Back to results
US 4,263,549 AGranted
Apparatus for determining differential mode and common mode noise
AssigneeCorcom, Inc.
InventorAlphonse A. Toppeto
Life of this patent
Estimating the term…
Abstract
Apparatus for isolating common mode and differential mode radio frequency noise in electronic and digital equipment from each other and quantitatively determining or displaying each for conformity to standard and for correction. The apparatus is likewise capable of determining and displaying the total of the two modes of noise.
Claims9
An accessory for a split toroidal r-f current probe of the type having a current sensing aperture, for use in the discrimination and measurement of common mode and differential mode noise, which comprises:
- a non-ferrous metallic barbell having a central portion of a length and cross-section to fit closely within the probe aperture and larger end portions to overlap the ends of said aperture, passageway means on opposite sides of said central portion and parallel to the central axis thereof to seat lengths of insulated wire therein and provided with holes meeting the ends of said passageway means and extending through said larger end portions for the passage of said wire.
Apparatus for determining differential and common mode r-f noise in electronic equipment, comprising:
- a pair of power lines connected between a source of power and an item of equipment, a split toroidal r-f current path probe having current sensing aperture means containing portions of said power lines to constitute the primary of the probe, non-ferrous metal shielding means having a central portion fitted closely in said aperture means and having means on the surface thereof to support said power line portions adjacent the periphery of said aperture means in substantial spaced relation from each other and each confronting a different half sector of said toroid whereby to expose said toroid to the flux fields of said portions;
- non-ferrous metal shielding means wholly and separately enclosing additional portions of said lines extending from said aperture means to points outwardly therefrom, a secondary output from said current probe, means for eliminating secondary current attributable to frequencies from said secondary output, means for displaying the r-f noise derived in the secondary of said probe from the vector sum of the noises in the primary, and means to calibrate said displaying means.
Dependencies are inferred from the claim text.