F. Bagnon, M. Leclercq, T. Millet, L. Boyer, P. Teste
{"title":"An original inverse method to determine the approximate electrical contact area between a clip and a bar","authors":"F. Bagnon, M. Leclercq, T. Millet, L. Boyer, P. Teste","doi":"10.1109/HOLM.2001.953221","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953221","url":null,"abstract":"The determination of the electrical contact area between two contact members is a recurrent problem which will probably never be solved exactly. In this paper, we present an original method which allows us to determine the approximate electrical contact area obtained when a branch of an elastic clip is pressed against a flat bar. This method is based on the measurement of the electric potential on the bar, on a U shaped contour located as close as possible to the clip. In the experimental set up, the contour potential V/sub m/(s) is quickly recorded, while the contact is fed by a stabilized current of /spl plusmn/30 A, to rule out thermal drifts and EMFs. The electrical potential is measured between the top of the clip and a metallic probe sliding on the contour, with a constant contact force. Assuming that the contact area is elliptic, the unknown parameters of the problem are the location of the ellipse and its main dimensions. The program used to determine these parameters couples a 2D finite element module with an optimization module of the MATLAB/sup (R)/ software. The algorithm starts with an arbitrary set of values for the parameters, uses the experimental boundary conditions and calculates the potential differences V/sub m/(s) corresponding to the experimental contour. Then the coupled \"optimization module and FEM module\" runs, changing the parameters, in order to make V/sub c/(s) as close as possible to V/sub m/(s). The various tests results of the methodology are very satisfactory.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115396490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"3D-simulation of arc motion between arc runners including the influence of ferromagnetic material","authors":"M. Lindmayer, M. Springstubbe","doi":"10.1109/HOLM.2001.953203","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953203","url":null,"abstract":"The behavior of the moving electric arc in low-voltage switching devices is determined by the complex interactions of magnetic forces, current flow, gas flow, heat conduction, and radiation. In this paper, three-dimensional simulations of arc motion between parallel arc runners are presented, which consider all these interactions. These simulations are carried out with a CFD (computational fluid dynamics) finite volume code. Based on earlier simulations (Karetta and Lindmayer, 1998; Karetta, 1998), the magnetic field, expressed as a vector potential formulation, is now treated by the same type of general transport equations as the other processes, which allows direct implementation into the CFD package used. This enables inclusion of the effects of ferromagnetic materials in the arc chamber, such as ferromagnetic flux concentrators or steel splitter plates. Typical simulation examples are presented for different design details.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116773900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fretting corrosion studies of an extrinsic conducting polymer and tin interface","authors":"J. Swingler, J. McBride","doi":"10.1109/HOLM.2001.953214","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953214","url":null,"abstract":"Novel contact connector materials such as conducting polymers are becoming available which improve performance and enable further miniaturisation. Studies of a polymer-tin interface have been carried out to characterise contact resistance performance under fretting conditions. Degradation mechanisms have been identified using contact resistance measurements and surface analysis tools. These mechanisms have been shown to be different to those found in the tin-tin interface. The polymer-tin interface performs significantly better than a clean tin-tin interface, requiring more than three times the number of fretting cycles to fail (attaining 200 m/spl Omega/). The study shows that debris is not deposited at the end of the wear track as in a tin-tin interface. Additionally, once the contact resistance attains high values, the polymer-tin interface recovers to low values. The elastic contact is proposed as an advantageous characteristic of conducting polymers which can be used to eliminate fretting at the contact interface.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114535778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Silver iodide as a solid lubricant for power contacts","authors":"S. Arnell, G. Andersson","doi":"10.1109/HOLM.2001.953217","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953217","url":null,"abstract":"Silver coated electrical contacts have excellent electrical and thermal properties, although some kind of lubricant is necessary to protect against wear and corrosion and also to give acceptable friction forces during operation. We have developed thin films of silver iodide for standard silver coating as a solid lubricant. The friction coefficient is reduced and wear resistance is improved as compared to unlubricated silver coatings. Silver iodide coating on contacts in an on-load-tap-changer, an electromechanical device installed in a power transformer to regulate the voltages of the transformer under load, is one example of an application resulting in low friction, considerably improved wear resistance and a low and stable contact resistance.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114874097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Hiltmann, A. Schumacher, K. Guttmann, E. Lemp, H. Sandmaier, W. Lang
{"title":"New micromachined membrane switches in silicon technology","authors":"K. Hiltmann, A. Schumacher, K. Guttmann, E. Lemp, H. Sandmaier, W. Lang","doi":"10.1109/HOLM.2001.953198","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953198","url":null,"abstract":"This paper presents a new generation of micromachined membrane switches containing a glass substrate and a silicon membrane. Upon external actuation, two planar substrate contacts are closed by a metal layer deposited on the switching membrane. The switching position is constant to better than 1 /spl mu/m and has been observed to move about 0.7 /spl mu/m over the achieved lifetime of 20 million electromechanical cycles under electrical loads of 12 V and 10 mA.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130940411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Gas flow and composition effects on arc motion in current limiting circuit breakers","authors":"K. Pechrach, J. McBride, P. Weaver","doi":"10.1109/HOLM.2001.953184","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953184","url":null,"abstract":"Arc motion in low voltage (240 VAC) high current (10/sup 3/-10/sup 4/ A) current limiting circuit breakers is dominated by arc root mobility. This is strongly affected by the gas flow and gas composition in the contact region, but there is little experimental data on these effects. New pressure and spectral data measurement during arc movement are presented using a flexible test apparatus and an arc imaging system. These measurements are used to investigate gas flow characteristics in the arc chamber. The chemical and physical phenomena occurring during the arc motion are discussed. The combination of optical and spectral data provides new insight into the arc motion. Also studied are the influences of arc chamber material, contact material, and contact opening speed. These data are used to improve arc control for a low contact opening velocity of 1 ms/sup -1/.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132663291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Study on a new contact material-Ag/SnO/sub 2/-La/sub 2/O/sub 3/-Bi/sub 2/O/sub 3/","authors":"Jingqin Wang, M. Wen, Baozhu Wang, Jianguo Lu","doi":"10.1109/HOLM.2001.953195","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953195","url":null,"abstract":"For this paper, a super-fine compound powder, Ag/SnO/sub 2/+La/sub 2/O/sub 3/+Bi/sub 2/O/sub 3/ has been obtained successfully using the chemical coprecipitation method, and a new contact material, Ag/SnO/sub 2/+La/sub 2/O/sub 3/+Bi/sub 2/O/sub 3/, was produced by the powder metallurgy method. Its properties are as follows: density is 9.75/spl sim/9.93 g/cm/sup 3/, resistivity is 2.31/spl sim/2.551 /spl Omega/cm, and hardness is 880/spl sim/985 MPa. Its microstructure shows that the fine oxides have a uniform distribution in the silver matrix. The results of make-break capacity and temperature rise testing show that the new material has better anti-arc erosion ability and lower temperature rise than that of commonly used Ag/CdO material.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121990860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of gassing materials in switching devices using monochromatic high speed imaging technique","authors":"Xin Zhou","doi":"10.1109/HOLM.2001.953201","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953201","url":null,"abstract":"The purpose of this paper is to investigate quantitative information on prospective gassing materials to be used in switching devices. Previous work indicates that gassing materials have a strong effect on current interruption and current limiting in these devices. However, few papers have been published to cover quantitative information on the amount of certain gassing species released, such as hydrogen, when the gassing material is exposed to a running arc. Monochromatic high speed imaging techniques were employed in this investigation to characterize hydrogen gassing properties of different materials based on hydrogen arc images and nitrogen arc images, respectively. Hydrogen plasma has a very high thermal conductivity that results in high arc voltages during interruption, which is critical to current limiting. Comparison among prospective gassing materials was made. The mass loss results derived from plasma emission intensities showed good agreement with direct mass loss measurements of gassing materials.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130183197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of connection design on the contact resistance of high power overlapping bolted joints","authors":"M. Braunovic","doi":"10.1109/HOLM.2001.953215","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953215","url":null,"abstract":"The effect of design changes on the contact resistance of overlapping bolted/pad joints was investigated. It was found that slanting the edges of the bus-bars/pads under 45/spl deg/ and making slots in the overlapping areas significantly reduce the contact resistance of a joint and improve its mechanical integrity. These improvements are results of enlarged contact area and creation of a uniform current distribution at the contact interface.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129243607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-speed sliding test characteristic of sliding contact containing solid lubricants for use under severe application conditions","authors":"Y. Watanabe","doi":"10.1109/HOLM.2001.953225","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953225","url":null,"abstract":"Development of a new sliding contact, usable under severe conditions such as high temperature, extremely low temperature or high vacuum, has recently become an urgent necessity. This research mainly examines the contact resistance and coefficient of friction of three kinds of self-lubricating composite materials with electrical conductivity and mechanical stiffness. The result showed that a composite material (CMML-1) containing the lowest quantity of solid lubricants (WS/sub 2/, graphite) was low in both contact resistance and coefficient of friction and lower in fluctuation. By EPMA analysis, the Sn contribution to electrical conductivity was suggested.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114497498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}