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Extending the GMR Current Measurement Range with a Counteracting Magnetic Field
Division of Building Science and Technology, City University of Hong Kong, Hong Kong
Department of Electronic Engineering, City University of Hong Kong, Hong Kong
* Author to whom correspondence should be addressed.
Received: 12 April 2013; in revised form: 6 June 2013 / Accepted: 14 June 2013 / Published: 21 June 2013
Abstract: Traditionally, current transformers are often used for current measurement in low voltage (LV) electrical networks. They have a large physical size and are not designed for use with power electronic circuits. Semiconductor-based current sensing devices such as the Hall sensor and Giant Magnetoresistive (GMR) sensor are advantageous in terms of small size, high sensitivity, wide frequency range, low power consumption, and relatively low cost. Nevertheless, the operational characteristics of these devices limit their current measurement range. In this paper, a design based on using counteracting magnetic field is introduced for extending the GMR current measurement range from 9 A (unipolar) to ±45 A. A prototype has been implemented to verify the design and the linear operation of the circuit is demonstrated by experimental results. A microcontroller unit (MCU) is used to provide an automatic scaling function to optimize the performance of the proposed current sensor.
Keywords: giant magnetoresistance; current sensor; linearization; physical sensor; magnetic field sensor; Helmholtz coil
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MDPI and ACS Style
Poon, T.Y.; Tse, N.C.F.; Lau, R.W.H. Extending the GMR Current Measurement Range with a Counteracting Magnetic Field. Sensors 2013, 13, 8042-8059.
Poon TY, Tse NCF, Lau RWH. Extending the GMR Current Measurement Range with a Counteracting Magnetic Field. Sensors. 2013; 13(6):8042-8059.
Poon, Tin Y.; Tse, Norman C.F.; Lau, Ricky W.H. 2013. "Extending the GMR Current Measurement Range with a Counteracting Magnetic Field." Sensors 13, no. 6: 8042-8059.