Patent ID: 6614218
Filing Date: 2003-09-02
Classification: G01R

Abstract:
A current transducer comprising a Rogowski coil having an electrically conductive coil member with a coil termination, a first integrator connected across the coil termination and a second integrator connected to the output of the first integrator, the first integrator being arranged to have a substantially constant gain at frequencies below a first frequency and to integrate the coil output at frequencies above the first frequency and the second integrator being arranged to have a substantially constant gain at frequencies above a second frequency and to integrate the output of the first integrator at frequencies below the second frequency, wherein the Rogowski coil is terminated with a coil damping resistor or resistors in combination, the resistor or resistors having a damping resistance value which is substantially the same as a characteristic impedance of the coil so as to damp the coil and reduce high frequency voltage oscillations; and wherein the first integrator comprises a cable connecting the coil to the second integrator and a cable damping resistance substantially equal to the characteristic impedance of the cable and connected in series with the cable and the second integrator.