Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170810
H. Fang, J. Jiang
Newly designed test equipment for studying relay contact materials and for testing relay contact performance is described. The equipment not only can simulate various parameters of a relay contact, e.g. contact make and break speeds, contact force at make, contact bounce, but it can also monitor parameters characterizing contact performance automatically, such as voltages across the contacts at make and break, contact welding force, and contact resistance. It can also measure the arcing time of each make and break. Under the same relay operating condition, the influence of contact materials on contact resistance, make and break current and arc time constant on arcing time distribution, and contact structure on arcing time were studied. The results obtained can be used to select contact materials for different relay operating conditions.<>
{"title":"The study of the simulation control and test system for relay contacts operation with microcomputer","authors":"H. Fang, J. Jiang","doi":"10.1109/HOLM.1991.170810","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170810","url":null,"abstract":"Newly designed test equipment for studying relay contact materials and for testing relay contact performance is described. The equipment not only can simulate various parameters of a relay contact, e.g. contact make and break speeds, contact force at make, contact bounce, but it can also monitor parameters characterizing contact performance automatically, such as voltages across the contacts at make and break, contact welding force, and contact resistance. It can also measure the arcing time of each make and break. Under the same relay operating condition, the influence of contact materials on contact resistance, make and break current and arc time constant on arcing time distribution, and contact structure on arcing time were studied. The results obtained can be used to select contact materials for different relay operating conditions.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122751486","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}
Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170816
K. Okada, M. Yoshida
New copper-graphite brushes lined with porous copper have been developed and tested. The new brushes are produced by applied powder metallurgy. They can absorb the vibration caused by sliding friction. The friction coefficient, specific wear rate, and contact voltage drop for the new brushes are superior to those of conventional ones without lining.<>
{"title":"Copper-graphite brushes lined with porous metals","authors":"K. Okada, M. Yoshida","doi":"10.1109/HOLM.1991.170816","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170816","url":null,"abstract":"New copper-graphite brushes lined with porous copper have been developed and tested. The new brushes are produced by applied powder metallurgy. They can absorb the vibration caused by sliding friction. The friction coefficient, specific wear rate, and contact voltage drop for the new brushes are superior to those of conventional ones without lining.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128455139","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}
Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170826
P. Lees, D.W.M. Williams
Palladium and palladium-alloy contact materials manufactured by both electroplating and skive inlay cladding technologies were evaluated for adhesive and abrasive wear behavior. The contact materials were coated with 0.1- mu m-thick hard gold electroplate and tested again to determine the effect of the coating on wear behavior. Selected contact finishes with the gold flash were subjected to fretting conditions in the presence of organic vapors to determine susceptibility to frictional polymer formation. It was found that, in general, palladium and palladium-alloy 'flats' cause rider wear, and the durability of wrought Pd-Ag was significantly improved by alloying with small amounts of Ni. The gold flash altered the wear behavior of plated Pd-Ni and clad Pd-Ag but not plated Pd-Ag and clad Pd-Ag-Ni. Type-I frictional polymers were produced on the gold flashed Pd-Ag electroplates and gold flashed Pd-Ag-Ni inlays but not on the gold flashed Pd-Ni electroplates. It was determined that the wear mechanism and therefore the resultant contact surface materials controlled the formation of frictional polymer. The increase in contact resistance at end of test was attributed to rider wear and the exposure of the nickel underplate.<>
{"title":"Fretting behavior of gold flashed palladium, palladium nickel and palladium silver contact materials","authors":"P. Lees, D.W.M. Williams","doi":"10.1109/HOLM.1991.170826","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170826","url":null,"abstract":"Palladium and palladium-alloy contact materials manufactured by both electroplating and skive inlay cladding technologies were evaluated for adhesive and abrasive wear behavior. The contact materials were coated with 0.1- mu m-thick hard gold electroplate and tested again to determine the effect of the coating on wear behavior. Selected contact finishes with the gold flash were subjected to fretting conditions in the presence of organic vapors to determine susceptibility to frictional polymer formation. It was found that, in general, palladium and palladium-alloy 'flats' cause rider wear, and the durability of wrought Pd-Ag was significantly improved by alloying with small amounts of Ni. The gold flash altered the wear behavior of plated Pd-Ni and clad Pd-Ag but not plated Pd-Ag and clad Pd-Ag-Ni. Type-I frictional polymers were produced on the gold flashed Pd-Ag electroplates and gold flashed Pd-Ag-Ni inlays but not on the gold flashed Pd-Ni electroplates. It was determined that the wear mechanism and therefore the resultant contact surface materials controlled the formation of frictional polymer. The increase in contact resistance at end of test was attributed to rider wear and the exposure of the nickel underplate.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129138019","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}
Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170815
A. Challita, B. K. Ahrens, D. Bauer
A current collection system which includes a cooling system capable of operating at high velocities and current densities is needed before a continuous-duty compact HPG (homopolar generator) can be designed and built. The authors developed a current collection system that is capable of continuous operation at current densities of 40 MA/m/sup 2/ and a tip speed of 250 m/s. The current collection system is an integrated current collection/actuation/cooling system. The current collectors are solid copper leaves, 0.33 mm thick, that are mounted on a circular holder. The actuation system is a piston that actuates the collectors onto the slipring axially. Thin film evaporation cooling, at the interface between the collector and slipring, is used to remove the heat generated. Thin coolant films are wiped on the slipring. A slipring current density of 13 MA/m/sup 2/ at 175 m/s for 20 s was demonstrated. The system reaches steady state operation in 4 s. A heat removal capability of 15 MW/m/sup 2/ with the thin film evaporation technique was demonstrated. The contact resistance density was about 20n Omega -m/sup 2/.<>
{"title":"Description and test results of a current collection system for continuous duty HPG","authors":"A. Challita, B. K. Ahrens, D. Bauer","doi":"10.1109/HOLM.1991.170815","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170815","url":null,"abstract":"A current collection system which includes a cooling system capable of operating at high velocities and current densities is needed before a continuous-duty compact HPG (homopolar generator) can be designed and built. The authors developed a current collection system that is capable of continuous operation at current densities of 40 MA/m/sup 2/ and a tip speed of 250 m/s. The current collection system is an integrated current collection/actuation/cooling system. The current collectors are solid copper leaves, 0.33 mm thick, that are mounted on a circular holder. The actuation system is a piston that actuates the collectors onto the slipring axially. Thin film evaporation cooling, at the interface between the collector and slipring, is used to remove the heat generated. Thin coolant films are wiped on the slipring. A slipring current density of 13 MA/m/sup 2/ at 175 m/s for 20 s was demonstrated. The system reaches steady state operation in 4 s. A heat removal capability of 15 MW/m/sup 2/ with the thin film evaporation technique was demonstrated. The contact resistance density was about 20n Omega -m/sup 2/.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114238965","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}
An analysis of the accumulated species on the surface of Co-hardened gold electroplates has been carried out. The samples were aged in a common basement air environment at 85, 125, and 150 degrees C for periods of 1 to 12 months. Different gold coating thicknesses were used: 0.3 and 1.0 mu m on phosphor bronze substrate with or without 5 mu m nickel underplates. The accumulation rates of surface films were evaluated using contact resistance probing. Auger electron spectroscopy was employed to characterize the surface species. The values of contact resistance (CR) recorded are consistent with parabolic growth kinetics and have been utilized to extrapolate estimated lifetimes based on the failure criteria of increases in CR to 20, 50, and 100 m Omega levels.<>
对共硬化金电镀板表面的沉积物质进行了分析。样品在85、125和150摄氏度的普通地下室空气环境中陈化1至12个月。不同的金涂层厚度:0.3和1.0 μ m在磷青铜基片上，有或没有5 μ m的镍基片。采用接触电阻探针法测定了表面膜的积累速率。利用俄歇电子能谱对表面物质进行了表征。所记录的接触电阻(CR)值与抛物线生长动力学一致，并已用于根据CR增加到20、50和100 m ω水平的失效标准推断估计的寿命。
{"title":"Surface accumulation rate of diffusing species on thin gold electroplates","authors":"L. Revay","doi":"10.1109/33.180053","DOIUrl":"https://doi.org/10.1109/33.180053","url":null,"abstract":"An analysis of the accumulated species on the surface of Co-hardened gold electroplates has been carried out. The samples were aged in a common basement air environment at 85, 125, and 150 degrees C for periods of 1 to 12 months. Different gold coating thicknesses were used: 0.3 and 1.0 mu m on phosphor bronze substrate with or without 5 mu m nickel underplates. The accumulation rates of surface films were evaluated using contact resistance probing. Auger electron spectroscopy was employed to characterize the surface species. The values of contact resistance (CR) recorded are consistent with parabolic growth kinetics and have been utilized to extrapolate estimated lifetimes based on the failure criteria of increases in CR to 20, 50, and 100 m Omega levels.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124449125","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}
Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170805
P. Engel
A test procedure is described which utilizes the composite microhardness rendered by a superficial Vickers test. At moderate loads (typically P=100 and 200 g) the superficial hardness reading yields information on the concerted influences (thicknesses and hardnesses) of all the films deposited over the substrate. From the Vickers microhardness measurement one can determine the properties (thickness and intrinsic hardness) of the surface film. Experimental data and the computational procedure are described for relatively thin platings, i.e. t/d values not exceeding 0.2. The role of the properties for each layer in a composite is investigated. An error analysis is given for evaluating the potential accuracy inherent in practical measurements.<>
{"title":"Vickers microhardness evaluation of multilayer platings for electrical contacts","authors":"P. Engel","doi":"10.1109/HOLM.1991.170805","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170805","url":null,"abstract":"A test procedure is described which utilizes the composite microhardness rendered by a superficial Vickers test. At moderate loads (typically P=100 and 200 g) the superficial hardness reading yields information on the concerted influences (thicknesses and hardnesses) of all the films deposited over the substrate. From the Vickers microhardness measurement one can determine the properties (thickness and intrinsic hardness) of the surface film. Experimental data and the computational procedure are described for relatively thin platings, i.e. t/d values not exceeding 0.2. The role of the properties for each layer in a composite is investigated. An error analysis is given for evaluating the potential accuracy inherent in practical measurements.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128518251","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}
The effects of thermally segregated sulfide films on the contact resistance of OFHC copper specimens have been examined. Contact resistances were measured in situ in UHV for SiC abraded and POL polished copper specimens at dry circuit levels. It was found that at low sulfur concentrations (<10 a/o) the segregated sulfide films did not have an appreciable effect on the contact resistance. Above a critical sulfur surface concentration of about 10 a/o, a sharp increase was observed in the contact resistance values. A saturation effect was observed at higher sulfur concentrations. A model was proposed to explain the growth mechanism of the segregated sulfide film that explains the contact resistance behavior. Sulfur was found to disappear from specimen surfaces after air exposure of about 72 hours. Contact resistance values obtained after air exposure showed a steady increase with exposure due to the growth of an oxide layer. The values of the contact resistance increased at about 2.13%/h for both SiC and POP specimens.<>
{"title":"Enhanced sulfur segregation in plastically deformed OFHC Cu and the effect of surface segregated sulfur on electric contact resistance","authors":"R. Kothari, R. Vook","doi":"10.1109/95.296377","DOIUrl":"https://doi.org/10.1109/95.296377","url":null,"abstract":"The effects of thermally segregated sulfide films on the contact resistance of OFHC copper specimens have been examined. Contact resistances were measured in situ in UHV for SiC abraded and POL polished copper specimens at dry circuit levels. It was found that at low sulfur concentrations (<10 a/o) the segregated sulfide films did not have an appreciable effect on the contact resistance. Above a critical sulfur surface concentration of about 10 a/o, a sharp increase was observed in the contact resistance values. A saturation effect was observed at higher sulfur concentrations. A model was proposed to explain the growth mechanism of the segregated sulfide film that explains the contact resistance behavior. Sulfur was found to disappear from specimen surfaces after air exposure of about 72 hours. Contact resistance values obtained after air exposure showed a steady increase with exposure due to the growth of an oxide layer. The values of the contact resistance increased at about 2.13%/h for both SiC and POP specimens.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129064305","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}
Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170828
J.G. Zhang, D. Zhai, M.D. Zhu, L. Chen, R. Vook, R. Kothari
It is shown that the sulfide films formed in a technical vacuum on copper are composed mainly of Cu/sub 2/O and Cu/sub 2/S, and have a composition slightly different from films formed by an H/sub 2/S exposure. AES (Auger electron spectroscopy) depth profiles and ESCA (electron spectroscopy for chemical analysis) experiments showed that surface segregated sulfide films formed in ultrahigh vacuum as well as those formed in a technical vacuum disappeared on air exposure of approximately 5 to 7 days. At the same time the characteristic oxygen photoemission lines from Cu/sub 2/O and CuO increased significantly. It is concluded that the sulfur was entirely replaced by oxygen and that the resulting free sulfur, which has a high vapor pressure at room temperature, simply evaporated. A similar tendency was observed for the sulfide film formed on wet H/sub 2/S exposure (1.5-2 p.p.m.) after a 7 day air exposure. An AES depth profile showed that part of the sulfide film was buried by oxide and part of it vanished. The polarity effect on thick films formed by wet H/sub 2/S was significant; it decreased with decreasing film thickness. A polarity effect was also found on a sulfur segregated surface formed in technical vacuum; however, it degraded rapidly with time.<>
{"title":"Comparison of sulfide films formed on copper by surface segregation and wet H2S exposure","authors":"J.G. Zhang, D. Zhai, M.D. Zhu, L. Chen, R. Vook, R. Kothari","doi":"10.1109/HOLM.1991.170828","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170828","url":null,"abstract":"It is shown that the sulfide films formed in a technical vacuum on copper are composed mainly of Cu/sub 2/O and Cu/sub 2/S, and have a composition slightly different from films formed by an H/sub 2/S exposure. AES (Auger electron spectroscopy) depth profiles and ESCA (electron spectroscopy for chemical analysis) experiments showed that surface segregated sulfide films formed in ultrahigh vacuum as well as those formed in a technical vacuum disappeared on air exposure of approximately 5 to 7 days. At the same time the characteristic oxygen photoemission lines from Cu/sub 2/O and CuO increased significantly. It is concluded that the sulfur was entirely replaced by oxygen and that the resulting free sulfur, which has a high vapor pressure at room temperature, simply evaporated. A similar tendency was observed for the sulfide film formed on wet H/sub 2/S exposure (1.5-2 p.p.m.) after a 7 day air exposure. An AES depth profile showed that part of the sulfide film was buried by oxide and part of it vanished. The polarity effect on thick films formed by wet H/sub 2/S was significant; it decreased with decreasing film thickness. A polarity effect was also found on a sulfur segregated surface formed in technical vacuum; however, it degraded rapidly with time.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121313386","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}
Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170830
I. Sletbak, R. Kristensen, H. Sundklakk, G. Nåvik, M. Runde
Laboratory experiments have shown that, when a current-carrying, loose copper wire connection is exposed to mechanical vibrations, a layer of Cu/sub 2/O grows to form a bridge between the contact members, bonding them to one another. Due to the strongly negative temperature coefficient of Cu/sub 2/O at high temperatures, the current is concentrated in a thin, glowing filament at or near the surface of the oxide bridge. The maximum temperature of this filament was found to be 1200-1300 degrees C. Under the action of this hot filament a rapid oxidation of the copper continues until, in the end, most of the circumference of the copper wires has been converted to Cu/sub 2/O to a depth of a few tenths of a mm. As the corrosion proceeds the power dissipation increases to values which can cause fire hazards if a similar situation occurs in electrical apparatus or installations. According to statistics, loose connections or broken wires are known to be the cause of many fires. The phenomenon described explains how a temperature high enough to initiate a fire can arise even when the current through the connection is limited by the load impedance to values of less than 1 ampere.<>
{"title":"Glowing contact areas in loose copper wire connections","authors":"I. Sletbak, R. Kristensen, H. Sundklakk, G. Nåvik, M. Runde","doi":"10.1109/HOLM.1991.170830","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170830","url":null,"abstract":"Laboratory experiments have shown that, when a current-carrying, loose copper wire connection is exposed to mechanical vibrations, a layer of Cu/sub 2/O grows to form a bridge between the contact members, bonding them to one another. Due to the strongly negative temperature coefficient of Cu/sub 2/O at high temperatures, the current is concentrated in a thin, glowing filament at or near the surface of the oxide bridge. The maximum temperature of this filament was found to be 1200-1300 degrees C. Under the action of this hot filament a rapid oxidation of the copper continues until, in the end, most of the circumference of the copper wires has been converted to Cu/sub 2/O to a depth of a few tenths of a mm. As the corrosion proceeds the power dissipation increases to values which can cause fire hazards if a similar situation occurs in electrical apparatus or installations. According to statistics, loose connections or broken wires are known to be the cause of many fires. The phenomenon described explains how a temperature high enough to initiate a fire can arise even when the current through the connection is limited by the load impedance to values of less than 1 ampere.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131131541","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}
Pub Date : 1900-01-01DOI: 10.1109/HOLM.1991.170814
J. McBride, S. Sharkh
The authors outline the theory of impact as it applies to electrical contacts. The concept of the coefficient of restitution is evaluated as a means of modeling the events at impact. The events occurring during the impact of electrical contacts are vital to the long-term reliability of the contacts; so design parameters are considered in terms of their influence upon the dynamics of impact and bounce. Experimental studies are presented which include the measurement of impact forces, impact time, and both current and voltage characteristics. The influence of preimpact arcing is evaluated in the medium current range, and is shown to have an effect on the events occurring during the first impact. A mathematical model is proposed for electrical contact bounce, but it is shown that reducing the arcing may not always reduce contact wear.<>
{"title":"Electrical contact phenomena during impact","authors":"J. McBride, S. Sharkh","doi":"10.1109/HOLM.1991.170814","DOIUrl":"https://doi.org/10.1109/HOLM.1991.170814","url":null,"abstract":"The authors outline the theory of impact as it applies to electrical contacts. The concept of the coefficient of restitution is evaluated as a means of modeling the events at impact. The events occurring during the impact of electrical contacts are vital to the long-term reliability of the contacts; so design parameters are considered in terms of their influence upon the dynamics of impact and bounce. Experimental studies are presented which include the measurement of impact forces, impact time, and both current and voltage characteristics. The influence of preimpact arcing is evaluated in the medium current range, and is shown to have an effect on the events occurring during the first impact. A mathematical model is proposed for electrical contact bounce, but it is shown that reducing the arcing may not always reduce contact wear.<<ETX>>","PeriodicalId":368900,"journal":{"name":"Electrical Contacts - 1991 Proceedings of the Thirty-Seventh IEEE HOLM Conference on Electrical Contacts","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121278171","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}
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