Number Publication Date
JPS56149807A true JPS56149807A (en) 1981-11-19

Family

ID=12925649

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5282680A Pending JPS56149807A (en) 1980-04-23 1980-04-23 Agc circuit

Country Status (1)

Country Link
JP (1) JPS56149807A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2569920A1 (en) * 1984-09-03 1986-03-07 Pioneer Electronic Corp SUPERHETERODYNE WITH AN ANTI-INTERFERENCE DEVICE

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2569920A1 (en) * 1984-09-03 1986-03-07 Pioneer Electronic Corp SUPERHETERODYNE WITH AN ANTI-INTERFERENCE DEVICE

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