Open AccessDesign and Simulation of a magnetic balance weak current sensor based on TMR
Author(s) -
Jiakuo Song,
Guoqing Zhang,
Yu Nie,
Guizhong Wang,
Hongbo Li,
Yingwei Hou
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1617/1/012038
Subject(s) - electromagnetic coil , current (fluid) , conductor , current sensor , voltage , magnetic field , electrical engineering , block diagram , physics , computer science , engineering , materials science , quantum mechanics , composite material
In this paper, a weak current sensor based on TMR is designed. The system structure, principle and conversion process of the sensor are introduced. The voltage current conversion circuit and feedback block diagram are analyzed emphatically. Then ANSYS Maxwell is used to simulate the electromagnetic field of the iron core and the coil. The results show that when the measured conductor and the secondary coil are connected with the current which is inversely proportional to the number of turns, the magnetic field in the air gap reaches a balance, close to the zero flux state. Finally, Multisim software is used to simulate the driving circuit of the system. The simulation results show that for DC and AC signals, the secondary current can track the primary current quickly, and the accuracy can reach 0.7% when measuring 1∼10mA weak current.