Abstract: A current transducer for measuring the flux from a current carrying conductor, the current transducer comprising a sensor core for concentrating magnetic flux from said current carrying conductor, the sensor core being shaped as a loop broken by a gap. The current transducer further comprises a fluxgate ring core for sensing the magnetic flux, and two excitation coils for generating excitation flux in the ring core and for detecting the magnetic flux of the current carrying conductor. Drive means for driving an excitation current through the excitation coils are present along with a detection circuit connected to the excitation coils for detecting the electronic signal of the excitation coil. The fluxgate ring core is arranged in the gap of the sensor core, and the excitation coils are wound around a first and a second part of the fluxgate ring core, respectively.

Abstract: Detector circuit for measuring relatively strong currents including a main current transformer (1) and two substantially identical auxiliary current transformers (2, 3) where a main current (I1) induces magnetomotive forces in said main current transformer (1), said magnetomotive forces being counteracted by magnetomotive forces induced by a compensating current (i1) while at the same time the two auxiliary transformers (2, 3) 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 (i1). According to the invention a compensating current is used for measuring current in a common winding (L3) 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 (i1) by means of a negative feedback loop.

Abstract: Detector circuit for measuring relatively strong currents including a main current transformer (1) and two substantially identical auxiliary current transformers (2, 3) where a main current (I1) induces magnetomotive forces in said main current transformer (1), said magnetomotive forces being counteracted by magnetomotive forces induced by a compensating current (i1) while at the same time the two auxiliary transformers (2, 3) 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 (i1). According to the invention a compensating current is used for measuring current in a common winding (L3) 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 (i1) by means of a negative feedback loop.