Research On The Nanosecond Pulse Power Supply Of Micro Electrochemical Machining Based On FPGA

Electrochemical micromachining (EMM) is a nontraditional machining method to remove material through metal ions, which has some advantages as higher processing accuracy, no wear of tool, no residual stress and deformation and no relation to the hardness of materials. Therefore, combining with CNC technology, it is easy to realize accurate processing on micro structure.This paper will analyze the factors which can affect the EMM on the aspect of power supply. Focusing on the equivalent circuit of EMM, describe and analyze every kinds of effecting factors. Lead to the high frequency pulse power supply application in EMM. List the advantages and disadvantages of applying this power supply in EMM.This paper will consider the key factor, power supply, which in EMM. To research a nanosecond pulse width power supply fit for EMM. This research is base on the FPGA. Through programming FPGA, it will generate the high frequency pulse. This pulse will control the MOSFET after across the driven chip. And then chop the DC voltage from the main circuit. And finally output the pulse voltage that its width can down to nanosecond. The hardware circuit design include main circuit、driven circuit and detective circuit. After testing, we manufacture the PCB for this circuit.To use Verilog as the programming language when design in FPGA. This language is use friendly and more efficient. The program designs include the program of high frequency pulse generating, the program of adjusting parameter by physical button, the program of detective signals processing. Utilize Quartus II software to design FPGA and Modelsim software to simulate. Carry out on-board test after the simulation. Utilize SignalTap II Logic Analyzer to test and choose the signals in need to monitor. Finally, optimize the parameter according to the design demand and the result of simulation. Make sure the output in a perfect situation.With the characteristic of EMM, some relevant experiments are made by using this setup. In these experiments, lots of influence elements are considered and some comparison and analysis are made, such as machining voltage, feed velocity, electrolyte and electrode shape, etc. After the study and analysis, some different results are discovered because of different machining parameters. Meanwhile, combined with this setup and finite element software, some experiments are made to simulate the electric field distribution of electrode under different machining parameters, which is used to provide experiment basement of HMM. By using electrochemical etching method, some micro cylinder electrodes and spiral electrodes are made. Finally, some micro structures are machining (such as micro holes) by micro cylinder electrodes and spiral electrodes, and some further comparisons are also been made.