Noise study of open-loop direct current-current transformer using magneto-resistance sensors

Low Field Optimization of a Non-Contacting High-Sensitivity GMR-Based DC/AC Current Sensor

“…Because of that, magnetic sensors are widely used in current measurements because they are non-intrusive and provide galvanic isolation. A good example of non-contact current detection, that can inspire many other applications, is presented in [ 2 ] where the ion beam equivalent current inside a particle accelerator, is measured through the magnetic field it creates. In this way, equivalent currents down to 100 μA can be measured.…”

“…In this way, equivalent currents down to 100 μA can be measured. Typical current sensors include the AC/DC current transformers [ 2 , 3 , 4 ], fluxgate magnetometers [ 5 , 6 ], Hall effect sensors [ 3 , 7 ], anisotropic magnetoresistive (AMR) [ 3 , 8 ], giant magnetoresistance (GMR) [ 2 , 3 , 9 , 10 ] and tunnelling magneto-resistance (TMR) sensors [ 2 , 11 ].…”

“…Several studies have presented the use of GMR sensors as current sensors, most detailing different methods to improve their performance and versatility. Some of the implemented methods are: magnetic shielding—for reduced susceptibility to interference magnetic fields [ 16 ], hysteresis modelling compensation [ 17 ], open loop operation [ 2 , 3 , 10 ], closed loop operation [ 18 ]—to reduce hysteresis and temperature dependency, low frequency capture—to increase the range of the GMR current sensor to ±800 A [ 19 ], negative feedback introduced by the Helmholtz coil—to increase the range of the sensor up to 5 times [ 9 ], or damping coil—to further increase the range by 5.23 times [ 20 ]. In [ 10 ], we demonstrated a novel method of improving the overall accuracy, thermal stability, power consumption and immunity to interference magnetic fields involving a double differential setup, adjustable permanent magnetic biasing and antiphase-operating GMR based sensors on top of a U-shaped current trace.…”

“…In [ 10 ], we demonstrated a novel method of improving the overall accuracy, thermal stability, power consumption and immunity to interference magnetic fields involving a double differential setup, adjustable permanent magnetic biasing and antiphase-operating GMR based sensors on top of a U-shaped current trace. As a general remark from the above enumeration, many current sensors are using: (i) a discrete solution, where the magnetic sensors, the current trace, coils and the corresponding electronics are implemented in a suitable setup to detect the current [ 2 , 3 , 8 , 9 , 10 , 11 ] or (ii) a compact solution as an integrated circuit where can be found inside the chip the current trace, the sensors [ 13 ] and the conditioning circuit [ 14 ].…”

A Novel High-Precision Digital Tunneling Magnetic Resistance-Type Sensor for the Nanosatellites’ Space Application

“…The measure range is up to ±2 Gauss; the resolution is 6.7 nT; the sampling speed is 10–157 sampling points/s the three-axis digital output is BCD or binary code; the baud rate can be chosen 9600 or 19,200; the serial port can be chosen standard RS485 or RS232 for single-point reading; the volume is 70 × 37 × 24 mm 3 ; and, the power consumption is 400 mW. It has a higher resolution and a better linearity error of 0.1–0.5% FS, but it has a big volume because of detection circuit and digital processing circuit [ 9 , 10 ]. Because of low sensitivity and linearity based on AMR and low-performance detection circuit in HMR2300, the precision of the magnetometer cannot be improved.…”