KR850001847Y1 - Video signal detecting circuit - Google Patents

Video signal detecting circuit Download PDF

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Publication number
KR850001847Y1
KR850001847Y1 KR2019830010027U KR830010027U KR850001847Y1 KR 850001847 Y1 KR850001847 Y1 KR 850001847Y1 KR 2019830010027 U KR2019830010027 U KR 2019830010027U KR 830010027 U KR830010027 U KR 830010027U KR 850001847 Y1 KR850001847 Y1 KR 850001847Y1
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transistor
signal
capacitor
terminal
input terminal
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KR2019830010027U
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Korean (ko)
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KR850004541U (en
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현재영
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삼성전자공업주식회사
정재은
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    • 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
    • H04N5/50—Tuning indicators; Automatic tuning control
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/12—Bandpass or bandstop filters with adjustable bandwidth and fixed centre frequency
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/26—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback
    • H03K3/28—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback
    • H03K3/281—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator
    • H03K3/282—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator astable
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising
    • H04N5/06—Generation of synchronising signals

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Channel Selection Circuits, Automatic Tuning Circuits (AREA)
  • Television Receiver Circuits (AREA)

Abstract

내용 없음.No content.

Description

방송신호 검출회로Broadcast signal detection circuit

첨부된 도면은 본 고안의 회로도이다.The accompanying drawings are circuit diagrams of the subject innovation.

* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings

“가”: 펄스증폭 및 동기 비교부“A”: pulse amplification and synchronous comparator

“나”: 의사 수평동기 신호발생용 비안정 멀티부“I”: Unstable multi part for generating pseudo horizontal synchronization signal

본 고안은 전자동조 선국방식에 사용되는 방송신호 검출회로에 관한 것이다.The present invention relates to a broadcast signal detection circuit used in the automatic tuning tuning method.

일반적으로 티브이(TV)의 전자동조선국 방식에서 방송신호를 검출하는 회로는 방송체널이 자동선국되는 모드(mode)시에 채널선택버튼에 의해 선국된 채널방송이 없으면 다음 방송신호가 있을때까지 자동적으로 주사하고 방송신호의 유무를 탐지하여 방송신호가 있는 경우에 탐색동작을 정지시키는 역활을 하는것인데, 종래의 방송신호 걸출회로에서는 수평동기신호를 DC화하거나 FBT(Fly Back Trans)에서 발생되는 귀선펄스를 이용하여 방송이 존재시는 상기 수평동기신호와 귀선펄스가 동시에 존재하고, 수평동기가 제대로 잡혀진 경우는 두펄스신호의 위상을 일치시켜 이 신호를 DC화하여 조정용 IC를 구동하고 있다.In general, a circuit for detecting a broadcast signal in a TV (automatic tuning channel) method automatically scans until there is a next broadcast signal if there is no channel broadcast tuned by a channel selection button in a mode in which the broadcast channel is automatically tuned. It detects the presence of a broadcast signal and stops the search operation when there is a broadcast signal. In the conventional broadcast signal outstanding circuit, the horizontal synchronization signal is converted into DC or the return pulse generated from FBT (Fly Back Trans) is generated. When the broadcast is present, the horizontal synchronous signal and the retrace pulse exist at the same time, and when the horizontal synchronous signal is properly captured, the signals of the two pulsing signals are matched with each other to drive the adjustment IC.

그러나, 콤포넌트방식의 TV수상기 튜너에는 편향회로를 가지고 있지않는 것이 일반적이므로 귀선펄스가 존재하지 않을뿐 아니라 방송신호가 없을시는 수평동기신호를 대신할 신호가 없게되어 정확한 동작을 시킬수 없다는 단점이 있다.However, since component TV receiver tuners generally do not have a deflection circuit, there is a disadvantage that there is no return pulse and there is no signal to replace the horizontal synchronization signal in the absence of a broadcast signal. .

본 고안은 이러한 점을 감안하여 안출한 것인데, 이는 콤포넌트 방식의 TV수상기와 같이 편향회로를 가지지않은 튜너에서 채널서치다, 엎운(up, down)시 의사 수평동기신호를 발생시키고, 방송채널이 자동선국되는 모드시에 방송신호가 있는 경우는 수평동기신호와 의사수평동기신호의 위상을 일치시켜 자동탐색동작을 정지시키려는 목적이 있는 것이다.The present invention has been devised in view of this point, which is a channel search in a tuner that does not have a deflection circuit like a component TV receiver, generates a pseudo horizontal synchronization signal when up and down, and a broadcast channel is automatically When there is a broadcast signal in the tuned mode, the purpose is to stop the automatic search operation by matching the phase of the horizontal sync signal with the pseudo horizontal sync signal.

이하에서 이를 상세히 설명하면 다음과 같다.This will be described in detail below.

통상의 복합동기신호 입려단(A)에 저항(Rl)을 거쳐 신호 증폭용트랜지스터(T1)의 입력단을 연결하고, 이의 에미티단엔 저항(R3). 콘덴서(Cl)의 적분회로를 연결하며, 이는 다시 콘덴서(C2), 다이오드(Dl)를 거쳐 동기 비교용 트랜지스터(T2,T5)의 베이스입력단과 컬렉터단에 각기 연결하며, 상기 트랜지스터(T2)의 컬렉터단은 저항(R6,R7)과 콘덴서(C3,C4)의 2단 적분회로를 거쳐 출력단(0)을 연결하므로서 펄스증폭 및 동기 비교부(가)를 구성하고, 한편으론, 상기 트랜지스터(T5)의 베이스 입력단엔 저항(R9,Rl0,R11,R13,R14,R15)과 콘덴서(C5,C7) 및 트랜지스터(T3,T4)로 구성된 통상의 비안정 멀티부(나)의 트랜지스터(T4) 컬렉터단을 저항(R8)을 거쳐 연결하는 한편, 트랜지스터(T8)의 베이스 입력단은 콘덴서(C6), 저항(R12)을 거쳐 복합동기신호 입력단자(A)에 연결하여서 된 것이다.The input terminal of the signal amplifying transistor (T 1 ) is connected to a conventional composite synchronous signal receiving terminal (A) via a resistor (R l ), and the emitter is resistor (R 3 ). The integrating circuit of the capacitor C l is connected to the base input terminal and the collector terminal of the synchronous comparison transistors T 2 and T 5 , respectively, via the capacitor C 2 and the diode D l , respectively. The collector stage of the transistor T 2 connects the output stage 0 through a two-stage integrated circuit of resistors R 6 and R 7 and capacitors C 3 and C 4 so that the pulse amplification and synchronous comparators On the other hand, at the base input terminal of the transistor T 5 , the resistors R 9 , R 10 , R 11 , R 13 , R 14 , R 15 , the capacitors C 5 , C 7 and the transistors T 3 T 4 ) connects a transistor (T 4 ) collector terminal of a conventional unstable multi-part (b) via a resistor (R 8 ), while the base input terminal of the transistor (T 8 ) is a capacitor (C 6 ), Connected to the composite synchronous signal input terminal (A) via a resistor (R 12 ).

미설명부호 R2는 트랜지스터(T1)의 에미터저항, R4,R5는 전압분할 저항, B+, B++는 전원이다.Reference numeral R 2 denotes an emitter resistor of the transistor T 1 , R 4 and R 5 denote a voltage divider resistor, and B + and B ++ denote a power supply.

이러한 구성의 본 고안은 TV방송신호가 없을때는 비안정멀티부(나)의 트랜지스터(T3)베이스 입력단에 저항(Rl2) 및 콘텐서(C6)를 통하여 가해지는 신호가 없으므로 이 비안정멀티부(나)는 자유발진에 의해 발진하게 되는데, 이때 이 비안정멀티부(나)의 자유발진 주파수는 다음과 같다.The present invention of such a configuration has no unstable signal because no signal is applied to the transistor (T 3 ) base input terminal of the unstable multi-part (B) through the resistor (R l2 ) and the capacitor (C 6 ) when there is no TV broadcast signal. The multi-part (B) is oscillated by free oscillation. At this time, the free oscillation frequency of the unstable multi-part (B) is as follows.

즉, B++×=V1………………(1)Ie B ++ × = V 1 . … … … … … (One)

V1=V1+B++(1-e-)…………(2)V 1 = V 1 + B ++ (1-e- )… … … … (2)

상기 (2)식을 풀면 t=0.2RC가 되고, 자유발진 주파수(fosc)는 0.2(R13,C7+R11,C5)가 된다.Solving equation (2) above, t = 0.2RC, and the free oscillation frequency fosc is 0.2 (R 13 , C 7 + R 11 , C 5 ).

위와같은 발진주파수를 가지는 출력신호가 저항(R8)을 통하여 트랜지스터 (T5)의 베이스단에 가해지는 한편, 펄스증폭 및 동기 비교부(가)의 트랜지스터(T1)베이스 입력단엔 가해지는 신호가 없으므로 트랜지스터(T2) 베이스 입력단은 저항(R4) 및 다이오드(Dl)를 통하여 가해진 바이어스 전압과 상기 트랜지스터(T5)의 컬렉터출력이 중첩되므로 트랜지스터(T2)는 ON-OFF동작을 반복하나 TR(2)콜렉터측의 저항(R6)과 콘텐서(C3)에 의한 Low Pass Filter에 의해서 TR(2)의 콜렉터 출력전압은 0.6Vpp정도로 크게 감쇄되어 그 전압을 출력단자(0)에서 체크(check)하면 약 0.3VDC의 Low Level전압으로 된다. 따라서 채널선국버튼에 의해 선택된 채널에 방송이 없으면 다음 방송신호가 있을때까지 자동적으로 주사하는 것이다.The output signal having the above oscillation frequency is applied to the base terminal of the transistor T 5 through the resistor R 8 , while the signal is applied to the base input terminal of the transistor T 1 of the pulse amplification and synchronous comparator. Since the transistor T 2 base input terminal overlaps the bias voltage applied through the resistor R 4 and the diode D 1 and the collector output of the transistor T 5 , the transistor T 2 performs ON-OFF operation. repeating one or TR (2) of the collector-side resistor (R 6) and cone tensor (C 3) collector output voltage of TR (2) by the Low Pass Filter is significantly attenuated so that 0.6Vpp voltage to the output terminal by the (0 ), It becomes low level voltage of about 0.3V DC . Therefore, if there is no broadcast on the channel selected by the channel selection button, it scans automatically until the next broadcast signal.

다음, TV방송이 존재하는 경우에는 복합동기신호가 펄스증폭 및 동기비교부(가)는 물론 비안정 멀티부(나)에 가해지므로 비안정멀티부(나)의 출력은 규칙빠른 동기신호 입력에 의하여 동기가 일치되어 그 출력은 이 동기신호 주파수로 일정하게 트랜지스터(T5)의 베이스입력단에 가해지고, 한편, 펄스증폭 및 동기 비교부(가)의 트랜지스터(T1)는 그 입력에 신호가 가해져서 그 출력이 콘덴서(C2)를 통하여 다이오드(D1)의 애노드에 가해지나 이 다이오드(D1)와 트랜지스터(T2)에 의하여 클램프되어 다이오드(Dl)의 애노드전위는-전위로 하강한다.Next, when there is a TV broadcast, the composite synchronous signal is applied to the pulse amplification and synchronous comparison part as well as to the unstable multi part (b). By synchronism, the output is applied to the base input terminal of the transistor T 5 at this synchronization signal frequency constantly. On the other hand, the transistor T 1 of the pulse amplification and synchronization comparison unit has a signal at its input. And its output is applied to the anode of diode D 1 through capacitor C 2 but clamped by diode D 1 and transistor T 2 so that the anode potential of diode D 1 is -potential. Descend.

그러므로 트랜지스터(T2)의 베이스에 가해지는 복합동기신호와 의사수평동기신호가 위상이 일치하는 경우는 이 트랜지스터(T2)는 OFF되고, 출력단자(0)엔 High레벨의 전압이 걸리게 되어 조정용 IC의 방송신호단자가 high로 되고, 탐색동작이 정지되는 것이다.Therefore, when the composite synchronous signal and the pseudo horizontal synchronous signal applied to the base of the transistor T 2 are in phase, the transistor T 2 is turned off, and the output terminal 0 is subjected to a high level voltage. The broadcast signal terminal of the IC becomes high and the search operation is stopped.

이러한 본 고안은 콤포넌트 방식의 TV수상기와 같이 편향회로를 가지지않는 튜너의 전자선국방식에서 자동선국 모드시에 의사수평동기신호를 발생시켜 그 일치성 여부에 따라 탐색동작의 진행 및 정지를 시킬수 있는 매우 유익한 특징이 있다.The present invention generates a pseudo horizontal synchronizing signal in the automatic tuning mode in the electronic tuning method of a tuner which does not have a deflection circuit like a component TV receiver, and allows the search operation to proceed and stop according to its consistency. There are beneficial features.

Claims (1)

통상의 TV수상기에 있어서, 복합동기신호 입력단(A)에 저항(R1)을 거쳐 트랜지스터(T1)의 입력단을 연결하고, 이의 출력단엔 저역필터(R3,Cl), 컨덴서(C2), 다이오드(D1)를 거쳐 트랜지스터(T2)의 베이스와 트랜지스터(T5)의 컬렉터를 연결하며, 상기 트랜지스터(T2)의 컬렉터단은 저항(R6,R7) 및 컨덴서(C3,C4)로 된 2단 저역필터를 연결하므로서 펄스증폭 및 동기 비교부(가)를 구성하고, 상기 복합동기신호입력단(A)의 일단이 저항(Rl2), 컨덴서(C6)를 거쳐 저항(R9~R11, R13~R15) 및 컨덴서 (C5,C7)와 트랜지스터(T3,T4)로 구성된 비안정 멀티부(나)의 트랜지스터 (T3)베이스단에 연결하고, 상기 트랜지스터(T4)의 출력단을 트랜지스터(T5)의 베이스단에 연결하여서 된 TV방송신호 검출회로.In a conventional TV receiver, the composite synchronous signal input terminal A is connected to the input terminal of the transistor T 1 via a resistor R 1 , and its output stage is a low pass filter R 3 , C l , and a capacitor C 2. ), The base of transistor T 2 and the collector of transistor T 5 are connected via a diode D 1 , and the collector terminals of transistor T 2 are resistors R 6 and R 7 and capacitor C. 3, the one end of the resistance (R l2), a capacitor of C 4) hameuroseo the second connecting stage low pass filter to a pulse amplifier and a sync comparing unit (a) constituting the said composite synchronizing signal input terminals (a) (C 6) through resistance (R 9 ~ R 11, R 13 ~ R 15) and capacitor (C 5, C 7) and the transistor (T 3, T 4) non-stable transistor (T 3) of the multi-part (B) consisting of a base terminal And the output terminal of the transistor (T 4 ) is connected to the base terminal of the transistor (T 5 ).
KR2019830010027U 1983-11-26 1983-11-26 Video signal detecting circuit KR850001847Y1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100542634B1 (en) * 2002-10-15 2006-01-16 은 석 이 A steel pipe coated with frp resin

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100542634B1 (en) * 2002-10-15 2006-01-16 은 석 이 A steel pipe coated with frp resin

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