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R. Valenzuela, J. J. Freijo, A. Salcedo, M. Vazquez and A. Hemando, “A Miniature dc Current Sensor Based on Magneto Impedance,” Journal of Applied Physics, Vol. 81, No. 8, 1997, pp. 4301-4303. doi:10.1063/1.364809

has been cited by the following article:

• TITLE: A High Dynamic Range GMI Current Sensor

  AUTHORS: Aktham Asfour, Jean-Paul Yonnet, Manel Zidi

  KEYWORDS: GMI; Current Sensor; Negative Feedback; DC-AC Current Measurements

  JOURNAL NAME: Journal of Sensor Technology, Vol.2 No.4, December 18, 2012

  ABSTRACT: The design and performances of a high dynamic range DC-AC current sensor utilizing Giant Magneto-Impedance (GMI) are presented. The sensor is based on a GMI element with negative feedback. The sensing element is a 30 μm diameter GMI Co-based amorphous wire. It is curled to a toroidal core of 2 cm diameter. A bias magnetic field of about 650 A/m is applied to the GMI element to obtain an asymmetric GMI effect. A strong negative feedback is introduced to ensure linearity in a wide dynamic range. Analog conditioning electronics was fully developed. This includes a square wave oscillator based on an inverter trigger; a peak detector and a high gain amplifier with zero adjust. The GMI element is driven at a 3 MHz frequency and 5 mA peak-to-peak current. The closed-loop operations are investigated and the performances of the sensor are presented. DC current measurements are performed. The sensor exhibits good sensitivity and very good linearity, free from hysteresis, in a wide dynamic range of ±40 A. The sensitivity is about 0.24 V/A and the linearity error is about 0.02% of the full scale (FS). The hysteresis error is smaller than the measurement accuracy. AC current measurements using the developed sensor have also been successfully achieved. The sensor bandwidth in closed-loop was about 1.7 kHz.