JPS56169973A - Automatic gain controlling device - Google Patents

Automatic gain controlling device

Info

Publication number
JPS56169973A
JPS56169973A JP7276980A JP7276980A JPS56169973A JP S56169973 A JPS56169973 A JP S56169973A JP 7276980 A JP7276980 A JP 7276980A JP 7276980 A JP7276980 A JP 7276980A JP S56169973 A JPS56169973 A JP S56169973A
Authority
JP
Japan
Prior art keywords
signal
circuit
fed
automatic gain
component
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
JP7276980A
Other languages
Japanese (ja)
Other versions
JPH0160987B2 (en
Inventor
Minoru Sakai
Masutomi Oota
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 JP7276980A priority Critical patent/JPS56169973A/en
Publication of JPS56169973A publication Critical patent/JPS56169973A/en
Publication of JPH0160987B2 publication Critical patent/JPH0160987B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/52—Automatic gain control

Abstract

PURPOSE:To accomplish a picture of accurate multiplex-character, by controlling the gain of a video amplifier circuit through the automatic gain signal of AC and DC components derived from a clock line signal picked up from a video signal. CONSTITUTION:A clock line signal of character multiplex signal outputted from a video amplifier circuit 13 is fed to an analog switch 12 through a buffer amplifier 21 and the clock line signal only is picked up. This signal is split into two, one is fed to a 2.86MHz resonance circuit 23, the component in 2.86MHz only is obtained at the output and amplified 24 and fed to a peak hold amplifier circuit 25. The output of this circuit is fed back to a circuit 13 as an AC component automatic gain control signal 17a, allowing to make the automatic gain control of the AC component. Further, another clock line signal is fed to a 358kHz resonance circuit 26, and a DC component gain signal 17b is fed back to the circuit 13 from an amplifier circuit 28. Thus, the amplitude level and DC level of the character multiplex signal is stabilized.
JP7276980A 1980-06-02 1980-06-02 Automatic gain controlling device Granted JPS56169973A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7276980A JPS56169973A (en) 1980-06-02 1980-06-02 Automatic gain controlling device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7276980A JPS56169973A (en) 1980-06-02 1980-06-02 Automatic gain controlling device

Publications (2)

Publication Number Publication Date
JPS56169973A true JPS56169973A (en) 1981-12-26
JPH0160987B2 JPH0160987B2 (en) 1989-12-26

Family

ID=13498905

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7276980A Granted JPS56169973A (en) 1980-06-02 1980-06-02 Automatic gain controlling device

Country Status (1)

Country Link
JP (1) JPS56169973A (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5383526A (en) * 1976-12-28 1978-07-24 Matsushita Electric Ind Co Ltd Receiving device for multiple information signal
JPS53139923A (en) * 1977-05-13 1978-12-06 Matsushita Electric Ind Co Ltd Automatic gain control unit
JPS5459027A (en) * 1977-10-19 1979-05-12 Matsushita Electric Ind Co Ltd Receiving device for multiplied information signal

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5383526A (en) * 1976-12-28 1978-07-24 Matsushita Electric Ind Co Ltd Receiving device for multiple information signal
JPS53139923A (en) * 1977-05-13 1978-12-06 Matsushita Electric Ind Co Ltd Automatic gain control unit
JPS5459027A (en) * 1977-10-19 1979-05-12 Matsushita Electric Ind Co Ltd Receiving device for multiplied information signal

Also Published As

Publication number Publication date
JPH0160987B2 (en) 1989-12-26

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