Patent ID: 6366076
Filing Date: 2002-04-02
Classification: G01R

Abstract:
A device for measuring the intensity of electric direct and alternating current passing through a conductor (1), comprising a measuring coil (4) without a magnetizable core surrounding said conductor (1) at least partially and adapted to provide a first measurement signal proportional to the time derivative of the current to be measured, and at least one measuring resistor through which the current to be measured flows, or at least one magnetic field detector (3) capable of detecting time independent magnetic fields arranged in the vicinity of said conductor (1), adapted to provide a second measurement signal proportional to the current to be measured, the device further comprising a circuit (7) to process said first and second measurement signals comprising a first order low-pass filter connected to the output of said measuring coil and a signal adding device for adding said first filtered and second measurement signals, the time constant of said low-pass filter being chosen in such a way that the output signal of the adding device is proportional to the intensity of the current to be said circuit, further comprising at least one amplification or reduction device arranged between the output of said first order low-pass filter and a first input of said adding device and/or between the output of said magnetic field detector and a second input of said adding device measured.