Effect of Heating Value on Contact Diameter at Low Speed Breaking Contact

Kazuaki MIYANAGA  Yoshiki KAYANO  Tasuku TAKAGI  Hiroshi INOUE  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E92-C   No.8   pp.1020-1022
Publication Date: 2009/08/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E92.C.1020
Print ISSN: 0916-8516
Type of Manuscript: Special Section LETTER (Special Section on Recent Development of Electro-Mechanical Devices (IS-EMD2008))
Category: Arc Discharge & Contact Phenomena
Keyword: 
electrical contact,  contact area,  bridge,  low speed breaking,  

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Summary: 
It is necessary to know how the contact voltage and contact area vary with time to clarify the physics of contact lifetime and contact resistance. In this paper, to clarify the effect of the heating value on the diameter of the contact area, the variations of the contact voltage and contact diameter with time are measured at a low-speed breaking contact near the thermal equilibrium condition under which a stable bridge is generated. The effect of the heating value on the relationship between the contact diameter and the length of the bridge at breaking is also discussed. In the results, the contact voltage waveform was found to be macroscopically proportional to the displacement of the moving electrode lc. On the other hand, the contact diameter dc decreased slightly with increasing lc. At all currents investigated dc decreased when lc increased. The length of the bridge at breaking was increased by increasing the current. A large heating value of the contact area resulted in a long bridge because the volume of the melted metal increases.