An Observation of the Breaking Arc between Silver Contacts Using a High Speed Color Video

Mitsuru TAKEUCHI  Takayoshi KUBONO  

IEICE TRANSACTIONS on Electronics   Vol.E82-C   No.1   pp.33-40
Publication Date: 1999/01/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Electromechanical Devices and Their Materials)
silver,  electric contact,  breaking arc,  spectrum,  cathode brightening spot,  high speed color video,  

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The distributions of a spectral intensity of the breaking arc between silver contacts in DC 45-66 V/2.5-5.0 A circuits have been measured using a high-speed color video. As a result, a cathode brightening spot, which has a high spectral intensity, exists near the cathode surface. The cathode brightening spot expands with the increase of the contact gap, but its length expands until about 18µm. When the contact gap spreads over about 180 µm, a dark positive column appears and grows between the cathode brightening spot and the anode surface. The higher the interrupted current is, the larger the diameter of the cathode brightening spot will be. The maximum diameter of cathode brightening spot is 500 µm under these experiments.