Patent ID: 6323635
Filing Date: 2001-11-27
Classification: G01R

Abstract:
Improved sensor for a Swain type clamp-on direct current ammeter having better signal to noise ratio (SNR) when acted upon by an undesired noise N source comprising an undesired magnetic field, including:a split core with magnetic material which is magnetically connected by lips when the said split core is closed around a conductor carrying a current I to be measured; andon said core a winding N.sub.S suited for switching the flux density .beta. of said magnetic material when driven by a current called operating parameter I.sub.sm ; andat least one of said core constructed with a non-uniform magnetic structure designed to concentrate the ampere turn H.sub.sm magnetomotive force from said current called I.sub.sm flowing in said winding N.sub.S so that the said flux density .beta. of said magnetic material in and about said lips is better switched, andsaid winding is wound in a non-uniform manner such that the turns are more bunched in high density winding sectors near the said lips; so that there is a greater number of turns per linear inch of core perimeter near the said lips so that thereby the said H.sub.sm adjacent to the said lips is greater than that in other sectors of said core more remote from said lips.