DC current injection and induced-voltage sensing track surge protector health, temperature, and configuration for timely replacement.
A transient voltage suppressor integrates a voltage injection circuit to monitor Zener diode conditions for short or open faults.
A built-in test circuit samples voltage at the node between series-connected transient voltage suppressors to verify device operability.
An intermediary measurement approach using an inductive transducer provides precise diode path condition assessment without relying on thermal fuses.
A switch signal generating unit injects a test frequency through the power transformer to verify internal electrical connections.