Patent ID: 7050281
Filing Date: 2006-05-23
Classification: H02H

Abstract:
1. A blade fuse element for determining whether a rare short circuit, which results from the generation of heat exceeding a predetermined value, has occurred in a load circuit, the blade fuse element comprising: a fuse portion which serves as a sensor for detecting a load current, which flows through the load circuit, and for generating a detection signal, wherein the fuse portion melts and breaks when a dead short circuit occurs in the load circuit; and a determining circuit connected to the fuse portion for determining whether a rare short circuit has occurred, wherein the determination circuit calculates one of a first parameter and a second parameter every predetermined time interval based on the detection signal, the first parameter relating to a first time period during which the load current exceeds a predetermined reference current value, and the second parameter relating to a second time period during which the load current is less than or equal to the predetermined reference current value, wherein the determining circuit cumulates the calculated one of the parameters every predetermined time interval to calculate a cumulative parameter value and determines whether a rare short circuit has occurred based on the cumulative parameter value.