JPS63113380U

JPS63113380U -

Info

Publication number: JPS63113380U
Application number: JP385987U
Authority: JP
Priority date: 1987-01-14
Filing date: 1987-01-14
Publication date: 1988-07-21

Description

[Brief explanation of the drawing]

第１図は本考案のテレビジヨン受像機のＦＭ復
調回路の概略構成を示すブロツク図、第２図及び
第６図ならびに第７図は動作説明用の特性例図、
第３図はテレビジヨン受像機のＦＭ復調回路の一
実施例の回路図、第４図は従来のテレビジヨン受
像機のＦＭ復調回路の一例構成を示すブロツク図
、第５図は既提案のテレビジヨン受像機のＦＭ復
調回路の一例構成を示すブロツク図である。１……入力端子、２……ＦＭ復調回路、３……
同調回路、４……制御回路、ＬＰＦ……低域通過
濾波器、Ｃ１〜Ｃ５，Ｃｐ１〜Ｃｐ３……コンデ
ンサ、Ｌ……コイル、Ｃｖ，Ｃｖ２……可変容量
ダイオード、Ｒ１〜Ｒ５……抵抗、５……出力端
子、６……１次巻線、７……２次巻線、Ｔ，Ｔｉ
，Ｔｉｖ……入力トランス。 FIG. 1 is a block diagram showing the schematic configuration of the FM demodulation circuit of the television receiver of the present invention; FIGS. 2, 6, and 7 are characteristic diagrams for explaining the operation;
Fig. 3 is a circuit diagram of an embodiment of an FM demodulation circuit of a television receiver, Fig. 4 is a block diagram showing an example configuration of an FM demodulation circuit of a conventional television receiver, and Fig. 5 is a circuit diagram of an example of an FM demodulation circuit of a conventional television receiver. 1 is a block diagram showing an example configuration of an FM demodulation circuit of a television receiver. 1...Input terminal, 2...FM demodulation circuit, 3...
Tuning circuit, 4... Control circuit, LPF... Low pass filter, C1 to C5, Cp1 to Cp3... Capacitor, L... Coil, Cv, Cv2... Variable capacitance diode, R1 to R5... Resistor, 5...Output terminal, 6...Primary winding, 7...Secondary winding, T, Ti
, Tiv...Input transformer.

Claims

[Claims for Utility Model Registration] 1. An F comprising at least one variable reactance element and a tuning circuit configured to determine the center frequency of FM demodulation.
The DC component obtained by applying the demodulated signal output from the FM demodulation circuit to a low-pass filter is supplied as a control signal to the variable reactance element of the above-mentioned tuning circuit in the M demodulation circuit. An FM demodulation circuit for a television receiver, wherein a control signal is also supplied to a variable reactance element provided as a tuning element in an input transformer in the FM demodulation circuit. 2. An FM demodulation circuit for a television receiver according to claim 1, which uses a variable capacitance diode as a variable reactance element.