Patent ID: 6690283
Filing Date: 2004-02-10
Classification: H02H

Abstract:
A protective device having a fuse and that connects a communication device to a communication wire and a power line and protects the communication device from a rapidly increasing current due to a rapid increase of voltage induced in the communication wire and/or the power line, comprising:first informing means for indicating to a user an operation of the protective device when the protective device is connected to the power line; current change detecting means for detecting a surge in the form of a rapid increase of current that occurs in the communication wire and/or the power line and that does not break the fuse; second informing means for indicating to the user that the current change detecting means has detected a surge in the communication wire and/or power line; and control means for controlling the operation of said second informing means based on a surge detection output from said current change detecting means.