JPH10283044A - Constant current power unit - Google Patents
Constant current power unitInfo
- Publication number
- JPH10283044A JPH10283044A JP9086538A JP8653897A JPH10283044A JP H10283044 A JPH10283044 A JP H10283044A JP 9086538 A JP9086538 A JP 9086538A JP 8653897 A JP8653897 A JP 8653897A JP H10283044 A JPH10283044 A JP H10283044A
- Authority
- JP
- Japan
- Prior art keywords
- resistor
- current
- current detection
- correction
- value
- 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.)
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Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、高精度な定電流電
源を供給する定電流電源装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant current power supply for supplying a high precision constant current power supply.
【0002】[0002]
【従来の技術】図4は、従来の定電流電源装置を示して
いる。1は、定電流電源装置10の電流源電源である。
2は、負荷7に流す定電流の値を指定する信号を定電流
電源装置10に入力するための入力端子である。3は、
負荷7に流す電流を入力端子2に印加される信号(指定
値)に合せるための誤差増幅器である。2. Description of the Related Art FIG. 4 shows a conventional constant current power supply. Reference numeral 1 denotes a current source power supply of the constant current power supply device 10.
Reference numeral 2 denotes an input terminal for inputting a signal designating a value of a constant current flowing through the load 7 to the constant current power supply device 10. 3 is
This is an error amplifier for adjusting a current flowing through the load 7 to a signal (specified value) applied to the input terminal 2.
【0003】4は、負荷7に供給する大電流を制御する
電流パワ−アンプである。5は、負荷7に流れている電
流を電圧に変換する電流検出抵抗である。6は、電流検
出抵抗5により変換された電圧を誤差増幅器3に送るバ
ッファアンプである。[0005] Reference numeral 4 denotes a current power amplifier for controlling a large current supplied to the load 7. Reference numeral 5 denotes a current detection resistor that converts a current flowing through the load 7 into a voltage. Reference numeral 6 denotes a buffer amplifier that sends the voltage converted by the current detection resistor 5 to the error amplifier 3.
【0004】上記定電流電源装置においては、入力端子
2に印加される電流値指定信号が、ある指定値(電圧
値)を指定すると、誤差増幅器3は、この指定値と電流
検出抵抗5の電圧値とを比較し、かつ、両者が一致する
ように電流パワ−アンプ4を制御することになる。In the above constant current power supply, when the current value designating signal applied to the input terminal 2 designates a certain designated value (voltage value), the error amplifier 3 applies the designated value and the voltage of the current detecting resistor 5 to each other. The current power amplifier 4 is controlled so as to compare the values with each other and to make the two coincide with each other.
【0005】[0005]
【発明が解決しようとする課題】近年、定電流電源を必
要とする分野においては、高精度に定電流電源を供給す
ることが要求されている。例えば、半導体のマスクを製
作する描画装置においては、半導体の集積度の向上に伴
い、レンズ電源として高精度な定電流電源が必要不可欠
となっている。In recent years, in a field requiring a constant current power supply, it is required to supply the constant current power supply with high accuracy. For example, in a drawing apparatus for manufacturing a semiconductor mask, a high-precision constant current power supply is indispensable as a lens power supply with the improvement in the degree of integration of the semiconductor.
【0006】しかし、図4の定電流電源装置において
は、周囲温度の変化や自己発熱などの原因により、電流
検出抵抗5の抵抗値が変化する。電流検出抵抗5の抵抗
値が変化すると、この電流検出抵抗5により変換される
電圧も変化することになる。However, in the constant current power supply device of FIG. 4, the resistance value of the current detection resistor 5 changes due to a change in ambient temperature, self-heating, or the like. When the resistance value of the current detection resistor 5 changes, the voltage converted by the current detection resistor 5 also changes.
【0007】よって、誤差増幅器3は、負荷7に流れる
電流を正確に表していない誤差を含んだ電圧値を、電流
値指定信号が指定する指定値(電圧値)と比較すること
になるため、負荷7に流れる電流は、温度変化による誤
差分だけ指定値とずれてしまう。Therefore, the error amplifier 3 compares a voltage value including an error that does not accurately represent the current flowing through the load 7 with a specified value (voltage value) specified by the current value specifying signal. The current flowing through the load 7 deviates from the specified value by an error due to a temperature change.
【0008】このような温度変化による誤差をなくすに
は、電流検出抵抗5を、温度係数の小さい高精度な抵抗
により構成すればよい。ところが、電流検出抵抗5は、
電源損失を抑えるために小さな抵抗値を有する抵抗によ
り構成され、このような抵抗は、一般に温度係数が大き
い。In order to eliminate such an error due to a temperature change, the current detection resistor 5 may be constituted by a high-precision resistor having a small temperature coefficient. However, the current detection resistor 5 is
In order to suppress power loss, the power supply is constituted by a resistor having a small resistance value, and such a resistor generally has a large temperature coefficient.
【0009】また、温度特性が良く(温度係数が小さ
く)、かつ、小さな抵抗値で大電流を流せるようなパワ
−抵抗も市販されているが、このパワ−抵抗は、非常に
高価である。A power resistor having good temperature characteristics (small temperature coefficient) and allowing a large current to flow with a small resistance value is also commercially available, but this power resistor is very expensive.
【0010】よって、電流検出抵抗にパワ−抵抗を用い
て定電流電源装置を構成すると、非常に高精度な定電流
電源を供給できるようになるが、反面、装置が高価にな
る欠点がある。Therefore, if a constant current power supply device is constituted by using a power resistor as a current detection resistor, a very high precision constant current power supply can be supplied. However, there is a disadvantage that the device is expensive.
【0011】本発明は、上記欠点を解決すべくなされた
もので、その目的は、温度特性の良くない安価な抵抗を
用いても、高精度な定電流電源を供給できるような定電
流電源装置を提供することである。SUMMARY OF THE INVENTION The present invention has been made to solve the above-described drawbacks, and has as its object to provide a constant current power supply device capable of supplying a high-precision constant current power supply even if an inexpensive resistor having poor temperature characteristics is used. It is to provide.
【0012】[0012]
【課題を解決するための手段】上記目的を達成するた
め、本発明の定電流電源装置は、定電流電源の電流の検
出を行う電流検出抵抗を有し、前記電流検出抵抗の両端
の電圧に基づいて前記電流の値を所定値に一致させるも
のであり、新たに、前記電流検出抵抗と実質的に等しい
温度特性を持ち、前記電流検出抵抗と温度条件が実質的
に同じになるように配置され、一端に前記電圧が印加さ
れる補正抵抗と、入力端子に前記補正抵抗の他端が接続
される演算増幅器と、前記演算増幅器の入力端子と出力
端子の間に接続される帰還抵抗とから構成される補正回
路を備えている。そして、本発明では、前記演算増幅器
の出力電圧に基づいて前記電流の値を所定値に一致させ
るようにしている。In order to achieve the above object, a constant current power supply according to the present invention has a current detection resistor for detecting a current of a constant current power supply. The current value is made equal to a predetermined value based on the current detection resistance, and is newly arranged so as to have a temperature characteristic substantially equal to the current detection resistance and to have substantially the same temperature conditions as the current detection resistance. A correction resistor having one end to which the voltage is applied, an operational amplifier having an input terminal connected to the other end of the correction resistor, and a feedback resistor connected between an input terminal and an output terminal of the operational amplifier. It has a correction circuit configured. In the present invention, the value of the current is made to match a predetermined value based on the output voltage of the operational amplifier.
【0013】本発明の定電流電源装置は、さらに、前記
所定値に相当する電圧と前記演算増幅器の出力電圧とを
比較し、両者を一致させることで前記電流の値を所定値
に一致させる手段を備えている。The constant current power supply of the present invention further comprises a means for comparing a voltage corresponding to the predetermined value with an output voltage of the operational amplifier, and matching the two to make the value of the current equal to the predetermined value. It has.
【0014】[0014]
【発明の実施の形態】以下、図面を参照しながら、本発
明の定電流電源装置について詳細に説明する。図1は、
本発明の定電流電源装置を示している。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a constant current power supply according to the present invention will be described in detail with reference to the drawings. FIG.
1 shows a constant current power supply device of the present invention.
【0015】1は、定電流電源装置10の電流源電源で
ある。2は、負荷7に流す定電流の値を指定する信号を
定電流電源装置10に入力するための入力端子である。
3は、負荷7に流す電流を入力端子2に印加される信号
(指定値)に合せるための誤差増幅器である。Reference numeral 1 denotes a current source power supply of the constant current power supply device 10. Reference numeral 2 denotes an input terminal for inputting a signal designating a value of a constant current flowing through the load 7 to the constant current power supply device 10.
Reference numeral 3 denotes an error amplifier for adjusting a current flowing through the load 7 to a signal (specified value) applied to the input terminal 2.
【0016】4は、負荷7に供給する大電流を制御する
電流パワ−アンプである。5は、負荷7に流れている電
流を電圧に変換する電流検出抵抗である。6は、電流検
出抵抗5により変換された電圧を補正回路8に送るバッ
ファアンプである。Reference numeral 4 denotes a current power amplifier for controlling a large current supplied to the load 7. Reference numeral 5 denotes a current detection resistor that converts a current flowing through the load 7 into a voltage. Reference numeral 6 denotes a buffer amplifier that sends the voltage converted by the current detection resistor 5 to the correction circuit 8.
【0017】補正回路8は、温度変化などによる電流検
出抵抗5の抵抗値の変化に伴う電圧値の変化分(誤差)
を取り除き、この補正された電圧値を誤差増幅器3に送
るための回路である。The correction circuit 8 calculates a change (error) in the voltage value due to a change in the resistance value of the current detection resistor 5 due to a temperature change or the like.
And a circuit for sending the corrected voltage value to the error amplifier 3.
【0018】図2は、図1の補正回路8の構成を示して
いる。9は、電流検出抵抗5の電圧値を補正する補正抵
抗である。補正抵抗9は、電流検出バッファアンプ6の
出力端子とオペアンプ11のマエナス側入力端子との間
に接続される。FIG. 2 shows the configuration of the correction circuit 8 of FIG. Reference numeral 9 denotes a correction resistor for correcting the voltage value of the current detection resistor 5. The correction resistor 9 is connected between the output terminal of the current detection buffer amplifier 6 and the input terminal on the maenas side of the operational amplifier 11.
【0019】この補正抵抗9は、電流検出抵抗5と同じ
温度特性(温度係数)を有していることが必要である。
また、同じ温度特性とは、補正抵抗9が複数の抵抗から
構成される合成抵抗である場合に、各々の抵抗について
は、電流検出抵抗5の温度特性と異なっているが、合成
抵抗については、電流検出抵抗5の温度特性と一致して
いるというものを含む。The correction resistor 9 needs to have the same temperature characteristics (temperature coefficient) as the current detection resistor 5.
The same temperature characteristic means that when the correction resistor 9 is a composite resistor composed of a plurality of resistors, each of the resistors is different from the temperature characteristic of the current detection resistor 5. Includes that it matches the temperature characteristics of the current detection resistor 5.
【0020】また、電流検出抵抗5と補正抵抗9は、同
じ温度条件(温度変化が同じであること)の下にある。
このような温度条件は、例えば、電流検出抵抗5と補正
抵抗9を互いに接着して配置するように構成すればよ
い。The current detection resistor 5 and the correction resistor 9 are under the same temperature condition (the temperature change is the same).
Such a temperature condition may be configured such that, for example, the current detection resistor 5 and the correction resistor 9 are bonded to each other.
【0021】10は、オペアンプ11の帰還抵抗であ
る。帰還抵抗10は、オペアンプ11の入力端子と出力
端子の間に接続される。12は、オペアンプ11のプラ
ス側入力端子の入力抵抗である。オペアンプ11の出力
電圧は、誤差増幅器3に与えられ、定電流電源の電流
を、電流値指定信号により指定される値に一致させるた
めに用いられる。Reference numeral 10 denotes a feedback resistor of the operational amplifier 11. The feedback resistor 10 is connected between an input terminal and an output terminal of the operational amplifier 11. Reference numeral 12 denotes an input resistance of a positive input terminal of the operational amplifier 11. The output voltage of the operational amplifier 11 is supplied to the error amplifier 3 and is used to make the current of the constant current power supply coincide with the value specified by the current value specifying signal.
【0022】上記定電流電源装置によれば、温度変化な
どによる電流検出抵抗5の抵抗値の変化に伴う電圧値の
変化分(誤差)を取り除く補正回路8を有し、この補正
回路8は、電流検出抵抗5と同じ温度特性を有する補正
抵抗9を有し、補正抵抗9の一端は、オペアンプ11の
マエナス側入力端子に接続され、補正抵抗9の他端に
は、電流検出抵抗5の電圧値が印加されている。According to the above constant current power supply device, there is provided a correction circuit 8 for removing a change (error) in the voltage value due to a change in the resistance value of the current detection resistor 5 due to a temperature change or the like. A correction resistor 9 having the same temperature characteristic as the current detection resistor 5 is provided. One end of the correction resistor 9 is connected to the input terminal on the maena side of the operational amplifier 11, and the other end of the correction resistor 9 has a voltage of the current detection resistor 5. The value has been applied.
【0023】また、電流検出抵抗5と補正抵抗9は、同
じ温度条件の下に置かれている。この場合、周囲温度の
変化や自己発熱などにより、電流検出抵抗5の抵抗値が
所定値だけ変化すると、同時に、補正抵抗9の抵抗値も
所定値だけ変化する。つまり、温度変化による抵抗値の
変化により、電流値が変化しないのに電流検出抵抗5に
印加される電圧値が変化したときには、補正抵抗9の抵
抗値も変化しているため、補正抵抗9に流れる電流は、
変化しない。The current detection resistor 5 and the correction resistor 9 are placed under the same temperature condition. In this case, when the resistance value of the current detection resistor 5 changes by a predetermined value due to a change in ambient temperature or self-heating, the resistance value of the correction resistor 9 also changes by a predetermined value. That is, when the voltage value applied to the current detection resistor 5 changes without changing the current value due to the change in the resistance value due to the temperature change, the resistance value of the correction resistor 9 also changes. The flowing current is
It does not change.
【0024】このように、補正抵抗9に流れる電流値
は、温度に依存しなくなるため、電流検出抵抗5を温度
特性の良くない安価な抵抗から構成しても、高精度な定
電流電源を供給できるようになる。As described above, since the value of the current flowing through the correction resistor 9 does not depend on the temperature, even if the current detection resistor 5 is formed of an inexpensive resistor having poor temperature characteristics, a high-precision constant current power supply is provided. become able to.
【0025】次に、本発明の定電流電源装置の動作と原
理について説明する。定電流値を指定する信号が入力端
子2より入力されると、誤差増幅器3は、この信号によ
り指定される電圧値と、電流検出抵抗5の電圧値を補正
回路8により補正した電圧値とを比較し、かつ、両者が
一致するように電流パワ−アンプ4を制御する。Next, the operation and principle of the constant current power supply of the present invention will be described. When a signal specifying a constant current value is input from the input terminal 2, the error amplifier 3 compares the voltage value specified by this signal with the voltage value obtained by correcting the voltage value of the current detection resistor 5 by the correction circuit 8. The current power amplifier 4 is controlled so as to compare and match the two.
【0026】電流パワ−アンプ4は、誤差増幅器3の出
力電圧(制御電圧)に基づいて、電流源電源1の電流を
電流検出抵抗5を経由して負荷7に与える。ここで、周
囲温度の変化や自己発熱などにより、電流検出抵抗5の
温度が変化すると、電流検出抵抗5の抵抗値も変化す
る。The current power amplifier 4 supplies the current of the current source power supply 1 to the load 7 via the current detection resistor 5 based on the output voltage (control voltage) of the error amplifier 3. Here, when the temperature of the current detection resistor 5 changes due to a change in ambient temperature or self-heating, the resistance value of the current detection resistor 5 also changes.
【0027】電流検出抵抗5の抵抗値をR、温度係数を
α、温度の変化量をΔtとすると、電流検出抵抗5の抵
抗値Rdは、(1)式により表される。 Rd = R+R×αΔt = R(1+αΔt) …(1) 即ち、(1)式によれば、温度の変化がΔtのとき、電
流検出抵抗5の抵抗値は、R×αΔtだけ変化すること
がわかる。Assuming that the resistance value of the current detection resistor 5 is R, the temperature coefficient is α, and the amount of change in temperature is Δt, the resistance value Rd of the current detection resistor 5 is expressed by equation (1). Rd = R + R × αΔt = R (1 + αΔt) (1) That is, according to the expression (1), when the temperature change is Δt, the resistance value of the current detection resistor 5 changes by R × αΔt. .
【0028】電流検出抵抗5に流れる電流をIとする
と、電流検出抵抗5に印加される電圧Vは、(2)式に
より表される。 V = Rd×I = R(1+αΔt)×I …(2) 即ち、(2)式によれば、電流検出抵抗5に流れる電流
Iに変化がなくても、電流検出抵抗5の温度変化Δtが
存在すると、電流検出抵抗5の電圧値Vも変化すること
がわかる。Assuming that the current flowing through the current detection resistor 5 is I, the voltage V applied to the current detection resistor 5 is expressed by the following equation (2). V = Rd × I = R (1 + αΔt) × I (2) That is, according to the expression (2), even if the current I flowing through the current detection resistor 5 does not change, the temperature change Δt of the current detection resistor 5 becomes It can be seen that when present, the voltage value V of the current detection resistor 5 also changes.
【0029】そこで、本発明では、温度変化による電圧
の変化分(誤差)、即ち、R×I×αΔtを、補正回路
8により除去し、温度変化による誤差を除去した電圧を
誤差増幅器3に与える。Therefore, in the present invention, the voltage change (error) due to the temperature change, that is, R × I × αΔt is removed by the correction circuit 8, and the voltage from which the error due to the temperature change is removed is supplied to the error amplifier 3. .
【0030】以下、図3を参照しつつ、本発明の補正回
路の原理について説明する。電流検出抵抗(抵抗値R
I)5に電流Iが流れていると仮定すると、そのとき、
電流検出抵抗5に発生する電圧V1は、 V1 = RI×I …(3) で表される。The principle of the correction circuit according to the present invention will be described below with reference to FIG. Current detection resistor (resistance value R
I) Assuming that a current I is flowing through 5, then:
The voltage V1 generated in the current detection resistor 5 is expressed as follows: V1 = RI × I (3)
【0031】アンプ回路が、オペアンプ11、抵抗(抵
抗値R1)9と、抵抗(抵抗値R2)10、抵抗(抵抗
値R3)12により構成される場合、オペアンプ11の
ゲインAvは、 Av = R2/R1 =V2(出力電圧)/V1(入力電圧) …(4) となる。即ち、図3のV1とV2の関係は、上記(4)
式より、 V2 = (R2/R1)×V1 …(5) で表される。When the amplifier circuit includes an operational amplifier 11, a resistor (resistance R1) 9, a resistor (resistance R2) 10, and a resistor (resistance R3) 12, the gain Av of the operational amplifier 11 is Av = R2. / R1 = V2 (output voltage) / V1 (input voltage) (4) That is, the relationship between V1 and V2 in FIG.
From the formula, V2 = (R2 / R1) × V1 (5)
【0032】上記(5)式に上記(3)式を代入する
と、以下の(6)式が得られる。 V2/I = (R2/R1)×RI …(6) ここで、抵抗(抵抗値RI)5の温度係数をα、抵抗
(抵抗値R1)9の温度係数をβ、抵抗(抵抗値R2)
10の温度係数をγとすると、上記(6)式は、以下の
ように変形することができる。By substituting the above equation (3) into the above equation (5), the following equation (6) is obtained. V2 / I = (R2 / R1) × RI (6) Here, the temperature coefficient of the resistor (resistance value RI) 5 is α, the temperature coefficient of the resistor (resistance value R1) 9 is β, and the resistance (resistance value R2).
If the temperature coefficient of 10 is γ, the above equation (6) can be modified as follows.
【0033】 V2/I = {R2(1+γΔt)/R1(1+βΔt)} ×RI(1+αΔt) …(7) 本発明では、抵抗5の温度係数αと抵抗9の温度係数β
が等しくなるように設定しているため、上記(7)式
は、以下の(8)式のようになる。V2 / I = {R2 (1 + γΔt) / R1 (1 + βΔt)} × RI (1 + αΔt) (7) In the present invention, the temperature coefficient α of the resistor 5 and the temperature coefficient β of the resistor 9 are used.
Are set to be equal, the above equation (7) becomes the following equation (8).
【0034】 V2/I = (RI/R1)×R2(1+γΔt) …(8) また、抵抗(抵抗値R2)10は、大電流を扱う抵抗で
はないため、金属被膜抵抗などの安価で、温度係数の小
さい抵抗を用いることができる。よって、上記(8)式
のγΔtの項は、無視できる。V2 / I = (RI / R1) × R2 (1 + γΔt) (8) Further, since the resistor (resistance value R2) 10 is not a resistor for handling a large current, it is inexpensive such as a metal film resistor and has a low temperature. A resistor with a small coefficient can be used. Therefore, the term of γΔt in the above equation (8) can be ignored.
【0035】従って、以下の(9)式が得られる。 V2/I = (RI/R1)×R2 …(9) 上記(9)式によれば、温度変化の項Δtを含んでいな
いため、温度変化による誤差は、補正回路により相殺さ
れたことになる。Accordingly, the following equation (9) is obtained. V2 / I = (RI / R1) × R2 (9) According to the above equation (9), since the term Δt of the temperature change is not included, the error due to the temperature change is canceled by the correction circuit. .
【0036】よって、温度特性の良くない安価な抵抗を
電流検出抵抗に使用しても、高精度な定電流電源を供給
できるような定電流電源装置を提供できる。なお、電流
検出抵抗5には大電流が流れるため、補正抵抗9に比べ
て自己発熱による温度上昇が著しい。よって、電流検出
抵抗5は、放熱フィンなどの冷却装置によって冷却する
のがよい。Therefore, it is possible to provide a constant current power supply capable of supplying a high-precision constant current power supply even if an inexpensive resistor having poor temperature characteristics is used for the current detection resistor. Since a large current flows through the current detection resistor 5, the temperature rise due to self-heating is remarkable as compared with the correction resistor 9. Therefore, the current detection resistor 5 is preferably cooled by a cooling device such as a radiation fin.
【0037】また、本発明では、電流検出抵抗5の温度
変化Δtと補正抵抗9の温度変化Δtが同じであること
が必要であるから、例えば、電流検出抵抗5と補正抵抗
9を互いに接着して配置し、電流検出抵抗5と補正抵抗
9の温度条件を同じに設定する。本発明は、計測器など
の基準定電流発生器にも適用できる。In the present invention, since the temperature change Δt of the current detection resistor 5 and the temperature change Δt of the correction resistor 9 need to be the same, for example, the current detection resistor 5 and the correction resistor 9 are bonded to each other. And the temperature conditions of the current detection resistor 5 and the correction resistor 9 are set to be the same. The present invention can be applied to a reference constant current generator such as a measuring instrument.
【0038】[0038]
【発明の効果】以上、説明したように、本発明の定電流
電源装置によれば、次のような効果を奏する。温度変化
による電流検出抵抗の抵抗値の変化に伴う電圧値の変化
分(誤差)を取り除く補正回路を設けている。この補正
回路は、電流検出抵抗と同じ温度特性を有する補正抵抗
を有し、補正抵抗の一端は、オペアンプのマエナス側入
力端子に接続され、補正抵抗の他端には、電流検出抵抗
の電圧値が印加される。また、電流検出抵抗と補正抵抗
は、同じ温度条件の下に置かれる。As described above, according to the constant current power supply of the present invention, the following effects can be obtained. A correction circuit is provided for removing a change (error) in the voltage value due to a change in the resistance value of the current detection resistor due to a temperature change. This correction circuit has a correction resistor having the same temperature characteristic as the current detection resistor. One end of the correction resistor is connected to the input terminal on the maena side of the operational amplifier, and the other end of the correction resistor has a voltage value of the current detection resistor. Is applied. The current detection resistor and the correction resistor are placed under the same temperature condition.
【0039】これにより、周囲温度の変化や自己発熱な
どにより、電流検出抵抗の抵抗値が所定値だけ変化して
も、同時に、補正抵抗の抵抗値も所定値だけ変化する。
つまり、温度変化による抵抗値の変化により、電流値が
変化しないのに電流検出抵抗に印加される電圧値が変化
したときには、補正抵抗の抵抗値も変化しているため、
補正抵抗に流れる電流は、変化しない。Thus, even if the resistance value of the current detection resistor changes by a predetermined value due to a change in ambient temperature or self-heating, the resistance value of the correction resistor also changes by a predetermined value.
That is, when the voltage value applied to the current detection resistor changes while the current value does not change due to the change in the resistance value due to the temperature change, the resistance value of the correction resistor also changes.
The current flowing through the correction resistor does not change.
【0040】このように、補正抵抗に流れる電流値は、
温度に依存しなくなるため、電流検出抵抗を温度特性の
良くない安価な抵抗から構成しても、高精度な定電流電
源を供給できるようになる。Thus, the value of the current flowing through the correction resistor is
Since it does not depend on temperature, it is possible to supply a high-precision constant current power supply even if the current detection resistor is formed of an inexpensive resistor having poor temperature characteristics.
【図1】本発明の定電流電源装置の構成を示す図。FIG. 1 is a diagram showing a configuration of a constant current power supply device of the present invention.
【図2】図1の補正回路の構成を示す図。FIG. 2 is a diagram illustrating a configuration of a correction circuit in FIG. 1;
【図3】本発明の補正回路の原理を示す図。FIG. 3 is a diagram showing the principle of a correction circuit according to the present invention.
【図4】従来の定電流電源装置の構成を示す図。FIG. 4 is a diagram showing a configuration of a conventional constant current power supply device.
1 :電流源電源、 2 :電流値指定信号の入力端子、 3 :誤差増幅器、 4 :電流パワ−アンプ、 5 :電流検出抵抗、 6 :電流検出バッファアンプ、 7 :負荷、 8 :補正回路、 9 :補正抵抗、 10 :帰還抵抗、 11 :オペアンプ、 12 :入力抵抗。 1: current source power supply, 2: input terminal for current value designation signal, 3: error amplifier, 4: current power amplifier, 5: current detection resistor, 6: current detection buffer amplifier, 7: load, 8: correction circuit, 9: correction resistance, 10: feedback resistance, 11: operational amplifier, 12: input resistance.
─────────────────────────────────────────────────────
────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成9年4月16日[Submission date] April 16, 1997
【手続補正1】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】0002[Correction target item name] 0002
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【0002】[0002]
【従来の技術】図4は、従来の定電流電源装置を示して
いる。1は、定電流電源装置13の電流源電源である。
2は、負荷7に流す定電流の値を指定する信号を定電流
電源装置13に入力するための入力端子である。3は、
負荷7に流す電流を入力端子2に印加される信号(指定
値)に合せるための誤差増幅器である。2. Description of the Related Art FIG. 4 shows a conventional constant current power supply. Reference numeral 1 denotes a current source power supply of the constant current power supply device 13 .
Reference numeral 2 denotes an input terminal for inputting a signal specifying a value of a constant current flowing through the load 7 to the constant current power supply device 13 . 3 is
This is an error amplifier for adjusting a current flowing through the load 7 to a signal (specified value) applied to the input terminal 2.
【手続補正2】[Procedure amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】0015[Correction target item name] 0015
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【0015】1は、定電流電源装置13の電流源電源で
ある。2は、負荷7に流す定電流の値を指定する信号を
定電流電源装置13に入力するための入力端子である。
3は、負荷7に流す電流を入力端子2に印加される信号
(指定値)に合せるための誤差増幅器である。Reference numeral 1 denotes a current source power supply of the constant current power supply device 13 . Reference numeral 2 denotes an input terminal for inputting a signal specifying a value of a constant current flowing through the load 7 to the constant current power supply device 13 .
Reference numeral 3 denotes an error amplifier for adjusting a current flowing through the load 7 to a signal (specified value) applied to the input terminal 2.
【手続補正3】[Procedure amendment 3]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】図1[Correction target item name] Fig. 1
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図1】 FIG.
【手続補正4】[Procedure amendment 4]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】図4[Correction target item name] Fig. 4
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図4】 FIG. 4
Claims (2)
抵抗を有し、前記電流検出抵抗の両端の電圧に基づいて
前記電流の値を所定値に一致させるような定電流電源装
置において、前記電流検出抵抗と実質的に等しい温度特
性を持ち、前記電流検出抵抗と温度条件が実質的に同じ
になるように配置され、一端に前記電圧が印加される補
正抵抗と、入力端子に前記補正抵抗の他端が接続される
演算増幅器と、前記演算増幅器の入力端子と出力端子の
間に接続される帰還抵抗とから構成される補正回路を具
備し、前記演算増幅器の出力電圧に基づいて前記電流の
値を所定値に一致させるようにしたことを特徴とする定
電流電源装置。1. A constant current power supply device having a current detection resistor for detecting a current of a constant current power supply, wherein the value of the current matches a predetermined value based on a voltage across the current detection resistor. It has a temperature characteristic substantially equal to the current detection resistor, is arranged so that the temperature condition is substantially the same as that of the current detection resistor, and has a correction resistor to which the voltage is applied at one end and the correction resistor at an input terminal. An operational amplifier to which the other end of the resistor is connected, and a correction circuit including a feedback resistor connected between an input terminal and an output terminal of the operational amplifier, wherein the correction circuit is configured based on an output voltage of the operational amplifier. A constant current power supply device wherein a current value is made to match a predetermined value.
幅器の出力電圧とを比較し、両者を一致させることで前
記電流の値を所定値に一致させる手段を具備したことを
特徴とする請求項1記載の定電流電源装置。2. A device according to claim 1, further comprising means for comparing a voltage corresponding to said predetermined value with an output voltage of said operational amplifier, and matching the two to make said current value equal to a predetermined value. Item 2. The constant current power supply device according to Item 1.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9086538A JPH10283044A (en) | 1997-04-04 | 1997-04-04 | Constant current power unit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9086538A JPH10283044A (en) | 1997-04-04 | 1997-04-04 | Constant current power unit |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH10283044A true JPH10283044A (en) | 1998-10-23 |
Family
ID=13889785
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP9086538A Pending JPH10283044A (en) | 1997-04-04 | 1997-04-04 | Constant current power unit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH10283044A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005315729A (en) * | 2004-04-28 | 2005-11-10 | Advantest Corp | Direct-current testing device |
JP2006234401A (en) * | 2005-02-22 | 2006-09-07 | Hioki Ee Corp | Method and device for inspecting circuit wire |
JP2007335134A (en) * | 2006-06-13 | 2007-12-27 | Hitachi High-Technologies Corp | Scanning electron microscope |
EP2020829A2 (en) | 2007-07-28 | 2009-02-04 | Funai Electric Co., Ltd. | Flourescent tube power supply and backlight |
KR100937039B1 (en) | 2007-11-12 | 2010-01-15 | 한국전자통신연구원 | A Bias Circuit having Compensation Capability for Threshold Voltage and Temperature Variations and Amplifier using the same |
CN114415770A (en) * | 2021-12-22 | 2022-04-29 | 深圳航天科技创新研究院 | Shimming current source device for magnetic resonance equipment |
-
1997
- 1997-04-04 JP JP9086538A patent/JPH10283044A/en active Pending
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005315729A (en) * | 2004-04-28 | 2005-11-10 | Advantest Corp | Direct-current testing device |
WO2005106513A1 (en) * | 2004-04-28 | 2005-11-10 | Advantest Corporation | Direct current test apparatus |
JP2006234401A (en) * | 2005-02-22 | 2006-09-07 | Hioki Ee Corp | Method and device for inspecting circuit wire |
JP4676218B2 (en) * | 2005-02-22 | 2011-04-27 | 日置電機株式会社 | Circuit wiring inspection method and circuit wiring inspection apparatus |
JP2007335134A (en) * | 2006-06-13 | 2007-12-27 | Hitachi High-Technologies Corp | Scanning electron microscope |
JP4719628B2 (en) * | 2006-06-13 | 2011-07-06 | 株式会社日立ハイテクノロジーズ | Scanning electron microscope |
EP2020829A2 (en) | 2007-07-28 | 2009-02-04 | Funai Electric Co., Ltd. | Flourescent tube power supply and backlight |
US7944154B2 (en) | 2007-07-28 | 2011-05-17 | Funai Electric Co., Ltd. | Fluorescent tube power supply and backlight |
KR100937039B1 (en) | 2007-11-12 | 2010-01-15 | 한국전자통신연구원 | A Bias Circuit having Compensation Capability for Threshold Voltage and Temperature Variations and Amplifier using the same |
CN114415770A (en) * | 2021-12-22 | 2022-04-29 | 深圳航天科技创新研究院 | Shimming current source device for magnetic resonance equipment |
CN114415770B (en) * | 2021-12-22 | 2023-11-14 | 深圳航天科技创新研究院 | Shimming current source device for magnetic resonance equipment |
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