JP3105697B2 - Constant current generation circuit - Google Patents
Constant current generation circuitInfo
- Publication number
- JP3105697B2 JP3105697B2 JP05108348A JP10834893A JP3105697B2 JP 3105697 B2 JP3105697 B2 JP 3105697B2 JP 05108348 A JP05108348 A JP 05108348A JP 10834893 A JP10834893 A JP 10834893A JP 3105697 B2 JP3105697 B2 JP 3105697B2
- Authority
- JP
- Japan
- Prior art keywords
- constant current
- voltage
- load
- operational amplifier
- constant
- 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 - Fee Related
Links
Description
【０００１】[0001]
【産業上の利用分野】本発明は、冷熱プラント制御装置
や通信制御装置等の各種制御装置におけるデータ入出力
部等に適用される定電流発生回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant current generating circuit applied to a data input / output unit in various control devices such as a cooling and heating plant control device and a communication control device.
【０００２】[0002]
【従来の技術】図３は、この種の定電流発生回路の基本
的構成を示すブロック図である。図に示すように、この
回路は、定電圧発生器１と、負荷変動検出器２と、電圧
出力器３と、定電流出力器４と、負荷６とからなってい
る。2. Description of the Related Art FIG. 3 is a block diagram showing a basic configuration of a constant current generating circuit of this kind. As shown in the figure, this circuit includes a constant voltage generator 1, a load fluctuation detector 2, a voltage output device 3, a constant current output device 4, and a load 6.
【０００３】負荷安定時（通常時）においては、定電圧
発生器１により発生した定電圧Ｖ1を電圧出力器３で受
け、電圧出力器３で定電圧Ｖ0 を発生させる。抵抗値Ｒ
の抵抗体等からなる定電流出力器４は、上記定電圧Ｖ0
と、定電流出力端５に現れる負荷６の電圧ＶL との電位
差に応じて、 Ｉ0 ＝（Ｖ0 ーＶL ）／Ｒ なる定電流を発生させる。When the load is stable (normal time), the constant voltage V1 generated by the constant voltage generator 1 is received by the voltage output unit 3, and the voltage output unit 3 generates the constant voltage V0. Resistance value R
The constant current output device 4 composed of a resistor or the like
A constant current I0 = (V0-VL) / R is generated in accordance with the potential difference between the voltage and the voltage VL of the load 6 appearing at the constant current output terminal 5.
【０００４】負荷６が変動すると、負荷電圧ＶL がΔＶ
だけ変化し、ＶL ＋ΔＶとなる。この変動は、負荷変動
検出器２で検出され、検出された電圧Ｖ2 が電圧出力器
３にを与えられる。このため電圧出力器３の出力電圧が
ΔＶだけ変化し、Ｖ0 ＋ΔＶとなる。これにより、電圧
出力器３と負荷６との間の電位差は、通常時と同じくＶ
0 −ＶL となる。かくして Ｉ0 ＝（Ｖ0 −ＶL ）／Ｒ なる定電流が常時発生することになる。When the load 6 fluctuates, the load voltage VL becomes ΔV
VL + ΔV. This fluctuation is detected by the load fluctuation detector 2, and the detected voltage V2 is supplied to the voltage output unit 3. Therefore, the output voltage of the voltage output unit 3 changes by ΔV, and becomes V0 + ΔV. As a result, the potential difference between the voltage output device 3 and the load 6 becomes V
0-VL. Thus, a constant current of I0 = (V0-VL) / R is always generated.
【０００５】図４は上記基本的構成に基づいて構成され
た従来の定電流発生回路の具体的構成を示す回路図であ
る。ツェナダイオード１１により得られる電圧ＶZDを入
力として、演算増幅器７が電圧Ｖ1 を出力する如く設け
られた部分は、図３の定電圧発生器１に相当している。
負荷２０の変動に伴う負荷電圧ＶL の変動分ΔＶを演算
増幅器１６が検出し、演算増幅器１３の正側入力端にＶ
2 なる電圧を出力する如く設けられた部分は、図３の負
荷変動検出器２に相当している。抵抗素子１８は図３の
定電流出力器４に相当している。演算増幅器１３が定電
圧発生器である演算増幅器７および負荷変動検出器であ
る演算増幅器７からの出力Ｖ1,Ｖ2 を入力として受け、
定電流出力器である抵抗素子１８に電圧Ｖ0 あるいはＶ
0 ＋ΔＶを出力する如く設けられた部分は、図３の電圧
出力器３に相当している。なお図４において、８，９，
１０，１２，１４，１５，１７は抵抗素子を示してお
り、１９は定電圧出力端を示している。FIG. 4 is a circuit diagram showing a specific configuration of a conventional constant current generating circuit configured based on the above basic configuration. The portion provided such that the voltage VZD obtained by the Zener diode 11 is input and the operational amplifier 7 outputs the voltage V1 corresponds to the constant voltage generator 1 in FIG.
The operational amplifier 16 detects the variation ΔV of the load voltage VL due to the variation of the load 20, and V is applied to the positive input terminal of the operational amplifier 13.
2 corresponds to the load fluctuation detector 2 in FIG. The resistance element 18 corresponds to the constant current output device 4 in FIG. The operational amplifier 13 receives, as inputs, outputs V1 and V2 from the operational amplifier 7 as a constant voltage generator and the operational amplifier 7 as a load fluctuation detector,
The voltage V0 or V is applied to the resistance element 18 which is a constant current output device.
The portion provided so as to output 0 + ΔV corresponds to the voltage output device 3 in FIG. In FIG. 4, 8, 9,
Reference numerals 10, 12, 14, 15, and 17 indicate resistance elements, and reference numeral 19 indicates a constant voltage output terminal.
【０００６】[0006]
【発明が解決しようとする課題】図４に示す従来の定電
流発生回路は、定電圧発生器，負荷変動検出器，電圧出
力器を構成する部分に、それぞれ高価格な演算増幅器を
３個も使用している。この為、構成が複雑でコスト高に
なる欠点があった。また上記定電圧発生器，負荷変動検
出器，電圧出力器等を形成するための基板として、大き
な基板面積を有するものが必要となり、定電流発生回路
全体が大型化する難点があった。なお基板面積に制約が
あるような場合には、設計・製作上種々不都合を来すお
それがあった。In the conventional constant current generating circuit shown in FIG. 4, three high-priced operational amplifiers are respectively provided in a portion constituting a constant voltage generator, a load fluctuation detector, and a voltage output device. I'm using For this reason, there was a drawback that the configuration was complicated and the cost increased. Further, a substrate having a large substrate area is required as a substrate for forming the constant voltage generator, the load fluctuation detector, the voltage output device, and the like, and there has been a problem that the entire constant current generating circuit is increased in size. If the substrate area is limited, various inconveniences may be caused in designing and manufacturing.
【０００７】本発明はこの様な事情を考慮して成された
ものであり、その目的は、所要機能を安定かつ確実に発
揮することのできる、構成が簡単で安価に製作可能な定
電流発生回路を提供することにある。SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide a constant current generator which can stably and surely perform required functions and has a simple structure and can be manufactured at low cost. It is to provide a circuit.
【０００８】[0008]
【課題を解決するための手段】上記課題を解決し目的を
達成するために本発明では次のような手段を講じた。す
なわち、本発明の定電流発生回路は、負荷(26)の変動に
伴う出力電流の変化を防止し、常に一定の電流を発生さ
せる定電流発生回路において、単一の演算増幅器(21)の
出力端と当該増幅器(21)の負側（反転）入力端との間を
定電圧に保つ如く接続されたツェナダイオード(24)と、
前記演算増幅器(21)の正側（非反転）入力端に対し、負
荷変動に伴う定電流出力端(25)の電圧変動成分を入力さ
せる手段（図示のダイレクト接続ライン）と、を備える
ようにした。Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention takes the following measures. That is, the constant current generation circuit of the present invention prevents the output current from being changed due to the fluctuation of the load (26), and in the constant current generation circuit that always generates a constant current, the output of the single operational amplifier (21) Between the input terminal and the negative (inverted) input terminal of the amplifier (21).
A zener diode (24) connected to maintain a constant voltage,
Means (direct connection line shown) for inputting a voltage fluctuation component of a constant current output terminal (25) accompanying a load fluctuation to a positive (non-inverting) input terminal of the operational amplifier (21). did.
【０００９】[0009]
【作用】上記手段を講じた結果、次のような作用が生じ
る。 (1)負荷安定時には、演算増幅器の出力端と負側入力端
との間が定電圧に保たれる結果、演算増幅器の性質上、
演算増幅器の出力端と負荷との間の電位差が一定とな
る。このため演算増幅器の出力端側に定電流が発生す
る。The following effects are obtained as a result of taking the above measures. (1) When the load is stable, a constant voltage is maintained between the output terminal and the negative input terminal of the operational amplifier.
The potential difference between the output terminal of the operational amplifier and the load becomes constant. Therefore, a constant current is generated at the output terminal side of the operational amplifier.
【００１０】(2)負荷変動時には、負荷において発生す
る電圧変動が演算増幅器で検出され、この演算増幅器の
出力電圧が上記電圧変動分だけ変化する。 (3)この結果、演算増幅器の出力端と負荷との間の電位
差が、負荷安定時と同じになるので、単一の演算増幅器
を主体として構成されたものでありながら、定電流を常
時安定に発生することが可能となる。(2) When the load fluctuates, a voltage fluctuation occurring in the load is detected by the operational amplifier, and the output voltage of the operational amplifier changes by the voltage fluctuation. (3) As a result, the potential difference between the output terminal of the operational amplifier and the load becomes the same as when the load is stable, so that the constant current is always stable even though it is composed mainly of a single operational amplifier. Can occur.
【００１１】[0011]
【実施例】図１は本発明の一実施例に係る定電流発生回
路の構成を示す回路図である。図１に示すように、演算
増幅器２１の出力端と負側（反転）入力端との間には、
ツェナダイオード２４が接続されている。このツェナダ
イオード２４は演算増幅器２１の出力端と負側入力端と
の間の電位差を安定に保持する機能を有している。演算
増幅器２１の正側（非反転）入力端に対し、負荷２６の
変動に伴う定電流出力端２５の電圧変動成分が入力する
ようになっている。２２は演算増幅器の負側入力端側に
介在している抵抗素子、２３は演算増幅器の出力端側に
介在している抵抗素子である。FIG. 1 is a circuit diagram showing a configuration of a constant current generating circuit according to one embodiment of the present invention. As shown in FIG. 1, between the output terminal of the operational amplifier 21 and the negative (inverted) input terminal,
The zener diode 24 is connected. The zener diode 24 has a function of stably maintaining the potential difference between the output terminal of the operational amplifier 21 and the negative input terminal. The voltage fluctuation component of the constant current output terminal 25 accompanying the fluctuation of the load 26 is input to the positive (non-inverting) input terminal of the operational amplifier 21. Reference numeral 22 denotes a resistance element interposed on the negative input end of the operational amplifier, and reference numeral 23 denotes a resistance element interposed on the output end of the operational amplifier.
【００１２】なお負荷２６としては、例えば白金等の温
度によって抵抗値が変化する金属が適用される。かかる
負荷２６に定電流を供給しておくと、温度変化により白
金の両端で測定される電位差が異なってくる。この電位
差の変化状況から、換算式を用いて温度を求めることが
できる。つまり本例は負荷２６を温度センサとして使用
する場合の例である。As the load 26, for example, a metal such as platinum whose resistance value changes according to the temperature is applied. When a constant current is supplied to the load 26, the potential difference measured at both ends of platinum becomes different due to a temperature change. The temperature can be obtained from the change in the potential difference using a conversion formula. That is, this example is an example in which the load 26 is used as a temperature sensor.
【００１３】負荷安定時（通常時）においては、演算増
幅器２１の出力端と演算増幅器２１の負側入力端との間
が、ツェナダイオード２４により定電圧に保たれる結
果、演算増幅器２１の性質上、演算増幅器２１の出力電
圧Ｖ0 と、定電流出力端２５に現れる負荷２６の電圧Ｖ
L との間の電位差が一定となる。この一定の電位差すな
わち演算増幅器２１の出力電圧Ｖ0 と負荷２６の電圧Ｖ
L との差に応じて、抵抗値Ｒの抵抗素子２３を介して Ｉ0 ＝（Ｖ0 ーＶL ）／Ｒ なる定電流が発生し、負荷２６に供給される。When the load is stable (normal operation), the voltage between the output terminal of the operational amplifier 21 and the negative input terminal of the operational amplifier 21 is maintained at a constant voltage by the Zener diode 24. Above, the output voltage V0 of the operational amplifier 21 and the voltage V of the load 26 appearing at the constant current output terminal 25
The potential difference between L and L becomes constant. This constant potential difference, that is, the output voltage V0 of the operational amplifier 21 and the voltage V of the load 26
In accordance with the difference from L, a constant current of I0 = (V0-VL) / R is generated through the resistance element 23 having the resistance value R and supplied to the load 26.
【００１４】負荷２６の変動により負荷電圧ＶL がΔＶ
だけ変化し、ＶL ＋ΔＶになると、この値が演算増幅器
２１の正側入力端に与えられるため、演算増幅器２１の
出力電圧もΔＶだけ変化し、Ｖ0 ＋ΔＶとなる。したが
って抵抗素子２３の両端間の電位差は通常時と同じくＶ
0 −ＶL となる。したがってこの場合も、 Ｉ0 ＝（Ｖ0 −ＶL ）／Ｒ なる定電流が発生することになる。かくして単一の演算
増幅器２１を主体としたものでありながら、所要機能を
安定かつ確実に発揮する定電流発生回路が得られる。The load voltage VL becomes ΔV due to the fluctuation of the load 26.
VL + .DELTA.V, this value is applied to the positive input terminal of the operational amplifier 21, so that the output voltage of the operational amplifier 21 also varies by .DELTA.V, and becomes V0 + .DELTA.V. Therefore, the potential difference between both ends of the resistance element 23 is V
0-VL. Therefore, also in this case, a constant current of I0 = (V0-VL) / R is generated. In this way, a constant current generating circuit can be obtained which has a required function in a stable and reliable manner while being mainly composed of the single operational amplifier 21.
【００１５】図２は、負荷を抵抗素子としてその値をい
くつか変え、本実施例の定電流発生回路の特性を実験的
に確認した結果を示す特性図である。この図から明らか
なように本実施例の定電流発生回路は、負荷変動にもか
かわらず十分安定した定電流特性を示す回路であること
が分かる。なお本発明は上記実施例に限定されるもので
はなく、本発明の要旨を逸脱しない範囲で種々変形実施
可能であるのは勿論である。FIG. 2 is a characteristic diagram showing the results of experimentally confirming the characteristics of the constant current generating circuit of this embodiment by changing the value of the load by using a resistor as a resistance element. As can be seen from the figure, the constant current generating circuit of the present embodiment is a circuit showing sufficiently stable constant current characteristics despite load fluctuations. It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.
【００１６】[0016]
【発明の効果】本発明によれば、所要機能を発揮するに
必要な演算増幅器が１個あれば良く、従来の定電流発生
回路に比べて構成が簡単で、基板面積が小さくてすみ、
低コストで製作可能な定電流発生回路を提供できる。According to the present invention, only one operational amplifier is required to perform the required function, and the configuration is simpler than that of the conventional constant current generating circuit, and the substrate area is small.
A constant current generation circuit that can be manufactured at low cost can be provided.
【図１】本発明の一実施例に係る定電流発生回路の構成
を示す回路図。FIG. 1 is a circuit diagram showing a configuration of a constant current generating circuit according to one embodiment of the present invention.
【図２】同実施例に係る定電流発生回路の特性を実験的
に確認した結果を示す図。FIG. 2 is a view showing results of experimentally confirming characteristics of the constant current generating circuit according to the embodiment.
【図３】一般的な定電流発生回路の基本的構成を示すブ
ロック図。FIG. 3 is a block diagram showing a basic configuration of a general constant current generation circuit.
【図４】従来の定電流発生回路の具体的構成を示す回路
図。FIG. 4 is a circuit diagram showing a specific configuration of a conventional constant current generation circuit.
２１…演算増幅器 ２２，２３…抵抗素子 ２４
…ツェナダイオード ２５…定電流出力端 ２６…負荷21: operational amplifier 22, 23: resistive element 24
... Zener diode 25 ... Constant current output terminal 26 ... Load
フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) H02J 1/04 G05F 1/10 Continuation of front page (58) Field surveyed (Int.Cl. 7 , DB name) H02J 1/04 G05F 1/10
Claims (1)
し、常に一定の電流を発生させる定電流発生回路におい
て、 単一の演算増幅器の出力端と当該増幅器の負側（反転）
入力端との間を定電圧に保つ如く接続されたツェナダイ
オードと、 前記演算増幅器の正側（非反転）入力端に対し、負荷変
動に伴う定電流出力端の電圧変動成分を入力させる手段
と、 を具備したことを特徴とする定電流発生回路。An output terminal of a single operational amplifier and a negative side (inversion) of the amplifier are provided in a constant current generating circuit for preventing a change in output current due to a change in load and constantly generating a constant current.
Zener die connected to keep constant voltage between input terminal
And a means for inputting a voltage fluctuation component of a constant current output terminal accompanying a load fluctuation to a positive (non-inverting) input terminal of the operational amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05108348A JP3105697B2 (en) | 1993-05-10 | 1993-05-10 | Constant current generation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05108348A JP3105697B2 (en) | 1993-05-10 | 1993-05-10 | Constant current generation circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06327150A JPH06327150A (en) | 1994-11-25 |
| JP3105697B2 true JP3105697B2 (en) | 2000-11-06 |
Family
ID=14482432
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05108348A Expired - Fee Related JP3105697B2 (en) | 1993-05-10 | 1993-05-10 | Constant current generation circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3105697B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20210068525A1 (en) * | 2019-09-06 | 2021-03-11 | Riley Spear | Bottle-cleaning utensil and method of use |
| KR102232520B1 (en) * | 2019-04-03 | 2021-03-26 | 안기풍 | Self-assembly laundry ball |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114610105A (en) * | 2022-04-21 | 2022-06-10 | 绵阳惠科光电科技有限公司 | Reference voltage circuit, gamma voltage circuit and display device |
-
1993
- 1993-05-10 JP JP05108348A patent/JP3105697B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102232520B1 (en) * | 2019-04-03 | 2021-03-26 | 안기풍 | Self-assembly laundry ball |
| US20210068525A1 (en) * | 2019-09-06 | 2021-03-11 | Riley Spear | Bottle-cleaning utensil and method of use |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06327150A (en) | 1994-11-25 |
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