JP3134169B2 - Fail safe circuit - Google Patents
Fail safe circuitInfo
- Publication number
- JP3134169B2 JP3134169B2 JP04128770A JP12877092A JP3134169B2 JP 3134169 B2 JP3134169 B2 JP 3134169B2 JP 04128770 A JP04128770 A JP 04128770A JP 12877092 A JP12877092 A JP 12877092A JP 3134169 B2 JP3134169 B2 JP 3134169B2
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- JP
- Japan
- Prior art keywords
- circuit
- voltage
- power supply
- fail
- transistor
- 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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Description
【０００１】[0001]
【産業上の利用分野】本発明は、パルスで駆動する負荷
を有する機器の故障時に、その機器に安全性をもたせる
フェールセーフ回路に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fail-safe circuit for providing safety to a device having a pulse-driven load when the device fails.
【０００２】[0002]
【従来の技術】従来の技術の例を図４を用いて説明す
る。パルスポンプ等に代表されるソレノイドコイル構成
の負荷４１は、商用電源４２に、商用電源４２の二線間
の不平均電流を検出した場合に機器への電源供給を遮断
する漏電遮断器４３を介して接続された、パルス電圧を
発生するパルス電源発生回路４４の出力により動作する
もので、パルスのＨｉ期間にコイルを励磁し、コイル中
央に配設したプランジャー（図示せず）を押し上げ、パ
ルスのＬｏｗ期間にコイルの励磁を停止することで、プ
ランジャーにピストン運動をさせ、油等を汲み上げる機
能をもたせている。2. Description of the Related Art An example of a conventional technique will be described with reference to FIG. A load 41 having a solenoid coil configuration typified by a pulse pump or the like is supplied to a commercial power supply 42 via an earth leakage breaker 43 that shuts off power supply to a device when an average current between two wires of the commercial power supply 42 is detected. The coil operates during the Hi period of the pulse and pushes up a plunger (not shown) disposed at the center of the coil, thereby generating a pulse voltage. By stopping the excitation of the coil during the Low period, the plunger is caused to perform a piston motion to pump oil or the like.
【０００３】このようなソレノイドコイル構成の負荷４
１は、通電される期間がパルスのＨｉ期間に限られるた
め、低コスト化を図る意味より、ポンプ能力の均一化を
図るために、コイルに流す電流を調整するコイルに直列
に接続された補正抵抗の発熱限界は、正規のパルスが印
加された場合に定格を越えない、つまり故障したり損焼
しない値に設計されている場合が多く、負荷に供給する
パルス電源発生回路４４の故障等で、負荷に連続でＨｉ
電圧が印加され続けた場合に発生する故障や焼損を防ぐ
ため、パルス電源発生回路４４と負荷４１の間に電流ヒ
ューズ４５を設けていた。The load 4 having such a solenoid coil configuration
1 is a correction that is connected in series with a coil that adjusts a current flowing through the coil in order to make pump performance uniform, in order to reduce cost because the period of energization is limited to the Hi period of the pulse. The heat generation limit of the resistor is often designed to a value that does not exceed the rating when a regular pulse is applied, that is, does not cause a failure or burnout. And Hi to the load continuously
A current fuse 45 is provided between the pulse power supply generation circuit 44 and the load 41 in order to prevent a failure or burning caused when the voltage is continuously applied.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、このよ
うなパルス電源発生回路４４と負荷４１の間に電流ヒュ
ーズ４５を設けることによる負荷４１への電源を遮断す
る方式においては、定常時動作する電流で電流ヒューズ
４５が切れることなく、故障時に溶断する電流ヒューズ
４５の値を決定することが、負荷４１に定常時流れる電
流と、故障時流れる電流の差が電流ヒューズ４５自体の
溶断電流のばらつきに対し、余裕がないために、通常動
作時に電流ヒューズ４５が溶断する誤動作や、故障時に
電流ヒューズ４５が溶断しないといった誤動作が発生す
る問題があった。However, in such a system in which the power supply to the load 41 is cut off by providing the current fuse 45 between the pulse power supply generating circuit 44 and the load 41, a current which operates in a steady state is used. Determining the value of the current fuse 45 that blows at the time of failure without the current fuse 45 being blown depends on the difference between the current that flows in the load 41 in the steady state and the current that flows at the time of the failure with respect to the variation in the blowing current of the current fuse 45 itself. Since there is no margin, there is a problem that a malfunction occurs in which the current fuse 45 is blown during a normal operation, and a malfunction occurs such that the current fuse 45 is not blown in a failure.
【０００５】本発明の目的は、上記従来技術の課題を解
決し、より故障検出精度が高く、安価で安全に機器の停
止を図ることのできるフェールセーフ回路を提供するこ
とにある。An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a fail-safe circuit which has higher failure detection accuracy, can stop the device safely at low cost.
【０００６】[0006]
【課題を解決するための手段】この目的を達成するため
本発明のフェールセーフ回路は、商用電源と、前記商用
電源の二線間の不平衡電流を検出した場合に機器への電
源供給を遮断する漏電遮断器と、前記漏電遮断器の二次
側の一方をグランドとしたパルス電源発生回路と、前記
パルス電源発生回路と並列に接続した積分回路と、前記
積分回路の電圧が所定の電圧を越えた場合に、前記漏電
遮断器の一次側の二線の一方から二次側の前記グランド
に対して不平衡電流を流すスイッチ回路から構成される
ものである。Means for Solving the Problems] fail safe circuit of the present invention to achieve this object, a commercial power supply, to the device when detecting an unbalanced current between the two lines of the commercial <br/> power Earth leakage breaker for interrupting the supply of power, a pulse power generation circuit having one of the secondary sides of the earth leakage breaker as ground, an integration circuit connected in parallel with the pulse power generation circuit, and a voltage of the integration circuit. If but it exceeds a predetermined voltage, the ground one from the secondary side of the primary side of the two-wire of the earth leakage breaker
And a switch circuit for supplying an unbalanced current to the switch.
【０００７】[0007]
【作用】本発明は上記した構成により、パルス電源発生
回路の負荷に並列に接続した積分回路により素早く検出
でき、前記積分回路の電圧がパルス電源発生回路等の故
障時に連続Ｈｉ電圧が出力された場合に上昇し、所定電
圧以上となってスイッチ回路が動作することで、漏電遮
断器の一次側の電流を二次側にバイパスして流すことに
より、前記漏電遮断器に電流の不平衡を発生させ、前記
漏電遮断器が動作することで機器への電源供給を遮断
し、機器の停止を行うものである。DETAILED DESCRIPTION OF THE INVENTION The present invention with the configuration described above, quickly detected by the integration circuit connected in parallel to the load pulse power generating circuit
Can, rises when the continuous Hi voltage at the time of failure such as a voltage Gapa pulse power generating circuit of the integrating circuit is output, when the switch circuit operates becomes a predetermined voltage or more, the earth leakage breaker of the primary side by flowing bypassing the current to the secondary side, the generate an unbalanced current to the earth leakage breaker, and cut off the power supply to the device by the <br/> earth leakage breaker operates, the device This is to stop.
【０００８】[0008]
【実施例】以下、本発明の一実施例のフェールセーフ回
路について図１、図２、図３を参照しながら説明する。
図１は本発明の一実施例のフェールセーフ回路のブロッ
ク図で、１は商用電源、２は商用電源１に並列に接続さ
れた漏電遮断器、３は漏電遮断器２の負荷側に接続され
た負荷及び積分回路にパルス電源を供給するパルス電源
発生回路、４はパルス電源発生回路３の出力を積分する
積分回路で、５は積分回路４で充放電された電圧が所定
電圧を越えた場合に、漏電遮断器２の一次側の二線の一
方と二次側の二線の一方との間に不平衡電流を流すスイ
ッチ回路、６はパルス電源発生回路３が出力するパルス
電源で動作する負荷、７は漏電遮断器２の一次側の二線
の一方、８は漏電遮断器２の二次側の一方を示す。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fail-safe circuit according to one embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a block diagram of a fail-safe circuit according to an embodiment of the present invention. 1 is a commercial power supply, 2 is a ground fault interrupter connected in parallel to the commercial power source 1 , and 3 is connected to the load side of the ground fault breaker 2. A pulse power generation circuit for supplying pulsed power to the load and the integration circuit, 4 is an integration circuit for integrating the output of the pulse power generation circuit 3, and 5 is when the voltage charged and discharged by the integration circuit 4 exceeds a predetermined voltage. A switch circuit for flowing an unbalanced current between one of the two primary wires of the earth leakage breaker 2 and one of the two secondary wires, and 6 is an output of the pulse power generation circuit 3. load operating at a pulse power source for, 7 one of the primary side of the two-wire fault interrupter 2, 8 denotes one of the secondary side of the earth leakage circuit breaker 2.
【０００９】図２は図１のブロック図における各ブロッ
クを実際の回路に応用した詳細回路図である。ただし、
漏電遮断器の内部回路については本発明に関し直接関係
がないため詳細な回路説明は省略する。FIG. 2 is a detailed circuit diagram in which each block in the block diagram of FIG. 1 is applied to an actual circuit. However,
Since the internal circuit of the earth leakage breaker is not directly related to the present invention, a detailed circuit description is omitted.
【００１０】漏電遮断器２の二次側交流をダイオード
９、抵抗Ｒ１、コンデンサ１０で半波整流し直流電圧に
変換し、フォトカプラ１１のオフ時にトランジスタ１２
をオンし、その結果トランジスタ１３をオンすること
で、直流電源を負荷に供給する。抵抗Ｒ５、Ｒ６、トラ
ンジスタ１４は負荷６に供給する電圧調整回路で、抵抗
Ｒ５、Ｒ６の値を負荷の定格電圧発生時にトランジスタ
１４をオンできる電圧（この場合約０．７Ｖ）に分圧す
るよう設定しておくと、トランジスタ１３の出力電圧が
所定電圧発生時にトランジスタ１４がオンし、トランジ
スタ１３のベース電流を減少させてトランジスタ１３の
出力電圧をおさえる動作となり、負荷への定電圧供給が
可能となる。フォトカプラ１１のオン時はトランジスタ
１２がオフとなりトランジスタ１３もオフ、従って負荷
６への電圧供給は停止する。The secondary AC of the earth leakage breaker 2 is half-wave rectified by a diode 9, a resistor R1, and a capacitor 10 and converted into a DC voltage.
Is turned on, and as a result, the transistor 13 is turned on, thereby supplying DC power to the load. The resistors R5 and R6 and the transistor 14 are voltage adjusting circuits for supplying the load 6. The resistors R5 and R6 are set to divide the value of the resistors R5 and R6 to a voltage (about 0.7 V in this case) that can turn on the transistor 14 when a rated voltage of the load is generated. By doing so, the transistor 14 is turned on when the output voltage of the transistor 13 generates a predetermined voltage, the operation of reducing the base current of the transistor 13 to suppress the output voltage of the transistor 13, and the constant voltage can be supplied to the load. . When the photocoupler 11 is turned on, the transistor 12 is turned off and the transistor 13 is turned off, so that the voltage supply to the load 6 is stopped.
【００１１】上記の通り、フォトカプラ１１のオン・オ
フにより負荷へのパルス電圧供給を行うものとなる。以
上の構成が図１におけるパルス電源発生回路３に相当す
る。As described above, the pulse voltage is supplied to the load by turning on / off the photocoupler 11. The above configuration corresponds to the pulse power generation circuit 3 in FIG.
【００１２】抵抗Ｒ７、Ｒ８、コンデンサ１５はパルス
電源発生回路３の出力を充放電する図１中の積分回路４
に相当する。パルス電源発生回路３のパルスＨｉ期間に
コンデンサ１５とＲ７の時定数で充電し、パルス電源発
生回路３のパルスＬｏｗ期間にコンデンサ１５とＲ８及
びコンデンサ１５とＲ７・負荷６の抵抗分の時定数で放
電する。The resistors R7 and R8 and the capacitor 15 charge and discharge the output of the pulse power supply generating circuit 3 and the integrating circuit 4 in FIG.
Is equivalent to The pulse power generation circuit 3 is charged with the time constant of the capacitor 15 and R7 during the pulse Hi period, and the pulse power generation circuit 3 is charged with the time constant of the resistance of the capacitors 15 and R8 and the resistance of the capacitor 15 and R7 and the load 6 during the pulse Low period. Discharge.
【００１３】ツェナーダイオード１６、トランジスタ１
７、抵抗Ｒ９、抵抗Ｒ１０は、図１中のスイッチ回路５
に相当する。ツェナーダイオード１６は、トランジスタ
１７のスレショルドレベルを設定するもので、ツェナー
ダイオード１６のオン時に、トランジスタ１７をオンと
し、漏電遮断器２の一次側二線中の一方７から抵抗Ｒ１
０を介して電流を漏電遮断器２の二次側二線中の一方８
に流すことで、漏電遮断器２の二線間に電流の不平衡現
象を発生させ、機器への電源供給を停止するものであ
る。[0013] Zener diode 16, transistor 1
7, the resistor R9 and the resistor R10 are connected to the switch circuit 5 in FIG.
Is equivalent to The Zener diode 16 sets the threshold level of the transistor 17. When the Zener diode 16 is turned on, the transistor 17 is turned on, and the resistor R1 is connected from one of the two primary wires of the earth leakage breaker 2 to the resistor R1.
0 through one of the two secondary lines of the earth leakage breaker 2
The current unbalance between the two wires of the earth leakage breaker 2
An elephant is generated, and the power supply to the device is stopped.
【００１４】なおツェナダイオード１６のかわりに、抵
抗を使用し、抵抗Ｒ９との分圧比をトランジスタ１７の
スレッショルドレベルに調整しても同等の動作をさせる
ことも可能である。The same operation can be performed by using a resistor instead of the Zener diode 16 and adjusting the voltage dividing ratio with the resistor R9 to the threshold level of the transistor 17.
【００１５】図３は図２の各部の電圧波形、及び回路部
品の動作図で、図３を用いて、本発明のフェールセーフ
回路の動作について説明する。FIG. 3 is a diagram showing the voltage waveform of each part in FIG. 2 and the operation of the circuit components. The operation of the fail-safe circuit of the present invention will be described with reference to FIG.
【００１６】定常動作において、Ｔ１からＴ２にかけて
パルス電源発生回路３の出力すなわち図２中の（ａ）は
Ｈｉとなり、積分回路４のコンデンサ１５の電圧は、抵
抗Ｒ７との時定数で上昇するが、Ｔ２からＴ３にかけて
パルス電源発生回路３の出力Ｌｏｗ期間で、コンデンサ
１５とＲ８及びコンデンサ１５とＲ７・負荷６の抵抗分
の時定数で放電するため積分回路出力すなわち図２中の
（ｂ）の電圧値は、ＶＤ（ツェナダイオード１６のスレ
ッショルド電圧）以下のため、トランジスタ１７はオフ
を保持する。In the normal operation, the output of the pulse power generation circuit 3, that is, (a) in FIG. 2 becomes Hi from T1 to T2, and the voltage of the capacitor 15 of the integration circuit 4 rises with the time constant of the resistance R7. , T2 to T3, during the output Low period of the pulse power generation circuit 3, the discharge is performed with the time constants of the resistors of the capacitors 15 and R8 and the capacitors 15 and R7 and the load 6, that is, the output of the integrating circuit, that is, (b) in FIG. Since the voltage value is equal to or lower than VD (threshold voltage of the Zener diode 16), the transistor 17 is kept off.
【００１７】Ｔ４において、パルス電源発生回路３を構
成するフォトカプラ１１、トランジスタ１３、トランジ
スタ１４の内１つでも、万一ショート故障した場合は、
パルス電源発生回路３の出力は連続オンとなり、パルス
のオフ期間がなくなることになる。その結果、積分回路
４は放電期間がなくなり、コンデンサ１５の電圧は上昇
し、Ｔ５においてツェナーダイオードのスレショルドを
越え、トランジスタ１７にベース電流が流れることによ
りトランジスタ１７がオンとなり、漏電遮断器２の電源
側から抵抗Ｒ１０を介して電流を漏電遮断器２の負荷側
に流すことで、Ｔ６において、漏電遮断器２の二線間に
電流の不平衡現象を発生させ、機器への電源供給を停止
する動作となる。At T4, if any one of the photocoupler 11, the transistor 13, and the transistor 14 constituting the pulse power generation circuit 3 is short-circuited,
The output of the pulse power generation circuit 3 is continuously turned on, and the off period of the pulse is eliminated. Thus, integrated circuit 4 eliminates the discharge period, the voltage of the capacitor 15 rises, exceeding the threshold of the Zener diode at T5, the transistor 17 the transistor 17 by the base current flows on, and the fault interrupter 2 Power By flowing a current from the side through the resistor R10 to the load side of the earth leakage breaker 2, a current imbalance phenomenon occurs between two wires of the earth leakage breaker 2 at T6, and the power supply to the equipment is performed. The operation is to stop the supply.
【００１８】[0018]
【発明の効果】以上のように、本発明によれば、パルス
で動作する負荷に対して、供給する電源が異常になった
場合に積分回路により素早く検出し、回路中において漏
電と同じ状態に陥らせて機器への電源供給を遮断するた
め、機器外部に漏電することがなく、安全に機器の停止
をおこなえる。As described above, according to the present invention, when an abnormality occurs in the power supply supplied to a pulse-operated load, the abnormality is quickly detected by the integrating circuit , and the same state as the electric leakage in the circuit is obtained. Since the power supply to the device is shut off by causing the power supply to fall, the device can be safely stopped without leakage to the outside of the device.
【００１９】漏電遮断器の動作点を、積分回路とツェナ
ーダイオードのスレショルドで設定できるために、簡単
に高い精度でパルスの異常状態の検出を行うことができ
るため、安価で確実な動作を実現できる。Since the operating point of the earth leakage breaker can be set by the threshold of the integrating circuit and the Zener diode, it is possible to easily detect the abnormal state of the pulse with high accuracy , thereby realizing an inexpensive and reliable operation. Wear.
【図１】本発明における一実施例のフェールセーフ回路
のブロック図FIG. 1 is a block diagram of a fail-safe circuit according to one embodiment of the present invention.
【図２】図１のブロック図における各ブロックを実際の
回路に応用した詳細回路図FIG. 2 is a detailed circuit diagram in which each block in the block diagram of FIG. 1 is applied to an actual circuit;
【図３】図２の各部の電圧波形、及び回路部品の動作図FIG. 3 is a diagram showing voltage waveforms at various parts in FIG. 2 and operation of circuit components.
【図４】従来例のパルス異常時の保護回路ブロック図FIG. 4 is a block diagram of a protection circuit in the event of a pulse abnormality in a conventional example.
１ 商用電源 ２ 漏電遮断器 ３ パルス電源発生回路 ４ 積分回路 ５ スイッチ回路 ６ 負荷 ７ 漏電遮断器一次側の二線の一方 ８ 漏電遮断器二次側の二線の一方 DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 Leakage breaker 3 Pulse power generation circuit 4 Integration circuit 5 Switch circuit 6 Load 7 One of the two lines on the primary side of the leakage breaker 8 One of the two lines on the secondary side of the leakage breaker
───────────────────────────────────────────────────── フロントページの続き (72)発明者 宮内 伸二 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (72)発明者 山本 融士 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (56)参考文献 特開 平２−265198（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H02H 11/00 H02H 3/00 - 3/08 H02J 3/00 H05B 45/00 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shinji Miyauchi 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-house (56) References JP-A-2-265198 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H02H 11/00 H02H 3/00-3/08 H02J 3/00 H05B 45/00
Claims (4)
平衡電流を検出した場合に機器への電源供給を遮断する
漏電遮断器と、前記漏電遮断器の二次側の二線の一方を
グランドとしたパルス電源発生回路と、前記パルス電源
発生回路と並列に接続した積分回路と、前記積分回路の
電圧が所定の電圧を越えた場合に、前記漏電遮断器の一
次側から二次側の前記グランドに対し不平衡電流を流す
スイッチ回路を設けたフェールセーフ回路。A power supply between a commercial power supply and two lines of the commercial power supply.
An earth leakage breaker that shuts off power supply to the device when a balanced current is detected, a pulse power generation circuit that uses one of the two secondary lines of the earth leakage breaker as ground, and a parallel with the pulse power generation circuit. And a switch circuit that flows an unbalanced current from the primary side to the secondary side of the earth leakage breaker when the voltage of the integration circuit exceeds a predetermined voltage. Fail-safe circuit provided.
に接続した抵抗とコンデンサとからなる充放電回路を用
いた請求項１記載のフェールセーフ回路。2. A charge / discharge circuit comprising a resistor and a capacitor connected in parallel to a pulse power generation circuit is used as the integration circuit .
2. The fail-safe circuit according to claim 1, wherein:
並列に接続した積分回路の電圧をツェナーダイオードを
介してトランジスタのベースに入力し、前記電圧が所定
の電圧を越えたときに前記トランジスタをオンとして漏
電遮断器の一次側と二次側のグランドとの間で抵抗を介
して電流をバイパスさせるように構成した請求項１また
は請求項２に記載のフェールセーフ回路。3. The switch circuit includes a Zener diode that controls a voltage of an integration circuit connected in parallel to a pulse power generation circuit.
Input to the base of the transistor through
The transistor is turned on when the voltage exceeds
Connect a resistor between the primary side of the circuit breaker and the ground of the secondary side.
Fail safe circuit of claim 1 or claim 2 constructed as to bypass current by.
並列に接続した積分回路の電圧の抵抗分圧電圧をトラン
ジスタのベースに入力し、前記電圧が所定の電圧を越え
たときに前記トランジスタをオンとして漏電遮断器の一
次側と二次側のグランドとの間で抵抗を介して電流をバ
イパスさせるように構成した請求項１または請求項２に
記載のフェールセーフ回路。4. A switch circuit for transducing a resistance divided voltage of a voltage of an integration circuit connected in parallel to a pulse power supply generation circuit.
Input to the base of the
The transistor is turned on when the
Current between the primary and secondary grounds through a resistor.
3. The fail-safe circuit according to claim 1 , wherein the fail-safe circuit is configured to bypass the circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04128770A JP3134169B2 (en) | 1992-05-21 | 1992-05-21 | Fail safe circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04128770A JP3134169B2 (en) | 1992-05-21 | 1992-05-21 | Fail safe circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05328600A JPH05328600A (en) | 1993-12-10 |
| JP3134169B2 true JP3134169B2 (en) | 2001-02-13 |
Family
ID=14993045
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04128770A Expired - Fee Related JP3134169B2 (en) | 1992-05-21 | 1992-05-21 | Fail safe circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3134169B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100712229B1 (en) * | 2004-01-07 | 2007-04-27 | (주)서광전기컨설팅 | Control device of circuit breaker for preventing electrical fire |
| CN108169592B (en) * | 2017-12-15 | 2023-11-24 | 西安智财全技术转移中心有限公司 | Intelligent detection circuit and intelligent detection method |
-
1992
- 1992-05-21 JP JP04128770A patent/JP3134169B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05328600A (en) | 1993-12-10 |
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| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |