Bidirectional Switch Failure Detection Without Load Power Reduction

The patent applies preliminary action by performing failure detection during periods when the bidirectional switch is already open (non-conduction periods). The detection is conducted in advance during these natural idle periods rather than requiring dedicated power reduction time, allowing the switch to be tested for short circuit failures by monitoring voltage differences across it when no current is flowing through the load.

The patent maintains continuity of useful action by ensuring that power is continuously supplied to the load without interruption. The failure detection is performed seamlessly during the AC cycle when the switch is naturally open, eliminating the need to decrease power or switch to backup supplies. The voltmeter continuously monitors voltage differences to detect failures while the load operates uninterrupted.

The patent applies self-service by enabling the bidirectional switch to be tested while it remains in its normal operational state. The switch continues to function as part of the power supply system without requiring manual intervention to switch to backup supplies. The voltmeter automatically detects failures by monitoring voltage differences during the switch's natural non-conduction periods, making the system self-diagnosing without increasing operational workload.

The patent applies universality by making the bidirectional switch serve dual functions: it simultaneously performs its primary function of controlling power flow to the load and its secondary function of enabling failure detection. During non-conduction periods, the same switch structure that controls power also allows voltage monitoring for failure detection, eliminating the need for separate testing procedures or backup power switching operations.