JPS6341982U

JPS6341982U -

Info

Publication number: JPS6341982U
Application number: JP13574286U
Authority: JP
Priority date: 1986-09-03
Filing date: 1986-09-03
Publication date: 1988-03-19
Also published as: JPH0448060Y2

Description

[Brief explanation of the drawing]

第１図は本考案の第１の実施例のブロツク図、
第２図は本考案の第２の実施例の回路図、第３図
は第２図に示す第２の実施例の動作を説明するた
めの選択信号及び切換え制御信号のタイミング図
、第４図は従来の音声中間周波数検出回路の一例
のブロツク図である。１……信号入力端子、２……４．５ＭＨ_ｚ帯域
フイルタ、３……５．５ＭＨ_ｚ帯域フイルタ、４
……６．０ＭＨ_ｚ帯域フイルタ、５……増幅器、
６……４．５ＭＨｚ帯域フイルタ、７……５．５
ＭＨｚ帯域フイルタ、８……６．０ＭＨ_ｚ帯域フ
イルタ、９……スイツチ回路、１０……レベル検
出回路、１１……切換え制御回路、１２……表示
及び帯域指定回路、１３，１４……増幅器、２１
，２１ａ，２１ｂ，２１ｃ……切換え制御信号、
２２……帯域検出信号、２３……レベル検出信号
、２４……帯域指定制御信号、２５，２６……選
択信号、３０，３１……差動増幅器。 FIG. 1 is a block diagram of the first embodiment of the present invention.
FIG. 2 is a circuit diagram of a second embodiment of the present invention, FIG. 3 is a timing diagram of selection signals and switching control signals for explaining the operation of the second embodiment shown in FIG. 2, and FIG. 4 1 is a block diagram of an example of a conventional audio intermediate frequency detection circuit. 1...Signal input terminal, 2...4.5MHz _band filter, 3...5.5MHz _band filter, 4
...6.0MHz _band filter, 5...amplifier,
6...4.5MHz band filter, 7...5.5
MHz band filter, 8... 6.0 _MHz band filter, 9... switch circuit, 10... level detection circuit, 11... switching control circuit, 12... display and band specification circuit, 13, 14... amplifier, 21
, 21a, 21b, 21c... switching control signal,
22... Band detection signal, 23... Level detection signal, 24... Band designation control signal, 25, 26... Selection signal, 30, 31... Differential amplifier.

Claims

[Scope of utility model registration request]

first, second and third band filters whose signal input ends are connected in parallel and each have a first, second and third band; and whose input ends are connected to the output end of said first band filter and said a first amplifier operated by a selection signal when a first band is selected; and a first amplifier whose input terminals are connected in parallel and connected to the output terminals of the second and third band filters; a second amplifier operating in alternation with the amplifier;
the first input terminal whose input terminals are connected in parallel;
and fourth, fifth, and sixth band filters each having the first, second, and third bands connected to the output terminal of the second amplifier; a level detection circuit that detects the level of a band detection signal corresponding to the band and outputs a level detection signal when the level exceeds a predetermined level; and a level detection circuit that outputs a switching control signal periodically and controls the switching according to the level detection signal. a switching control circuit for stopping the signal and outputting the selection signal; and a switching input terminal connected to the output terminals of the fourth, fifth, and sixth bandpass filters to sequentially switch the switching in accordance with the switching control signal. An audio intermediate frequency detection circuit comprising: a switch circuit that switches input terminals and outputs the band detection signal.