Wide-band current transducers using common mode filter chokes

Dedicated wide band current transformers exist. However, in this paper, an evaluation is made of the characteristics of a current transducer based on a standard available common mode filter inductor. Based on the inductance and resonance frequency, a frequency span of 0.5 Hz up to 50 MHz can be achieved. The performance is possible by the fact that the used amorphous materials have a very high permeability and that the resonances of the windings at high frequency can be controlled. The following limitations are discussed: by saturation at low frequency and DC components, due to the load resistance, due to eddy currents and of the inserted primary conductor.