Protection device to prevent differential mode transient voltage flow

摘要

A differential mode surge protection apparatus includes first and second solid state protection devices in series between respective input and output connection points. The apparatus may be provided in conjunction with a common mode protection apparatus such as an isolation transformer. Alternatively, the apparatus may be provided integrated into a single miniaturized protection package. In a preferred embodiment, the apparatus includes a surge arrestor arranged to supplement protection conferred by the first and second solid state protection devices. The surge arrestor is capable of being triggered prior to breakdown of either the first or second solid state protection devices. The apparatus may be incorporated into digital processing cards such as LAN cards and also into cables to conveniently provide differential mode protection.