JPS6310215A - Constant current circuit - Google Patents
Constant current circuitInfo
- Publication number
- JPS6310215A JPS6310215A JP61155318A JP15531886A JPS6310215A JP S6310215 A JPS6310215 A JP S6310215A JP 61155318 A JP61155318 A JP 61155318A JP 15531886 A JP15531886 A JP 15531886A JP S6310215 A JPS6310215 A JP S6310215A
- Authority
- JP
- Japan
- Prior art keywords
- constant voltage
- current
- transistor
- voltage
- 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.)
- Pending
Links
- 230000000694 effects Effects 0.000 abstract description 3
- 230000002411 adverse Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 2
Landscapes
- Control Of Electrical Variables (AREA)
- Amplifiers (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は定電圧素子を用いた定電流回路に関するもので
ある。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a constant current circuit using constant voltage elements.
従来の技術
従来の定電流回路の一例を第２図に示す。第２図におい
て１はツェナーダイオードからなる定電圧素子、２．３
．４はカレントミラー回路を構成する第１．第２．第３
のトランジスタ、５はコレクタ及びベースがそれぞれ第
２のトランジスタ３のコレクタ及び第１のトランジスタ
２のコレクタに接続された第４のトランジスタ、６は第
４のトランジスタ５のエミッタと基準電位間に接続され
た抵抗、７は上記カレントミラー回路を構成する第３の
トランジスタ４のコレクタを出力とする出力端子、８は
電源端子、９は電源端子８と第１のトランジスタ２のコ
レクタの間に接続された始動抵抗である。上記構成にお
いて、定電圧素子１は第１．第２．第３のトランジスタ
２，３．４によって構成されるカレントミラー回路のコ
レクタ電流によってバイアスされる。カレントミラー回
路のコレクタ電流の電流値は第１．第２．第３゜第４の
トランジスタ２．３．４．５のコレクタ電流をそれぞれ
Ｉ ＣＯ２、Ｉ ＣＯ２、Ｉ ＣＯ２、Ｉ ＣＯ２、定
電圧素子１の非基準電位１りの電圧をｖＺ、抵抗６の抵
抗値をＲ６、第４のトランジスタ５のベース・エミッタ
間電圧をＶＢＥとすると、
ｌ ＣＱ２二ＩＣＱ３＝ ＩＣＱ４＝ ＩＣＱ５’−（
Ｖｚ−ＶＢＥ） ／ Ｒｓ ・−”（１）で決まる
。（１）式から明らかなように、カレントミラー回路の
コレクタ電流ｆ ＣＱ２ 、 ｒ ＣＱ３１１ ＣＱ
４は電源電圧ＶＣＣに関係なく一定であるため、定電圧
素子１も定電流でバイアスされ、その結果、出力端子７
に安定した電流が得られる。ただし、この回路では電源
電圧がＯｖからＶＣＣに向けて立ち上がる時、（１）式
のコレクタ電流ＩＣＱ２１ １ＣＱ３． ＩＣＱ４１
１ ＣＱＳが零であり、この定電流回路は起動しない。2. Description of the Related Art An example of a conventional constant current circuit is shown in FIG. In Figure 2, 1 is a constant voltage element consisting of a Zener diode, 2.3
．． 4 constitutes a current mirror circuit. Second. Third
5 is a fourth transistor whose collector and base are respectively connected to the collector of the second transistor 3 and the collector of the first transistor 2; 6 is a fourth transistor connected between the emitter of the fourth transistor 5 and a reference potential; 7 is an output terminal whose output is the collector of the third transistor 4 constituting the current mirror circuit, 8 is a power supply terminal, and 9 is connected between the power supply terminal 8 and the collector of the first transistor 2. This is starting resistance. In the above configuration, the constant voltage element 1 is the first. Second. It is biased by the collector current of a current mirror circuit constituted by the third transistors 2, 3.4. The current value of the collector current of the current mirror circuit is 1. Second. 3rd゜The collector current of the fourth transistor 2.3.4.5 is respectively I CO2, I CO2, I CO2, I CO2, the voltage of the non-reference potential 1 of the constant voltage element 1 is vZ, and the resistance of the resistor 6 is If the value is R6 and the voltage between the base and emitter of the fourth transistor 5 is VBE, then l CQ22 ICQ3=ICQ4=ICQ5'-(
Vz-VBE) / Rs ・-" (1).As is clear from equation (1), the collector current of the current mirror circuit f CQ2 , r CQ311 CQ
4 is constant regardless of the power supply voltage VCC, the constant voltage element 1 is also biased with a constant current, and as a result, the output terminal 7
A stable current can be obtained. However, in this circuit, when the power supply voltage rises from Ov to VCC, the collector current ICQ21 1CQ3. ICQ41
1 CQS is zero and this constant current circuit does not start.
このため起動時には、電源端子８から始動抵抗９を介し
て定電圧素子１に始動電流を流すのが一般的である。Therefore, at startup, a starting current is generally passed from the power supply terminal 8 to the constant voltage element 1 via the starting resistor 9.
発明が解決しようとする問題点
このような従来の定電流回路では、起動時に定電圧素子
１に流れる電流ＩＺは、電源電圧をＶ ＣＣ％始動抵抗
９の抵抗値をＲ９、定電圧素子１の非基準電位側電圧を
Ｖｚとすると、
Ｉ ｚ＝ Ｉ ＣＱ２＋ （Ｖｃｃ −Ｖｚ） ／ Ｒ
ｓ −（２）となる。Problems to be Solved by the Invention In such a conventional constant current circuit, the current IZ flowing through the constant voltage element 1 at the time of startup is determined by the power supply voltage being VCC%, the resistance value of the starting resistor 9 being R9, and the resistance value of the constant voltage element 1 being VCC%. If the non-reference potential side voltage is Vz, I z = I CQ2+ (Vcc - Vz) / R
s - (2).
（２）式において、Ｉ ＣＱ２は（１）式で求めた通り
電源電圧ＶＣＣに関係なく一定であるが、始動抵抗９を
流れる電流（ＶＣＣＶＺ）／Ｒ９は電源電圧ＶＣＣの変
動により変化する。このため、起動時に定電圧素子１の
非基準電位側電圧Ｖｚが電源電圧ＶＣＣの影響を受け、
その結果、ｖｚ ＶＢＥで表わされる抵抗６の非基準
電位側電圧も変動するため出力端子７に安定な電流が得
られないという問題があった。In equation (2), I CQ2 is constant regardless of power supply voltage VCC as determined by equation (1), but current (VCCVZ)/R9 flowing through starting resistor 9 changes due to fluctuations in power supply voltage VCC. Therefore, at startup, the non-reference potential side voltage Vz of the constant voltage element 1 is influenced by the power supply voltage VCC,
As a result, the voltage on the non-reference potential side of the resistor 6, represented by vzVBE, also fluctuates, resulting in a problem that a stable current cannot be obtained at the output terminal 7.
本発明は、このような従来の問題点を解決するもので起
動時に電源電圧の変動の影響を受けない定電流回路を提
供することを目的とする。The present invention solves these conventional problems and aims to provide a constant current circuit that is not affected by fluctuations in power supply voltage during startup.
問題点を解決するための手段
この目的を達成するために本発明は、始動抵抗と直列に
第２の定電圧素子を接続するとともに、上記始動抵抗と
第２の定電圧素子の接続点と本来の定電圧素子（以下こ
れを第１の定電圧素子と呼ぶ）の間にトランジスタまた
はダイオード等のスイッチング素子を接続したものであ
る。Means for Solving the Problems In order to achieve this object, the present invention connects a second constant voltage element in series with the starting resistor, and connects the connection point between the starting resistor and the second constant voltage element with the original A switching element such as a transistor or a diode is connected between constant voltage elements (hereinafter referred to as first constant voltage elements).
作用
この構成によって、起動の初期には上記スイッチング素
子を介して第１の定電圧素子に始動電流を供給し、その
後は上記スイッチング素子を遮断して第１の定電圧素子
への電流供給を断つことができる。このため、起動後に
電源電圧が変動しても第１の定電圧素子の非基準電位側
電圧は電源電圧の変動の影響を受けない。Effect: With this configuration, a starting current is supplied to the first constant voltage element through the switching element at the initial stage of startup, and thereafter the switching element is cut off to cut off the current supply to the first constant voltage element. be able to. Therefore, even if the power supply voltage fluctuates after startup, the non-reference potential side voltage of the first constant voltage element is not affected by the power supply voltage fluctuation.
実施例 以下、本発明の実施例を第１図とともに説明する。Example Embodiments of the present invention will be described below with reference to FIG.
第１図において、第２図と同一機能を有する素子には同
一符号を付して説明を省略する。１０は始動抵抗９に直
列に接続されたツェナーダイオードからなる第２の定電
圧素子、１１は上記第１゜第２の定電圧素子の非基準電
位側の端子間に接続され、起動の初期に導通し、その後
遮断されるスイッチングトランジスタである。In FIG. 1, elements having the same functions as those in FIG. 2 are given the same reference numerals, and their explanations will be omitted. 10 is a second constant voltage element consisting of a Zener diode connected in series with the starting resistor 9; 11 is connected between the non-reference potential side terminals of the first and second constant voltage elements; It is a switching transistor that is turned on and then turned off.
第１図の定電流回路において、起動の初期には始動抵抗
９を介して第２の定電圧素子１０に起動電流が流れる。In the constant current circuit shown in FIG. 1, a starting current flows through the starting resistor 9 to the second constant voltage element 10 at the beginning of starting.
このため、第２の定電圧素子１０の端子電圧が上昇し、
スイッチングトランジスタ１１を順方向にバイアスする
。その結果、起動電流がスイッチングトランジスタ１１
のベース・エミッタを介して第１の定電圧素子１に供給
される。ところが、第１の定電圧素子１の端子電圧がＶ
ｚ−ＶＢＢ（ただし、Ｖｚは第２の定電圧素子１０の端
子電圧）まで上昇すると、スイッチングトランジスタ１
１が逆バイアスになって遮断され、始動電流は第１の定
電圧素子１に供給されなくなる。Therefore, the terminal voltage of the second constant voltage element 10 increases,
The switching transistor 11 is forward biased. As a result, the starting current increases to the switching transistor 11.
The voltage is supplied to the first constant voltage element 1 via the base and emitter of. However, the terminal voltage of the first constant voltage element 1 is V
When the voltage rises to z-VBB (where Vz is the terminal voltage of the second constant voltage element 10), the switching transistor 1
1 becomes reverse biased and is cut off, and the starting current is no longer supplied to the first constant voltage element 1.
このため、仮に電源電圧ＶＣＣが変動しても、出力端子
７の出力電流は電源電圧ＶＣＣの変動の影響を受けない
。なお、通常動作状態で出力端子７から定電流が得られ
ることについては従来とまったく同様である。Therefore, even if the power supply voltage VCC fluctuates, the output current of the output terminal 7 is not affected by the fluctuation of the power supply voltage VCC. Note that the fact that a constant current can be obtained from the output terminal 7 in the normal operating state is exactly the same as in the conventional case.
なお、第１図ではスイッチング素子としてトランジスタ
１１を用いたが、カソードを第１の定電圧素子１に、ア
ノードを第２の定電圧素子１０に接続したダイオードで
もよい。また第２の定電圧素子１０は抵抗でもよく要は
その端子電圧が第１の定電圧素子１の端子電圧と同等も
しくはそれ以下のものであればよい。Although the transistor 11 is used as the switching element in FIG. 1, a diode having a cathode connected to the first constant voltage element 1 and an anode connected to the second constant voltage element 10 may also be used. Further, the second constant voltage element 10 may be a resistor, as long as its terminal voltage is equal to or lower than the terminal voltage of the first constant voltage element 1.
発明の効果
以上のように本発明は、第２の定電圧素子とスイッチン
グ素子の働きにより起動の初期に第１の定電圧素子に始
動電流を流し、その後、始動電流が第１の定電圧素子に
流れるのを遮断するようにしているので、起動後の電源
電圧変動の影響を受けないようにすることができる。Effects of the Invention As described above, the present invention allows the starting current to flow through the first constant voltage element at the initial stage of startup through the functions of the second constant voltage element and the switching element, and then the starting current flows through the first constant voltage element. Since the current flow is blocked, it is possible to avoid being affected by power supply voltage fluctuations after startup.
第１図は本発明の一実施例の定電流回路図、第２図は従
来の定電流回路の回路図である。
１・・・・・・定電圧素子、２・・・・・・第１のトラ
ンジスタ、３・・・・・・第２のトランジスタ、４・・
・・・・第３のトランジスタ、５・・・・・・第４のト
ランジスタ、６・・・・・・抵抗、７・・・・・・出力
端子、８・・・・・・電源端子、９・・・・・・抵抗、
１０・・・・・・定電圧素子、１１・・・・・・スイッ
チングトランジスタ。
７−−−更兎三量丑
第２図
λFIG. 1 is a constant current circuit diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional constant current circuit. DESCRIPTION OF SYMBOLS 1... Constant voltage element, 2... First transistor, 3... Second transistor, 4...
...Third transistor, 5...Fourth transistor, 6...Resistor, 7...Output terminal, 8...Power terminal, 9...Resistance,
10... Constant voltage element, 11... Switching transistor. 7---Sarato Sangyo ox 2nd figure λ
Claims (1)
ンジスタ、前記第１のトランジスタのコレクタと基準電
位点との間に接続された第１の定電圧素子、ベース及び
コレクタが前記第１、第２のトランジスタの各コレクタ
にベースとコレクタとを接続された第４のトランジスタ
、前記第４のトランジスタのエミッタと基準電位点との
間に接続された第１抵抗、電源端子と基準電位点との間
に接続された第２抵抗および第２の定電圧素子の直列回
路、および前記第１、第２の定電圧素子間に接続された
、スイッチング素子を備えた定電流回路。a first, second, and third transistor constituting a current mirror circuit; a first constant voltage element connected between the collector of the first transistor and a reference potential point; a base and a collector of the first transistor; a fourth transistor whose base and collector are connected to each collector of the second transistor; a first resistor connected between the emitter of the fourth transistor and a reference potential point; a power supply terminal and a reference potential point; A constant current circuit comprising a series circuit of a second resistor and a second constant voltage element connected between them, and a switching element connected between the first and second constant voltage elements.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61155318A JPS6310215A (en) | 1986-07-02 | 1986-07-02 | Constant current circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61155318A JPS6310215A (en) | 1986-07-02 | 1986-07-02 | Constant current circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6310215A true JPS6310215A (en) | 1988-01-16 |
Family
ID=15603263
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61155318A Pending JPS6310215A (en) | 1986-07-02 | 1986-07-02 | Constant current circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6310215A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02274315A (en) * | 1989-04-13 | 1990-11-08 | Amada Co Ltd | Compound device for bending and welding |
| JPH05283947A (en) * | 1991-05-10 | 1993-10-29 | Samsung Semiconductor Inc | Bias-starting circuit |
| JP2007279957A (en) * | 2006-04-05 | 2007-10-25 | Seiko Epson Corp | Current source circuit and comparator having the same |
| JP2008019950A (en) * | 2006-07-12 | 2008-01-31 | Inax Corp | Flow regulating valve device |
-
1986
- 1986-07-02 JP JP61155318A patent/JPS6310215A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02274315A (en) * | 1989-04-13 | 1990-11-08 | Amada Co Ltd | Compound device for bending and welding |
| JPH05283947A (en) * | 1991-05-10 | 1993-10-29 | Samsung Semiconductor Inc | Bias-starting circuit |
| JP2007279957A (en) * | 2006-04-05 | 2007-10-25 | Seiko Epson Corp | Current source circuit and comparator having the same |
| JP2008019950A (en) * | 2006-07-12 | 2008-01-31 | Inax Corp | Flow regulating valve device |
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