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:
Feb. 06, 1979
Filed:
Jul. 21, 1977
Applicant:
Inventor:
Thomas A Gross, Lincoln, MA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 45 ; 361 44 ; 361 87 ;
Abstract
Ground fault protective systems are disclosed in which fault signals are generated in response to differential currents carried by electrical supply lines. A circuit breaker interrupts power on the supply lines when the fault signals exceed a given magnitude and duration. Downstream reactances to ground from one or more supply lines give rise to spurious fault signals which do not characterize true ground fault conditions. These spurious fault signals are cancelled prior to detection by means of neutralizing auxiliary circuits. The resulting fault signals exhibit a high signal-to-noise ratio.