Patent ID: 7224559
Filing Date: 2007-05-29
Classification: B60L,H02H

Abstract:
1. A detection circuit that detects a difference between a source current and a return current, the detection circuit comprising: a constantly biased magnetic core through which conductors of the source and return currents extend; a sense winding around said core; an AC source connected with said sense winding that transmits an AC signal to said core through said sense winding; and a sensing circuit connected with said sense winding that senses a change in small signal impedance of said sense winding relative to said core, wherein said core comprises a first core, and said sense winding comprises a first sense winding, said detection circuit further comprising: a second constantly biased magnetic core through which conductors of the source and return currents extend, said second core opposedly biased relative to said first core; a second sense winding around said second core, said second sense winding carrying said AC signal; and a pair of capacitors that provide a differential voltage in response to said change in small signal impedance, said differential voltage representative of the difference between the source and return currents.