【摘要】 美国林肯焊机ＮＡ—５控制系统由１７块控制电路板、各主令按钮开关、控制箱、控制电缆、保护继电器、工作继电器及马达总成等部分组成。阐述了各控制板的作用及相互联系，较详细地分析了功率板、控制板、电压板、逻辑板等主要电路板的工作原理，并通过定量和定性分析，揭示了控制电路板的信号处理过程及其信号变化规律，有助于对ＮＡ—５控制系统的理解。更多还原

【Abstract】 The NA 5 control system of USA lincoln welder is composed of 17 control electric circuit boards, each master push button switch, control box, control cable, protective relay, working relay and motor assembly etc. The function and relative relation of each control board is expounded. The working principle of main electric board such as power board, control board, voltage board; logic board etc. is detailly analysed. It is revealed that signal treatment process and its signal variation rules of control electric board with better understanding of NA 5 control system through quantitatwe analysis and qualitative analysis.更多还原