The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 03, 1978
Filed:
Jun. 23, 1975
Darryl F Proctor, Redmond, WA (US);
Peter T Skelly, Issaquah, WA (US);
Darrell D Cole, Seattle, WA (US);
Proctor & Associates Company, Redmond, WA (US);
Abstract
An electromagnetic sensing apparatus includes one or more magnetic cores coupled by windings to a pair of transmission line conductors for sensing the presence, and in some cases the magnitude and direction of loop currents flowing in the transmission line, without interfering with the transmission of signal information therealong. In one embodiment, the direction of loop current flow in the transmission line conductors is detected by applying a steady-state electromagnetic bias to the magnetic core to cause a polarity or direction determining asymmetrical response in a sense circuit that is electromagnetically coupled to the core by a sense winding. In another embodiment, a pair of separate magnetic cores are used, each having associated drive windings connected in series with the transmission line conductors, and associated sense windings. The various drive and sense windings are wound on the magnetic cores so as to cause detection of the direct loop current flowing in the transmission line conductors, and at the same time to cause self-cancellation of any electromagnetic coupled of the sensing signal to the drive windings which would otherwise appear as interference or noise on the transmission line.