JPH0334703Y2 - - Google Patents
Info
- Publication number
- JPH0334703Y2 JPH0334703Y2 JP1985106478U JP10647885U JPH0334703Y2 JP H0334703 Y2 JPH0334703 Y2 JP H0334703Y2 JP 1985106478 U JP1985106478 U JP 1985106478U JP 10647885 U JP10647885 U JP 10647885U JP H0334703 Y2 JPH0334703 Y2 JP H0334703Y2
- Authority
- JP
- Japan
- Prior art keywords
- electric field
- weak electric
- comparator
- display
- signal level
- 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.)
- Expired
Links
- 230000005684 electric field Effects 0.000 claims description 40
- 238000001514 detection method Methods 0.000 claims description 7
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Landscapes
- Noise Elimination (AREA)
Description
【考案の詳細な説明】
〔産業上の利用分野〕
本考案は、受信中の電界が悪化したことを報知
する弱電界表示回路に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a weak electric field display circuit that notifies that the electric field being received has deteriorated.
車載用のFM受信機等には受信中の電界強度を
表示するシグナルレベルメータを備えるものがあ
るが、最近のように受信機の性能が向上してくる
と、電界強度そのものを知るよりも、聴くに耐え
る限界以下に電界が低下したか否かを知ることの
方が重要になることもある。
Some car-mounted FM receivers are equipped with signal level meters that display the electric field strength during reception, but as the performance of receivers has improved recently, it has become more difficult to know the electric field strength itself. Sometimes it is more important to know whether the electric field has fallen below the audible limit.
上述した弱電界はシグナルレベルメータによつ
ても知ることはできる。しかしながら、このため
には限界点をユーザが記憶しておく必要があり、
正確さに欠ける。また、選局時或いは離調時にシ
グナルレベルが低下することと、受信中（同調
時）に電界変動でシグナルレベルが低下すること
を区別できないので、特に後者を表示することを
目的とした弱電界表示器としては適切ではない。
本考案は受信中に電界強度が一定値以上に低下し
た場合だけ弱電界表示する回路を提供しようとす
るものである。
The above-mentioned weak electric field can also be detected using a signal level meter. However, this requires the user to remember the breaking point.
Lacks accuracy. Furthermore, since it is not possible to distinguish between a decrease in signal level when tuning or tuning out, and a decrease in signal level due to electric field fluctuations during reception (when tuning), weak electric fields are used especially to display the latter. Not suitable as a display device.
The present invention attempts to provide a circuit that displays a weak electric field only when the electric field strength decreases to a certain value or more during reception.
本考案は、受信機の中間周波段で得られるシグ
ナルレベルを弱電界表示の基準値と比較するコン
パレータと、該コンパレータの弱電界検出出力を
受けて点灯する弱電界表示器と、該受信機のチユ
ーニング時または離調時に発生する信号を導入し
てそのときの該コンパレータの弱電界検出出力に
よる前記弱電界表示器の点灯制御を禁止する不要
表示禁止回路とを備えたことを特徴とするもので
ある。
The present invention includes a comparator that compares the signal level obtained at the intermediate frequency stage of the receiver with a reference value for the weak electric field display, a weak electric field indicator that lights up in response to the weak electric field detection output of the comparator, and the receiver. The apparatus is characterized by comprising an unnecessary display prohibition circuit that introduces a signal generated during tuning or detuning and prohibits lighting control of the weak electric field indicator by the weak electric field detection output of the comparator at that time. be.
弱電界表示器はシグナルレベルを監視するコン
パレータの弱電界検出出力を受けて点灯するが、
チユーニング時や離調時には該コンパレータの弱
電界検出出力による弱電界表示器の点灯制御が無
効にされ、放送波を受信中に電界強度が限界点以
下に低下したときだけ該表示器は弱電界検出出力
により有効に点灯制御されて電界悪化を報知す
る。
The weak electric field indicator lights up in response to the weak electric field detection output of the comparator that monitors the signal level.
During tuning or detuning, the lighting control of the weak electric field indicator by the weak electric field detection output of the comparator is disabled, and the indicator detects the weak electric field only when the electric field strength drops below the limit point while receiving broadcast waves. The lighting is effectively controlled by the output to notify of deterioration of the electric field.
第１図は本考案の一実施例を示す回路図で、１
はコンパレータ、２は弱電界表示器、３は不要表
示禁止回路である。コンパレータ１はその＋側入
力に抵抗R1，R2で分圧されたシグナルレベルVs
を受け、これを一側入力の基準値と比較する。こ
の基準値は抵抗R3と可変抵抗VRで電源電圧Vcc
を分圧することにより得られるが、その値は可変
抵抗VRで任意に設定できる。シグナルレベルVs
は第２図に示すようにアンテナ入力（電界強度）
と比例関係にある電圧で、受信機の中間周波段で
中間周波信号を検波するときに得られる。
FIG. 1 is a circuit diagram showing an embodiment of the present invention.
is a comparator, 2 is a weak electric field indicator, and 3 is an unnecessary display prohibition circuit. Comparator 1 has a signal level Vs divided by resistors R 1 and R 2 on its + side input.
is received and compared with the reference value of one side input. This reference value is set by resistor R3 and variable resistor VR to supply voltage Vcc.
It is obtained by dividing the voltage, but its value can be set arbitrarily using a variable resistor VR. Signal level Vs
is the antenna input (electric field strength) as shown in Figure 2.
It is a voltage that is proportional to , and is obtained when detecting an intermediate frequency signal at the intermediate frequency stage of the receiver.
弱電界の表示開始点をアンテナ入力で例えば
20dBμVに設定するには、そのときのシグナルレ
ベルVs20を抵抗R1，R2で分圧した値
Vs20×R1／R1＋R2
をコンパレータ１の基準電圧とすればよい。この
ようにするとVs＞Vs20でコンパレータ１の出力
はＨ（ハイ）、VsVs20でＬになる。R4，R5はそ
の出力分圧用の抵抗、C1は発振防止用のコンデ
ンサである。 For example, the display start point of the weak electric field can be set using the antenna input.
To set the voltage to 20 dBμV, the reference voltage of the comparator 1 may be set to the value obtained by dividing the signal level V s20 at that time by the resistors R 1 and R 2 , V s20 ×R 1 /R 1 +R 2 . In this way, the output of comparator 1 becomes H (high) when Vs>V s20 , and becomes L when VsV s20 . R 4 and R 5 are resistors for output voltage division, and C 1 is a capacitor for preventing oscillation.
弱電界表示器２は発光ダイオードD1と電流制
限用抵抗R6、それに表示制御用のトランジスタ
Q1からなる。トランジスタQ1はダイオードD1と
並列に接続されているので、トランジスタQ1が
オフになるとダイオードD1がオン（点灯）する。
トランジスタQ1がオフになるのはコンパレータ
１の出力がＬ、従つてVsVS20のときであるが、
これを制限するのが不要表示禁止回路３である。 The weak electric field indicator 2 includes a light emitting diode D1 , a current limiting resistor R6 , and a display control transistor.
Consists of Q1 . Transistor Q 1 is connected in parallel with diode D 1 , so when transistor Q 1 turns off, diode D 1 turns on (lights up).
Transistor Q1 turns off when the output of comparator 1 is L, therefore VsV S20 ,
The unnecessary display prohibition circuit 3 restricts this.
この回路３は例えば逆流阻止用のダイオード
D2や電流制限抵抗R7からなるが、要するに正規
の受信状態でないときにトランジスタQ1を強制
的にオンにし、この間にコンパレータ１の出力が
ＬになつてもダイオードD1を点灯させないため
のものである。つまり、シグナルレベルVsの変
動要因には、受信中の電界変動、チユーニン
グ中の受信出力低下、離調による受信出力低下
等があり、このうち以外は弱電界表示の対象と
はならない。このため、例えばのチユーニング
中にはミユート信号MUTEが発生されるので、
これを回路３で導入してトランジスタQ1を強制
的にオンにする。このときコンパレータ１の出力
はＬであるが、トランジスタQ1をオフにできな
いのでダイオードD1は点灯しない。 This circuit 3 is, for example, a reverse current blocking diode.
It consists of D 2 and current limiting resistor R 7 , but in short, it forcibly turns on transistor Q 1 when it is not in a normal reception state, and prevents diode D 1 from lighting up even if the output of comparator 1 becomes L during this time. It is something. In other words, factors that cause the signal level Vs to change include electric field fluctuations during reception, a decrease in reception output during tuning, and a decrease in reception output due to detuning, and anything other than these is not subject to weak electric field display. For this reason, the mute signal MUTE is generated during tuning, for example.
This is introduced in circuit 3 to forcibly turn on transistor Q1 . At this time, the output of comparator 1 is L, but since transistor Q 1 cannot be turned off, diode D 1 does not light up.
これに対し、受信中は回路３の出力がＬ（また
はオープン）であるので、コンパレータ１の出力
がＬになるとトランジスタQ1がオフしてダイオ
ードD1が点灯する。 On the other hand, since the output of the circuit 3 is L (or open) during reception, when the output of the comparator 1 becomes L, the transistor Q 1 is turned off and the diode D 1 is turned on.
以上述べたように本考案によれば、受信中に電
界強度が一定値以下に低下したときのみ弱電界検
出出力により有効に制御されて電界が悪化したこ
とを知らせる弱電界表示回路（プアー・レセプシ
ヨン・インジケータ）を実現できる。
As described above, according to the present invention, the weak electric field display circuit (poor reception) is effectively controlled by the weak electric field detection output only when the electric field strength drops below a certain value during reception, and notifies the user that the electric field has deteriorated.・Indicators) can be realized.
第１図は本考案の一実施例を示す回路図、第２
図はシグナルレベルとアンテナ入力との関係を示
す特性図である。
図中、１はコンパレータ、２は弱電界表示器、
３は不要表示禁止回路である。
Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a characteristic diagram showing the relationship between signal level and antenna input. In the figure, 1 is a comparator, 2 is a weak electric field indicator,
3 is an unnecessary display prohibition circuit.
Claims (1)
を弱電界表示の基準値と比較するコンパレータ
と、該コンパレータの弱電界検出出力を受けて点
灯する弱電界表示器と、該受信機のチユーニング
時または離調時に発生する信号を導入してそのと
きの該コンパレータの弱電界検出出力による前記
弱電界表示器の点灯制御を禁止する不要表示禁止
回路とを備えたことを特徴とする弱電界表示回
路。 A comparator that compares the signal level obtained at the intermediate frequency stage of the receiver with a weak electric field display reference value, a weak electric field indicator that lights up in response to the weak electric field detection output of the comparator, and a weak electric field indicator that lights up when the receiver is tuned or separated. 1. A weak electric field display circuit comprising: an unnecessary display prohibition circuit that introduces a signal generated in time and prohibits lighting control of the weak electric field indicator based on the weak electric field detection output of the comparator at that time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985106478U JPH0334703Y2 (en) | 1985-07-12 | 1985-07-12 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985106478U JPH0334703Y2 (en) | 1985-07-12 | 1985-07-12 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6214386U JPS6214386U (en) | 1987-01-28 |
| JPH0334703Y2 true JPH0334703Y2 (en) | 1991-07-23 |
Family
ID=30981875
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1985106478U Expired JPH0334703Y2 (en) | 1985-07-12 | 1985-07-12 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0334703Y2 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5847175B2 (en) * | 1980-08-04 | 1983-10-20 | ニツケイ理研株式会社 | Lid structure for pressure cooker |
| JPS59158119A (en) * | 1983-02-25 | 1984-09-07 | Sony Corp | Level display device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5847175U (en) * | 1981-09-22 | 1983-03-30 | 日本ビクター株式会社 | Electric field strength digital display |
-
1985
- 1985-07-12 JP JP1985106478U patent/JPH0334703Y2/ja not_active Expired
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5847175B2 (en) * | 1980-08-04 | 1983-10-20 | ニツケイ理研株式会社 | Lid structure for pressure cooker |
| JPS59158119A (en) * | 1983-02-25 | 1984-09-07 | Sony Corp | Level display device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6214386U (en) | 1987-01-28 |
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