JPS6218804A - Power amplifier for electromagnetic proportional control valve - Google Patents
Power amplifier for electromagnetic proportional control valveInfo
- Publication number
- JPS6218804A JPS6218804A JP60157383A JP15738385A JPS6218804A JP S6218804 A JPS6218804 A JP S6218804A JP 60157383 A JP60157383 A JP 60157383A JP 15738385 A JP15738385 A JP 15738385A JP S6218804 A JPS6218804 A JP S6218804A
- Authority
- JP
- Japan
- Prior art keywords
- output
- arithmetic unit
- operational amplifier
- control valve
- comparator
- 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
Landscapes
- Amplifiers (AREA)
- Magnetically Actuated Valves (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、電磁比例制御弁用のパワーアンプに関し、一
層詳細には、電磁弁を構成するソレノイドを駆動するた
めに用いられる温度ドリフトの少ない安定した出力が得
られるパワーアンプに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power amplifier for an electromagnetic proportional control valve, and more particularly to a power amplifier for driving a solenoid that constitutes an electromagnetic valve, which provides a stable output with little temperature drift. Regarding the amplifier.
従来から、電流の大きさによって空気の流量や圧力を無
段階に制御するものとして電磁比例制御弁が多数採用さ
れるに至っている。電磁比例制御弁はその内部に比例ソ
レノイドを組み込んでいる。この比例ソレノイドは有効
ストロークの範囲内では励磁電流に対する吸引力が一定
となる特性を有する。従って、電磁比例制御弁は比例ソ
レノイドの吸引力がその励磁電流の大きさに比例すると
いう関係を利用して、空気流量・圧力の制御を行う。BACKGROUND ART Conventionally, many electromagnetic proportional control valves have been used to steplessly control the flow rate and pressure of air depending on the magnitude of electric current. The electromagnetic proportional control valve incorporates a proportional solenoid inside it. This proportional solenoid has a characteristic that the attraction force against the exciting current is constant within the range of the effective stroke. Therefore, the electromagnetic proportional control valve controls the air flow rate and pressure by utilizing the relationship that the attraction force of the proportional solenoid is proportional to the magnitude of its excitation current.
一般的に、電磁比例制御弁ではソレノイドを イ駆動
してシリンダ等のストロークの制御をする 目ために
励磁コイルに対して頻繁に通電する。こ りの結果、
当該励磁コイル自体が発熱し、あるい がは、電磁比
例制御弁の周囲の温度変化が惹起し、さらには弁内を還
流する流体温度の変化に起因 ソして前記励磁コイル
のインピーダンスが大きく え変わる。このために、
励磁電流が大きく変化す フることになり、これが比
例ソレノイドの出力の こ変化として顕れる。すなわ
ち、励磁コイルに定 ルミ圧を印加するだけでは、所
望の空気流量、あ 這るいは、圧力の制御が達成され
ず、安定性並び １に再現性を欠く不都合を露呈する
。 ａそこで、該る欠点を除去するため
に、ソレノ フィト駆動用のパワーアンプに帰還回路
を用いる 背解決策が当然考慮されてくる。然しなか
ら、こ ての場合、帰還回路として差動増幅器を組み
込むと、当該増幅器自体を構成する抵抗の抵抗値の
騒ばらつき、あるいは、温度係数の相違から温度 負
ドリフトにより帰還精度が低下するという別の １、
都合が顕れてくる。すなわち、これらのこと、ソレノイ
ドを構成する励磁電流の変化とな、結局、設定された弁
自体の位置制御が不安“となり、また、再現性を欠くこ
とを意味する。Generally, in electromagnetic proportional control valves, the excitation coil is frequently energized to control the stroke of the cylinder, etc. by driving the solenoid. As a result of stiffness,
The excitation coil itself generates heat, or the impedance of the excitation coil increases due to changes in the temperature around the electromagnetic proportional control valve, and furthermore due to changes in the temperature of the fluid circulating inside the valve. change. For this,
This results in a large change in the excitation current, which manifests itself as a change in the output of the proportional solenoid. In other words, simply applying a constant luminous pressure to the excitation coil does not achieve the desired control of air flow rate, air flow, or pressure, which exposes the disadvantage of lack of stability and reproducibility. Therefore, in order to eliminate this drawback, a solution that uses a feedback circuit in the power amplifier for driving the solenoid is naturally considered. However, in this case, if a differential amplifier is incorporated as a feedback circuit, the resistance value of the resistor that makes up the amplifier itself will be
Another problem is that feedback accuracy decreases due to noise variations or negative temperature drift due to differences in temperature coefficients.
Convenience will emerge. In other words, due to these changes in the excitation current constituting the solenoid, the set position control of the valve itself becomes unstable and lacks reproducibility.
この不都合を解決する手段としては、特に、レノイドを
駆動する信号を帰還用の差動増幅を介することなく、直
接、入力側のオペアン゛に帰還させる構成が考えられる
。然しなから、の方式によれば、帰還用抵抗はオペアン
プの転入力端子に接続されているために、前記帰用抵抗
の後に生じる電位はオペアンプ駆動用、源から供給され
る電位に対し負の電位となる要がある。このために、実
際上は、オペアン□を駆動する電源とは別異の電源系を
接続し、運用抵抗に係る電位が負となるように構成しい
る。As a means to solve this problem, it is particularly possible to have a configuration in which the signal that drives the lenoid is directly fed back to the input side operational amplifier without going through a differential amplification for feedback. However, according to the method, since the feedback resistor is connected to the inverting input terminal of the operational amplifier, the potential generated after the feedback resistor is negative with respect to the potential supplied from the source for driving the operational amplifier. It is necessary to have a potential. For this reason, in practice, a power supply system different from the power supply for driving the operational amplifier □ is connected, so that the potential related to the operational resistance becomes negative.
すなわち、前記のような構成ではオペアンプ動用の電源
と帰還用抵抗の後に生じる電位を電位に保持するための
パワー出力用電源の二の直流電源系を用意しなければな
らない。このことは、回路構成自体を複雑化すると共に
、特に、基板等を用いて電磁比例制御弁の制御系を小型
化しようとする要請に沿えないという不都合を生じる。That is, in the above configuration, it is necessary to prepare two DC power supply systems: a power supply for operating the operational amplifier and a power output power supply for maintaining the potential generated after the feedback resistor at the potential. This results in the inconvenience of complicating the circuit configuration itself and, in particular, not being able to meet the demand for miniaturizing the control system of the electromagnetic proportional control valve using a board or the like.
本発明は前記の不都合を克服するためになされたもので
あって、単一の直流電源によってオペアンプを駆動する
と共にフィードバック系からの帰還信号の電位を負電位
に保持し、しかも温度ドリフトが少なく、従って、動作
の安定した電磁比例制御弁に好適に用いられるパワーア
ンプを提供することを目的とする。The present invention has been made to overcome the above-mentioned disadvantages, and it drives an operational amplifier with a single DC power supply, maintains the potential of the feedback signal from the feedback system at a negative potential, and has little temperature drift. Therefore, it is an object of the present invention to provide a power amplifier suitable for use in an electromagnetic proportional control valve with stable operation.
前記の目的を達成するために、本発明は単一の直流電源
と、第１の線形演算器と、この第１線形演算器の出力側
に接続される比較器と、前記比較器に出力信号を送給す
る関数発生器と、前記比較器の出力側に接続されて電磁
比例制御弁を構成するソレノイドを駆動する出力部と、
この出力部からの出力信号を受け前記第１線形演算器に
帰還信号を送る第２の線形演算器とがらなり、少なくと
も、前記第１線形演算器Ｑこ接続される雰点澗整器と、
関数発生器に接続される周期調整器と第２線形演算器と
に前記直流電源から送給される共通の電圧を印加して付
勢するよう構成することを特徴とする。To achieve the above object, the present invention includes a single DC power supply, a first linear arithmetic unit, a comparator connected to the output side of the first linear arithmetic unit, and an output signal to the comparator. a function generator that supplies a function generator, and an output section that is connected to the output side of the comparator and drives a solenoid that constitutes an electromagnetic proportional control valve;
a second linear arithmetic unit that receives the output signal from the output unit and sends a feedback signal to the first linear arithmetic unit;
The present invention is characterized in that a common voltage supplied from the DC power source is applied to the period adjuster and the second linear arithmetic unit connected to the function generator to energize them.
次に、本発明に係る電磁比例制御弁のパワーアンプにつ
いて好適な実施例を挙げ、添付の図面を参照しながら以
下詳細に説明する。Next, preferred embodiments of a power amplifier for an electromagnetic proportional control valve according to the present invention will be described in detail with reference to the accompanying drawings.
第１図において、参照符号工０は本発明に係る電磁比例
制御弁を構成するソレノイド駆動用の制御回路を示す。In FIG. 1, reference symbol 0 indicates a control circuit for driving a solenoid constituting an electromagnetic proportional control valve according to the present invention.
前記制御回路１０は、基本的には電源回路１２）関数発
生器１４、第１の線形演算器１６、第２の線形演算器１
８、比較器２０および出力部２２とから構成される。電
源回路１２には、この場合、例えば、＋２４■の電圧を
導入し、出力側にはＧＮＤ端子１２ａ、−１８■の出力
を供給する端子１２ｂ、−８Ｖの出力を供給する端子１
２ｃおよび一２４Ｖの出力電圧を供給する端子１２ｄを
設けておく。これらの端子１２ａ、１２ｂ、１２Ｃおよ
び１２ｄは破線で囲繞された関数発生器１４、線形演算
器１６．１８および比較器２０を一体的にモジュール化
した回路に設けられた端子に接続する。The control circuit 10 basically includes a power supply circuit 12) a function generator 14, a first linear arithmetic unit 16, and a second linear arithmetic unit 1.
8, a comparator 20 and an output section 22. In this case, for example, a voltage of +24■ is introduced into the power supply circuit 12, and the output side includes a GND terminal 12a, a terminal 12b that supplies an output of -18V, and a terminal 1 that supplies an output of -8V.
A terminal 12d for supplying an output voltage of 2c and -24V is provided. These terminals 12a, 12b, 12C and 12d are connected to terminals provided in a circuit in which the function generator 14, linear arithmetic units 16, 18 and comparator 20 are integrally modularized, which are surrounded by broken lines.
次に、前記第１線形演算器１６はオペアンプ１６ａを含
み、前記オペアンプ１６ａの一方の入力端子には利得調
整器２４の出力端子を接続し、なお、前記利得調整器２
４は一方において制御信号の入力端子となる。可変抵抗
を含む零点調整器２６の出力側は前記オペアンプ１６ａ
の反転入力端子に接続され、また、周期調整器２８の出
力側は前記関数発生器１４を構成するオペアンプ１４ａ
の反転入力端子に接続する。Next, the first linear arithmetic unit 16 includes an operational amplifier 16a, and one input terminal of the operational amplifier 16a is connected to the output terminal of a gain adjuster 24.
4 serves as an input terminal for a control signal on one side. The output side of the zero point regulator 26 including a variable resistor is connected to the operational amplifier 16a.
The output side of the period adjuster 28 is connected to the inverting input terminal of the operational amplifier 14a constituting the function generator 14.
Connect to the inverting input terminal of
ところで、前記第１線形演算器１６を構成するオペアン
プ１６ａの出力側は比較器２０を構成するアンプ２０ａ
の一方の入力端子に接続され、なお、この入力端子には
関数発生器１４の出力側も接続されている。一方、前記
アンプ２０ａの非反転入力端子には抵抗Ｒ，、Ｒ２が接
続され、且つ、この比較器２０の出力側はその出力信号
によって通断するスイッチングトランジスタＴｒ、に接
続される。前記トランジスタＴｒ、の出力側はモジュー
ルの外部に外付けされている。By the way, the output side of the operational amplifier 16a forming the first linear arithmetic unit 16 is connected to the amplifier 20a forming the comparator 20.
The output side of the function generator 14 is also connected to this input terminal. On the other hand, resistors R, R2 are connected to the non-inverting input terminal of the amplifier 20a, and the output side of the comparator 20 is connected to a switching transistor Tr, which is turned on or off by the output signal thereof. The output side of the transistor Tr is externally connected to the outside of the module.
前記出力部２２は、図から容易に諒解されるように、実
質的にはスイッチングトランジスタＴｒｚとパワートラ
ンジスタＴｒ３とから構成されており、その出力側は電
流検出用抵抗Ｒ３と電磁比例制御弁のソレノイド３０に
接続されている。As can be easily understood from the figure, the output section 22 is substantially composed of a switching transistor Trz and a power transistor Tr3, and its output side is connected to a current detection resistor R3 and a solenoid of an electromagnetic proportional control valve. 30.
なお、この場合、電流検出用抵抗Ｒ３はモジュール内部
の第２″ｆＬｆＡ形演算器１８を構成するオペアンプ１
８ａの反転入力端子と非反転入力端子とに夫々接続され
ており、前記の通り、この第２線形演算器１８の出力側
は前記第１線形演算器１６を構成するオペアンプ１６ａ
の非反転入力端子に接続さている。In this case, the current detection resistor R3 is connected to the operational amplifier 1 constituting the second fLfA type arithmetic unit 18 inside the module.
As mentioned above, the output side of this second linear arithmetic unit 18 is connected to the inverting input terminal and non-inverting input terminal of the second linear arithmetic unit 16, respectively.
is connected to the non-inverting input terminal of
本発明に係る電磁比例制御弁のパワーアンプは基本的に
は以上のように構成されるものであり、次にその作用並
びに効果について説明する。The power amplifier of the electromagnetic proportional control valve according to the present invention is basically constructed as described above, and its operation and effects will be explained next.
前記の通り、電源回路１２には＋２４Ｖの直流電圧が供
給されて、−２４■、−１８■および一８Ｖの出力を得
る。前記−２４Ｖの出力電圧は出力部２２を構成するト
ランジスタＴｒ、のエミッタ側に印加する。一方、前記
−１８Ｖの出力電圧は零点調整器２６、周期調整器２８
、第２線形演算器１日に印加される。すなわち、零点調
整器２６に印加される前記−１８Ｖの電圧は関数発生δ
１４を構成するオペアンプ１４ａのオフセット電圧を調
整する役割を果たす。一方、第２線形演算器１８はこれ
に印加される一１８Ｖの電源電圧によって駆動されるよ
うに構成している。すなわち、前記の説明から明らかな
通り、この発明では、特に、零点調整器２６、周期調整
器２８およびオペアンプ１８への電源を夫々に共通に一
１８Ｖが印加されるように構成している。このようにす
ることによって電源系をより筒素化出来る。As mentioned above, the power supply circuit 12 is supplied with a DC voltage of +24V and obtains outputs of -24V, -18V and -8V. The -24V output voltage is applied to the emitter side of the transistor Tr constituting the output section 22. On the other hand, the output voltage of -18V is determined by the zero point regulator 26 and the period regulator 28.
, is applied to the second linear arithmetic unit 1. That is, the voltage of -18V applied to the zero point adjuster 26 is the function generation δ
It plays a role of adjusting the offset voltage of the operational amplifier 14a that constitutes the operational amplifier 14. On the other hand, the second linear arithmetic unit 18 is configured to be driven by a power supply voltage of -18V applied thereto. That is, as is clear from the above description, in the present invention, in particular, the power supply to the zero point adjuster 26, the period adjuster 28, and the operational amplifier 18 is configured so that -18V is applied in common to each of them. By doing so, the power supply system can be made more cylindrical.
そこで、以上のような設定状態において、利得調整器２
４を調整してその目標値を選択し、一方、零点調整器２
６を調整してオペアンプ１６ａのオフセット電圧を決定
し、電磁比例制御弁にバイアス電流を流すことが出来る
。従って、前記オペアンプ１６ａからは利得調整器２４
の出力信号、零点調整器２６の出力信号および第２線形
演算器１８のオペアンプ１８ａの出力信号の和に相当す
る信号が比較器２０に出力される。Therefore, in the above setting state, the gain adjuster 2
4 to select its target value, while zero point adjuster 2
6 to determine the offset voltage of the operational amplifier 16a, allowing a bias current to flow through the electromagnetic proportional control valve. Therefore, from the operational amplifier 16a, the gain adjuster 24
A signal corresponding to the sum of the output signal of , the output signal of the zero point adjuster 26 and the output signal of the operational amplifier 18a of the second linear arithmetic unit 18 is output to the comparator 20.
一方、−１８Ｖの電圧を印加される周期調整器２日の出
力信号は関数発生器１４を構成するオペアンプ１４ａの
一方の入力端子に導入され、また、前記オペアンプ１４
ａの他方の入力端子には電源回路１２からの一８■に係
る基準電圧が印加される。これによって、関数発生器１
４では、例えば、−８Ｖ乃至−３■の振幅の範囲内で鋸
歯状波を発生し、この鋸歯状波は比較器２０を構成する
オペアンプ２０ａに導入される。前記の通り、比較器２
０の反転入力端子には第１線形演算器１６の出力信号が
導入されるように構成されており、結局、この反転入力
端子には前記関数発生器１４の出力信号と第１線形演算
器１６の出力信号との和の信号が導入される。この信号
は、前記比較器２０の非反転入力端子側に接続された抵
抗Ｒ１、Ｒ２および比較器の出力レベルによって決定さ
れる基準電圧Ｖｏ 、ＶＬ （Ｖｌｌ ＞ ＶＬ ）
と比較され、基準電圧■、よりも高い場合には低レベル
信号りを出力し、一方、基準電圧ＶＬよりもなことは勿
論である。On the other hand, the output signal of the period adjuster 2nd to which a voltage of -18V is applied is introduced into one input terminal of the operational amplifier 14a constituting the function generator 14.
A reference voltage from the power supply circuit 12 is applied to the other input terminal of a. This allows function generator 1
4, a sawtooth wave is generated within the amplitude range of -8V to -3V, for example, and this sawtooth wave is introduced into the operational amplifier 20a forming the comparator 20. As mentioned above, comparator 2
0 is configured so that the output signal of the first linear arithmetic unit 16 is introduced into the inverting input terminal, and as a result, the output signal of the function generator 14 and the first linear arithmetic unit 16 are input to this inverting input terminal. A signal that is the sum of the output signal of is introduced. This signal is a reference voltage Vo, VL (Vll > VL) determined by the resistors R1 and R2 connected to the non-inverting input terminal side of the comparator 20 and the output level of the comparator.
It is compared with the reference voltage VL, and if it is higher than the reference voltage VL, a low level signal is output.On the other hand, it is of course higher than the reference voltage VL.
４８図面のＮｊｉｌな説明
第１図は本発明に係る電磁比例制御弁のソレノイドを駆
動制御するためのブロック図、第２図は第１図のブロッ
ク図の内容を詳細に説明する回路図である。Figure 1 is a block diagram for driving and controlling the solenoid of the electromagnetic proportional control valve according to the present invention, and Figure 2 is a circuit diagram explaining in detail the contents of the block diagram in Figure 1. .
Claims (2)
１線形演算器の出力側に接続される比較器と、前記比較
器に出力信号を送給する関数発生器と、前記比較器の出
力側に接続されて電磁比例制御弁を構成するソレノイド
を駆動する出力部と、この出力部からの出力信号を受け
前記第１線形演算器に帰還信号を送る第２の線形演算器
とからなり、少なくとも、前記第１線形演算器に接続さ
れる零点調整器と、関数発生器に接続される周期調整器
と第２線形演算器とに前記直流電源から送給される共通
の電圧を印加して付勢するよう構成することを特徴とす
る電磁比例制御弁用パワーアンプ。(1) a single DC power supply, a first linear arithmetic unit, a comparator connected to the output side of the first linear arithmetic unit, and a function generator that sends an output signal to the comparator; an output section that is connected to the output side of the comparator and drives a solenoid constituting an electromagnetic proportional control valve; and a second linear operation that receives an output signal from the output section and sends a feedback signal to the first linear operation unit. and at least a zero point adjuster connected to the first linear arithmetic unit, a period adjuster connected to the function generator, and a second linear arithmetic unit, a common voltage supplied from the DC power supply. A power amplifier for an electromagnetic proportional control valve, characterized in that it is configured to be energized by applying a voltage.
て、第１線形演算器、第２線形演算器、比較器および関
数発生器を単一のモジュールに組み込んでなる電磁比例
制御弁用パワーアンプ。(2) A power amplifier according to claim 1, for an electromagnetic proportional control valve, comprising a first linear arithmetic unit, a second linear arithmetic unit, a comparator, and a function generator incorporated into a single module. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60157383A JPH0779212B2 (en) | 1985-07-17 | 1985-07-17 | Power amplifier for solenoid proportional control valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60157383A JPH0779212B2 (en) | 1985-07-17 | 1985-07-17 | Power amplifier for solenoid proportional control valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6218804A true JPS6218804A (en) | 1987-01-27 |
| JPH0779212B2 JPH0779212B2 (en) | 1995-08-23 |
Family
ID=15648444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60157383A Expired - Lifetime JPH0779212B2 (en) | 1985-07-17 | 1985-07-17 | Power amplifier for solenoid proportional control valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0779212B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0337511U (en) * | 1989-08-24 | 1991-04-11 | ||
| JPH0622706U (en) * | 1992-08-07 | 1994-03-25 | 東芝エンジニアリング株式会社 | Automatic cleanup device |
| WO2004040113A1 (en) * | 2002-10-30 | 2004-05-13 | Mikuni Corporation | Fuel injection method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5614668A (en) * | 1979-07-17 | 1981-02-12 | Japan Electronic Control Syst Co Ltd | Current controller for solenoid valve |
| JPS5642775A (en) * | 1979-09-11 | 1981-04-21 | Nippon Denso Co Ltd | Driver for solenoid valve |
| JPS56160111A (en) * | 1980-04-17 | 1981-12-09 | Sony Corp | Amplifier of pulse duration modulated signal |
| JPS57186768U (en) * | 1981-05-23 | 1982-11-26 | ||
| JPS5943760U (en) * | 1982-09-16 | 1984-03-22 | 三菱重工業株式会社 | Solenoid valve control circuit |
| JPS59182715U (en) * | 1983-05-19 | 1984-12-05 | 株式会社 鷺宮製作所 | Solenoid proportional valve control device |
-
1985
- 1985-07-17 JP JP60157383A patent/JPH0779212B2/en not_active Expired - Lifetime
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5614668A (en) * | 1979-07-17 | 1981-02-12 | Japan Electronic Control Syst Co Ltd | Current controller for solenoid valve |
| JPS5642775A (en) * | 1979-09-11 | 1981-04-21 | Nippon Denso Co Ltd | Driver for solenoid valve |
| JPS56160111A (en) * | 1980-04-17 | 1981-12-09 | Sony Corp | Amplifier of pulse duration modulated signal |
| JPS57186768U (en) * | 1981-05-23 | 1982-11-26 | ||
| JPS5943760U (en) * | 1982-09-16 | 1984-03-22 | 三菱重工業株式会社 | Solenoid valve control circuit |
| JPS59182715U (en) * | 1983-05-19 | 1984-12-05 | 株式会社 鷺宮製作所 | Solenoid proportional valve control device |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0337511U (en) * | 1989-08-24 | 1991-04-11 | ||
| JPH0622706U (en) * | 1992-08-07 | 1994-03-25 | 東芝エンジニアリング株式会社 | Automatic cleanup device |
| WO2004040113A1 (en) * | 2002-10-30 | 2004-05-13 | Mikuni Corporation | Fuel injection method |
| US7309025B2 (en) | 2002-10-30 | 2007-12-18 | Mikuni Corporation | Fuel injection method |
| CN100400834C (en) * | 2002-10-30 | 2008-07-09 | 株式会社三国 | Fuel injection method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0779212B2 (en) | 1995-08-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2674876B2 (en) | Adjusting branch power supply | |
| JPH0424611A (en) | Liquid crystal display device with automatic contrast adjusting function | |
| KR19980064252A (en) | Low Dropout Voltage Regulator with PMOS Pass Element | |
| KR920017329A (en) | Adaptive voltage regulator | |
| JPH04172991A (en) | Current control circuit | |
| KR970010485B1 (en) | Multiple output circuit of lamp for projection tv. | |
| JPS6218804A (en) | Power amplifier for electromagnetic proportional control valve | |
| KR890000611B1 (en) | Electro-pneumatic control systems | |
| JPH06174489A (en) | Temperature compensating circuit | |
| US5907260A (en) | Differential amplifying circuit | |
| JP3345339B2 (en) | Dual tracking circuit | |
| JP2502627B2 (en) | Heater control device | |
| JPH0227622Y2 (en) | ||
| JP2001117068A (en) | Power source circuit for liquid crystal | |
| SU1188866A1 (en) | Sawtooth voltage generator | |
| JP2982175B2 (en) | Motor speed control device | |
| JP2005156161A (en) | Heater control circuit | |
| JPS63195713A (en) | Constant voltage/current control device | |
| KR200149733Y1 (en) | Voltage controlling circuit of serial stabilizing power supply | |
| JPH0630418B2 (en) | Reversal current output device | |
| JP2722769B2 (en) | Gain control circuit | |
| JPS62152203A (en) | Power amplifier for driving proportional solenoid valve | |
| JPS6283570A (en) | Control device for opening of electromagnetic valve | |
| US5504380A (en) | Method and apparatus for controlling a current generator | |
| JPH01103702A (en) | Turning-on/off regulator |