Abstract:The closed-loop current sensor based on Hall effect used in servo system is studied. The relationship between the magnetic flux signal, signal noise, and distortion in the magnetic circuit system, as well as their impact on the design of back-end circuits are analyzed. For the magnetic circuit system, an open-loop " double-rectangle " shaped flux-concentrating core structure design is adopted, and materials exhibiting high magnetic permeability, low resistivity, minimal coercivity, and reduced thermal expansion coefficient are selected; For the secondary coil, a flat-shaped enameled wire is adopted and a special heat treatment process technique is applied. By innovatively optimizing the magnetic circuit system materials and design structure, as well as the improvement of the secondary coil process, accurate measurement of current within the range of ±130A has been achieved. The experimental results from the loaded test of the servo system demonstrate that the measurement accuracy and linearity of the current sensor have been significantly improved, meeting the application requirements of the aerospace servo system.