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. 23, 2010
Filed:
Nov. 04, 2005
Andreas Marcussen, Frederiksberg, DK;
Andreas Marcussen, Frederiksberg, DK;
Liaisons Electroniques-Mecaniques LEM S.A., Plan-les-Ouates, CH;
Abstract
Detector circuit for measuring relatively strong currents including a main current transformer () and two substantially identical auxiliary current transformers () where a main current (I) induces magnetomotive forces in said main current transformer (), said magnetomotive forces being counteracted by magnetomotive forces induced by a compensating current (i) while at the same time the two auxiliary transformers () are magnetised in antiphase by means of a square wave/modulation signal. Furthermore the detector circuit includes a synchronous rectifier for generating an adjusting signal for the compensating current (i). According to the invention a compensating current is used for measuring current in a common winding (L) surrounding the main transformer as well as the auxiliary transformers while at the same time a possible error signal in the shape of a voltage difference between the auxiliary transformers is used to adjust the compensating current (i) by means of a negative feedback loop.