JPS57118446A - Control method of peak differential wave detection type fm demodulating circuit - Google Patents

Control method of peak differential wave detection type fm demodulating circuit

Info

Publication number
JPS57118446A
JPS57118446A JP56003100A JP310081A JPS57118446A JP S57118446 A JPS57118446 A JP S57118446A JP 56003100 A JP56003100 A JP 56003100A JP 310081 A JP310081 A JP 310081A JP S57118446 A JPS57118446 A JP S57118446A
Authority
JP
Japan
Prior art keywords
circuit
signal
control
differential amplifier
differential wave
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
JP56003100A
Other languages
Japanese (ja)
Other versions
JPS6313608B2 (en
Inventor
Yoshio Amamiya
Masanori Ogino
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP56003100A priority Critical patent/JPS57118446A/en
Publication of JPS57118446A publication Critical patent/JPS57118446A/en
Publication of JPS6313608B2 publication Critical patent/JPS6313608B2/ja
Granted 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
    • H03G3/34—Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise signals, e.g. squelch systems

Abstract

PURPOSE:To suppress the occurrence of an abnormal sound and to perform the complete muting, by applying an AC signal for control to a control input terminal to which the mute pulse is supplied and gives the control to a resonance circuit so that the AC signal level becomes minimum at an output terminal. CONSTITUTION:A peak differential wave detecting circuit 3 contains a resonance circuit 4 provided between input terminals 6 and 7 of a differential amplifier con sisting of transistors 8-11 plus a constant current source 12. A double balance gain control circuit 5 consists of the 1st differential amplifier comprising transistors 16 and 17 and the 2nd differential amplifier connected to a constant current source 20. An Ac signal is applied to a control input terminal 21 in order to avoid (an abnormal sound) that is caused with application of the mute pulse. Then the circuit 4 is controlled so that the amplitude level is set minimum for the AC signal emerging to an aural output.
JP56003100A 1981-01-14 1981-01-14 Control method of peak differential wave detection type fm demodulating circuit Granted JPS57118446A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56003100A JPS57118446A (en) 1981-01-14 1981-01-14 Control method of peak differential wave detection type fm demodulating circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56003100A JPS57118446A (en) 1981-01-14 1981-01-14 Control method of peak differential wave detection type fm demodulating circuit

Publications (2)

Publication Number Publication Date
JPS57118446A true JPS57118446A (en) 1982-07-23
JPS6313608B2 JPS6313608B2 (en) 1988-03-26

Family

ID=11547920

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56003100A Granted JPS57118446A (en) 1981-01-14 1981-01-14 Control method of peak differential wave detection type fm demodulating circuit

Country Status (1)

Country Link
JP (1) JPS57118446A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0511925Y2 (en) * 1987-03-17 1993-03-25

Also Published As

Publication number Publication date
JPS6313608B2 (en) 1988-03-26

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