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.

Date of Patent:
Nov. 24, 1998

Filed:

Sep. 17, 1996
Applicant:
Inventors:

Graham Dilkes, Manchester, GB;

Carl C Ennis, Manchester, GB;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361110 ; 361 71 ; 361 93 ;
Abstract

A power-line trip circuit models the transient characteristic of a change in load (e.g. appearance of a fault current, or switch-on to a normal load) and compares the current actually flowing in the power lines with this modelled or simulated transient. Line currents that do have a transient component but do not exceed normal limits are not then sufficient to trip a circuit breaker associated with the power lines, whereas transient-bearing currents that do exceed such limits, i.e. fault currents, are recognized as such and the circuit breaker is tripped. This circuit allows fast, reliable tripping even in the presence of a substantial transient overshoot.


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