JPH0574085B2 - - Google Patents
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- Publication number
- JPH0574085B2 JPH0574085B2 JP5317084A JP5317084A JPH0574085B2 JP H0574085 B2 JPH0574085 B2 JP H0574085B2 JP 5317084 A JP5317084 A JP 5317084A JP 5317084 A JP5317084 A JP 5317084A JP H0574085 B2 JPH0574085 B2 JP H0574085B2
- Authority
- JP
- Japan
- Prior art keywords
- constant current
- load
- output
- circuit
- winding
- 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 - Lifetime
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Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
- G05F1/10—Regulating voltage or current
- G05F1/12—Regulating voltage or current wherein the variable actually regulated by the final control device is AC
- G05F1/32—Regulating voltage or current wherein the variable actually regulated by the final control device is AC using magnetic devices having a controllable degree of saturation as final control devices
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Automation & Control Theory (AREA)
- Control Of Electrical Variables (AREA)
Description
【発明の詳細な説明】
発明の属する技術分野
本発明は、定電流回路に関し、特に、他の定電
流回路と直列に接続して負荷に電流を供給する場
合に負荷分担を安定させるための負荷分担用の抵
抗を有する定電流回路に関する。[Detailed Description of the Invention] Technical Field [0001] The present invention relates to a constant current circuit, and particularly to a constant current circuit for stabilizing load sharing when connected in series with another constant current circuit to supply current to the load. The present invention relates to a constant current circuit having a sharing resistor.
従来技術
第１図に示すように、負荷６に対して複数の定
電流回路１，１′を直列に接続して、負荷６に定
電流を供給する場合は、定電流回路１，１′の出
力回路にそれぞれ負荷分担用抵抗５を接続するこ
とによつて負荷分担を安定させている。すなわ
ち、定電流回路１および１′は、定電流源４と負
荷６との間に直列に接続された電流検出器２と、
電流検出器２の出力電圧が一定値になるように定
電流源４を制御する制御回路３と、前記負荷分担
用抵抗５とから構成されている。Prior Art As shown in Fig. 1, when a plurality of constant current circuits 1, 1' are connected in series to a load 6 to supply a constant current to the load 6, the constant current circuits 1, 1' are Load sharing is stabilized by connecting load sharing resistors 5 to each output circuit. That is, the constant current circuits 1 and 1' include a current detector 2 connected in series between a constant current source 4 and a load 6;
It is comprised of a control circuit 3 that controls a constant current source 4 so that the output voltage of the current detector 2 becomes a constant value, and the load sharing resistor 5.
第２図は、定電流回路１の従来例を示す回路図
である。すなわち、電流検出器２は、定電流源４
と負荷７の間に直列に接続された巻回数N1の巻
線を有し、該巻線に流れる電流I1と巻回数N1と
の積、すなわちアンペア・ターンI1N1に比例し
た電圧を出力して制御回路３に供給する。第３図
は、電流検出器２の直流励磁アンペア・ターン
ATと出力電圧VDとの関係を示す図である。直流
励磁アンペア・ターンAT−出力電圧変換比をｇ
とすると、電流検出器２の出力電圧VDは、
VD＝ｇ・I1・N1 …(1)
となる。この出力電圧VDが、制御回路３の内蔵
する比較増幅器Ａで基準電圧Ｅと比較され、
VD＝Ｅ …(2)
になるような制御信号が定電流源４に与えられ、
定電流源４の出力電流I1が所定の一定値になるよ
うに制御される。ここで、負荷７の両端電圧を
VL、負荷７に流れる電流をIL、負荷分担用抵抗５
の抵抗値をRP、負荷分担用抵抗５を流れる電流
をI2とすると、
IL＝I1−I2＝I1−VL／RP …(3)
と表わすことができる。従つて、負荷分担用抵抗
５による損失Ｗは、
Ｗ＝VL 2／RP …(4)
となる。すなわち、負荷分担用抵抗５を接続した
ことによつて、定電流回路の出力インピーダンス
が有限値RPとなり、その出力特性は、第４図に
実線で示す特性となる。負荷分担用抵抗５を接続
しない場合は、定電流源４の出力電流I1と負荷電
流ILとは等しく、定電流になるため定電流回路の
出力インピーダンスは、定電流源４の出力インピ
ーダンスと等しく、無限大の出力インピーダンス
であるが、負荷分担用抵抗５を接続することによ
つて有限の出力インピーダンスRPとなる。これ
によつて、複数の定電流回路を直列に接続した場
合の負荷分担を以下に述べるように安定させるこ
とができる。 FIG. 2 is a circuit diagram showing a conventional example of the constant current circuit 1. That is, the current detector 2 has a constant current source 4
has a winding with a number of turns N 1 connected in series between the The voltage is output and supplied to the control circuit 3. Figure 3 shows the DC excitation ampere turns of current detector 2.
FIG. 3 is a diagram showing the relationship between AT and output voltage VD . DC excitation ampere-turn AT - output voltage conversion ratio g
Then, the output voltage V D of the current detector 2 is V D =g·I 1 ·N 1 (1). This output voltage V D is compared with a reference voltage E by a comparison amplifier A built in the control circuit 3, and a control signal such that V D = E (2) is given to the constant current source 4,
The output current I 1 of the constant current source 4 is controlled to be a predetermined constant value. Here, the voltage across the load 7 is
V L , the current flowing to load 7 is I L , load sharing resistor 5
When the resistance value of is R P and the current flowing through the load sharing resistor 5 is I 2 , it can be expressed as I L =I 1 −I 2 =I 1 −V L /R P (3). Therefore, the loss W due to the load sharing resistor 5 is as follows: W=V L 2 /R P (4). That is, by connecting the load sharing resistor 5, the output impedance of the constant current circuit becomes a finite value R P , and its output characteristics become the characteristics shown by the solid line in FIG. 4. When the load sharing resistor 5 is not connected, the output current I 1 of the constant current source 4 and the load current I L are equal and become constant currents, so the output impedance of the constant current circuit is equal to the output impedance of the constant current source 4. Equally, the output impedance is infinite, but by connecting the load sharing resistor 5, it becomes a finite output impedance R P. This makes it possible to stabilize load sharing when a plurality of constant current circuits are connected in series, as described below.
第５図は、第１図で示すように２個の定電流回
路１，１′を直列にして負荷６に接続した場合の
負荷分担特性を示す図である。実線で示した直線
ａおよびｃは、それぞれ定電流回路１，１′の出
力特性を示し、縦軸は出力電流を、横軸は出力電
圧を示す。ただし、定電流回路１の出力電圧VA
は図中左端から右向きにとり、定電流回路１′の
出力電圧VBは右端から左向きにとつている。今、
定電流回路１の定電流源４の出力電流IAと、定電
流回路１′の定電流源４の出力電流IBとが、
IA＝IB …(5)
であり、直線ａとｃの傾斜が等しいとすると、定
電流回路１，１′の出力電圧VA，VBは直線ａとｃ
の交点で決まり、同図に示すように、VA＝VBと
なり、負荷６には負荷電流ILが流れる。このとき
負荷６の両端の電圧2VLはVA＋VBである。従つ
て、
VA＝VB＝VL …(6)
となり、均等に負荷分担される。 FIG. 5 is a diagram showing load sharing characteristics when two constant current circuits 1 and 1' are connected in series to the load 6 as shown in FIG. Straight lines a and c shown by solid lines indicate the output characteristics of the constant current circuits 1 and 1', respectively, the vertical axis shows the output current, and the horizontal axis shows the output voltage. However, the output voltage V A of constant current circuit 1
is taken from the left end to the right in the figure, and the output voltage V B of the constant current circuit 1' is taken from the right end to the left. now,
The output current I A of the constant current source 4 of the constant current circuit 1 and the output current I B of the constant current source 4 of the constant current circuit 1' are I A = I B (5), and the straight lines a and c Assuming that the slopes of are equal, the output voltages V A and V B of constant current circuits 1 and 1' are linear
As shown in the figure, V A = V B , and the load current I L flows through the load 6. At this time, the voltage 2V L across the load 6 is V A +V B. Therefore, V A = V B = V L (6), and the load is shared equally.
次に、温度変動または入力電源変動等によつ
て、定電流回路１，１′の定電流源４の出力電流
IA，IBがそれぞれ許容範囲±ΔI1内の最大の変動
を生じ、定電流回路１の定電流源４の出力電流が
ΔI1だけ増加して、定電流回路１の出力特性が第
５図に一点鎖線で示した直線ｂに示すようにな
り、定電流回路１′の定電流源４の出力がΔI1減
少して定電流回路１′の出力特性が直線ｄに示す
ようになつた場合は、定電流回路１と１′の分担
電圧にΔVの変動が生じる。定電流源４の出力電
流の許容精度を±Ｂ％とすると、出力電流変動値
は、
±ΔI1＝±Ｂ・I1／100 …(7)
であるから、上記分担電圧差ΔVは、
ΔV＝RP・ΔI1
＝RP・Ｂ・I1／100 …(8)
となる。すなわち、分担電圧差は、定電流源４の
出力電流I1，I1の精度Ｂ、および定電流回路の出
力インピーダンスRPに比例する。この分担差を
少なくするためには、出力電流I1が大きい程I1の
精度を良くし、RPを小さくしなければならない。 Next, due to temperature fluctuations or input power fluctuations, etc., the output current of the constant current source 4 of the constant current circuits 1 and 1'
I A and I B each produce the maximum variation within the allowable range ±ΔI 1 , the output current of the constant current source 4 of the constant current circuit 1 increases by ΔI 1 , and the output characteristics of the constant current circuit 1 change to the fifth The output characteristic of the constant current source 4 of the constant current circuit 1' has decreased by ΔI 1 , and the output characteristics of the constant current circuit 1' have become as shown by the straight line d, as shown by the dashed line in the figure. In this case, a variation of ΔV occurs in the voltage shared between constant current circuits 1 and 1'. Assuming that the allowable accuracy of the output current of the constant current source 4 is ±B%, the output current fluctuation value is ±ΔI 1 = ±B・I 1 /100 (7), so the above shared voltage difference ΔV is ΔV =R P・ΔI 1 =R P・B・I 1 /100 (8). That is, the shared voltage difference is proportional to the output current I 1 of the constant current source 4, the accuracy B of I 1 , and the output impedance RP of the constant current circuit. In order to reduce this difference in distribution, the larger the output current I 1 is, the better the accuracy of I 1 must be, and the smaller R P must be.
現在、アナログ通信システムである海底同軸伝
送方式用の給電方式は、両端局に上述のような定
電流回路を含む定電流装置を設置して、海底同軸
の途中に接続された中継器に、100mA（5MHz方
式の場合）、または156mA（36MHz方式の場合）
の定電流を供給している。このような定電流回路
を、1A〜2Aの電流を供給する必要があるデイジ
タル伝送システムの海底光伝送方式に使用した場
合には、電圧分担差ΔVを上記海底同軸伝送方式
の場合と同程度とするためには、定電流装置の出
力インピーダンスRPを下げる必要がある。しか
し、出力インピーダンスRPを下げることは、式
(4)から明らかなように、負荷分担用抵抗５での損
失が増大することになり、その発熱量が増大し、
負荷分担用抵抗５を大型化しなければならない。 Currently, the power supply method for the submarine coaxial transmission method, which is an analog communication system, is to install a constant current device containing the above-mentioned constant current circuit at both end stations, and to supply 100 mA to a repeater connected in the middle of the submarine coaxial line. (for 5MHz method) or 156mA (for 36MHz method)
It supplies a constant current of. When such a constant current circuit is used in a submarine optical transmission method of a digital transmission system that needs to supply a current of 1A to 2A, the voltage sharing difference ΔV will be the same as in the case of the submarine coaxial transmission method described above. In order to do this, it is necessary to lower the output impedance R P of the constant current device. However, lowering the output impedance R P can be done by using the formula
As is clear from (4), the loss in the load sharing resistor 5 increases, and the amount of heat generated increases.
The load sharing resistor 5 must be made larger.
発明の目的
本発明の目的は、上述の従来の欠点を解決し、
大きな抵抗値の負荷分担用抵抗によつて出力イン
ピーダンスを所定の値に保持させることが可能
で、負荷分担用抵抗による損失を低減させた定電
流回路を提供することにある。OBJECT OF THE INVENTION The object of the invention is to solve the above-mentioned conventional drawbacks and
It is an object of the present invention to provide a constant current circuit in which output impedance can be maintained at a predetermined value by a load sharing resistor having a large resistance value, and loss due to the load sharing resistor is reduced.
発明の構成
本発明の定電流回路は、定電流源と負荷との間
に直列に接続された電流検出器と、該電流検出器
の出力によつて前記定電流源を制御する制御回路
と、前記定電流源の出力に接続された負荷分担用
の抵抗とを備えた定電流回路において、前記電流
検出器は、前記定電流源と負荷の間に直列に接続
された第１の巻線と、該第１の巻線の負荷側と前
記負荷分担用の抵抗との間に接続された第２の巻
線とを有して、前記第１の巻線のアンペア・ター
ンと上記第２の巻線のアンペア・ターンの和に比
例した電圧を出力し、前記制御回路は、上記電流
検出器の出力電圧が所定値になるように前記電流
源を制御することを特徴とする。Configuration of the Invention The constant current circuit of the present invention includes: a current detector connected in series between a constant current source and a load; and a control circuit that controls the constant current source using the output of the current detector. In the constant current circuit including a load sharing resistor connected to the output of the constant current source, the current detector includes a first winding connected in series between the constant current source and the load. , a second winding connected between the load side of the first winding and the load sharing resistor, the ampere-turns of the first winding and the second A voltage proportional to the sum of ampere-turns of the winding is output, and the control circuit controls the current source so that the output voltage of the current detector becomes a predetermined value.
発明の実施例
次に、本発明について、図面を参照して詳細に
説明する。Embodiments of the Invention Next, the present invention will be described in detail with reference to the drawings.
第６図は、本発明の一実施例を示す回路図であ
る。すなわち、電流検出器２′の電流検出巻線と
して、定電流源４と負荷７との間に、従来と同様
な巻回数N1の第１の巻線を直列に接続し、該第
１の巻線の負荷側に、巻回数N2の第２の巻線を
接続し、該第２の巻線の他端に負荷分担用抵抗５
を接続する。電流検出器２′の第１の巻線には、
定電流源４から電流I1′が流入し、その１部は第
２の巻線を通つて前記負荷分担用抵抗５に電流I2
を流し、残りは負荷電流ILとなる。従つて、電流
検出器２′の出力電圧VDは、上記２つの巻線のア
ンペア・ターンの合計に比例した電圧となる。電
流検出器２′の出力電圧VDを制御回路３に入力さ
せ、制御回路３は該入力電圧VDを基準電圧Ｅと
比較して、前記式(2)が成立するように定電流源４
を制御する。 FIG. 6 is a circuit diagram showing one embodiment of the present invention. That is, as the current detection winding of the current detector 2', a first winding with the number of turns N 1 similar to the conventional one is connected in series between the constant current source 4 and the load 7. A second winding with a number of turns N 2 is connected to the load side of the winding, and a load sharing resistor 5 is connected to the other end of the second winding.
Connect. The first winding of the current detector 2' includes:
A current I 1 ' flows from the constant current source 4, and a part of it flows through the second winding to the load sharing resistor 5 as a current I 2
flows, and the remainder becomes the load current I L. Therefore, the output voltage V D of the current detector 2' is proportional to the sum of the ampere turns of the two windings. The output voltage V D of the current detector 2' is input to the control circuit 3, and the control circuit 3 compares the input voltage V D with the reference voltage E, and controls the constant current source 4 so that the above formula (2) holds.
control.
第７図は、電流検出器２′の直流励磁アンペ
ア・ターンATと出力電圧VDの関係を示す図であ
り、その特性は、第３図に示した従来の特性と同
じである。ただし、第７図においては、第１およ
び第２の巻線のアンペア・ターンの合計、すなわ
ち、I1′N1＋I2N2が横軸に取られている。従つ
て、
VD＝Ｅ＝ｇ（I1′N1＋I2N2） …(9)
が成立し、負荷電流ILは、
IL＝I1′−I2＝I1′−VL／RP …(10)
となる。I2＝０のとき、すなわち第２の巻線をオ
ープンしたときのI1′をI1とすると、I1は前記式(1)
を満足する。式(1)と(9)から、
I1N1＝I1′N1＋I2N2 …(11)
となる。従つて、
I1′＝I1−I2N2／N1
＝I1−N2VL／N1RP …(12)
これを(10)式に代入すると、
IL＝I1−N2VL／N1RP−VL／RP
＝I1−（１＋N2／N1）VL／RP
＝I1−VL／RP′ …(13)
ただし、RP′＝RP／（１＋N2／N1） …(14)
従つて、RP′＜RP …(15)
である。従つて、本実施例の特性は、第８図で直
線ｆで示すようになる。同図に直線ｅで示すよう
な従来と同様な特性を得るためには、負荷分担用
抵抗５の抵抗値RPを、第２図で示した従来例に
比して、高抵抗にすることができる。すなわち、
本実施例は、負荷分担用抵抗５による損失を、従
来に比して低減することができるという効果があ
る。 FIG. 7 is a diagram showing the relationship between the DC excitation ampere-turn AT and the output voltage V D of the current detector 2', and its characteristics are the same as the conventional characteristics shown in FIG. 3. However, in FIG. 7, the sum of ampere-turns of the first and second windings, ie, I 1 'N 1 +I 2 N 2 , is plotted on the horizontal axis. Therefore, V D = E = g (I 1 ′N 1 + I 2 N 2 ) …(9) holds, and the load current I L is I L = I 1 ′−I 2 = I 1 ′−V L /R P …(10). If I 1 ' is I 1 when I 2 = 0, that is, when the second winding is open, then I 1 is calculated using the above formula (1).
satisfy. From equations (1) and (9), I 1 N 1 = I 1 'N 1 + I 2 N 2 (11). Therefore, I 1 ′=I 1 −I 2 N 2 /N 1 =I 1 −N 2 V L /N 1 R P …(12) Substituting this into equation (10), I L =I 1 − N 2 V L /N 1 R P −V L /R P =I 1 −(1+N 2 /N 1 )V L /R P =I 1 −V L /R P ′ …(13) However, R P ′ =R P /(1+N 2 /N 1 )...(14) Therefore, R P ′<R P ...(15). Therefore, the characteristics of this embodiment are as shown by the straight line f in FIG. In order to obtain the same characteristics as the conventional example shown by the straight line e in the figure, the resistance value R P of the load sharing resistor 5 must be made higher than that of the conventional example shown in Fig. 2. I can do it. That is,
This embodiment has the effect that the loss due to the load sharing resistor 5 can be reduced compared to the conventional one.
発明の効果
以上のように、本発明においては、電流検出器
に第１の巻線と第２の巻線を設け、第２の巻線の
一端を第１の巻線の負荷側に接続し、上記第１の
巻線を通して負荷に電流を供給し、前記第２の巻
線の他端を負荷分担用抵抗の一端に接続し、該電
流検出器の出力電圧が基準電圧と等しくなるよう
に定電流源を制御するように構成したから、負荷
分担用抵抗の抵抗値を高くしても本回路の出力イ
ンピーダンを下げることが可能である。従つて、
負荷分担用抵抗の損失を低減することができると
いう効果がある。Effects of the Invention As described above, in the present invention, a current detector is provided with a first winding and a second winding, and one end of the second winding is connected to the load side of the first winding. , supplying current to the load through the first winding, connecting the other end of the second winding to one end of the load sharing resistor, and making the output voltage of the current detector equal to the reference voltage. Since the constant current source is configured to be controlled, the output impedance of this circuit can be lowered even if the resistance value of the load sharing resistor is increased. Therefore,
This has the effect of reducing the loss of the load sharing resistor.
第１図は２個の定電流回路を直列に接続して負
荷に定電流を供給する給電方式の一例を示すブロ
ツク図、第２図は上記給電方式に使用される定電
流回路の従来例を示す回路図、第３図は上記従来
例の電流検出器の特性を示す図、第４図は上記従
来の定電流回路の出力特性を示す図、第５図は第
１図の給電方式の２個の定電流回路の負荷分担を
示すための特性図、第６図は本発明の一実施例を
示す回路図、第７図は上記実施例の電流検出器の
特性を示す図、第８図は上記実施例の出力特性を
示す図である。
図において、１，１′……定電流回路、２，
２′……電流検出器、３……制御回路、４……定
電流源、５……負荷分担用抵抗、６……給電方式
の負荷、７……負荷。
Figure 1 is a block diagram showing an example of a power supply system that connects two constant current circuits in series to supply a constant current to a load, and Figure 2 shows a conventional example of a constant current circuit used in the above power supply system. 3 is a diagram showing the characteristics of the conventional current detector described above, FIG. 4 is a diagram showing the output characteristics of the conventional constant current circuit described above, and FIG. FIG. 6 is a circuit diagram showing an embodiment of the present invention. FIG. 7 is a diagram showing the characteristics of the current detector of the above embodiment. FIG. FIG. 3 is a diagram showing the output characteristics of the above embodiment. In the figure, 1, 1'...constant current circuit, 2,
2'...Current detector, 3...Control circuit, 4...Constant current source, 5...Load sharing resistor, 6...Load of power supply system, 7...Load.
Claims (1)
流検出器と、該電流検出器の出力によつて前記定
電流源を制御する制御回路と、前記定電流源の出
力に接続された負荷分担用の抵抗とを備えた定電
流回路において、前記電流検出器は、前記定電流
源と負荷の間に直列に接続された第１の巻線と、
該第１の巻線の負荷側と前記負荷分担用の抵抗と
の間に接続された第２の巻線とを有して、前記第
１の巻線のアンペア・ターンと上記第２の巻線の
アンペア・ターンの和に比例した電圧を出力し、
前記制御回路は、上記電流検出器の出力電圧が所
定値になるように前記電流源を制御することを特
徴とする定電流回路。1. A current detector connected in series between a constant current source and a load, a control circuit that controls the constant current source using the output of the current detector, and a control circuit connected to the output of the constant current source. In a constant current circuit including a load sharing resistor, the current detector includes a first winding connected in series between the constant current source and the load;
a second winding connected between the load side of the first winding and the load sharing resistor; Outputs a voltage proportional to the sum of ampere turns of the line,
A constant current circuit, wherein the control circuit controls the current source so that the output voltage of the current detector becomes a predetermined value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5317084A JPS60196823A (en) | 1984-03-19 | 1984-03-19 | Constant current circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5317084A JPS60196823A (en) | 1984-03-19 | 1984-03-19 | Constant current circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60196823A JPS60196823A (en) | 1985-10-05 |
| JPH0574085B2 true JPH0574085B2 (en) | 1993-10-15 |
Family
ID=12935381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5317084A Granted JPS60196823A (en) | 1984-03-19 | 1984-03-19 | Constant current circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60196823A (en) |
-
1984
- 1984-03-19 JP JP5317084A patent/JPS60196823A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60196823A (en) | 1985-10-05 |
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