Counter-measures for relay failures due to dynamic welding: a robust engineering design

In prior work, contact welding phenomena were observed in automotive relays during break of motor inrush current. The switching performance of the type of relay investigated could be correlated with the parameters: over-travel, coil suppression, and the break current. In the present work the author also explores the impact of both the contact material and the contact surface topography. He further assesses the robustness of the system "relay" with those parameters using the Taguchi methods for robust design. Furthermore, the robustness of two alternative automotive relay types are discussed.