JPH0733455Y2 - Band compression circuit - Google Patents
Band compression circuitInfo
- Publication number
- JPH0733455Y2 JPH0733455Y2 JP1989139925U JP13992589U JPH0733455Y2 JP H0733455 Y2 JPH0733455 Y2 JP H0733455Y2 JP 1989139925 U JP1989139925 U JP 1989139925U JP 13992589 U JP13992589 U JP 13992589U JP H0733455 Y2 JPH0733455 Y2 JP H0733455Y2
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- circuit
- signal
- detection
- output
- band
- Prior art date
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Description
【考案の詳細な説明】 （産業上の利用分野） この考案は、FM信号の帯域圧縮回路に関し、特に安定な
負帰還動作を可能とするFM検波回路の帯域圧縮回路に関
する。DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a band compression circuit for FM signals, and more particularly to a band compression circuit for an FM detection circuit that enables stable negative feedback operation.
（従来の技術） 従来、良質な音声を得るためのFM検波回路としては、帯
域圧縮回路を用いた種々回路が採用されている。それら
の中で代表的な回路を第２図に示す。(Prior Art) Conventionally, various circuits using a band compression circuit have been adopted as an FM detection circuit for obtaining high-quality voice. A typical circuit among them is shown in FIG.
第２図の回路において、入力中間周波数信号21はミキサ
ー回路22と中間周波数フイルタ23を経てFM検波回路24で
FM検波される。In the circuit shown in FIG. 2, the input intermediate frequency signal 21 passes through a mixer circuit 22 and an intermediate frequency filter 23, and an FM detection circuit 24.
FM detected.
また、検波出力は低域通過フイルタ（LPF）26により不
要な高域成分を除去されて、FM変調回路25に入力され
る。FM変調回路25でFM変調された信号はミキサー回路22
に供給されて、入力中間周波数信号21と混合される。こ
こで、ミキサー回路22、中間周波数フイルタ23、FM検波
回路24、低域通過フイルタ（LPF）26、FM変調回路25か
らミキサー回路22へ戻るループは負帰還回路を構成して
いる。Further, the detection output is input to the FM modulation circuit 25 after the unnecessary high-pass component is removed by the low-pass filter (LPF) 26. The signal modulated by the FM modulation circuit 25 is mixed by the mixer circuit 22.
And is mixed with the input intermediate frequency signal 21. Here, the loop returning from the mixer circuit 22, the intermediate frequency filter 23, the FM detection circuit 24, the low-pass filter (LPF) 26, and the FM modulation circuit 25 to the mixer circuit 22 constitutes a negative feedback circuit.
そして、中間周波数信号21として入力されたFM変調信号
は、FM検波回路24においてその周波数偏移量にしたがっ
た検波出力を発生するが、この検波出力によりFM変調回
路25で変調された出力は、始めに入力された中間周波数
信号21と、その変調成分、すなわち、瞬時個々時間毎の
周波数偏移量は相似となる。したがって、負帰還信号と
してミキサー回路22で元の入力中間周波数信号21と混合
されると、元の信号の周波数偏移量を減少する方向とし
て動作する。すなわち、入力中間周波数信号21は、その
帯域を圧縮されたこととなる。Then, the FM modulation signal input as the intermediate frequency signal 21 generates a detection output according to the frequency deviation amount in the FM detection circuit 24, but the output modulated by the FM modulation circuit 25 by this detection output is The intermediate frequency signal 21 input at the beginning and its modulation component, that is, the frequency shift amount at each instantaneous individual time are similar. Therefore, when it is mixed with the original input intermediate frequency signal 21 in the mixer circuit 22 as a negative feedback signal, it operates in the direction of decreasing the frequency deviation amount of the original signal. That is, the input intermediate frequency signal 21 has its band compressed.
（考案が解決しようとする課題） 上述従来の第２図に示す負帰還回路を用いた回路では、
負帰還回路が音声復調回路と同一の経路を使用している
ため、音声復調回路として隣接チャンネルからの妨害を
防止するために、狭帯域の中間周波数フイルタを使わな
くてはならなくなる。一方、帯域外の遮断特性の良い狭
帯域のフイルタは、その遅延時間特性において、帯域の
中心部とその両端における遅延時間特性の差が大きいだ
けでなく、帯域内（特にその両端部において）の特性が
波打ついわゆる“あばれ”が大きいことはよく知られた
事実である。このようなフイルタが負帰還回路のループ
中に存在する場合、帯域内の信号の遅延時間が一定とな
らないため信号の周波数（本願の場合は周波数偏移量）
の値により帰還信号との位相差が変動し、不安定な動作
となるという問題があった。また遅延時間が大きいこと
は安定動作範囲での十分な信号帯域の圧縮動作が得られ
ないという問題点があった。(Problems to be Solved by the Invention) In the circuit using the negative feedback circuit shown in FIG.
Since the negative feedback circuit uses the same path as the voice demodulation circuit, a narrow band intermediate frequency filter must be used as the voice demodulation circuit in order to prevent interference from an adjacent channel. On the other hand, a narrow-band filter with good out-of-band blocking characteristics not only has a large difference in delay time characteristics between the center part of the band and its both ends, but also in the band (particularly at both ends). It is a well-known fact that the so-called "bare" where the characteristics are wavy is great. When such a filter exists in the loop of the negative feedback circuit, the delay time of the signal within the band is not constant, so the frequency of the signal (the frequency shift amount in the case of the present application).
There is a problem that the phase difference with the feedback signal fluctuates depending on the value of and the operation becomes unstable. Further, the large delay time causes a problem that a sufficient compression operation of the signal band in the stable operation range cannot be obtained.
そこで、この考案の目的は、安定な遅延特性と帯域圧縮
のためのミキサー回路への２つの信号の遅延時間の差を
補償して安定な帯域圧縮動作を可能とする帯域圧縮回路
を提供することにある。Therefore, an object of the present invention is to provide a band compression circuit that enables stable band compression operation by compensating for the difference in delay time between two signals to the mixer circuit for stable delay characteristics and band compression. It is in.
（課題を解決するための手段） 前述の課題を解決するため、この考案による帯域圧縮回
路は、 検波出力で再変調してFM信号帯域を圧縮する帯域圧縮回
路において、 入力中間周波数信号を所定時間遅延させる遅延回路と、
帯域圧縮のため検波出力で再変調を行なうFM変調回路
と、前記遅延回路の出力信号と前記FM変調回路の出力信
号とを混合する第１のミキサー回路と、前記第１のミキ
サー回路の出力に接続され隣接チャンネル妨害信号を排
除する狭帯域フイルタと、前記狭帯域フイルタの出力信
号をFM検波する第１のFM検波回路と、 入力中間周波数信号と前記FM変調回路の出力信号とを混
合する第２のミキサー回路と、前記第２のミキサー回路
の出力に接続された広帯域フイルタと、前記広帯域フイ
ルタの出力信号をFM検波する第２のFM検波回路とを備
え、 前記第２のFM検波回路の検波出力信号を前記FM変調回路
の変調信号としたことを特徴とした。(Means for Solving the Problems) In order to solve the above-mentioned problems, the band compression circuit according to the present invention is a band compression circuit that re-modulates an FM signal band by re-modulating with a detection output and outputs an input intermediate frequency signal for a predetermined time. Delay circuit to delay,
An FM modulation circuit that performs remodulation with a detection output for band compression, a first mixer circuit that mixes an output signal of the delay circuit and an output signal of the FM modulation circuit, and an output of the first mixer circuit. A narrow band filter connected to eliminate adjacent channel interference signals, a first FM detection circuit for performing FM detection of an output signal of the narrow band filter, and a first mixing circuit for mixing an input intermediate frequency signal and an output signal of the FM modulation circuit. 2 mixer circuits, a wide band filter connected to the output of the second mixer circuit, and a second FM detection circuit for performing FM detection of the output signal of the wide band filter, the second FM detection circuit The detection output signal is a modulation signal of the FM modulation circuit.
（作用） 帯域圧縮のための負帰還回路における第２のミキサー回
路〜広帯域フイルタ〜第２のFM検波回路〜FM変調回路の
ループと、音声復調回路における第１のミキサー回路〜
狭帯域フイルタ回路〜第１のFM検波回路をそれぞれ独立
した構成にしたので、それぞれ最適な機能動作を得るこ
とが可能となった。(Operation) Second mixer circuit in negative feedback circuit for band compression-Wideband filter-Second FM detection circuit-FM modulation circuit loop and first mixer circuit in voice demodulation circuit-
Since the narrow band filter circuit to the first FM detection circuit are independently configured, it is possible to obtain the optimum functional operation.
すなわち、負帰還回路のループにおいて絶対遅延時間の
“あばれ”の少ない広帯域フイルタを使用したので信号
帯域内の全周波数において遅延時間を一定とするととも
に、FM変調回路の出力である帯域圧縮用の信号を第１の
ミキサーに加える際の遅延時間に見合った遅延回路を第
１のミキサーの前に置いて入力中間周波数信号との位相
を合わせている。That is, since a wide band filter with a small absolute delay time is used in the loop of the negative feedback circuit, the delay time is kept constant at all frequencies within the signal band, and the band compression signal output from the FM modulation circuit is used. Is placed in front of the first mixer to match the phase with the input intermediate frequency signal by placing a delay circuit corresponding to the delay time when the signal is added to the first mixer.
したがって、第２のミキサー回路における負帰還回路の
ループの遅延時間は一定の値となってその安定な範囲で
動作させられると同時に、第１のミキサー回路における
帯域圧縮動作はその２つの入力信号間の位相差が補償さ
れているので、良好で充分な帯域圧縮が可能となる。Therefore, the delay time of the loop of the negative feedback circuit in the second mixer circuit becomes a constant value and the circuit is operated in the stable range, and at the same time, the band compression operation in the first mixer circuit is performed between the two input signals. Since the phase difference is compensated, good and sufficient band compression can be performed.
更に、音声復調の系統における中間周波数フイルタは必
要とされる隣接チャンネル妨害を満たすに十分な狭帯域
フイルタの使用が可能となり、良好な音声復調が可能と
なる。Further, as the intermediate frequency filter in the voice demodulation system, a narrow band filter sufficient to satisfy the required adjacent channel interference can be used, and good voice demodulation can be performed.
（実施例） 次に、この考案について図面を参照しながら説明する。
第１図は、この考案による帯器圧縮回路の一実施例を示
すブロック図である。(Example) Next, this invention is demonstrated, referring drawings.
FIG. 1 is a block diagram showing an embodiment of a band compression circuit according to the present invention.
周波数f1の中間周波数信号１は、遅延回路２で所定時間
だけ遅延されて第１のミキサー回路３に入力される。入
力中間周波数信号１は、また第２のミキサー回路７にも
供給される。The intermediate frequency signal 1 having the frequency f 1 is delayed by the delay circuit 2 for a predetermined time and input to the first mixer circuit 3. The input intermediate frequency signal 1 is also supplied to the second mixer circuit 7.
第１のミキサー回路３は、FM変調回路６からの周波数f2
の信号と遅延回路２からの遅延された中間周波数信号f1
とを混合して周波数変換処理を行ない、周波数f3の混合
信号を狭帯域中間周波数フイルタ４に出力する。The first mixer circuit 3 has a frequency f 2 from the FM modulation circuit 6.
Signal and the delayed intermediate frequency signal f 1 from the delay circuit 2
Are mixed and frequency conversion processing is performed, and a mixed signal of frequency f 3 is output to the narrow band intermediate frequency filter 4.
この狭帯域中間周波数フイルタ４の出力は、第１のFM検
波回路５でFM検波されて出力音声信号VOとして出力され
る。The output of the narrow band intermediate frequency filter 4 is FM-detected by the first FM detection circuit 5 and output as the output audio signal V O.
一方、第２のミキサー回路７は、入力中間周波数信号f1
とFM検波変調回路６の出力信号f2とを混合して周波数変
換を行ない、同じく周波数f3の混合出力を広帯域中間周
波数フイルタ８に供給する。On the other hand, the second mixer circuit 7 outputs the input intermediate frequency signal f 1
And the output signal f 2 of the FM detection modulation circuit 6 are mixed to perform frequency conversion, and the mixed output of the frequency f 3 is supplied to the wide band intermediate frequency filter 8 as well.
広帯域中間周波数フイルタ８の出力は第２のFM検波回路
９によりFM検波されて、検波信号Ｖを得て、低域通過フ
イルタ（LPF）10に供給する。The output of the wide band intermediate frequency filter 8 is FM-detected by the second FM detection circuit 9 to obtain a detection signal V, which is supplied to the low-pass filter (LPF) 10.
低域通過フイルタ10で隣接チャンネルからの妨害などの
高域の雑音成分を除去して得られた低域成分信号Ｖは、
FM変調回路６に出力され、そこでFM変調されて、前記周
波数f2の信号を第１のミキサー回路３と第２のミキサー
回路７のそれぞれに供給する。The low-pass component signal V obtained by removing high-pass noise components such as interference from adjacent channels by the low-pass filter 10 is
The signal having the frequency f 2 is output to the FM modulation circuit 6 and is FM-modulated there to be supplied to each of the first mixer circuit 3 and the second mixer circuit 7.
以上のような回路構成により、帯域圧縮する際の原信号
と圧縮のためのFM変調信号、すなわち負帰還信号との位
相差を少なくして安定な帯域圧縮を可能とする。以下、
その回路動作を詳細に説明する。The circuit configuration as described above enables stable band compression by reducing the phase difference between the original signal for band compression and the FM modulation signal for compression, that is, the negative feedback signal. Less than,
The circuit operation will be described in detail.
上述した通り、入力中間周波数信号１は、遅延回路２と
第２のミキサー回路７に供給される。第２のミキサー回
路７の出力は、また広帯域中間周波数フイルタ８、第２
のFM検波回路９、低域通過フイルタ10を通ってFM変調回
路６でFM変調されて、FM変調信号が第１のミキサー回路
３と第２のミキサー回路７に供給される。As described above, the input intermediate frequency signal 1 is supplied to the delay circuit 2 and the second mixer circuit 7. The output of the second mixer circuit 7 is also fed to the wide band intermediate frequency filter 8, the second
The signal is subjected to FM modulation by the FM modulation circuit 6 through the FM detection circuit 9 and the low-pass filter 10 and the FM modulation signal is supplied to the first mixer circuit 3 and the second mixer circuit 7.
ここで、広帯域中間周波数フイルタ８は隣接チャンネル
妨害を余り気にしないでよいので、一定の絶対遅延時間
で示される遅延時間を持ったフイルタが採用できる。こ
の絶対遅延時間により、FM変調信号も入力中間周波数信
号１に対して遅延された信号となって第１のミキサー回
路３に供給されることになる。Here, since the wide band intermediate frequency filter 8 does not have to worry about adjacent channel interference, a filter having a delay time indicated by a constant absolute delay time can be adopted. Due to this absolute delay time, the FM modulation signal also becomes a signal delayed with respect to the input intermediate frequency signal 1 and is supplied to the first mixer circuit 3.
したがって、第１のミキサー回路３において、安定に周
波数変換（すなわち帯域圧縮動作）を行なうには、広帯
域中間周波数フイルタ８により生じた遅延時間を補償す
る必要があり、遅延回路２は、この補償処理を行なうた
めのものである。Therefore, in order to perform stable frequency conversion (that is, band compression operation) in the first mixer circuit 3, it is necessary to compensate for the delay time generated by the wide band intermediate frequency filter 8, and the delay circuit 2 performs this compensation processing. Is for doing.
さて、第１図の実施例のブロック図は、いわゆるFM負帰
還回路である。そして、この実施例は、負帰還経路を構
成する第２のFM検波回路９の系統と、音声信号を取り出
すための第１のFM検波回路５の系統とを備える。Now, the block diagram of the embodiment of FIG. 1 is a so-called FM negative feedback circuit. Then, this embodiment includes a system of the second FM detection circuit 9 which constitutes a negative feedback path and a system of the first FM detection circuit 5 for taking out an audio signal.
第１のFM検波回路５の系統は、音声信号を取り出すため
の回路であるため、専ら隣接チャンネル妨害改善を目的
とする狭帯域中間周波数フイルタ４を有する。Since the system of the first FM detection circuit 5 is a circuit for extracting a voice signal, it has a narrow band intermediate frequency filter 4 exclusively for improving adjacent channel interference.
一方、FM検波回路９の系統は、負帰還信号を取り出し、
且つこの負帰還信号が入力信号と極端な遅延時間差を生
じさせないために、広帯域中間周波数フイルタ９が用い
られ、より安定な負帰還動作を可能とする。On the other hand, the system of the FM detection circuit 9 takes out the negative feedback signal,
In addition, since the negative feedback signal does not cause an extreme delay time difference from the input signal, the wide band intermediate frequency filter 9 is used, which enables more stable negative feedback operation.
次にこの考案の負帰還動作による帯域圧縮動作について
説明する。Next, the band compression operation by the negative feedback operation of this invention will be described.
ここで、入力中間周波数の周波数偏移をfDEV1、FM変調
回路６の周波数偏移をfDEV2、第１のミキサー回路３と
第２のミキサー回路７の出力の周波数偏移をfDEV3とす
る。なお、第１のミキサー回路３と第２のミキサー回路
７の出力においては中心周波数が変換されることになる
が、ここでは周波数偏移について着目する。Here, the frequency deviation of the input intermediate frequency is f DEV1 , the frequency deviation of the FM modulation circuit 6 is f DEV2 , and the frequency deviation of the outputs of the first mixer circuit 3 and the second mixer circuit 7 is f DEV3 . . The center frequency is converted at the outputs of the first mixer circuit 3 and the second mixer circuit 7. Here, attention is paid to the frequency deviation.
また、第１のFM検波回路３の復調感度をk1（V/Hz）と
し、第２のFM検波回路７の復調感度をk2（V/Hz）とし、
FM変調回路７の変調感度をk3（V/Hz）とすると、次の関
係が成り立つ。Further, the demodulation sensitivity of the first FM detection circuit 3 is k 1 (V / Hz), and the demodulation sensitivity of the second FM detection circuit 7 is k 2 (V / Hz),
If the modulation sensitivity of the FM modulation circuit 7 is k 3 (V / Hz), the following relationship holds.
第２のミキサー回路７の出力周波数偏移fDEV3は、 fDEV3＝fDEV1−fDEV2 …（１） 第２のFM検波回路９の出力Ｖは、 Ｖ＝k2 fDEV3 …（２） FM変調回路６の出力周波数偏移fDEV2は、 fDEV2＝k3 V …（３） したがって、（１）〜（３）式を用いて、fDEV1とfDEV3
の関係を求めると、 fDEV3＝｛1/（１＋k2 k3）｝fDEV1 …（４） （４）式に示すように第２のミキサー７の出力周波数偏
移fDEV3は入力中間周波数の周波数偏移fDEV1の｛1/（１
＋k2 k3）｝に圧縮される。The output frequency deviation f DEV3 of the second mixer circuit 7 is f DEV3 = f DEV1 −f DEV2 (1) The output V of the second FM detection circuit 9 is V = k 2 f DEV3 (2) FM The output frequency deviation f DEV2 of the modulation circuit 6 is f DEV2 = k 3 V (3) Therefore, using the formulas (1) to (3), f DEV1 and f DEV3
The relation of f DEV3 = {1 / (1 + k 2 k 3 )} f DEV1 (4) As shown in the equation (4), the output frequency deviation f DEV3 of the second mixer 7 is the input intermediate frequency. Frequency deviation f DEV1 {1 / (1
+ K 2 k 3 )}.
一方、第１のミキサー回路３を、第２のミキサー回路７
と同じ構成にしておけば、その出力の周波数偏移も同様
にfDEV3であるので、音声信号を取り出す系統における
信号帯域も｛1/（１＋k2 k3）｝に圧縮される。On the other hand, the first mixer circuit 3 is replaced by the second mixer circuit 7
With the same configuration as above, the frequency shift of the output is also f DEV3 , so that the signal band in the system for extracting the audio signal is also compressed to {1 / (1 + k 2 k 3 )}.
第１のミキサー回路３の２つの入力信号（周波数f1とf
2）の位相差は、遅延回路２によって一致させられてい
るから安定な負帰還帯域圧縮が可能となることは明らか
である。The two input signals of the first mixer circuit 3 (frequency f1 and f
Since the phase difference of 2) is matched by the delay circuit 2, it is clear that stable negative feedback band compression is possible.
以上のようにして圧縮されたFM信号は、狭帯域の中間周
波数フイルタを通ってもスペクトラムが欠落することな
く通過し、歪の発生を最小限に抑えることができる。一
方、隣接チャンネル妨害信号は中間周波数フイルタが狭
帯域であるので排除される。したがって、FM検波回路５
によって音声信号が復調され、妨害が少なく歪の発生も
少ない音声信号が得られることになる。The FM signal compressed as described above passes without narrowing the spectrum even when passing through the narrow band intermediate frequency filter, and the occurrence of distortion can be suppressed to the minimum. On the other hand, the adjacent channel interference signal is eliminated because the intermediate frequency filter has a narrow band. Therefore, FM detection circuit 5
Thus, the audio signal is demodulated, and an audio signal with less interference and less distortion is obtained.
（考案の効果） 以上説明したように、この考案では、負帰還系のFM変調
信号の遅延をミキサー回路の前段に設けた遅延回路によ
って補償しているので安定な負帰還帯域圧縮が可能とな
る。また、負帰還系に広帯域フイルタを挿入しているの
で絶対遅延時間の“あばれ”が少なくなる。更に、この
考案では音声復調系のフイルタを分離しているので妨害
排除のため帯域幅を充分に狭帯域にでき、隣接チャンネ
ル妨害の改善が大きい。(Effect of Device) As described above, in this device, the delay of the FM modulation signal of the negative feedback system is compensated by the delay circuit provided in the preceding stage of the mixer circuit, so that stable negative feedback band compression is possible. . In addition, since the wide band filter is inserted in the negative feedback system, the "delay" of the absolute delay time is reduced. Further, in this invention, since the filter of the voice demodulation system is separated, the band width can be made sufficiently narrow to eliminate interference, and the improvement of adjacent channel interference is great.
第１図は、この考案による帯域圧縮回路の一実施例を示
すブロック図、第２図は従来の帯域圧縮回路を示すブロ
ック図である。 １……入力中間周波数信号、２……遅延回路、3,7……
ミキサー回路、４……狭帯域中間周波数フイルタ、5,9
……FM検波回路、６……FM変調回路、８……広帯域中間
周波数フイルタ、10……低域通過フイルタ。FIG. 1 is a block diagram showing an embodiment of a band compression circuit according to the present invention, and FIG. 2 is a block diagram showing a conventional band compression circuit. 1 ... Input intermediate frequency signal, 2 ... Delay circuit, 3,7 ...
Mixer circuit, 4 ... Narrow band intermediate frequency filter, 5,9
…… FM detection circuit, 6 …… FM modulation circuit, 8 …… Broadband intermediate frequency filter, 10 …… Low-pass filter.
Claims (1)
る帯域圧縮回路において、 入力中間周波数信号を所定時間遅延させる遅延回路と、
帯域圧縮のため検波出力で再変調を行なうFM変調回路
と、前記遅延回路の出力信号と前記FM変調回路の出力信
号とを混合する第１のミキサー回路と、前記第１のミキ
サー回路の出力に接続され隣接チャンネル妨害信号を排
除する狭帯域フイルタと、前記狭帯域フイルタの出力信
号をFM検波する第１のFM検波回路と、 入力中間周波数信号と前記FM変調回路の出力信号とを混
合する第２のミキサー回路と、前記第２のミキサー回路
の出力に接続された広帯域フイルタと、前記広帯域フイ
ルタの出力信号をFM検波する第２のFM検波回路とを備
え、 前記第２のFM検波回路の検波出力信号を前記FM変調回路
の変調信号としたことを特徴とする帯域圧縮回路。1. A band compression circuit for remodulating with a detection output to compress an FM signal band, a delay circuit delaying an input intermediate frequency signal for a predetermined time,
An FM modulation circuit that performs remodulation with a detection output for band compression, a first mixer circuit that mixes an output signal of the delay circuit and an output signal of the FM modulation circuit, and an output of the first mixer circuit. A narrow band filter connected to eliminate adjacent channel interference signals, a first FM detection circuit for performing FM detection of an output signal of the narrow band filter, and a first mixing circuit for mixing an input intermediate frequency signal and an output signal of the FM modulation circuit. 2 mixer circuits, a wide band filter connected to the output of the second mixer circuit, and a second FM detection circuit for performing FM detection of the output signal of the wide band filter, the second FM detection circuit A band compression circuit, wherein a detection output signal is a modulation signal of the FM modulation circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989139925U JPH0733455Y2 (en) | 1989-12-04 | 1989-12-04 | Band compression circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989139925U JPH0733455Y2 (en) | 1989-12-04 | 1989-12-04 | Band compression circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0379520U JPH0379520U (en) | 1991-08-14 |
| JPH0733455Y2 true JPH0733455Y2 (en) | 1995-07-31 |
Family
ID=31686941
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1989139925U Expired - Lifetime JPH0733455Y2 (en) | 1989-12-04 | 1989-12-04 | Band compression circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0733455Y2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11074557B2 (en) | 2016-03-31 | 2021-07-27 | Advanced Custom Engineered Systems & Equipment Co. | Systems and method for interrogating, publishing and analyzing information related to a waste hauling vehicle |
| US11267646B2 (en) | 2008-11-07 | 2022-03-08 | Advanced Custom Engineered Systems & Equipment Co. | Method and apparatus for monitoring waste removal and administration |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100982456B1 (en) * | 2009-12-29 | 2010-09-16 | 김지훈 | A system of decoration light using an optical fiber |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5423459A (en) * | 1977-07-25 | 1979-02-22 | Nippon Telegr & Teleph Corp <Ntt> | Delay detector |
-
1989
- 1989-12-04 JP JP1989139925U patent/JPH0733455Y2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5423459A (en) * | 1977-07-25 | 1979-02-22 | Nippon Telegr & Teleph Corp <Ntt> | Delay detector |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11267646B2 (en) | 2008-11-07 | 2022-03-08 | Advanced Custom Engineered Systems & Equipment Co. | Method and apparatus for monitoring waste removal and administration |
| US11286108B2 (en) | 2008-11-07 | 2022-03-29 | Advanced Custom Engineered Systems & Equipment Co. | Method and apparatus for monitoring waste removal and administration |
| US11074557B2 (en) | 2016-03-31 | 2021-07-27 | Advanced Custom Engineered Systems & Equipment Co. | Systems and method for interrogating, publishing and analyzing information related to a waste hauling vehicle |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0379520U (en) | 1991-08-14 |
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