JPH0165532U

JPH0165532U -

Info

Publication number: JPH0165532U
Application number: JP1988133705U
Authority: JP
Priority date: 1988-10-13
Filing date: 1988-10-13
Publication date: 1989-04-26
Also published as: JPH0336139Y2

Description

[Brief explanation of the drawing]

第１図は本考案の一実施例の要部ブロツク構成
図、第２図は同本考案の実施例における信号低域
濾波器の濾波特性図、第３図は本考案で使用し得
る要部回路の構成図、第４図は第３図における信
号波形図である。１……高周波入力部、２……電圧制御局部発振
器、３……混合器、４……信号低域濾波器、５…
…信号増幅器、６……９０゜移相器、７……混合
器、８……信号低域濾波器、１０……位相比較器
、１１……ＰＬＬ低域濾波器、１５……位相比較
器、１６……ＰＬＬ低域濾波器、１９……制御入
力回路、２４……音声中間増幅器、２７……電圧
制御発振器、２８，２９，３０……Ｔ−ＦＦ。 Fig. 1 is a block diagram of the main parts of an embodiment of the present invention, Fig. 2 is a filtering characteristic diagram of a signal low-pass filter in an embodiment of the invention, and Fig. 3 is a main part that can be used in the present invention. The circuit configuration diagram, FIG. 4, is a signal waveform diagram in FIG. 3. DESCRIPTION OF SYMBOLS 1... High frequency input part, 2... Voltage controlled local oscillator, 3... Mixer, 4... Signal low pass filter, 5...
... Signal amplifier, 6 ... 90° phase shifter, 7 ... Mixer, 8 ... Signal low-pass filter, 10 ... Phase comparator, 11 ... PLL low-pass filter, 15 ... Phase comparator , 16... PLL low-pass filter, 19... Control input circuit, 24... Audio intermediate amplifier, 27... Voltage controlled oscillator, 28, 29, 30... T-FF.

Claims

[Claims for Utility Model Registration] (1) A high frequency input section, a voltage controlled local oscillator,
a 90° phase shifter that shifts the output of the voltage controlled local oscillator by 90°, and first and second mixers that detect in-phase and quadrature components with respect to the video carrier output from the high frequency input section; a phase comparator that detects the phase difference between the video carrier wave and the output of the voltage-controlled local oscillator from the outputs of the first and second mixers; A phase lock loop is added to the voltage controlled local oscillator to synchronize the phase of the output of the voltage controlled local oscillator with the phase of the video carrier wave, and the phase lock loop synchronizes the phase of the output of the voltage controlled local oscillator with the phase of the video carrier. the phase of the output of the voltage controlled local oscillator is synchronized with the phase of the video carrier wave in the video carrier, and the voltage controlled local oscillator and the 90° phase shifter an oscillator;
A flip-flop circuit that divides the output frequency of this voltage-controlled oscillator by two, and a first and second flip-flop circuit that further divides the output frequency of this flip-flop circuit by two and has an output relationship that is delayed by a period corresponding to one cycle of the voltage-controlled oscillator. A television channel selection device comprising a second flip-flop circuit. (2) In the description of claim (1) of the utility model registration, the video signal contained in the output of the mixer that detects the in-phase component with respect to the video carrier waves in the first and second mixers. A television channel selection device comprising a signal reduction filter that filters a detection output and an audio intermediate frequency signal, and a signal amplifier that amplifies the output. (3) In the statement of claim (1) of the utility model registration, the phase lock loop is a first phase lock loop, and in addition to the phase lock loop, a second phase lock loop synthesizes a video carrier frequency of a channel desired to be selected. 1. A television channel selection device comprising a phase lock loop, wherein the first phase lock loop becomes a closed circuit after the second phase lock loop reaches a steady state. (4) A television channel selection device as set forth in claim (1) of the utility model registration, characterized in that the mixer, voltage-controlled local oscillator, and flip-flop circuit are constructed of GaAs devices.