Contact Life and Switching Behavior of Compact PCB Power Relays

Power relays for mounting on printed circuit boards with just half of the case volume compared to low-profile ISO microrelays were tested in repetitious switching load operations. Operation voltage was 14 V and relay temperature was 120 °C. The tests for normally open type relays used lamps (11A) and horns (8A), and those for transfer (changeover) type relays used wiper motors (8.5A, intermittent operation). First failure cycles in each of the 10 relay tests were found to be of sufficiently high value, 2.2 million for lamps, 3.3 million for horns, and 2.4 million for wiper motors. Cycles at cumulative failure rates determined that the durability margins of the relays were acceptable for use.