Rating power connectors using voltage drop

Typically, measuring temperature rise at rated current has been used to rate power contacts in connector applications. In some cases this is done after accelerated aging tests. In this paper, it is proposed that voltage drop and change in voltage drop be used to evaluate the performance of power contacts. This method is intended to replace the standard use of thermocouples to monitor performance throughout an accelerated test series. Criterion is developed empirically from high current testing of tin plated power contacts. Moreover, data from accelerated aging tests followed by high current cycling tests are used to establish an empirical basis for change in voltage drop criteria. These results are analyzed using basic contact theory to relate loss of metallic contact to change in voltage (resistance) criteria. The ultimate goal is to develop a method using voltage drop as a performance indicator to quantify the current level at which power contacts reliably work. To this end, a series of tests are conducted at various current levels to establish a relation between current level and failure rate. Subsequently, the relationship of voltage drop stability and reliability are established to provide a methodology in current rating power contacts.