The life and times of an A-spot - A tutorial on sliding contacts

The A-spot, or groups of A-spots, are fundamental to the electrical and mechanical performance of all electrical contacts. It is only through the observance of the behavior of sliding contacts which are uniquely critical for static and dynamic contact resistance, friction, and extended wear, can the role of the A-spots be seen. A scenario for sliding contact behavior has been developed based largely on information gleaned from papers presented at the Holm Conference and four decades of practical experience in addressing problems with sliding contacts in slip ring assemblies.