Parallel Switching Circuit Testing for Open-Failure Detection

The patent applies segmentation by dividing the testing process into individual device assessments. The controller activates each switching device sequentially and independently, measuring current through each device separately using the pulldown circuit. This segmentation allows detection of individual device failures even when multiple devices operate in parallel, resolving the contradiction between high current capacity and failure detectability.

The pulldown device serves as an intermediary element that facilitates precise current measurement during testing. By providing a known low-impedance path to ground, it allows the controller to measure current through individual switching devices accurately. The pulldown circuit is only active during testing phases, minimizing its impact on overall system complexity while enabling precise measurements.

The patent implements periodic action through sequential activation of switching devices. The controller systematically cycles through each device, activating one at a time for current measurement while keeping others inactive. This periodic testing approach ensures reliable individual device assessment while maintaining an efficient test sequence that minimizes overall testing time compared to exhaustive individual testing methods.