Some Factors Affecting the Static Resistance of Electric Contacts

The variations of the contact resistance and temperature distribution in the vicinity of an electric contact are shown for different types of right-circular conicoid contacts. The limiting cases of such contact geometry are the circle and the hemisphere. The paper shows how the resistance and temperature-distribution are relatively affected by the conception of a simplified geometric shape for the contact area. To determine the effect of the elongation of an area on the contact resistance, new form-factor curves are given which are applicable for all contact materials, pressures, and temperatures. Graphs are also given showing the relation between the maximum temperature and the interface temperature in various bimetal contacts which are in common use.