JPS59149774U

JPS59149774U - RF modulator

Info

Publication number: JPS59149774U
Application number: JP4298983U
Authority: JP
Inventors: 杉本　共延
Original assignee: 日本電気ホームエレクトロニクス株式会社
Priority date: 1983-03-24
Filing date: 1983-03-24
Publication date: 1984-10-06

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図は本考案の前提となるＲＦモジュレータの要部ブ
ロック回路図、第２図は本考案に係るＲＦモジュレータ
の具体的回路図、第３図は第２図における音声変調波下
側波帯の除去回路の具体的回路図、及び第４図は従来の
除去回路の回路図である。１・・・・・・搬送波発生装置、２・・・・・・映像信
号処理装置、３・・・・・・音声信号処理装置、４・・
・・・・出力装置、５、ａｌ・・・・・・共振素子、６
．２２・曲・チャンネル選択スイッチ、８．２６・・・
・・・映像信号用入力端子、１１．２７・・・・・・音
声信号用入力端子、１６・・・・・・バンドパスフィル
タ、１７．２８・・・・・・ＲＦ信号用出力端子、２３
・・・・・・トラップ回路、２４・・・・・・切換口　
−路、２５・・・・・・除去回路、３０・・・・・・−
次側コイル、３２・・・・・・二次側コイル、３３・・
・・・・（第１の）コンデンサ、３５・・・・・・（第
２の）コンデンサ、３４・・・・・・スイッチングダイ
オード、３６・・・・・・切換スイッチ。Figure 1 is a block circuit diagram of the essential parts of the RF modulator that is the premise of the present invention, Figure 2 is a specific circuit diagram of the RF modulator according to the present invention, and Figure 3 is the lower sideband of the audio modulation wave in Figure 2. FIG. 4 is a specific circuit diagram of the removal circuit of FIG. 4, and FIG. 4 is a circuit diagram of a conventional removal circuit. 1...Carrier wave generation device, 2...Video signal processing device, 3...Audio signal processing device, 4...
...output device, 5, al...resonance element, 6
．． 22. Song/channel selection switch, 8.26...
...Video signal input terminal, 11.27...Audio signal input terminal, 16...Band pass filter, 17.28...RF signal output terminal, 23
...Trap circuit, 24...Switching port
- path, 25...removal circuit, 30...-
Secondary coil, 32...Secondary coil, 33...
... (first) capacitor, 35 ... (second) capacitor, 34 ... switching diode, 36 ... changeover switch.

Claims

[Claims for Utility Model Registration] A carrier wave generation device that selects and generates carrier waves of different frequencies, a video signal processing device that modulates the amplitude of an input video signal using the selected carrier wave, and a modulation signal of a predetermined frequency that modulates an input audio signal. It is composed of an audio signal processing device that performs frequency modulation and frequency conversion using the carrier wave, and an output device that mixes each output signal from the video and audio signal processing device and derives an RF multiplied signal through a bandpass filter, The output device includes a trap circuit that removes a lower sideband signal of the output wave component of the frequency-converted audio signal and a switching circuit that includes a switching element that selects the trap frequency, and connects the trap circuit to a coil and a capacitor. An RF modulator comprising a parallel circuit, wherein a second capacitor is connected to the parallel circuit via the switching element, and the switching element is made conductive or non-conductive depending on the selection of the carrier wave. “