Patent ID: 6570392
Filing Date: 2003-05-27
Classification: G01R,H02H

Abstract:
An arc fault detecting device for protecting an electric power line comprising:a sensor coupled to the power line for detecting broad band arc noise caused by an arc fault in the electric power line; a detector connected to the sensor for generating a pulse having a time width proportional to the time during which a random pulse of broad band arc noise generated by the arc fault in the electric power line is present; a counter connected to the detector; a first memory for storing a value proportional to the width of a present pulse; a second memory for storing a value proportional to the width of a prior pulse; a comparator; an output connected to the comparator which indicates if an arc fault has occurred; in which the comparator compares the value in the first memory to the value in the second memory and increments a counter if the difference is greater than a first predetermined value, and outputs an arc fault detection signal when the counter value is greater than or equal to a second predetermined value.