双路绝缘栅型场效应管亚微秒级电火花脉冲电源

Dual-Channel MOSFET Sub-Microsecond Micro-EnergyPulse Power Source Used in Electrical Discharge Machining

以绝缘栅型场效应管 ( MOSFET)作为开关元件的独立式单路控制微能脉冲电源设计存在着缺陷 ,不利于稳定加工 .通过对实验中采集到的波形分析 ,找出了缺陷产生的原因 ,在此基础上 ,设计了双路控制的 MOSFET开关电路 ,并根据 MOSFET的开关特性 ,采用合理电路参数 ,计算出理论波形 .通过对比实验 ,不仅验证了实际波形与理论波形吻合 ,而且改进后的电源可以将波形有效压缩至亚微秒级 ,加工表面放电痕的形貌得到了极大改善 ,提高了加工的尺寸精度和表面精度 。

The single-channel control micro-energy pulse source whose switch element is MOSFET has inherent drawback. There exists an uncertain gap voltage during the pulse interval, which prolongs the discharge time and decreases the surface accuracy seriously. Moreover it drives up the average voltage and results in the misoperation of the control unit. Based on the analysis of the waveshape collected in machining, a dual-channel MOSFET micro-energy pulse power source is designed to make the gap voltage fall down to zero in order to eliminate the uncertain gap voltage. According to the switch characteristics of the MOSFET, reasonable circuit parameters are used, and the theoretical waveshape is calculated. From the waveshape picked during experiment, it shows that the practical waveshape and the theoretical waveshape are anastomotic, and the pulse width can be contracted to sub-microsecond. By means of comparison experiment, it shows that the surface texture is improved remarkably, and the course of machining becomes trouble-free machining. And the dimension accuracy and surface accuracy of the workpiece increase dramatically.