Reliability of commercial relays during life tests at low electrical contact load

The influence of the electrical stress on the contact resistance behavior of several signal and power relays has been investigated during life tests comprising two million operations. The results obtained with the aid of a specially developed test device showed characteristic contact resistance patterns for different electrical loads, contact materials, and designs. Under certain load conditions the contact resistance was increased by carbon deposits, while both lower and higher loads caused lower contact resistance values.<
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