Bi-level voltage surge protection

Abstract

A stand-alone voltage surge suppression device for use with household appliances is arranged for connection to conventional female wall type outlets. The device is made to plug into an outlet socket and protect the adjacent sockets. The surge components of the device include two sets of varistors and thermofuses. In this embodiment, there are two sets of varistors and thermofuses. One is a primary varistor and fuse combination set at a lower voltage, and the other is a secondary group set at a higher voltage. Both take effect in surge protection, however, with enough hits, the lower one will fail first. Even so, the secondary group will still provide sufficient, although reduced amount of protection. In order for the user to know the status of the unit, there are two indicator lamps on the outside of the device. The surge protector preferably includes a light source arranged to indicate when the primary pair of varistors stops functioning. The surge protector may further include a first light source arranged to indicate when the primary pair of varistors stops functioning and a second light source arranged to indicate when the secondary pair of varistors stops functioning.

Dependencies are inferred from the claim text.