Patent ID: 6081122
Filing Date: 2000-06-27
Classification: G01R

Abstract:
An electrical ground fault detection apparatus comprising:a transformer core;an active electrical circuit having a capacity to deliver electrical energy from an electrical power source to an electrically-driven instrument, said active electrical circuit including a first wire, said first wire including X windings about said transformer core in a first direction, where X is any number greater than zero;a plurality N of return electrical wires where N is an integer greater than one, said return electrical wires having a capacity to return electrical energy from said electrically-driven instrument to said electrical power source, said return electrical wires being configured to be connected in series with said active electrical circuit distal said electrically-driven instrument, said return electrical wires being connected in parallel with respect to one another, one of said return electrical wires including a second winding about said transformer core in a second direction opposite said first direction, said second winding including N.multidot.X windings about said transformer core, another of said return electrical wires not winding about said transformer core; anda sensing and signalling circuit having a low pass filter, a capacity to sense a flux in said transformer core, and a capacity to generate a signal when a flux exists in said transformer core.