Disclosed is a helically wound core of ferrous material (14) used as a differential current sensor core in the ground fault sensor of a ground fault interrupter circuit. The ferrous material comprises a single strand of wire which is wound in helical fashion to create a tubular shaped core comprising a series of wire loops (all part of the single strand) parallel to each other and running the length of the tubular shape. The core is placed around a pair of current carrying lines (10, 12) to be monitored for ground faults (one line leading to and one line leading away from the power source) to interact with the magnetic fields of the lines. By utilizing wire as the core material, the amount of surface area can be greatly increased over the prior art cores without increasing the cross-sectional area (and, therefore, the overall size) of the core.

Title
Wire wound core
Application Number
PCT/US1992/005200
Publication Number
1993/016479
Application Date
June 17, 1992
Publication Date
August 19, 1993
Inventor
Koch Stuart
Agent
SIMPSON Mark D
Assignee
Brett Products
IPC
H01H 83/14
H01F 38/30
H01F 03/06
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