JPS5920736U

JPS5920736U - Automatic signal switching circuit

Info

Publication number: JPS5920736U
Application number: JP11487482U
Authority: JP
Inventors: 玄葉　伴治
Original assignee: 株式会社東芝
Priority date: 1982-07-30
Filing date: 1982-07-30
Publication date: 1984-02-08

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

第１図は従来の映像同期検波装置のブロック図、第２図
は本考案に係る自動信号切換回路を適用した映像同期検
波装置のブロック図、第３図は本考案に係る自動信号切
換回路の回路図、第４図は実測値データ表１を説明する
ための回路図、第５図力至第７図は第３図に示した自動
信号切換回路の他の実施例を示す部分回路図である。１１．１２・・・・・・信号源、１３・・・・・・出力
端子、Ｄ１〜Ｄ６・・・ダイオード、Ｃ１〜Ｃ９・・・
・・・コンデンサ、Ｒ１−Ｒ１５・・・・・・抵抗、Ｑ
□〜Ｑ６・・・・・・トランジスタ、十Ｂ・・・・・・
直流電源、Ｉ。・・・・・・定電流源回路。Fig. 1 is a block diagram of a conventional video synchronous detection device, Fig. 2 is a block diagram of a video synchronous detection device to which an automatic signal switching circuit according to the present invention is applied, and Fig. 3 is a block diagram of an automatic signal switching circuit according to the present invention. The circuit diagram, FIG. 4 is a circuit diagram for explaining the actual measurement data table 1, and FIG. 5 to FIG. 7 are partial circuit diagrams showing other embodiments of the automatic signal switching circuit shown in FIG. be. 11.12... Signal source, 13... Output terminal, D1-D6... Diode, C1-C9...
... Capacitor, R1-R15 ... Resistor, Q
□～Q6...Transistor, 10B...
DC power supply, I.・・・・・・Constant current source circuit.

Claims

[Scope of utility model registration request]

(1) A signal level detection circuit that inputs a signal from a signal input terminal and detects the signal level, a transistor that conducts or non-conducts depending on the signal level output from this detection circuit, and a first and second transistor. The cathodes of these diodes are connected together, the connection point is connected to the output terminal of the transistor, a signal is inputted from the signal input terminal to the anode of the first diode, and the anode of the second diode is connected to the signal output terminal. a diode circuit, and the first diode circuit.
, further comprising one or more circuit configurations each consisting of a current supply circuit connected between the anode of the second diode and a DC power supply, and connecting the portions of these circuit configurations corresponding to the emitters of the transistors to each other. . An automatic signal switching circuit characterized in that the diode circuit is made conductive or non-conductive depending on whether the transistor is conductive or non-conductive, and the impedance of the signal transmission path is changed.

(2) The automatic signal switching circuit according to claim 1, wherein an inductance is connected in parallel between the anodes of the first and second diodes of the diode circuit.