Design and Simulation of a magnetic balance weak current sensor based on TMR. (August 2020)

• Record Type: Journal Article
• Authors: Song, Jiakuo; Zhang, Guoqing; Nie, Yu; Wang, Guizhong; Li, Hongbo; Hou, Yingwei
• Is Part Of: Journal of physics. Volume 1617(2020)
• Publication Date: 2020-08
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/1617/1/012038
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: 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.