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:
Apr. 27, 1982
Filed:
Oct. 15, 1980
Michel Souillard, Fontenay aux Roses, FR;
Enertec, Montrouge, FR;
Abstract
The invention relates to protective apparatus used on AC power lines. An embodiment of an apparatus for putting the invention into practice comprises impedance sensing means having an impedance characteristic defining at least three distinguishable zones in its RX diagram, and being arranged to produce respective different signals, one for each zone, indicating the zone in which the sensed impedance lies. The movement of the point representative of the apparent impedance of the line across these zones is different according to whether the movement is due to loss of synchronism between the generators supplying the line or due to power oscillations. A logic circuit is provided to detect this difference in movement.