JPS5858416A - Ultrasonic measuring device for velocity of flow - Google Patents
Ultrasonic measuring device for velocity of flowInfo
- Publication number
- JPS5858416A JPS5858416A JP56157870A JP15787081A JPS5858416A JP S5858416 A JPS5858416 A JP S5858416A JP 56157870 A JP56157870 A JP 56157870A JP 15787081 A JP15787081 A JP 15787081A JP S5858416 A JPS5858416 A JP S5858416A
- Authority
- JP
- Japan
- Prior art keywords
- transmitter
- sing
- flow
- transmitted
- signal
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/66—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Volume Flow (AREA)
Abstract
Description
【発明の詳細な説明】
本発明はシングアラウンド法により液体、気体等の流通
を測定する装置の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an apparatus for measuring the flow of liquid, gas, etc. by the sing-around method.
従来のシングアラウンド法による流速測定装置を第１図
に示す。図中、■は波４彫型形回路２と送信器３と受信
器４と増幅器５よシなるシングアラウンド系、６は送受
切替回路、７は切換スイッチ、８ａ、８ｂは超音波の送
受波器、９はアップ・ダウンカウンタである。このよう
な装置において、まず送信器３と送受波器８ａ。FIG. 1 shows a conventional flow velocity measuring device using the single-around method. In the figure, ■ is a sing-around system consisting of wave 4 shaped circuit 2, transmitter 3, receiver 4, and amplifier 5, 6 is a transmission/reception switching circuit, 7 is a changeover switch, and 8a and 8b are ultrasonic transmission/reception waves. 9 is an up/down counter. In such a device, first, the transmitter 3 and the transducer 8a.
受信器４と送受波器８ｂ’ｔそれぞれ接続する如く送受
切替回路６を動作させ、これに連動して切換スイッチ７
をアップ・ダウンカウンタ９のアップ入力端子に接続す
る。送信器３で発生したパルス信号は送受波器８４で超
音波ノソルスに変換され、流体１０の流れの方向Ａと同
方向に送受波器８ｂに向けて送出される。送受波器８ｂ
にて受信された超音波パルスは再度電気信号に変換され
、受信器４．増幅器５にて増幅され、更に波形整形回路
２にて波形整形された後、アップ・ダウンカウンタ９及
び送信器３へ送出され、アップ・ダウンカウンタ９をカ
ウントアツプするとともに送信器３をトリガし再度パル
ス信号を発生させる。以下、上記同様の動作を所定時間
縁シ返した後、送受切替回路６及び切換スイッチ７を切
替えて送受波器８ｂよシ流体１０の流れの方向Ａに逆っ
て超音波パルスを送受波器８ａへ向けて送出する如くな
し、上記同様の動作ニよシアラグ・ダウンカウンタ９の
内容を所定時間カウントダウンする。而してアップ・ダ
ウンカウンタ９の内容す竜゛わち流体１０の流れと同方
向に超音波パルスを送出した場合と流れに逆って超音波
パルスを送出した場合のシングアラウンド周波数の差か
ら流速を算出する如くなっている。The transmitter/receiver switching circuit 6 is operated so that the receiver 4 and the transducer 8b't are connected, and the selector switch 7 is operated in conjunction with this.
is connected to the up input terminal of the up/down counter 9. The pulse signal generated by the transmitter 3 is converted into an ultrasonic wave by the transducer 84, and is sent toward the transducer 8b in the same direction as the flow direction A of the fluid 10. Transducer/receiver 8b
The ultrasonic pulses received by the receiver 4. are converted into electrical signals again. After being amplified by the amplifier 5 and further waveform-shaped by the waveform shaping circuit 2, it is sent to the up/down counter 9 and the transmitter 3, which increments the up/down counter 9 and triggers the transmitter 3 again. Generate a pulse signal. Thereafter, after repeating the same operation as described above for a predetermined period of time, the transmission/reception switching circuit 6 and the changeover switch 7 are switched to transmit ultrasonic pulses from the transducer 8b to the transducer 8b in the opposite direction of the flow direction A of the fluid 10. In the same manner as above, the contents of the shear lag down counter 9 are counted down for a predetermined period of time. Therefore, the contents of the up/down counter 9 are calculated based on the difference in the sing-around frequency when the ultrasonic pulse is sent in the same direction as the flow of the fluid 10 and when the ultrasonic pulse is sent out against the flow. It is designed to calculate the flow velocity.
第２図は従来の他の流速測定装置を示すもので、第２図
中、１１は減算器、１２，１３はカウンタ、１４，１５
は第１図のシングアラウンド系１と同様な構成をそれぞ
れ有するシングアラウンド系（υ、（２八 １６ ａ
ｒ １６ ｂはシングアラウンド系（υに接続した超音
波の送受波器、１７ａ、１７ｂはシングアラウンド系（
２）に接続した送受波器であシ、シングアラウンド系（
１）は送受波器１６ａと送受波器１６ｂ間で流体１０の
流れの方向Ａと同方向に超音波パルス全送受信しカウン
タ１２をカウントアツプし、クングアラウンド系（２）
は送受波器１７ａと送受波器１７ｂ間で流体１０の流れ
の方向Ａと反対の方向に超音波パルスを送受信しカウン
タ１３をカウントアツプし、該カウンタ１２と１３の計
数値を減算器１１で減算し、シングアラウンド周波数の
差を求め、流速を得る如くなっている。Fig. 2 shows another conventional flow rate measuring device, in which 11 is a subtracter, 12, 13 are counters, 14, 15
are sing-around systems (υ, (28 16 a
r 16 b is the sing-around system (ultrasonic transducer connected to υ, 17a and 17b are the sing-around system (
2) with a transducer connected to the sing-around system (
In 1), all ultrasonic pulses are transmitted and received between the transducer 16a and the transducer 16b in the same direction as the flow direction A of the fluid 10, and the counter 12 is counted up.
transmits and receives ultrasonic pulses between the transducer 17a and the transducer 17b in the direction opposite to the flow direction A of the fluid 10, counts up the counter 13, and calculates the counted values of the counters 12 and 13 using the subtracter 11. The flow velocity is obtained by subtracting and finding the difference in sing-around frequencies.
しかしながら上記第１図の装置では送受波器８ａ−８ｂ
間での超音波パルスの送受信の方向を変えるために送受
切替回路６及び切換スイッチ７ｔ−必要とし、流れの方
向Ａと同方向に超音波パルスを送受信する時間と流れの
方向Ａと逆方向に超音波パルスを送受信する時間とが異
なるために測定中に流速が変化した場合、誤差が生じ、
特に短い周期の流速変動をとらえにくいという欠点があ
った。However, in the device shown in FIG. 1, the transducers 8a-8b
In order to change the direction of transmission and reception of ultrasonic pulses between them, a transmission/reception switching circuit 6 and a changeover switch 7t are required. If the flow velocity changes during measurement due to different times when transmitting and receiving ultrasonic pulses, errors will occur.
In particular, it had the disadvantage that it was difficult to detect short-period flow velocity fluctuations.
また第２図の装置では送受波器を２組４個必要とし、２
組の送受波器１６ａ 、１６ｂの測定位置と送受波器１
７ａ 、１７ｂの測定位置との間で流速が異った場合、
誤差が生じるという欠点があった。In addition, the device shown in Figure 2 requires 2 sets of 4 transducers, and 2
Measurement positions of the set of transducers 16a and 16b and transducer 1
If the flow velocity differs between the measurement positions 7a and 17b,
There was a drawback that errors occurred.
本発明は上記従来の欠点を除去するため、シングアラウ
ンド法による超音波流速測定装置において、異なる周波
数のパルス信号にて動作する第１及び第２のクングアラ
ウンド系と、２個１組の送受波器とを有し、該１組の送
受波器の一方を上記第１のクングアラウンド系の送信側
と上記第２のシングアラウンド系の受信側に、また他方
を上記第２のシングアラウンド系の送信側と上記第１の
シングアラウンド系の受信側にそれぞれノ・イブリツド
トラノスを介して接続し、上記１組の送受波器間で流体
の流れと同方向及び反対方向に同時に超音波パルスを送
受信するようにしたもので、その目的とするところは流
速の時間的変動及び部分的な相違による測定誤差のない
流速測定装置を提供することにある。以下、図面につい
て詳細に説、明する。In order to eliminate the above-mentioned conventional drawbacks, the present invention provides an ultrasonic flow rate measuring device using the sing-around method, which includes a first and a second sing-around system that operate with pulse signals of different frequencies, and a pair of transmitting/receiving systems. one set of transducers is used as the transmitting side of the first sing-around system and the receiving side of the second sing-around system, and the other is used as the transmitting side of the first sing-around system and the other as the receiving side of the second sing-around system. The transmitting side of the system and the receiving side of the first single-around system are connected via hybrid transducers, respectively, and ultrasonic waves are simultaneously transmitted in the same direction and in the opposite direction of the fluid flow between the pair of transducers. The purpose of this device is to provide a flow velocity measurement device that is free from measurement errors due to temporal fluctuations and local differences in flow velocity. The drawings will be described and explained in detail below.
第３図は本発明の一実施例を示すものである。FIG. 3 shows an embodiment of the present invention.
図中、２０は第１のシングアラウンド系で、周波数ｆ、
の信号よシなるパルス信号を発生する送信器２１、周波
数ｆｌの信号のみを通過させるバンドパスフィルタ２２
、増幅器２３、検波器２４、波形整形回路２５とよシな
る。また３０は第２のクングアラウンド系で、上記周波
数ｆｌと異なる周波数ｆ２の信号よ勺なるノぞルス信号
を発生する送信器３１、周波数ｆ２の信号のみを通過さ
せるバンドパスフィルタ３２、増幅器３３、検波器３４
％波形整形回路３５とよシなる。４１ａ。In the figure, 20 is the first sing-around system, with frequencies f,
a transmitter 21 that generates a pulse signal similar to the signal of , and a bandpass filter 22 that passes only the signal of frequency fl.
, an amplifier 23, a detector 24, and a waveform shaping circuit 25. Reference numeral 30 designates a second clock-around system, which includes a transmitter 31 that generates a signal with a frequency f2 different from the frequency fl, a bandpass filter 32 that passes only the signal with the frequency f2, and an amplifier 33. , detector 34
It is similar to the % waveform shaping circuit 35. 41a.
４１ｂは流体１０中にその流れの方向に沿って距＠Ｄだ
け離隔して互いに対向設置された１組の超音波の送受波
器、４２．４３はハイブリッドトランス、４４．４５は
計数回路、４６は減算回路である。41b is a pair of ultrasonic transducers installed facing each other along the flow direction of the fluid 10 at a distance @D apart from each other; 42.43 is a hybrid transformer; 44.45 is a counting circuit; 46 is a subtraction circuit.
次に上記回路の動作及び流速の算出について述べる。送
信器２１及び３１からそれぞれ発生した周波数ｆ１及び
ｆ２のパルス信号はハイブリッドトランス４２及び４３
から送受波器４１ａ及び４１ｂに送出される。周波数ｆ
１のパルス信号は送受波器４１ａで超音波ノξルスに変
換され送受波器４１ｂに向けて送信され、同様に周波数
ｆ２のノξルス信号は送受波器４１ｂで超音波ノソルス
に変換され送受波器４１ａに向けて送信される。ここで
流体１０が矢印ＡＩＩＰ方向、すなわち周波数ｆ１の超
音波、（＋ルスの伝搬する方向と四方向に速度Ｖで流れ
、静止状態における流体１０中の音波の伝搬速度ｅｃと
すると、周波数ｆ１の超音波パルスの伝搬速度は（ｃ＋
ｖ）ｓ周波数計、の超音波パルスの伝搬速度はＣＣ−ｖ
）となる。従って周波数ｆ、の超音波、ｏルス及び周波
数ｆ、の超音波ノクルスが送受波器４１ａ−４１ｂ間を
伝搬するのにかかる時間ｔ１及びｔ、は、それぞれ（１
）式及び（２）式の如くなる。Next, the operation of the above circuit and calculation of flow velocity will be described. Pulse signals of frequencies f1 and f2 generated from transmitters 21 and 31, respectively, are transmitted to hybrid transformers 42 and 43.
The signal is transmitted from the transmitter/receiver to the transducers 41a and 41b. frequency f
The pulse signal of 1 is converted into an ultrasonic pulse by the transducer 41a and transmitted to the transducer 41b, and similarly the ξ pulse signal of frequency f2 is converted to an ultrasonic pulse by the transducer 41b and transmitted and received. The signal is transmitted toward the wave transmitter 41a. Here, if the fluid 10 flows in the direction of the arrow AIIP, that is, in the direction of propagation of the ultrasonic wave of the frequency f1, and the propagation direction of the ultrasonic wave (+Russ), at a speed of V, and the propagation speed of the sound wave in the fluid 10 in a stationary state is ec, then The propagation speed of the ultrasonic pulse is (c+
v) The propagation velocity of the ultrasonic pulse of the s frequency meter is CC-v
). Therefore, the times t1 and t required for the ultrasonic pulse of frequency f and the ultrasonic noculus of frequency f to propagate between the transducers 41a and 41b are (1
) and (2).
１、シ□ ・・・・・・（１）
Ｃ＋Ｖ
ｉ、ｅ＝□ ・・・・・・（２）
−Ｖ
流体１０を伝搬した周波数ｆ、及びｆ、の超音波パルス
は送受波器４１ｂ及び４１ａでそれぞれ受信され電気信
号に変換され、ハイブリッドトランス４３及び４２を介
して第１のシングアラウンド系？０及び第２のシングア
ラウ／ｉ−′系３゜に送出される。第１のシングアラウ
ンド系２゜に送出された周波数ｆ、のパルス信号は−マ
ンドパスフイルタ２２で不要ノイズ等が除去され、増幅
器２３にて増幅され、更に検波器２４で検波される。検
波器２４で検波された信号は波形整形回路２５で波形整
形された後、送信器２１及び計数回路４４に送出され、
送信器２１をトリガして再び周波数ｆ、のパルス信号を
発生させるとともに計数回路４４を１っカウントアツプ
する。1, C□ ......(1) C+V i, e=□ ......(2) -V The ultrasonic pulses of frequencies f and f propagated through the fluid 10 are transmitted to the transducer 41b. and 41a, the signals are received and converted into electrical signals, and sent to the first sing-around system ? through hybrid transformers 43 and 42, respectively. 0 and a second single arrow/i-' system 3°. The pulse signal of frequency f sent to the first sing-around system 2° has unnecessary noise removed by a -mand pass filter 22, amplified by an amplifier 23, and further detected by a detector 24. The signal detected by the detector 24 is waveform-shaped by the waveform shaping circuit 25, and then sent to the transmitter 21 and the counting circuit 44.
The transmitter 21 is triggered to generate a pulse signal of frequency f again, and the counting circuit 44 is counted up by one.
同様にＩＩＩＥ２の７ングアラクンド系３ｏに送出され
た周波ａ ｆａのパルス信号はバンドパスフィルタ３２
でノイズ等が除去され、更に増幅器３３゜検波器３４全
通して波形整形回路３５で波形整形され、その後、送信
器３１及び計数回路４５に送出され、送信器３１ ’ｉ
） リガして再び周波 ゛□数ｆ２のパルス信
号を発生させるとともに計数回路４５を１つカウントア
ツプする。Similarly, the pulse signal of frequency afa sent to the 7-channel aracundo system 3o of IIIE2 is passed through the bandpass filter 32.
Noise etc. are removed by the amplifier 33° detector 34, the waveform is shaped by the waveform shaping circuit 35, and then sent to the transmitter 31 and the counting circuit 45.
) The pulse signal with the frequency f2 is generated again and the counting circuit 45 is counted up by one.
上記動作を所定時間Ｔの間繰り返し、計数回路４４と４
５の計数値を減算回路４６で減算する。ここで、計数回
路４４及び４５の計数値をそれぞれＱｌ及びＱｚとし、
電気信号が回路を伝搬するのに要する時間を無視すると
、計数値Ｑ＋ 。The above operation is repeated for a predetermined time T, and the counting circuits 44 and 4
The count value of 5 is subtracted by the subtraction circuit 46. Here, the count values of the counting circuits 44 and 45 are respectively Ql and Qz,
Neglecting the time required for the electrical signal to propagate through the circuit, the count value Q+.
Ｑｚは（３）式、（４）式の如くなる。Qz is expressed by equations (3) and (4).
Ｃ＋ｖ
ＦｔＬ数値Ｑ１とＱｌとの差、すなわち減算回路４Ｂの
出力をＱａとすると。C+v FtL Let Qa be the difference between the numerical values Q1 and Ql, that is, the output of the subtraction circuit 4B.
：＝：“１１１１−ｍ− り となる。従って流体１０の流速Ｖは（０式の如くなる。:=:“1111-m- the law of nature becomes. Therefore, the flow velocity V of the fluid 10 is as shown in equation (0).
Ｖ” Ｑａ ・・・（５）Ｔ
上記（５）式において時間Ｔ及び距離りはあらかじめ定
められておシ、減Ｘ回路４６の出力値Ｑ３ヲ（５）式に
代入するのみで流体１０の流速Ｖを求めることができる
。V" Qa ... (5) T In the above equation (5), the time T and the distance are determined in advance. By simply substituting the output value Q3 of the reducing X circuit 46 into the equation (5), the The flow velocity V can be determined.
このように上記実施例によれば、１組の送受波器４１
ａ ｔ ４ ｌ ｂ ’ｆｌ”周波数の異なるパルス信
号で動作する第１及び第２のシングアラウンド系２０及
び３０にて共用し、流体ｌＯの流れと同方向の超音波パ
ルスと流れに逆らう超音波パルスを同時に送受信するよ
うになしたので、第１図の従来例のように流速の時間的
変化に対して計測誤差を生じることなく、また第２図の
従来例のように測定位置の違いによる計測誤差を生じる
ことなく、常に正確な流速を連続的に測定できる。In this way, according to the above embodiment, one set of transducers 41
a t 4 l b 'fl'' Commonly used by the first and second sing-around systems 20 and 30 that operate with pulse signals of different frequencies, an ultrasonic pulse in the same direction as the flow of the fluid IO and an ultrasonic wave that opposes the flow. Since the pulses are transmitted and received simultaneously, there is no measurement error caused by temporal changes in flow velocity, as in the conventional example shown in Figure 1, and there is no measurement error caused by differences in measurement positions, as in the conventional example shown in Figure 2. Accurate flow velocity can always be measured continuously without measurement errors.
以上説明したように本発明によれば、シングアラウンド
法による超音波流速測定装置において、異なる周波数の
ノξルス信号にて動作する第１及び第２のシングアラウ
ンド系と、２個１組の送受波器とを有し、該１組の送受
波器の一方を上記第１のシングアラウンド系の送信側と
上記第２のシングアラウンド系の受信側に、また他方を
上記第２のシングアラウンド系の送信側と上記第１のシ
ングアラウンド系の受信側にそれぞれハイブリッドトラ
ンスを介して接続し、上記１組の送受波器間で流体の流
れと同方向及び反対方向に同時に超音波パルスを送受信
するようにしたので、流速の時間的変動が激しい場所で
も誤差なく連続的に流速を計測でき、また部分的に流速
の異なる場所での局部流速や狭域流速の測定もできる。As explained above, according to the present invention, in an ultrasonic flow rate measurement device using the sing-around method, the first and second sing-around systems that operate using ξ nose signals of different frequencies, and a set of two transmitting and receiving systems are provided. one set of transducers is used as the transmitting side of the first sing-around system and the receiving side of the second sing-around system, and the other is used as the transmitting side of the first sing-around system, and the other side is used as the transmitting side of the second sing-around system. and the receiving side of the first single-around system via hybrid transformers, and transmit and receive ultrasonic pulses simultaneously in the same direction and in the opposite direction of the fluid flow between the pair of transducers. As a result, the flow velocity can be measured continuously without error even in places where the flow velocity fluctuates rapidly over time, and it is also possible to measure local flow velocities and narrow area flow velocities in places where the flow velocities are partially different.
また従来例と異なシ送受切替回路等を必要とせず、送受
波器も１組（２個）のみでよく、より簡単な構成となシ
、装置全体としての小型・軽量化を図ることができる等
の効果がある。In addition, there is no need for a transmitter/receiver switching circuit, etc., which is different from the conventional example, and only one set (two) of transducers is required, resulting in a simpler configuration, and the overall device can be made smaller and lighter. There are other effects.
図面は本発明の説明に供する−もので、第１図は従来の
流速測定装置の概略構成図、第２図は従来の他の流速測
定装置の概略構成図、第３図は本発明の流速測定装置の
一実施例を示す概略構成図である。
１０・・・流体、２０・・・第１のシングアラウンド系
、３０・・・第２のシングアラウンド系、４１ａ、４１
ｂ・・・送受波器、４２．４３・・・ノ１イブリッドト
ランス
特許出願人 沖電気工業株式会社
代理人 弁理士 吉 １） 精 孝−−Σ−The drawings are for explaining the present invention, and FIG. 1 is a schematic diagram of a conventional flow rate measuring device, FIG. 2 is a schematic diagram of another conventional flow rate measuring device, and FIG. 3 is a diagram of a flow rate measuring device of the present invention. FIG. 1 is a schematic configuration diagram showing an example of a measuring device. DESCRIPTION OF SYMBOLS 10... Fluid, 20... First sing-around system, 30... Second sing-around system, 41a, 41
b... Transducer/receiver, 42.43...No. 1 Hybrid transformer Patent applicant Oki Electric Industry Co., Ltd. agent Patent attorney Yoshi 1) Takashi Seitaka --Σ-
Claims (1)
、異なる周波数のパルス信号にて動作する第１及び第２
のシングアラウンド系と、２個１組の送受波器とを有し
、該１組の送受波器の一方を上記第１のシングアラウン
ド系の送信側と上記第２のシングアラウンド系の受信側
に、また他方を上記第２のシングアラウンド系の送信側
と上記第１のシングアラウンド系の受信側にそれぞれハ
イブリッドトランスを介して接続し、上記１組の送受波
器間で流体の流れと同方向及び反対方向に同時に超音波
パルスを送受信するよ・うにしたこと？特徴とする超音
波流速測定装置。In an ultrasonic current measuring device using the sing-around method, the first and second
a sing-around system, and a set of two transducers, one of which is connected to the transmitting side of the first sing-around system and the receiving side of the second sing-around system. and the other is connected to the transmitting side of the second sing-around system and the receiving side of the first sing-around system through hybrid transformers, so that the fluid flow is the same between the pair of transducers. Have you tried transmitting and receiving ultrasonic pulses simultaneously in one direction and in the opposite direction? Features of ultrasonic flow velocity measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56157870A JPS5858416A (en) | 1981-10-03 | 1981-10-03 | Ultrasonic measuring device for velocity of flow |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56157870A JPS5858416A (en) | 1981-10-03 | 1981-10-03 | Ultrasonic measuring device for velocity of flow |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5858416A true JPS5858416A (en) | 1983-04-07 |
| JPS63723B2 JPS63723B2 (en) | 1988-01-08 |
Family
ID=15659199
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56157870A Granted JPS5858416A (en) | 1981-10-03 | 1981-10-03 | Ultrasonic measuring device for velocity of flow |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5858416A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5227540A (en) * | 1975-08-21 | 1977-03-01 | Nec Corp | Constant-voltage supply circuit |
-
1981
- 1981-10-03 JP JP56157870A patent/JPS5858416A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5227540A (en) * | 1975-08-21 | 1977-03-01 | Nec Corp | Constant-voltage supply circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63723B2 (en) | 1988-01-08 |
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