Research On The Nanosecond Pulse Power Supply Of Micro-electrochemical Machining

Electrochemical micromachining is a nontraditional machining method to fix material in the level of ions,which has some advantages as no loss of the tool,no mechanical stress,higher processing accuracy and more processing varieties etc.In theory,combining with modern digital technology,it could achieve high-accuracy machining of micro structure.This paper will analysis various factors affecting electrochemical micromachining,Focus on the key factor,power supply,to research the power supply of nanosecond pulse width for electrochemical micromachining.The overall design adopts the technique of dc chopper,peak value of the output voltage is 10 v,frequency of the pulse is between100 KHZ to 200 KHZ,minimum of duty cycle could reach 0.1,minimum of pulse width is about 500 ns.This power supply is based on a FPGA chip.High frequency signals for controlling output from the FPGA by programming.After amplifying by amplifying circuit,the signals could drive switching states of the MOSFETs in chopper circuit to chop the dc voltage in the main processing circuit.The final output is pulse voltage of nanosecond pulse width.The circuit design includes the transition and adjustment of voltage in the main loop,the amplification of the control signals in the amplifying circuit,the chopper circuit and short circuit protection in the feedback circuit.Draw schematics and manufacture the PCBs.Choose Verilog HDL when using FPGA chip,Program structure of Verilog HDL is flexible and easy to understand,the code is more efficient.Design of programming part includes the module of producing the high frequency signals,the program of adjustment by keys and processing of feedback signal.In the final,the output signasl are used to control switching states of the MOSFETs in chopper circuit,The adjustment of frequency and duty ratio achieve by the physical keys on the development board.Programmes design by Quartus?and simulate by Modelsim.