Patent ID: 7554784

Claim:
A surge detection circuit coupled to an input terminal, wherein the input terminal is further coupled to an input circuit, the surge detection circuit comprising: a surge detector, coupled to the input terminal, to detect a surge applied to the input terminal and generate an output signal indicating the detection result; and a determination unit, coupled to the surge detector, which includes: a counter to count the number of times the surge is detected by the surge detector based on the output signal of the surge detector; a memory to store an accumulated value of the detected number of times counted by the counter; and a controller to determine whether a characteristic of the input circuit has deteriorated based on the accumulated value and generate a warning signal based on the determination result, wherein the input circuit includes: a plurality of parallel coupled switches connected to the input terminal; and a plurality of input circuits respectively connected in series to the plurality of switches; wherein the controller connects the plurality of input circuits to the input terminal by selectively turning the plurality of switches on and off based on the accumulated value.