{"title":"Thermal models of short arc between high current contacts","authors":"P. Borkowski, E. Walczuk","doi":"10.1109/HOLM.2001.953220","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953220","url":null,"abstract":"General assumptions, initial equations and thermal models of a short arc between high-current contacts are described in the paper. Mathematical analysis and computer simulation have been carried out for selected practical examples of biased contacts. It has been proved that thermal power received by the anode is greater than that received by the cathode.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"49 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":"123413714","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":"Simulation of arc motion between straight parallel electrodes","authors":"D. Podolsky, A. Sokolov, V. Kapustin","doi":"10.1109/HOLM.2001.953185","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953185","url":null,"abstract":"The model of current distribution in arc roots comprising dotted current emitting sources is proposed. A new approach to the potential boundary conditions is discussed. The paper presents the qualitative analysis of the arc motion based on the electrical field model described. The main result is the dependence of arc motion characteristics on the arc root location on the electrode. The three regions of arc motion, the zone of accelerated arc motion, the zone of arc deceleration, and the zone of arc erosion are found. Results of modeling agree with experimental data.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"11 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":"125381270","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":"Carbon fiber contactor in polymer resistive position sensors","authors":"Shengli Liu","doi":"10.1109/HOLM.2001.953223","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953223","url":null,"abstract":"Potentiometric position sensors are widely used in many industries. Applications in the automotive industry are most apparent and important. The position sensors are typically constructed with a polymer resistive element and a sliding electrical contactor or \"wiper\" that is made from various noble metals or alloys. Electrical noise and wear are often associated with such position sensors. A new concept for contactors in the position sensors has been proposed that use carbon fiber to form contact tips that result in an exceptionally large number of contact points. Preliminary tests have demonstrated improved electrical performance and durability with this system. This paper discusses the design requirements and performance characteristics of position sensors using these carbon fiber contactors.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"29 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":"124998150","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":"A fundamental experiment on operating characteristics of Ag, Pd and Cu contacts in inert atmosphere","authors":"J. Makimoto, K. Sawa, M. Hasegawa","doi":"10.1109/HOLM.2001.953196","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953196","url":null,"abstract":"The purpose of this work is to research the effects of the surrounding atmosphere of contacts on arc discharge and contact reliability in various aspects, and in future, to construct a systematic physical theory for various phenomena in gases, especially in inert gases. By filling the contact part with inert gas, prevention of increase in contact resistance is expected. This paper examines the operational performances of three typical contact materials, Ag, Pd and Cu, in a DC inductive (20 mH) load circuit with load current up to 3.0 A in air and in nitrogen gas. As a result, it is shown that in nitrogen atmosphere, contact resistance is lower and more stable and material wear and transfer is smaller than in air. Thus nitrogen gas has the effect of delaying and restraining deterioration of contact reliability. These consequences are considered to come from the difference of morphology and products on the contact surface, and moreover, the difference of arc duration and arc discharge phase.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"7 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":"127366916","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":"Lubrication mechanisms of hot-dipped tin separable electrical contacts","authors":"S. Noel, N. Lecaude, D. Alamarguy, L. Tristani","doi":"10.1109/HOLM.2001.953210","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953210","url":null,"abstract":"Degradation phenomena occurring during the lifetime of tinned separable electrical contacts remain a factor of loss of reliability that can be minimised. In a previous paper, friction, wear and electrical properties of hot-dipped tin coatings on bronze substrates have been analysed with various techniques in order to show the improvement due to a well-suited fluorinated lubricant layer. Contacts were of the sphere on plane type obtained from strips of tinned CuSn/sub 4/ (as received for the flats, and formed by stamping for the dimples). Macroscopic friction cycles simulating insertion and withdrawal of separable contacts were performed as well as fretting cycles. Efficiency of the lubricant was strongly related to the film thickness in the case of macroscopic friction of dimple on flat contacts. For a sufficient film thickness, different behaviours were observed for different molecules. Here, the particularity of lubrication mechanisms of hot-dipped tin contacts is analysed. The evolution of static contact resistance values before friction and during the friction tests correlated to the wear behaviour shows the influence of some of the lubricant properties such as viscosity and chain structure.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"44 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":"126789617","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":"Comparison of coefficient of friction and contact resistance during sliding wear on clad gold-nickel surfaces","authors":"N. Gabel, H. Hardee, P. Lees","doi":"10.1109/HOLM.2001.953222","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953222","url":null,"abstract":"This paper presents analysis of experimental sliding wear data for four hard-gold flash over gold-diffused nickel material systems (GF-DGNi). The surface hardness of the DGNi material was altered by varying both the gold surface concentration and the amount of gold reduction after the diffusion anneal. These material systems were evaluated for unlubricated and lubricated sliding wear durability. The lubricant used was a 6-ring polyphenyl ether, OS-138, that was applied by dipping the specimens in a 2.50% solution of OS-138 in a propylene glycol monomethyl ether carrier. A gold flash palladium connector pin and a strip of metal that had been clad with the gold-nickel material system were mated to form a pseudo-crossed-rod configuration for each of these sliding wear experiments. Sliding wear experiments were conducted at 50 g and 150 g normal load. The amplitude of the motion was 1.14 mm with a velocity of 1 mm/s. Each experiment was conducted for a minimum of 2000 wear cycles and five replications were made for each experimental test condition. A new sliding wear test machine and software program were developed for this test series to appropriately handle the clad metal samples and to allow simultaneous measurement of coefficient of friction and electrical contact resistance during each wear cycle.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"3 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":"126949389","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":"Performance improvement for sliding contacts utilizing tip polishing","authors":"M. Čačic","doi":"10.1109/HOLM.2001.953224","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953224","url":null,"abstract":"The potentiometer uses a sliding contact over a resistive track to transfer a mechanical position to an electrical resistance or voltage potential. The sliding stamped contact is subject to a die break condition on the contacting surface. Important to the performance of the device is contact resistance variation, which can be directly affected by the die break condition. A new process called tip polishing has been developed to selectively polish the contact tip. Samples of tip polished and unfinished parts were subjected to a 10 million-cycle dither test and the results compared. It was concluded that tip polishing has a major effect on controlling the contact resistance variation.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"64 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":"131179773","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":"Break arc study for the new electrical level of 42 V in automotive applications","authors":"N. Ben Jemaa, L. Doublet, L. Morin, D. Jeannot","doi":"10.1109/HOLM.2001.953189","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953189","url":null,"abstract":"In order to fulfil increasing need for electric power in automobiles, satisfy environmental requirements and decrease car weight, the supply must change from 14 V to 42 V. In this work using 42 V, we studied arc parameters such as break arc duration and extinction gap for different materials, contact opening speeds and circuit loads (correlated with circuit time constant L/R). We found that these main arc parameters are greatly enhanced compared to the 14 V arc. In the case of inductive or resistive load, it was found that there are two domains: a low current domain where the material has no significant effect, and a high current domain where some materials (primarily AgSnO/sub 2/) induce high arc durations and large extinction gap. In addition, increasing opening speed reduces arc duration in all cases. The increased opening speed can however increase the extinction gap for inductive loads and decrease it for resistive circuits. We found that reducing arc duration is always beneficial with regards to erosion, but in some cases it may increase the extinction gap. At 42 V, erosion and material transfer from cathode to anode are similar to that found at low extinction gaps (<1 mm) at 14 V. At large extinction gap, however, these transfer phenomena are considerably modified by a new mechanism that induces erosion of the cathode and anode. It was found that classification of material behavior versus erosion is different at this voltage. For example AgSnO/sub 2/, which is claimed as a best compromise at 14 V for all loads, cannot be used at 42 V as it exhibits high erosion and requires a larger contact gap to ensure successful break.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"30 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":"117100114","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":"High cycle fretting corrosion studies on tin-coated contact materials","authors":"Christopher E. Heaton, Shaun L. McCarthy","doi":"10.1109/HOLM.2001.953213","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953213","url":null,"abstract":"The high-cycle (above 20,000) fretting contact characteristics of matte tin-plated copper are reported in this paper. Current loads extended from 0.1 mA to 100 mA with an open circuit voltage of 12 V. As observed in the past, there is a plateau in the contact resistance versus fretting cycles above 20,000 cycles. Here, we report on changes in the plateau as a function of load current. Box plots of the median values of the distribution of contact resistances show a dramatic decrease with increasing current. Contact voltages are also seen to range from 1 to 12 V, depending on the current. These results are discussed in terms of changes in the granular interface between the contacts with increasing current.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"34 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":"130784307","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":"Press-sinter-repress Ag-SnO/sub 2/ contacts with lithium and copper sintering additives for contactor applications","authors":"E. Streicher, C. Leung, R. Bevington, S. Allen","doi":"10.1109/HOLM.2001.953186","DOIUrl":"https://doi.org/10.1109/HOLM.2001.953186","url":null,"abstract":"Ag-SnO/sub 2/ contacts have been made by extrusion for several years because it is easier to achieve high density by this method. However, the brittle nature of this material, especially with 12% or more oxides, resulted in high manufacturing cost. This paper discusses a patented material that uses sintering aids and special silver morphology to assist sintering to high densities. By this method, discrete contacts can be made by powder metal mixing, pressing, sintering and repressing to high densities. Electrical performance similar to extruded materials was obtained. Electrical test results including life testing at 90 A 240 VAC and weld strength comparisons are reported. The erosion process is discussed.","PeriodicalId":136044,"journal":{"name":"Proceedings of the Forth-Seventh IEEE Holm Conference on Electrical Contacts (IEEE Cat. No.01CH37192)","volume":"23 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":"125310040","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}