JPH02297818A - Current control unit of contact - Google Patents
Current control unit of contactInfo
- Publication number
- JPH02297818A JPH02297818A JP11670389A JP11670389A JPH02297818A JP H02297818 A JPH02297818 A JP H02297818A JP 11670389 A JP11670389 A JP 11670389A JP 11670389 A JP11670389 A JP 11670389A JP H02297818 A JPH02297818 A JP H02297818A
- Authority
- JP
- Japan
- Prior art keywords
- contact
- contacts
- current
- contact resistance
- large current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims abstract description 13
- 238000009413 insulation Methods 0.000 abstract description 4
- 230000007423 decrease Effects 0.000 abstract description 3
- 230000006378 damage Effects 0.000 description 8
- 239000003990 capacitor Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/60—Auxiliary means structurally associated with the switch for cleaning or lubricating contact-making surfaces
- H01H1/605—Cleaning of contact-making surfaces by relatively high voltage pulses
Landscapes
- Keying Circuit Devices (AREA)
Abstract
Description
この発明は、低電流を開閉する接点の絶縁皮膜などの傷
害を除去して電気的接触を良好にするための接点用電流
制御装置に関するものである。The present invention relates to a current control device for contacts that removes damage to the insulation coating of contacts that open and close low currents to improve electrical contact.
エレベータの行き過ぎを防ぐ終点スイッチや、エレベー
タの扉の閉成状態を確認する戸閉検出スイッチ等に流れ
る電流は、回路の電子化に伴い微小となり、かつ小形化
してきている。このため、接点開閉時のエネルギによる
接点面の活性化や電流による接点面上の絶縁皮膜の破壊
などが困難になっている。
この対策として、Ｗｉ閉電流、通電電流を太きぐするこ
とが提案されている。
第４図は、従来の接点用電流制御装置の回路図であり、
接点閉成毎に接点間に一定時間大電流を流し、これによ
り接点面に生じた絶縁膜など、低負荷電流を開閉する接
点の傷害となるものを除去して接点のクリーン化を伴う
ものである。
同図において、１は戸閉スイッチなどの接点であり、こ
の接点１の一端は＋Ｖｌｌ［に接続され、その他端は抵
抗２及びホトカブラ３の一次側（発光ダイオード）を介
してアースに接続されている。
ホトカブラ３の二次側（ホトトランジスタ）は十Ｖ電源
と、アース間に抵抗４を介して接続され、そして、接点
１の開閉に伴いオン・オフされるホトカプラ３のオン・
オフ信号は制御回路５に出力されるようになっている。
前記抵抗２とホトカブラ３の一次側との直列回路には、
トランジスタ６が抵抗７を介して並列に接続され、さら
にトランジスタ８が抵抗９，１゜を介して並列に接続さ
れている。前記抵抗１ｏにはコンデンサ１１と抵抗１２
との直列回路が並列に接続され、この直列回路のコンデ
ンサ１１と抵抗１２との接続点に前記トランジスタ６の
ベースが接続されている。１３はトランジスタ６のエミ
ッタ・ベース間に接続したダイオード、１４及び１５は
トランジスタ８のベースバイアス用の抵抗である。
次に、上記のように構成された従来の接点用電流制御装
置の動作を第５図のタイムチャートを参照して説明する
。
接点１が開放された初期状態では、接点電流工ｏ＝０で
ある（第５図ｅ参照）。この時、ホトカブラ３はオフ状
態になっているため、制御回路５には＋Ｖ電源を抵抗４
で設定した電圧レベルのｒＨＪ信号が入力される。また
、接点１が閉状態になると、ホトカブラ３の一次側には
電流Ｉ、が流れるため、ホトカブラ３がオンし、制御回
路５の入力接続点をアースに落とす。このため、制御回
路５の入力信号は“Ｌ”になる。
一方、接点１が閉成されると、トランジスタ８が第５図
（ｂ）に示すようにオンし、コンデンサ１１が充電され
始める。この時、コンデンサ１１の両端電圧は第５図（
Ｃ）のように変化する。そして、コンデンサ１１がチャ
ージアップするまでの時間Ｔ、の間、トランジスタ６が
オンしく第５図（ｄ）参照）、これに伴い抵抗７に負荷
電流Ｉ２が流れる。従って、接点１には接点の閉と同時
に時間Ｔ、の間ｌ０＝Ｉ、＋Ｉ２の接点電流が流れ、そ
の接点電流Ｉ。は通常状態よりＩ２だけ増加する。これ
により、接点間にはジュール熱が発生し、絶縁皮膜等を
破壊して接点をクリーンな状態にする。The current flowing through the end point switch that prevents the elevator from overshooting, the door close detection switch that confirms the closed state of the elevator door, and the like has become smaller and smaller as circuits become more electronic. For this reason, it is difficult to activate the contact surface due to energy when opening and closing the contact, and to destroy the insulating film on the contact surface due to current. As a countermeasure to this problem, it has been proposed to increase the Wi closing current and conducting current. FIG. 4 is a circuit diagram of a conventional contact current control device,
A large current is passed between the contacts for a certain period of time each time the contacts are closed, and this removes anything that could damage the contacts that open and close low-load currents, such as an insulating film that has formed on the contact surface, thereby cleaning the contacts. be. In the figure, 1 is a contact such as a door close switch, and one end of this contact 1 is connected to +Vll[, and the other end is connected to ground via a resistor 2 and the primary side (light emitting diode) of a photocoupler 3. There is. The secondary side (phototransistor) of the photocoupler 3 is connected between a 1V power source and ground via a resistor 4, and the photocoupler 3 is turned on and off as the contact 1 opens and closes.
The off signal is output to the control circuit 5. The series circuit between the resistor 2 and the primary side of the photocoupler 3 includes:
Transistor 6 is connected in parallel via resistor 7, and transistor 8 is further connected in parallel via resistor 9,1°. A capacitor 11 and a resistor 12 are connected to the resistor 1o.
A series circuit is connected in parallel, and the base of the transistor 6 is connected to the connection point between the capacitor 11 and the resistor 12 of this series circuit. 13 is a diode connected between the emitter and base of transistor 6, and 14 and 15 are resistors for biasing the base of transistor 8. Next, the operation of the conventional contact current control device configured as described above will be explained with reference to the time chart shown in FIG. In the initial state where the contact 1 is open, the contact current o=0 (see FIG. 5e). At this time, since the photocoupler 3 is in the off state, the +V power supply is connected to the control circuit 5 through the resistor 4.
The rHJ signal at the voltage level set in is input. When the contact 1 is closed, a current I flows through the primary side of the photocoupler 3, so the photocoupler 3 is turned on and the input connection point of the control circuit 5 is grounded. Therefore, the input signal of the control circuit 5 becomes "L". On the other hand, when contact 1 is closed, transistor 8 is turned on as shown in FIG. 5(b), and capacitor 11 begins to be charged. At this time, the voltage across the capacitor 11 is as shown in Figure 5 (
C). Then, during the time T until the capacitor 11 is charged up, the transistor 6 is turned on (see FIG. 5(d)), and the load current I2 flows through the resistor 7 accordingly. Therefore, a contact current of l0=I, +I2 flows through contact 1 for a time T at the same time as the contact is closed, and the contact current I. increases by I2 from the normal state. As a result, Joule heat is generated between the contacts, destroying the insulating film and leaving the contacts in a clean state.
上述のような従来の接点用電流制御装置では、接点１が
閉成される毎に接点間に通常の数倍に相当する大きな電
流が流れるため、接点の電気的寿命を極度に低下させた
り、あるいは接点が審理するなど、別の接点傷害が発生
し易（なるという問題があった。
この発明は上記のような問題点を解決するためになされ
たもので、接点の電気的寿命の増大を図ると共に、絶縁
皮膜等による接点の接触不良のない信頼性の高い接点の
電流制御装置を得ることを目的とする。In the conventional current control device for contacts as described above, a large current equivalent to several times the normal current flows between the contacts each time the contact 1 is closed, which may extremely shorten the electrical life of the contacts. Otherwise, there was a problem in which other contact damage such as contact breakage was likely to occur. This invention was made to solve the above problems, and it In addition, it is an object of the present invention to obtain a highly reliable contact current control device that is free from poor contact due to insulating films or the like.
【課題を解決するための手段］
この発明に係る接点の電流制御装置は、接点の接触抵抗
を検出し、この接触抵抗が予め定めた基準値以上になっ
た時出力信号を送出する検出回路と、この検出回路から
の出力信号により動作され一１前記接点間に大電流を流
す回路手段とを備えてなるものである。
【作用】
接点の閉状態において、検出回路が検出した接点の接触
抵抗が基準値以上であることを判断すると、回路手段を
動作させて接点間に大電流を流し、これによって絶縁皮
膜等の接点傷害を除去し、接点を接触不良のない状態に
する。
したがって、この発明にあっては、傷害除去のための大
電流は必要以上に流れることがなく、接点の電気的寿命
を増大できると共に、信頼性の高い接点を提供し得る。[Means for Solving the Problems] A contact current control device according to the present invention includes a detection circuit that detects the contact resistance of the contact and sends an output signal when the contact resistance exceeds a predetermined reference value. , and circuit means which is operated by an output signal from the detection circuit and causes a large current to flow between the contacts. [Function] When the detection circuit determines that the contact resistance of the contact detected by the contact is equal to or higher than the reference value in the closed state of the contact, the circuit means is operated to flow a large current between the contacts, thereby causing the contact resistance of the insulating film, etc. Remove the damage and make the contacts free from poor contact. Therefore, in the present invention, a large current for removing damage does not flow more than necessary, and the electrical life of the contact can be increased, and a highly reliable contact can be provided.
以下、この発明の実施例を図面に基づいて説明する。
第１図は、この発明による接点用電流制御装置の一実施
例を示す回路図である。
第１図において、第４図と同一の部分には同一符号を付
して説明する。１６は接点１の接触抵抗がある値以上に
なったことを検出する検出回路で、＋■電源とアース間
に直列に接続した抵抗１７及び１８と、抵抗２とホトカ
ブラ３の一次側との直列回路に並列に接続した抵抗１９
，２０の直列回路と、演算増幅器２１とから構成されて
いる。
前記演算増幅器２１の非反転入力端は、抵抗１７と１８
との接続点Ｐ、に接続され、さらに反転入力端は抵抗１
９．２０との接続点Ｐ２に接続されている。これにより
演算増幅Ｎ２１の非反転入力端には、＋ｖｇ源の電圧を
抵抗１７．１８で分圧した抵抗１８の両端に発生する電
圧Ｖａが供給され、また反転入力端には接点１の接触抵
抗、抵抗１９，２０により決定される抵抗２０の両端電
圧ｖｂが供給される。そして、演算増幅器２１の出力信
号は接点１に傷害除去用の負荷電流Ｉ２を流すトランジ
スタ６のベースに供給されるようになっている。
次に、上記のように構成された本実施例の動作を第２図
及び第３図を参照して説明する。
第２図は動作説明用のフローチャートであり、第３図は
そのタイムチャートである。
まず、接点１が開の初期状態では、接点電流Ｉ。＝０で
ある。次に、接点１が第３図（ａ）に示すように閉状態
になると（ステップＳｌ）、ホトカプラ３の一次側に電
流Ｉ、が流れるため、ホトカプラ３はオン動作し、その
オン動作に伴う信号が制御回Ｗｓ５に供給される。この
時、接点１の開成に伴い接点１を介して抵抗１９．２０
に＋Ｖ電源が供給されるため、抵抗２０の両端には接点
１の接触抵抗に応じた電圧が発生し、この両端電圧ｖｂ
が演算増幅器２１の反転入力端に供給される。
ここで、演算増幅器２１は、これに入力される電圧Ｖａ
とｖｂとを比較し、接点１の接触抵抗が予め設定した基
準値より大きいか小さいかを判定する（ステップ８２）
。
接点１の接触抵抗が第３図（ｂ）に示す基準値より小さ
い時はＶ ａ ＜ Ｖ ｂとなるため（ステップＳ３）
、演算増幅器２１の出力はｒＬＪとなり、トランジスタ
６はオフのままとなる（ステップＳ４）。この時の接点
電流Ｉ。はｌ０＝Ｉ、となる。
一方、絶縁皮膜の生成などにより接点１の接触抵抗が基
樵値以上になると、電圧Ｖａとｖｂ間はＶ ａ ） Ｖ
ｂとなるため（ステップＳ５）、演算増幅ｉ＃２１の
出力はｒＨＪとなり、トランジスタ６が第３図（Ｑ）に
示すようにオンする（ステップ８６）。これに伴い、抵
抗７とトランジスタ６の直列回路には負荷電流工２が流
れ、接点電流Ｉ。
はｌ０＝Ｉ 、 十Ｉ、となる。すなわち、接点１を流
れる電流は第３図（ｄ）に示すように通常時よりＩ。分
増加するため（ステップＳ７）、接点間の絶縁皮膜等は
ジュール熱によって破壊され（ステップＳ８）、接点抵
抗値は減少する（ステップ３９）。これにより接点抵抗
が基準値以下に抵抗すると、Ｖ ａ ＜ Ｖ ｂとなる
ため、演算増幅ＷＩｒ２１の出力はｒＬＪに反転し、ト
ランジスタ６はオフする。
上述のような本実施例にあっては、接点１の接触抵抗を
演出回路１６により監視し、その接触抵抗が予め定めた
基準値以上になった時にトランジスタ６をオンして大電
流を接点間に流し、これによ抄接点の接触抵抗が基準値
以下に減少しなならば、トランジスタ６をオフして大電
流を遮断するようにしたものであるから、従来のように
接点１が閉成する毎に大電流が流れることがなく、シか
も大電流は絶縁皮膜などの傷害が生じなときのみ流れ、
必要以上に大電流が流れないため、接点１の電気的寿命
が増大し、接点溶着も未然に防止することができる。
なお、この発明における検出口４１６及び傷害除去用の
大電流供給回路は上記実施例に示す回路方式のものに限
定されない。Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a circuit diagram showing an embodiment of a contact current control device according to the present invention. In FIG. 1, the same parts as in FIG. 4 will be described with the same reference numerals. 16 is a detection circuit that detects when the contact resistance of contact 1 exceeds a certain value; Resistor 19 connected in parallel to the circuit
, 20 in series, and an operational amplifier 21. The non-inverting input terminal of the operational amplifier 21 is connected to resistors 17 and 18.
The inverting input terminal is connected to the connection point P, and the inverting input terminal is connected to the resistor 1.
It is connected to connection point P2 with 9.20. As a result, the non-inverting input terminal of the operational amplifier N21 is supplied with the voltage Va generated across the resistor 18 obtained by dividing the voltage of the +vg source by the resistor 17.18, and the contact resistance of contact 1 is supplied to the inverting input terminal. , the voltage vb across the resistor 20 determined by the resistors 19 and 20 is supplied. The output signal of the operational amplifier 21 is supplied to the base of a transistor 6 which causes a load current I2 for damage removal to flow through the contact 1. Next, the operation of this embodiment configured as described above will be explained with reference to FIGS. 2 and 3. FIG. 2 is a flowchart for explaining the operation, and FIG. 3 is a time chart thereof. First, in the initial state where contact 1 is open, contact current I. =0. Next, when the contact 1 becomes closed as shown in FIG. 3(a) (step Sl), the current I flows through the primary side of the photocoupler 3, so the photocoupler 3 turns on, A signal is supplied to the control circuit Ws5. At this time, with the opening of contact 1, a resistance of 19.20
Since +V power is supplied to the resistor 20, a voltage corresponding to the contact resistance of the contact 1 is generated at both ends of the resistor 20, and this voltage at both ends vb
is supplied to the inverting input terminal of the operational amplifier 21. Here, the operational amplifier 21 has a voltage Va input thereto.
and vb are compared, and it is determined whether the contact resistance of contact 1 is larger or smaller than a preset reference value (step 82).
. When the contact resistance of contact point 1 is smaller than the reference value shown in FIG. 3(b), V a < V b (step S3).
, the output of the operational amplifier 21 becomes rLJ, and the transistor 6 remains off (step S4). Contact current I at this time. becomes l0=I. On the other hand, if the contact resistance of contact 1 exceeds the basic value due to the formation of an insulating film, etc., the voltage between Va and vb will be V a ) V
b (step S5), the output of operational amplifier i#21 becomes rHJ, and transistor 6 turns on as shown in FIG. 3(Q) (step 86). Accordingly, a load current 2 flows through the series circuit of the resistor 7 and the transistor 6, and a contact current I flows. becomes l0=I, 10I. That is, as shown in FIG. 3(d), the current flowing through contact 1 is I compared to the normal state. Since the contact resistance value increases (step S7), the insulating film between the contacts is destroyed by Joule heat (step S8), and the contact resistance value decreases (step S39). As a result, when the contact resistance becomes less than the reference value, Va<Vb, so the output of the operational amplifier WIr21 is inverted to rLJ, and the transistor 6 is turned off. In this embodiment as described above, the contact resistance of the contact 1 is monitored by the production circuit 16, and when the contact resistance exceeds a predetermined reference value, the transistor 6 is turned on and a large current is applied between the contacts. If the contact resistance of the contact does not decrease below the reference value, the transistor 6 is turned off and the large current is cut off. Large currents do not flow every time the device is used, and large currents only flow when there is no damage to the insulation film, etc.
Since an unnecessarily large current does not flow, the electrical life of the contact 1 is increased and contact welding can be prevented. Note that the detection port 416 and the large current supply circuit for injury removal in this invention are not limited to the circuit system shown in the above embodiment.
以上のように、この発明によれば接点の接触抵抗を検出
する検出回路を設け、この検出回路が接点の接触抵抗が
予め定めた基準値以上であると判断した時のみ接点間に
大電流を流すように構成したので、接点の電気的寿命を
増大できると共に、接触不良のない信頼性の高い接点を
提供することができる。As described above, according to the present invention, a detection circuit that detects the contact resistance of the contacts is provided, and a large current is applied between the contacts only when this detection circuit determines that the contact resistance of the contacts is equal to or higher than a predetermined reference value. Since the contact is configured to flow, the electrical life of the contact can be increased, and a highly reliable contact without contact failure can be provided.
第１ｒＩ！Ｊはこの発明による接点用電流ＩＩＪＩＩＩ
装置の一実施例を示す回路図、第２図はその動作説明用
のフローチャート、第３図は同じ（そのタイムチャート
、第４図は従来の接点用電流制御装置の回路図、第５図
はそのタイムチャートである。
ｌ・・・接点、３・・・ホトカプラ、５・・・＃御回路
、６・・・トランジスタ、２，４．７・・・抵抗、１６
・・・検出回路、１７，１８，１９，２０・・・抵抗、
２１・・演算増幅器。
なお、図中同一符号は同−又は相当部分を示す。1st rI! J is the contact current IIJIII according to this invention
A circuit diagram showing one embodiment of the device, FIG. 2 is a flowchart for explaining its operation, FIG. 3 is the same (time chart thereof), FIG. 4 is a circuit diagram of a conventional contact current control device, and FIG. This is a time chart. 1... Contact, 3... Photocoupler, 5... #Control circuit, 6... Transistor, 2, 4.7... Resistor, 16
...detection circuit, 17,18,19,20...resistance,
21...Operation amplifier. Note that the same reference numerals in the figures indicate the same or equivalent parts.
Claims (1)
る電流制御装置において、前記接点の接触抵抗を検出し
、この接触抵抗が予め定めた基準値以上になった時出力
信号を送出する検出回路と、この検出回路からの出力信
号により動作され前記接点間に大電流を流す回路手段と
を備えてなる接点の電流制御装置。In a current control device that controls the current flowing through a contact that opens and closes between a power source and a load, a detection device that detects the contact resistance of the contact and sends an output signal when this contact resistance exceeds a predetermined reference value. 1. A contact current control device comprising: a circuit; and circuit means operated by an output signal from the detection circuit to cause a large current to flow between the contacts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11670389A JPH02297818A (en) | 1989-05-10 | 1989-05-10 | Current control unit of contact |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11670389A JPH02297818A (en) | 1989-05-10 | 1989-05-10 | Current control unit of contact |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02297818A true JPH02297818A (en) | 1990-12-10 |
Family
ID=14693743
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11670389A Pending JPH02297818A (en) | 1989-05-10 | 1989-05-10 | Current control unit of contact |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02297818A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0696637A (en) * | 1992-07-30 | 1994-04-08 | Yazaki Corp | Corrosion prevention circuit for switch |
| JPH09131047A (en) * | 1995-10-31 | 1997-05-16 | Fuji Denki Kogyo Kk | Dc/dc converter for low electric power |
| WO2004021382A2 (en) * | 2002-08-28 | 2004-03-11 | Teravicta Technologies, Inc. | Micro-electromechanical switch performance enhancement |
| EP1585150A1 (en) | 2004-04-05 | 2005-10-12 | Fujitsu Ten Limited | Circuit for preventing corrosion of contact |
| US7362011B2 (en) | 2004-04-05 | 2008-04-22 | Fujitsu Ten Limited | Apparatus for preventing corrosion of contact |
| US7410563B2 (en) | 2004-04-05 | 2008-08-12 | Fujitsu Ten Limited | Method and apparatus for preventing corrosion of contact |
| JP2011193224A (en) * | 2010-03-15 | 2011-09-29 | Mitsubishi Electric Corp | Contact resistance recovery device and monitoring device |
| JP2016218775A (en) * | 2015-05-21 | 2016-12-22 | 新コスモス電機株式会社 | Alarm |
| CN111122979A (en) * | 2018-10-30 | 2020-05-08 | 矢崎总业株式会社 | Deterioration regeneration system and deterioration regeneration method |
-
1989
- 1989-05-10 JP JP11670389A patent/JPH02297818A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0696637A (en) * | 1992-07-30 | 1994-04-08 | Yazaki Corp | Corrosion prevention circuit for switch |
| JPH09131047A (en) * | 1995-10-31 | 1997-05-16 | Fuji Denki Kogyo Kk | Dc/dc converter for low electric power |
| WO2004021382A2 (en) * | 2002-08-28 | 2004-03-11 | Teravicta Technologies, Inc. | Micro-electromechanical switch performance enhancement |
| WO2004021382A3 (en) * | 2002-08-28 | 2004-07-01 | Teravicta Technologies Inc | Micro-electromechanical switch performance enhancement |
| JP2005536854A (en) * | 2002-08-28 | 2005-12-02 | テラビクタ・テクノロジーズ・インコーポレーテッド | Enhancing the performance of microelectromechanical switches |
| EP1585150A1 (en) | 2004-04-05 | 2005-10-12 | Fujitsu Ten Limited | Circuit for preventing corrosion of contact |
| US7362011B2 (en) | 2004-04-05 | 2008-04-22 | Fujitsu Ten Limited | Apparatus for preventing corrosion of contact |
| US7410563B2 (en) | 2004-04-05 | 2008-08-12 | Fujitsu Ten Limited | Method and apparatus for preventing corrosion of contact |
| US7550878B2 (en) | 2004-04-05 | 2009-06-23 | Fujitsu Ten Limited | Circuit for preventing corrosion of contact |
| JP2011193224A (en) * | 2010-03-15 | 2011-09-29 | Mitsubishi Electric Corp | Contact resistance recovery device and monitoring device |
| JP2016218775A (en) * | 2015-05-21 | 2016-12-22 | 新コスモス電機株式会社 | Alarm |
| CN111122979A (en) * | 2018-10-30 | 2020-05-08 | 矢崎总业株式会社 | Deterioration regeneration system and deterioration regeneration method |
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