Abstract: A low let-through voltage surge suppression or protection circuit for protecting hardware or equipment from electrical surges. During operation when no surge condition is present, the circuit allows propagation of signals from a source to a load along a signal path. When a surge is present, the circuit senses and diverts the surge away from the signal path, utilizing common mode and/or differential mode surge protection. An electronic filter is connected in parallel with surge suppression circuit elements for reducing the let through voltage that would otherwise propagate and require a higher power surge suppression circuit element to mitigate. Cascading multiple electronic filters in parallel with surge suppression circuit elements further reduces voltage let through.

Abstract: An active surge suppression or protection circuit for protecting hardware or equipment from electrical surges. During operation when no surge condition is present, the circuit passes signals from an input source to a connected load along a signal path. When a surge is present, the circuit automatically senses and diverts the surge away from the signal path. A switching component is provided along the signal path for either allowing transmission or preventing transmission of a signal along the signal path. Upon diverting the surge, the circuit automatically changes the switching component from a closed state (for allowing transmission) to an open state (for preventing transmission). After the surge has passed, the circuit automatically changes the switching component from the open state to the closed state. Other automatic circuit behaviors may also be achieved in response to the diversion of a surge condition from the signal path.