以数字信号为基控制的可控硅焊机的数字触发

Study on Digital Trigger of Silicon Coutrolled Rectifier Welder Based on Digital Singal Process

用PROTEL99-SIM仿真软件分析了可控硅焊机单结晶体管 (UJT)移相触发电路受温度变化的影响 ,仿真结果表明 ,单结晶体管移相触发电路温漂对触发脉冲移相时间的影响较大 ,从而影响焊接参数输出的稳定性。另外 ,数字化焊接电源已成为焊接电源的发展趋势 ,这其中要求焊机的数字化触发。针对以上问题本文研究通过高集成度数字信号处理芯片 (DSPs)软件编程产生可控硅整流焊机主电路的触发信号。试验证明 ,通过软件编程DSPs产生的触发信号可靠稳定 ,软件简单明了 ,使原来复杂的移相触发电路变成移相触发软件的编程 ,为焊机的数字化、信息化控制打下了基础。

This paper analyzes that temperature variation affects unjunction transistor phase shift trigger circuit of silicon controlled rectifier (SCR) welder by PROTEL99 SIM simulation software. And the results show that temperature drift of the unijunction transistor deeply affects the phase shift time, thus affects the stability of welders outputs. On the other hand, digital welding machine now becomes more and more popular, which demands welders digital trigger. The study is based on the digital signal process( DSP S) ,taken use of the software to produce trigger in order to control the main circuit of welding machine. The study shows that the trigger from DSP is credibale and the software is comparatively simple. All of these make complex shift trigger circuit into software program. It brings welding machine into true digital control age.