Design Of A Steady Magnetic Field Generator

Magnetic field is used widely in industrial production and scientific experiments. In terms of different application environment, different magnetic field generator (MFG) should be designed. The steady MFG designed for some research institute is used for generating an exterior magnetic field in the test of material. It has many advantages, such as an adjustable magnetic induction intensity, high evenness and stability, and so on.Based on the requirements, axial symmetry air-cored coil is selected as the generator of magnetic field. The thesis studies axis distribution of magnetic field and carries on the simulation and computation using MATLAB. Then, the air-cored cylindrical winding is selected. This thesis gives the detailed analyses of relation between winding structure parameters and center field intensity, uniformity as well as spatial axial magnetic field, then makes the optimization design from two aspects, coil quality and the consumed power. The thesis compares the two results, and finally the optimization design parameters of air-cored cylindrical winding is selected based on the results. The thesis also gives the manufacture parameters of the air-cored cylindrical winding.According to the requirements of coil power supply, the paper designs one kind of constant current source based on the switching power supply. It analyzes and designs the source's rectification and filter circuit, the chop circuit, the control circuit, the protection circuit, the detect and display circuit and the accessory power supply circuit. The source is adjustable with 0～5A output current and has 1000W as the output maximum power. The current stability surpasses 0.1%.The performance is reliable with a long working time.Finally the thesis gives the test of coil magnetic field and analyzes the test data. The MFG has an adjustable center magnetic induction intensity with 0～0.1T. Magnetic field central area's uniformity is smaller than 0.15%. Magnetic field strength distributes uniformly at 80mm length in axis direction. The performance index satisfies the material testing requirements.