JPS6313367B2 - - Google Patents
Info
- Publication number
- JPS6313367B2 JPS6313367B2 JP56195943A JP19594381A JPS6313367B2 JP S6313367 B2 JPS6313367 B2 JP S6313367B2 JP 56195943 A JP56195943 A JP 56195943A JP 19594381 A JP19594381 A JP 19594381A JP S6313367 B2 JPS6313367 B2 JP S6313367B2
- Authority
- JP
- Japan
- Prior art keywords
- changeover switch
- circuit
- switching
- band
- reception
- 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
- 238000001514 detection method Methods 0.000 claims description 6
- 230000008054 signal transmission Effects 0.000 claims description 5
- 230000035939 shock Effects 0.000 description 7
- 239000003990 capacitor Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 244000145845 chattering Species 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/34—Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise signals, e.g. squelch systems
- H03G3/348—Muting in response to a mechanical action or to power supply variations, e.g. during tuning; Click removal circuits
Landscapes
- Noise Elimination (AREA)
Description
【発明の詳細な説明】
本発明は多バンドの受信機に関し、バンド切換
時のシヨツク音を確実に阻止するようにしたもの
である。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-band receiver that reliably prevents shock noise when switching bands.
近年、FM，AM受信機等においては、PLLを
使用して電子的に同調を行なうものが多い。そし
てこの種の受信機においては、同調制御回路を、
たとえばマイクロコンピユータ等で構成し、バン
ド切換時に同調制御回路からミユート信号を出力
し、このミユート信号で信号伝送路に挿入された
ミユーテイング回路を駆動することによつて、バ
ンド切換時の電源の切換えによるシヨツク音を除
去するようにしている。ところが、上記同調制御
回路は、マイクロコンピユータ等で構成されてい
るため、実際にバンド切換スイツチが切換えられ
ても、それが検知されてミユート信号が出力され
るまでには、スイツチのチヤタリング除去のため
の信号処理時間や内部のプログラムによる信号処
理の遅れがあり、切換えスイツチによる電源の切
換えよりも遅れてミユート信号が発生される。こ
のため、バンド切換時にFM，AMの各電源が切
換わつた後にミユーテイングがかかることにな
り、バンドを切換えた瞬間からミユート信号が出
力されるまでの期間に、電源の切換えに起因する
シヨツク音が現われるという問題がある。 In recent years, many FM and AM receivers use PLL to perform electronic tuning. In this type of receiver, the tuning control circuit is
For example, it is configured with a microcomputer, etc., outputs a mute signal from a tuning control circuit when switching bands, and uses this mute signal to drive a muting circuit inserted in the signal transmission path. I'm trying to remove the shot sound. However, since the above-mentioned tuning control circuit is composed of a microcomputer, etc., even if the band changeover switch is actually changed, by the time it is detected and the mute signal is output, it is necessary to remove the chattering of the switch. There is a delay in signal processing due to the signal processing time and internal program, and the mute signal is generated later than the switching of the power supply by the changeover switch. For this reason, muting is applied after the FM and AM power supplies are switched when switching bands, and the shock noise caused by switching the power supplies occurs during the period from the moment the band is switched until the mute signal is output. There is a problem of appearing.
本発明はこのような従来の問題を解決する受信
機を提供するものである。 The present invention provides a receiver that solves these conventional problems.
以下本発明の一実施例を第１図、第２図ととも
に説明する。 An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
第１図において、１はFM受信回路、２はAM
受信回路、３は各受信回路１，２に共通に設けら
れた低周波回路、４はその後段に設けられたミユ
ーテイング回路、５は電力増幅器、６はスピーカ
であり、これらが受信系に相当する。一方、７は
マイクロコンピユータ等で構成された同調制御回
路、７ａはそのミユート信号出力端子、Sdはセ
グメント出力端子、K3，K2はキーマトリクス入
力端子、８はループフイルタ、９はプリスケーラ
であり、これらは周知のシンセサイザー用の
PLLを構成している。すなわち同調制御回路７
の内部にはプログラマブル分周器及び位相比較器
が設けられており、またFM受信回路１の内部に
は高部発振器を構成する電圧制御発振器が設けら
れており、上記プログラマブル分周器、位相比較
器、ループフイルタ、電圧制御発振器、プリスケ
ーラ９をループ状に接続してPLLを構成し、上
記プログラマブル分周器の分周比を可変すること
によりFMの受信周波数が可変できるように構成
されている。またAM受信回路２の内部にも電圧
制御発振器が設けられており、これと同調制御回
路７内のプログラマブル分周器と位相比較器とル
ープフイルタ８とでPLLが構成されている。１
０は同調制御回路７をFM受信モードとAM受信
モードに切換えるモード切換スイツチ１０ａと、
電源＋ＢをFN側とAM側に切換える電源切換ス
イツチ１０ｂとで構成されたバンド切換スイツチ
であり、上記２回路のスイツチ１０ａ，１０ｂは
互に連動して切換わるように構成されている。１
１，１２はFM，AMの各電源ラインに挿入され
た検出回路であり、それぞれ、微分用のコンデン
サC1，C2、抵抗R1，R2とその出力を整流するダ
イオードD1，D2で構成されている。 In Figure 1, 1 is the FM receiver circuit, 2 is the AM
A receiving circuit, 3 is a low frequency circuit provided in common to each receiving circuit 1 and 2, 4 is a muting circuit provided at the subsequent stage, 5 is a power amplifier, and 6 is a speaker, which corresponds to the receiving system. . On the other hand, 7 is a tuning control circuit composed of a microcomputer, etc., 7a is its mute signal output terminal, Sd is a segment output terminal, K 3 and K 2 are key matrix input terminals, 8 is a loop filter, and 9 is a prescaler. , these are for well-known synthesizers.
It constitutes a PLL. That is, the tuning control circuit 7
A programmable frequency divider and a phase comparator are provided inside the FM receiving circuit 1, and a voltage controlled oscillator constituting a high-part oscillator is provided inside the FM receiving circuit 1. A loop filter, a voltage controlled oscillator, and a prescaler 9 are connected in a loop to form a PLL, and the FM reception frequency can be varied by varying the division ratio of the programmable frequency divider. . A voltage controlled oscillator is also provided inside the AM receiving circuit 2, and a programmable frequency divider, a phase comparator, and a loop filter 8 in the tuning control circuit 7 constitute a PLL. 1
0 is a mode changeover switch 10a for switching the tuning control circuit 7 between FM reception mode and AM reception mode;
This is a band changeover switch composed of a power changeover switch 10b that switches the power supply +B to the FN side and the AM side, and the switches 10a and 10b of the two circuits mentioned above are configured to be switched in conjunction with each other. 1
1 and 12 are detection circuits inserted in each of the FM and AM power supply lines, which respectively include capacitors C 1 and C 2 for differentiation, resistors R 1 and R 2 , and diodes D 1 and D 2 that rectify their outputs. It consists of
第２図ａ，ｂ，ｃ，ｄはそれぞれ第１図のａ，
ｂ，ｃ，ｄ点の電圧波形を示している。 Figure 2 a, b, c, d are respectively a, b, c, and d in Figure 1.
The voltage waveforms at points b, c, and d are shown.
上記構成において、バンド切換スイツチ１０を
AM側からFM側へ切換えると、同調制御回路７
がFM受信モードに切換わるとともに、ミユート
信号出力端子７ａから第２図ｃに示すようなミユ
ート信号が出力される。ところが、この場合、同
調制御回路７は、上述のように、マイクロコンピ
ユータ等でバンドが切換わつたことを判断してか
らシユート信号を出力するため、第２図ｃに示す
ように切換えた瞬間からτだけ（実際には15μsec
程度）遅れてミユート信号が現われる。一方、電
源切換スイツチ１０ｂの切換えにより、FM，
AMの各検出回路１１，１２のａ点、ｂ点には、
それぞれ第２図ａ，ｂに示すように電源電圧の変
動分を微分した電圧が得られる。この電圧をダイ
オードD1，D2で整流して正極性の電圧のみをと
り出し、これを前述のミユート信号に加え合わせ
ると、第２図ｄのような信号になる。そこでこの
信号をミユーテイング回路４に加えれば、バンド
が切換わつた直後からミユーテイングがかかり、
信号伝送路が遮断される。したがつてバンド切換
時のシヨツク音を確実に阻止することができる。
なお、検出回路１１，１２のコンデンサＣ，Ｃと
抵抗Ｒ，Ｒは、第２図ａのように立ち上がりの速
い微分出力を得るために、それぞれ10μFおよび
2.7KΩ程度に設定される。また、このように小さ
い時定数の微分回路を用いているために、その微
分出力のみではバンド切え時のシヨツク音を阻止
するのに要する充分な時間幅の出力が得られない
ため、同調制御回路７からのミユート信号と加え
合わせるようにして、シヨツク音を完全に防止す
るようにしている。 In the above configuration, the band changeover switch 10 is
When switching from AM side to FM side, tuning control circuit 7
is switched to the FM reception mode, and a mute signal as shown in FIG. 2c is output from the mute signal output terminal 7a. However, in this case, as described above, the tuning control circuit 7 outputs the shoot signal after determining that the band has been switched using a microcomputer or the like, so that the tuning control circuit 7 outputs the shoot signal from the moment the band is switched as shown in FIG. 2c. Only τ (actually 15 μsec
degree) The mute signal appears with a delay. On the other hand, by switching the power selector switch 10b, FM,
At points a and b of each AM detection circuit 11, 12,
As shown in FIGS. 2a and 2b, voltages obtained by differentiating fluctuations in the power supply voltage are obtained. This voltage is rectified by diodes D 1 and D 2 to extract only the positive polarity voltage, and when this is added to the aforementioned mute signal, a signal as shown in FIG. 2d is obtained. Therefore, if this signal is applied to the muting circuit 4, muting will start immediately after the band is switched.
The signal transmission path is cut off. Therefore, it is possible to reliably prevent the shock noise when switching bands.
The capacitors C and C and the resistors R and R of the detection circuits 11 and 12 are set to 10 μF and 10 μF, respectively, in order to obtain a differential output with a fast rise as shown in Fig. 2a.
It is set to about 2.7KΩ. In addition, since a differentiator circuit with such a small time constant is used, the differential output alone cannot provide an output with a sufficient time width required to suppress the shock sound when the band breaks, so tuning control is required. By adding it to the mute signal from circuit 7, the shock noise is completely prevented.
なお、FMからAMに切換えたときも同様の原
理でシヨツク音が除去される。またFM，AMの
切換えに限らず、その他のバンドの切換えにも応
用できる。また上記実施例ではバンド切換スイツ
チ１０を機械的スイツチで構成したが、タツチス
イツチ等を用いて電子的に切換えるようにしても
よいことはいうまでもない。 Note that when switching from FM to AM, the shock sound is removed using the same principle. Furthermore, it can be applied not only to switching between FM and AM, but also to switching between other bands. Further, in the above embodiment, the band changeover switch 10 is configured as a mechanical switch, but it goes without saying that the band changeover switch 10 may be electronically changed using a touch switch or the like.
このように本発明はバンド切換時の電源電圧の
変動分を微分し、その一方の極性の微分出力を同
調制御回路のミユート信号に加え合わせてミユー
テイング回路を駆動するようにしたものであるか
ら、バンド切換直後から信号伝送路を遮断し、切
換時のシヨツク音を確実に阻止することができ
る。 As described above, the present invention differentiates the variation in the power supply voltage at the time of band switching, and adds the differentiated output of one polarity to the muting signal of the tuning control circuit to drive the muting circuit. Immediately after the band is switched, the signal transmission path is shut off, and the shock noise at the time of switching can be reliably prevented.
第１図は本発明の一実施例の回路図、第２図ａ
〜ｄは第１図の各部の電圧波形図である。
１……FM受信回路、２……AM受信回路、３
……低周波回路、４……ミユーテイング回路、５
……電力増幅器、６……スピーカ、７……同調制
御回路、７ａ……ミユート信号出力端子、８……
ループフイルタ、９……プリスケーラ、１０……
バンド切換スイツチ、１１，１２……検出回路。
Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2a
-d are voltage waveform diagrams at various parts in FIG. 1...FM receiving circuit, 2...AM receiving circuit, 3
...Low frequency circuit, 4...Muting circuit, 5
... Power amplifier, 6 ... Speaker, 7 ... Tuning control circuit, 7a ... Mute signal output terminal, 8 ...
Loop filter, 9... Prescaler, 10...
Band changeover switch, 11, 12...detection circuit.
Claims (1)
れぞれ受信する複数の受信回路と、上記各受信回
路の受信周波数を電子的に可変するとともに、バ
ンド切換時にバンド切換スイツチが切換えられた
ことを検知してその切換えより少し遅れてミユー
ト信号を出力する同調制御回路と、上記同調制御
回路を上記各受信回路に対応する受信モードに切
換えるモード切換スイツチおよびこれに連動して
各受信回路の電源を切換える電源切換スイツチか
らなるバンド切換スイツチと、上記電源切換スイ
ツチの切換時の各電源電圧の変化分を微分し、そ
の一方の極性の出力のみをとり出す検出回路とを
備え、上記同調制御回路のミユート信号と上記検
出回路の出力とを加算し、この加算出力で信号伝
送路に挿入されたミユーテイング回路を駆動し、
バンド切換時に上記信号伝送路を遮断するように
したことを特徴とする受信機。1 A plurality of receiving circuits each receiving a plurality of bands with different reception frequency bands, and a system that electronically varies the reception frequency of each of the above-mentioned receiving circuits, and detects that a band changeover switch has been switched at the time of band switching. a tuning control circuit that outputs a mute signal a little later than the switching, a mode changeover switch that switches the tuning control circuit to a reception mode corresponding to each of the reception circuits, and a power supply that switches the power supply of each reception circuit in conjunction with this switch. It is equipped with a band changeover switch consisting of a changeover switch, and a detection circuit that differentiates the changes in each power supply voltage when the power changeover switch is switched and takes out only the output of one of the polarities. and the output of the above-mentioned detection circuit, and this added output drives a muting circuit inserted in the signal transmission path,
A receiver characterized in that the signal transmission path is cut off when switching bands.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19594381A JPS5896429A (en) | 1981-12-04 | 1981-12-04 | Receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19594381A JPS5896429A (en) | 1981-12-04 | 1981-12-04 | Receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5896429A JPS5896429A (en) | 1983-06-08 |
| JPS6313367B2 true JPS6313367B2 (en) | 1988-03-25 |
Family
ID=16349545
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19594381A Granted JPS5896429A (en) | 1981-12-04 | 1981-12-04 | Receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5896429A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4203059C1 (en) * | 1992-02-04 | 1993-04-29 | Grundig E.M.V. Elektro-Mechanische Versuchsanstalt Max Grundig Hollaend. Stiftung & Co Kg, 8510 Fuerth, De |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5549046A (en) * | 1978-10-04 | 1980-04-08 | Pioneer Electronic Corp | Change-over state detection circuit of change-over switch |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55162416U (en) * | 1979-05-11 | 1980-11-21 |
-
1981
- 1981-12-04 JP JP19594381A patent/JPS5896429A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5549046A (en) * | 1978-10-04 | 1980-04-08 | Pioneer Electronic Corp | Change-over state detection circuit of change-over switch |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5896429A (en) | 1983-06-08 |
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