JPH0330507A - Squelch circuit - Google Patents
Squelch circuitInfo
- Publication number
- JPH0330507A JPH0330507A JP16389289A JP16389289A JPH0330507A JP H0330507 A JPH0330507 A JP H0330507A JP 16389289 A JP16389289 A JP 16389289A JP 16389289 A JP16389289 A JP 16389289A JP H0330507 A JPH0330507 A JP H0330507A
- Authority
- JP
- Japan
- Prior art keywords
- noise
- circuit
- output
- outputted
- squelch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims description 6
- 230000007257 malfunction Effects 0.000 abstract description 3
- 230000001629 suppression Effects 0.000 abstract description 2
- 230000002950 deficient Effects 0.000 abstract 2
- 230000002542 deteriorative effect Effects 0.000 abstract 1
- 230000002159 abnormal effect Effects 0.000 description 1
- MKUXAQIIEYXACX-UHFFFAOYSA-N aciclovir Chemical class N1C(N)=NC(=O)C2=C1N(COCCO)C=N2 MKUXAQIIEYXACX-UHFFFAOYSA-N 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Landscapes
- Filters And Equalizers (AREA)
- Noise Elimination (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明はスケルチ回路、特に受信機のノイズを効率よく
取り除くための回路構成に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a squelch circuit, and particularly to a circuit configuration for efficiently removing noise in a receiver.
［従来の技術］
従来から、受信機においてノイズの出力を抑止するスケ
ルチ回路か用いられており、このスケルチ回路は受信点
の信号電波かきわめて弱いときや、送信電波か出力され
ていないときに、大きなノイズか人力する場合かあるの
て、このノイズをノイズ検出器で検出器により検出し、
ノイズを出力させないようにするものである。[Prior Art] Conventionally, a squelch circuit has been used in a receiver to suppress the output of noise, and this squelch circuit is used when the signal radio wave at the receiving point is extremely weak or when the transmitting radio wave is not output. This noise may be detected by a noise detector, as it may be a large noise or may be caused by manual effort.
This prevents noise from being output.
［解決すべき課題］
上記従来のスケルチ回路ては、ノイズ検出器か故障した
場合にはノイズか検出されないため、受信機における電
波回線悪化時に復調信号のノイズか増加してもスケルチ
回路は動作せず、ノイズがそのまま出力されてしまう。[Problem to be solved] In the conventional squelch circuit described above, if the noise detector fails, noise will not be detected. Therefore, the squelch circuit will not operate even if the noise of the demodulated signal increases when the radio wave line at the receiver deteriorates. Otherwise, the noise will be output as is.
したかって、受信機からは異常な復調信号か出力される
ことになり、受信信号を利用する各種機器の誤動作を誘
発するという聞届かあった。As a result, the receiver outputs an abnormal demodulated signal, which is reported to cause malfunctions in various devices that use the received signal.
本発明は上記問題点にかんがみてなされたもので、その
目的は、ノイズ検出器が故障した場合であっても、受信
機のノイズを良好に抑止することのできるスケルチ回路
を提供することにある。The present invention has been made in view of the above problems, and an object of the present invention is to provide a squelch circuit that can satisfactorily suppress receiver noise even if the noise detector fails. .
［課題の解決手段］
上記目的を達成するために、本発明は、ノイズ検出器に
より受信機のノイズを検出し、このノイズ量が大きいと
きに受信復調信号の出力を抑止するスケルチ回路におい
て、上記ノイズ検出器の故障状態を検知する故障検知回
路を設け、この検知回路によりノイズ検出器故障時にも
受信復調信号の出力を抑止する構成としである。[Means for Solving the Problems] In order to achieve the above object, the present invention provides a squelch circuit that detects noise in a receiver using a noise detector and suppresses output of a received demodulated signal when the amount of noise is large. A failure detection circuit for detecting a failure state of the noise detector is provided, and the configuration is such that this detection circuit suppresses output of the received demodulated signal even when the noise detector fails.
［作用コ
上記構成によれば、故障検知回路によりノイズ検出器の
故障状態か検知されると、通常状態においてノイズか大
きいときと同様に受信復調信号の出力か抑止される。[Operation] According to the above configuration, when the failure detection circuit detects a failure state of the noise detector, the output of the received demodulated signal is suppressed in the same way as when the noise is large in the normal state.
［実施例］
以下、本発明の一実施例について図面を参照しながら詳
細に説明する。[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
第１図には、実施例に係るスケルチ回路の構成か示され
ており、受信機内復調器の出力を入力してノイズ量を検
出するノイズ検出器１と、１＝のノイズ検出器ｌの出力
によりノイズレベルかｒ・め定められた所定値を超えた
か否かを判定するノイズレベル判定器２と、このライス
１ノベル判定器２の出力（Ｉｌｏ）にノ＾づいて復調器
から人力された受信復調信号を出力（人力か゛０パのと
き）し、または抑１Ｆ（入力か“ｌ”のとき）するイン
ヒビット回路３か設けられている。FIG. 1 shows the configuration of the squelch circuit according to the embodiment, and includes a noise detector 1 that inputs the output of the demodulator in the receiver and detects the amount of noise, and an output of the noise detector l of 1. A noise level determiner 2 determines whether the noise level exceeds a predetermined value. An inhibit circuit 3 is provided which outputs the received demodulated signal (when the input power is 0) or suppresses it (when the input is "L").
上記回路構成に加えて、実施例ては、自動利ｔ［ｋ制御
（ＡＧＣ）電圧を入力し、このＡＣｉＣ電圧レベルか予
め定められた所定値を超えたか否かを判定スるＡＧＣレ
ベル判定器４と１このＡＧＣレベル判定器４と上記ノイ
ズレベル判定′、？Ａ２の出力からノイズ判定器ｌの故
障状態を判定するスケルチロジック回路５を設けており
、これらの回路は判定結果をＩｌｏで出力する。In addition to the above circuit configuration, the embodiment includes an AGC level determination device that inputs an automatic gain control (AGC) voltage and determines whether or not this ACiC voltage level exceeds a predetermined value. 4 and 1 This AGC level judgment device 4 and the above noise level judgment ',? A squelch logic circuit 5 is provided which determines the failure state of the noise determiner l from the output of A2, and these circuits output the determination result at Ilo.
実施例の故障検知回路は、ＡＧＣレベル判定器４とノイ
ズレベル判定器２の出力を入力するスケルチロジック回
路５により構成されることになる。すなわち、ＡＧＣレ
ベル判定判定塁上り電波回線の悪化が判定されると同時
に、ノイズレベル判定器２によりノイズ量が小さいと判
定された場合に、ノイズ検出器ｌか故障状態であると判
定する。The failure detection circuit of the embodiment is constituted by a squelch logic circuit 5 which inputs the outputs of the AGC level determiner 4 and the noise level determiner 2. That is, when it is determined that the AGC level determination base-up radio wave line has deteriorated and at the same time the noise level determiner 2 determines that the amount of noise is small, it is determined that the noise detector 1 is in a failure state.
実施例は以上の構成からなり、以下にその作用を説明す
る。The embodiment has the above configuration, and its operation will be explained below.
まず、ノイズ検出器ｌが正常に動作している場合には、
ノイズレベル判定器２の出力により受信復調信号の出力
抑制制御が行われ、ノイズ量が小のときは“０°゛ （
正論理の場合）かインヒビット回路３に出力され、イン
ヒビット回路３からは受信復調信号かそのまま出力され
る。また、ノイズ埴が大のときはｌ ”かインヒビット
回路３に出力され、受信復調信号は抑止されインヒビッ
ト回路３からは出力されず、スケルチ機能を果すことに
なる。First, if the noise detector l is operating normally,
Output suppression control of the received demodulated signal is performed based on the output of the noise level judger 2, and when the amount of noise is small, the output is “0°゛ (
(in the case of positive logic) is output to the inhibit circuit 3, and the inhibit circuit 3 outputs the received demodulated signal as it is. Furthermore, when the noise level is large, l'' is output to the inhibit circuit 3, and the received demodulated signal is suppressed and not output from the inhibit circuit 3, thus performing a squelch function.
−・方、ノイズレベル判定器２か、ノイズｙ１１か小で
あること（０°°）を判定し、ＡＧＣレベル判定器４か
電波回線の悪化状態を判定すると、スケルチロジック回
路５はノイズ検出器ｌか故障状ｙミ１であると判定し、
スケルチロジック回路５がらは“１″か出力される。こ
れにより、インヒビット回路３は動作して復：Ａ器出力
をインヒビッ１−するので、ノイズ（受信復調信号）の
出力か防１１−される。- On the other hand, when the noise level determiner 2 determines that the noise y11 is small (0°°), and the AGC level determiner 4 determines the deterioration of the radio wave line, the squelch logic circuit 5 determines that the noise y11 is small (0°°). It is determined that the failure condition is ymi1,
The squelch logic circuit 5 outputs "1". As a result, the inhibit circuit 3 operates to inhibit the output of the demodulator A, thereby preventing the output of noise (received demodulated signal).
［発明の効果］
以上説明したように、本発明によれば、ノイズ検出器の
故障状態を検知し、受信復調信号の出力を抑止するよう
にしたのて、ノイズ検出器か故障した場合ても受信機か
らノイズか出力されるのを防市でき、受信信号を人力す
る関連機器の誤動作を防止することか＋１丁能となる。[Effects of the Invention] As explained above, according to the present invention, the failure state of the noise detector is detected and the output of the received demodulated signal is suppressed. It is possible to prevent noise from being output from the receiver and to prevent malfunctions of related equipment that manually inputs received signals.
第１図は本発明の実施例に係るスケルチ回路の構成を示
す回路フロック図である。
ｌ・ノイズ検出器 ２．ノイズレベル判定器３ イン
ヒビ・・ｌト回路 ４ ： ＡＧＣレベル判定器５ニス
ケルチロシック回路FIG. 1 is a circuit block diagram showing the configuration of a squelch circuit according to an embodiment of the present invention. l・Noise detector 2. Noise level determiner 3: Inhibit circuit 4: AGC level determiner 5: Niskeltilochic circuit
Claims (1)
イズ量が大きいときに受信復調信号の出力を抑止するス
ケルチ回路において、上記ノイズ検出器の故障状態を検
知する故障検知回路を設け、この検知回路によりノイズ
検出器故障時にも受信復調信号の出力を抑止することを
特徴とするスケルチ回路。In a squelch circuit that detects noise in a receiver using a noise detector and suppresses output of a received demodulated signal when the amount of noise is large, a failure detection circuit that detects a failure state of the noise detector is provided, and this detection circuit A squelch circuit is characterized in that it suppresses output of a received demodulated signal even when a noise detector fails.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16389289A JPH0330507A (en) | 1989-06-28 | 1989-06-28 | Squelch circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16389289A JPH0330507A (en) | 1989-06-28 | 1989-06-28 | Squelch circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0330507A true JPH0330507A (en) | 1991-02-08 |
Family
ID=15782788
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16389289A Pending JPH0330507A (en) | 1989-06-28 | 1989-06-28 | Squelch circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0330507A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6257687B1 (en) | 1999-05-18 | 2001-07-10 | Nec Corporation | Method for driving ink jet printing head and circuits of the same |
| JP2009278430A (en) * | 2008-05-15 | 2009-11-26 | Japan Radio Co Ltd | Fault determination system and, method |
| JP2011117361A (en) * | 2009-12-03 | 2011-06-16 | Honda Motor Co Ltd | Engine rocker arm switching device |
-
1989
- 1989-06-28 JP JP16389289A patent/JPH0330507A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6257687B1 (en) | 1999-05-18 | 2001-07-10 | Nec Corporation | Method for driving ink jet printing head and circuits of the same |
| JP2009278430A (en) * | 2008-05-15 | 2009-11-26 | Japan Radio Co Ltd | Fault determination system and, method |
| JP2011117361A (en) * | 2009-12-03 | 2011-06-16 | Honda Motor Co Ltd | Engine rocker arm switching device |
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